Co-reporter:Hongchao Mao, Suobo Zhang
Journal of Colloid and Interface Science 2017 Volume 490(Volume 490) pp:
Publication Date(Web):15 March 2017
DOI:10.1016/j.jcis.2016.11.023
There has been much recent interest in the use of porous materials derived from self-assembling, shape-persistent organic cages due to their solubility and easy post-synthetic modification. Herein we report the preparation of novel mixed-matrix membranes (MMMs) employing the porous organic cage Noria and its derivatives Noria-Boc and Noria-COtBu as the fillers, and a fluorine containing polyimide, 6FDA-DAM, as the polymeric matrix. The physical structures and properties of Noria and its derivatives were measured and investigated. Noria with substituents of Boc (cleaved by thermal treatment during the process of membrane fabrication) and COtBu groups tend to show much better compatibility with polyimide than Noria itself, resulting in homogeneous dispersion of nanoaggregates and fine adhesion between the two phases in the derived Noria/6FDA-DAM and Noria-COtBu/6FDA-DAM MMMs. Gas permeation tests revealed that Noria and Noria-COtBu nanoparticles have different effect on gas separation performance of MMMs. The introduction of Noria into 6FDA-DAM tends to enhance CO2/CH4 selectivity and thus improve its gas separation properties, though a decrease in the observed permeability could be observed. In contrast, the introduction of Noria-COtBu with higher surface area and larger pores tends to increase the free volume and gas permeability of MMMs. These results show that both the morphology and the gas separation properties of MMMs could be tuned by tailoring the structures of porous organic cages.Fine compatibility and improved gas separation performance in mixed-matrix membranes based on porous organic cages could be achieved by tailoring their properties through post-modification.Download high-res image (138KB)Download full-size image
Co-reporter:Jifu Zheng, Qingyi He, Nian Gao, Ting Yuan, Suobo Zhang, Hui Yang
Journal of Power Sources 2014 Volume 261() pp:38-45
Publication Date(Web):1 September 2014
DOI:10.1016/j.jpowsour.2014.03.041
•FSPES-x membranes with perfluoroalkyl sulfonic acid groups were synthesized.•The perfluorosulfonated reaction without employing any metal and basic catalysts.•FSPES-3 shows high conductivity, OCV and superior cell performance.A new series of cardo poly(arylene ether sulfone/nitrile)s FSPES-x with perfluoroalkyl sulfonic acid groups have been successfully prepared by the perfluorosulfonic acid lactone ring-opening reaction without using any metal or base catalysts. These materials have been characterized by IR, NMR and TGA. The results indicate that this simple and metal-free method of preparation is highly efficient for controlling both the degree of perfluorosulfonation and the position of the sulfonate group and no side reactions such as crosslinking is observed. The FSPES-x membranes (IEC = 1.17–1.64 m equiv g−1) show the desired characteristics such as good film-forming ability, excellent thermal and mechanical properties, low methanol permeability, high conductivity (up to 0.083 S cm−1 at room temperature), as well as appropriate cell performance compared to Nafion®117. With these properties, such fluorinated sulfonic acid side-chain-type polymers are promising PEM materials for application in fuel cells.
Co-reporter:Limei Wang, Jianhua Zhu, Jifu Zheng, Suobo Zhang and Liyan dou
RSC Advances 2014 vol. 4(Issue 48) pp:25195-25200
Publication Date(Web):21 May 2014
DOI:10.1039/C4RA02286F
A series of cardo poly(aryl ether sulfone) copolymers bearing pendant sulfonated aliphatic side chains were synthesized and electrospun into nanofibers. The sulfonated poly(aryl ether sulfone) nanofibrous mats were filled with appropriate amounts of Nafion solution. The composite membranes showed significantly reduced swelling and excellent mechanical properties as well as appropriate proton conductivity. These membranes in particular exhibited much lower methanol permeability, in the range of 10−7 cm2 s−1, and higher selectivity, at about 105 S s cm−3, than did Nafion 117 in our experiments. The results show that the fabricated nanofiber-based composite membranes can be used as a promising proton exchange membrane for direct methanol fuel cell applications.
Co-reporter:Xue Dong, Shenghai Li, Qifeng Zhang and Suobo Zhang
RSC Advances 2014 vol. 4(Issue 43) pp:22625-22631
Publication Date(Web):13 May 2014
DOI:10.1039/C4RA02156H
A novel copolymer poly(ether ether ketone) bearing pendant tertiary amine groups (TAPEEK-x) was synthesized by 3,3′-dimethylaminemethylene-4,4′-biphenol (DABP), 4,4′-bisfluorodiphenylketone (BFDPA) and bisphenol A (BPA). After reaction with iodomethane, the copolymer turned to poly(ether ether ketone) with pendant quaternary ammonium groups (QAPEEK-x). Afterward, QAPEEK-x copolymer was dissolved in formic acid and coated on PAN ultrafiltration membrane as a composite membrane. The NF membrane preparation conditions, such as drying temperature, formic acid concentration, copolymer concentration, feed concentration, and tolerance in chlorine solution were investigated. The experiments showed that the membrane whose coating polymer concentration was 0.5 wt% in 88% formic acid had the best flux of 12.6 L m−2 h−1 at 0.4 MPa and best rejection of 99.4% for 500 ppm MgCl2. In addition, the membrane showed excellent tolerance ability of chlorine with a little decrease of MgCl2 rejection. To some extent, this study provides a new insight to improve membrane separation capability and stability in the desalination process.
Co-reporter:Yanqin Yang, Qiang Zhang, Suobo Zhang and Shenghai Li
RSC Advances 2014 vol. 4(Issue 11) pp:5568-5574
Publication Date(Web):14 Nov 2013
DOI:10.1039/C3RA44919J
Two novel porous copolymers PBP-N-25 and PBP-N-50 were synthesized from triphenylamine and 4,4′-bis(chloromethyl)biphenyl using a combination of oxidative polymerization and Friedel–Crafts alkylation process promoted by anhydrous FeCl3. The polymers were predominantly microporous, with apparent BET surface areas of 1362 m2 g−1 for PBP-N-25 and 1338 m2 g−1 for PBP-N-50. PBP-N-25 and PBP-N-50 possessed benzene vapor uptakes of 94.1 wt% and 107.3 wt% and cyclohexane vapor uptakes of 95.3 wt% and 83.8 wt%, while the water vapor uptakes were only 1.7 wt% and 1.2 wt%, respectively. The large amount of phenyl and methylene linkers resulted in the polymers' hydrophobicity and affinity toward aromatic and aliphatic compounds. The benzene/water vapor selectivities of PBP-N-25 and PBP-N-50 were as high as 53.5 and 63.6. Monolithic polymer M-PBP-N-25 with an apparent BET surface area of 551 m2 g−1 was prepared, which exhibited a good performance for oil/water separation. Owing to its hydrophobic nature and low density, the monolith was floating on the surface of water before and after collecting all of the oil from water. After removing the monolith from the surface, oil and water separated instantly.
Co-reporter:Hongchao Mao, Suobo Zhang
Polymer 2014 Volume 55(Issue 1) pp:102-109
Publication Date(Web):14 January 2014
DOI:10.1016/j.polymer.2013.11.037
Two novel iptycene-based tetramine monomers were successfully synthesized by nucleophilic aromatic substitution of triptycene-1,4-diol and pentiptycene-6,13-diol with 5-chloro-2-nitro-aniline, followed by reduction, respectively. These monomers were polymerized with 4,4-binaphthyl-1,1,8,8-tetracarboxylic dianhydride to obtain two novel iptycene-based poly[bis(benzimidazobenzisoquinolinones)]s (PBIBI–TPD and PBIBI–PPD) by a one-step, high-temperature solution polycondesation. Incorporation of iptycene groups especially the pentiptycene group in the polymer backbones improved their solubility and thermal stability. The resulting membranes exhibited good gas permeability owing to the high internal free volume elements introduced by the iptycene groups as well as high gas selectivity due to the restricted local segmental mobility arising from the interlocking of these groups in the polymer backbone. The membrane of PBIBI–PPD showed high CO2 permeability (112 barrer) and moderately good CO2/N2 and CO2/CH4 selectivity (22 and 31) for mixed gas separation.
Co-reporter:Yanqin Yang, Qiang Zhang, Zhiguang Zhang and Suobo Zhang
Journal of Materials Chemistry A 2013 vol. 1(Issue 35) pp:10368-10374
Publication Date(Web):01 Jul 2013
DOI:10.1039/C3TA11621B
A series of novel microporous polyimides (SMPIs) were synthesized from 4,4′-binaphthyl-1,1′,8,8′-tetracarboxylic dianhydride (BTDA), 6,6′-disulfonic-4,4′-binaphthyl-1,1′,8,8′-tetracarboxylic dianhydride (SBTDA) and tetrakis(4-aminophenyl)methane (TAPM). The non-sulfonated SMPI-0 (SMPI-x, where “x” is the molar percent of SBTDA) exhibited a BET surface area of 574 m2 g−1 and a CO2 uptake of 2.53 mmol g−1, while sulfonated samples, i.e. SMPI-10, SMPI-50 and SMPI-100, possessed relatively low BET surface areas (from 23 to 112 m2 g−1) but high CO2 capture capacities (from 2.82 to 3.15 mmol g−1) and CO2/N2 selectivities (from 32 to 57). With the increase of sulfonation degree, the polymers were graded from hydrophobic to hydrophilic. Hydrophobic SMPI-0 and SMPI-10 adsorbed a large amount of non-polar benzene (134.7 wt% for SMPI-0 and 104.7 wt% for SMPI-10) and cyclohexane (42.5 wt% for SMPI-0 and 42.8 wt% for SMPI-10) vapor, whereas hydrophilic SMPI-50 and SMPI-100 adsorbed more polar methanol (68.5 wt% for SMPI-50 and 72.2 wt% for SMPI-100).
Co-reporter:Jing Wang;Junhua Wang;Haifeng Wang;Suobo Zhang
Journal of Applied Polymer Science 2013 Volume 127( Issue 3) pp:1601-1608
Publication Date(Web):
DOI:10.1002/app.37523
Abstract
The novel positively charged poly(ether ether ketone)s (PEEKs) with pendant quaternary ammonium groups were synthesized by copolymerization of 3, 3′-dimethylaminemethylene-4,4′-biphenol (DABP), 3,3′,4,4′-tetramethylbiphenol, and 4,4′-bisfluorobenzophenone followed by reaction with iodomethane. The resulting copolymers were used to prepare thin film composite (TFC) nanofiltration (NF) membranes via the dip-coating method. The effects of different parameters such as copolymer concentration and curing time on the membrane performance (flux and rejection of inorganic salts) were investigated. The optimum parameters were that 1.5 wt % quaternary ammonium PEEK containing 1.8 quaternary ammonium groups per unit with 0.5 wt % DMSO coated on the polysulfone (PSf) support membrane and cured at 100°C. The results of the performance testing showed that the trend for rejection was R > R > RNaCl > R (R = rejection), which was a typical positively charged membrane. The best performance of these composite nanofiltration membranes was 91.3% rejection for 500 ppm MgCl2 and 62.5 L/m2 h water permeability at 0.4 MPa. The MWCO of the membrane was 800 Da. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Co-reporter:Nian Gao;Suobo Zhang
Journal of Applied Polymer Science 2013 Volume 128( Issue 1) pp:1-12
Publication Date(Web):
DOI:10.1002/app.38810
Abstract
Cardo poly(arylene ether sulfone)s are an important type of high performance engineering thermoplastics. They possess unique properties, including good processability, thermal stability, and good insulating and mechanical properties as well as excellent chemical resistance. They are potential candidates for the preparation of ion exchange, water purification, and gas separation membranes. This review focuses on the synthesis of phenolphthalein-based cardo poly(arylene ether sulfone)s, including synthesis of cardo bisphenols and their polymers, and their application to separation membranes. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Co-reporter:Tunyu Wang, Lei Dai, Qifeng Zhang, Ang Li, Suobo Zhang
Journal of Membrane Science 2013 440() pp: 48-57
Publication Date(Web):
DOI:10.1016/j.memsci.2013.03.066
Co-reporter:Tunyu Wang, Yanqin Yang, Jifu Zheng, Qifeng Zhang, Suobo Zhang
Journal of Membrane Science 2013 448() pp: 180-189
Publication Date(Web):
DOI:10.1016/j.memsci.2013.08.012
Co-reporter:Dr. Qiang Zhang;Dr. Yanqin Yang; Suobo Zhang
Chemistry - A European Journal 2013 Volume 19( Issue 30) pp:10024-10029
Publication Date(Web):
DOI:10.1002/chem.201300334
Abstract
This article describes the synthesis and functions of phosphine or phosphine oxide functionalized networks (PPP or PPPO; PP=porous polymer). These materials were predominantly microporous and exhibited high surface areas (SBET: 1284 and 1353 m2 g−1 for PPP and PPPO, respectively), with high CO2 (2.46 and 3.83 mmol g−1 for PPP and PPPO, respectively) uptake capacities. Pd nanoparticles can be simply incorporated into the functionalized networks (PPPPd or PPPOPd) through a facile one-step impregnation. A yield of 98 % was obtained in the Suzuki reaction between 1-chlorobenzene and p-tolylboronic acid with the PPPPd system, which was higher than that obtained when PPPOPd (53.2 %) or [Pd(PPh3)4] (38.2 %) was used as the catalyst. The superior catalytic ability of PPPPd can be attributed to the structural features that incorporate triarylphosphine within a microporous structure.
Co-reporter:Yanqin Yang, Qiang Zhang, Suobo Zhang, Shenghai Li
Polymer 2013 Volume 54(Issue 21) pp:5698-5702
Publication Date(Web):4 October 2013
DOI:10.1016/j.polymer.2013.08.039
This article describes the synthesis and characterization of microporous organic copolymers (PP-N-x, where “x” is the molar percent of triphenylamine) prepared from triphenylamine and dichloro-p-xylene using a combination of oxidative polymerization and Friedel–Crafts alkylation process promoted by anhydrous FeCl3. The samples possessed BET specific surface areas from 318 to 1530 m2 g−1 with the increasing content of dichloro-p-xylene. The highest CO2 uptake of 4.60 mmol g−1 was observed for PP-N-25, which was one of the highest values among MOPs reported to date under these conditions. The polymers possessed stable and reversible CO2 adsorption–desorption performance in at least 5 consecutive runs without noticeable deterioration of CO2 uptake capacities.
Co-reporter:Yanqin Yang, Qiang Zhang, Jifu Zheng, Suobo Zhang
Polymer 2013 Volume 54(Issue 13) pp:3254-3260
Publication Date(Web):7 June 2013
DOI:10.1016/j.polymer.2013.04.038
Two types of microporous polymeric networks have been prepared from monomers containing N-tert-butoxycarbonyl-protected pyrrole by FeCl3-mediated oxidative coupling polymerization. These materials were predominantly microporous (with BET surface areas of 828 m2 g−1 and 1408 m2 g−1), exhibiting high CO2 uptake capacities (1.96 mmol g−1 and 2.69 mmol g−1 at 273 K, 1 bar). Novel microporous polymeric films (with BET surface areas of 570 m2 g−1 and 593 m2 g−1) were fabricated through in situ polymerization of monomers on a flat glass dish using a sol–gel process catalyzed by trifluoroacetic acid.
Co-reporter:Huidong Qian, Jifu Zheng, Suobo Zhang
Polymer 2013 Volume 54(Issue 2) pp:557-564
Publication Date(Web):24 January 2013
DOI:10.1016/j.polymer.2012.12.005
For the first time, microporous polyamide networks have been synthesized via the interfacial polymerization of piperazine and acyl chloride monomers containing tetrahedral carbon and silicon cores. These polyamides, with Brunauer–Emmett–Teller surface area between 488 and 584 m2 g−1, show a CO2 uptake of up to 9.81 wt% and a CO2/N2 selectivity of up to 51 at 1 bar and 273 K, suggesting their great potential in the area of carbon capture and storage applications. We have developed the interfacial polymerization on the surface of the porous polyacrylonitrile substrate, resulting in the formation of ultrathin microporous membranes with thicknesses of about 100 nm. These nanofiltration (NF) membranes exhibited an attractive water flux of 82.8 L m−2 h−1 at 0.4 MPa and a high CaCl2 (500 mg/L) rejection of 93.3%. These NF membranes follow the salt rejection sequence of CaCl2 > NaCl > Na2SO4, demonstrating the positively charged character of these membranes.
Co-reporter:Limei Wang;Liyan Dou;Suobo Zhang
Journal of Polymer Research 2013 Volume 20( Issue 9) pp:
Publication Date(Web):2013 September
DOI:10.1007/s10965-013-0232-3
The hydroxide conductivity poly(aryl ether sulfone) with hexaalkyl guanidinium groups side chain(PES-G-Cl) was electrospun to bead-free nanofibers. The polymer concentration and environmental temperature are important parameters that influence the quality of electrospun fibers. We have synthesized the novel composite membranes composed of PES-G-Cl nanofibers and (vinylbenzyl) trimethylammonium chloride(VBTC) ionomers. As a result, the membrane stability, such as dimensions and thermal stabilities of the composite membrane was greatly improved and water uptake of the composite membrane also decreased when compared to that determined in the membrane without nanofibers. In addition, the hydroxide ion conductivity of the composite membrane indicated a significantly higher value when compared to that determined in the membrane with the conventional solvent-casting method. Consequently, nanofibers proved to be promising materials as a composite anion exchange membrane containing nanofibers may have potential application in fuel cells.
Co-reporter:Jing Wang, Jifu Zheng, Zhuo Zhao and Suobo Zhang
Journal of Materials Chemistry A 2012 vol. 22(Issue 42) pp:22706-22712
Publication Date(Web):10 Sep 2012
DOI:10.1039/C2JM34417C
A series of poly(arylene ether sulfone) containing pendent imidazole groups (PSf-Im-x) have been successfully synthesized based on a novel monomer 2,2′-bis-(2-methyl-imidazol-1-yl-methyl)-biphenyl-4,4′-diol (MIPO). The pendent imidazole groups along the polymer chain were expected to provide functional sites for the acid–base interaction with the doping phosphoric acid (PA) when they are used as polymer electrolyte membranes for high temperature fuel cell applications. The PA content of the linear PSf-Im-x membranes is about 172.3–235.8% in 85 wt% H3PO4 at room temperature. The volume swelling of these membranes is 114.4–194.0%, lower than that of polybenzimidazole (PBI) with similar PA content. The proton conductivities of the membranes are 0.021–0.053 S cm−1 at 140 °C under absolutely dehydrated state. The low volume swelling and good proton conductivity may be attributed to the “side-chain-type” structures of pendent imidazole groups, which facilitate ion transport. To obtain higher acid doping while maintaining mechanical properties, cross-linked membranes were prepared by the reaction of the imidazole group of the polymer and p-xylene dichloride. The PA content of the membranes with 20% cross-linking is 313.2% in 85 wt% H3PO4 at 80 °C. The stress at breaking and the proton conductivity of the membrane is 3.2 MPa at room temperature and 0.063 S cm−1 at 140 °C in an absolutely dehydrated state.
Co-reporter:Shenghai Li, Suobo Zhang, Qifeng Zhang and Guorui Qin
Chemical Communications 2012 vol. 48(Issue 100) pp:12201-12203
Publication Date(Web):12 Nov 2012
DOI:10.1039/C2CC36871D
A novel SPES-NH2–GA-Nafion® composite membrane with higher proton conductivity and lower methanol permeability was fabricated by covalent crosslinking layer-by-layer self-assembly of an unbalanced charged polyampholyte (SPES-NH2) and glutaraldehyde (GA) with controllable free sulfonic acid content.
Co-reporter:Zhuo Zhao, Feixiang Gong, Suobo Zhang, Shenghai Li
Journal of Power Sources 2012 Volume 218() pp:368-374
Publication Date(Web):15 November 2012
DOI:10.1016/j.jpowsour.2012.07.011
A series of poly(arylene ether sulfone)s containing quaternized triptycene groups are synthesized through a chloromethylation reaction following a quaternization process. The resulting ionomers are soluble in polar aprotic solvents; thus, flexible, tough membranes could be prepared by solution casting. Novel anion exchange membranes based on these ionomers are obtained by anion exchange with hydroxide ions. All anion exchange membranes show conductivities above 10−2 S cm−1 at room temperature. The highest hydroxide conductivity is 7.2 × 10−2 S cm−1, which is achieved by the anion exchange membrane with ion exchange capacity (IEC) = 2.61 mmol g−1. Meanwhile, these anion exchange membranes have low water uptake and good dimensional stability even at high IEC values. For example, the membrane water uptake (IEC = 1.97 mmol g−1) is only 21% at room temperature, and the swelling ratio is 11%. The anion exchange membranes are stable in alkaline conditions. All the membranes have no significant change in 4 M NaOH solution at 25 °C after 30 days. All results suggest that these anion exchange membranes have potential application in alkaline fuel cells.Highlights► Poly(arylene ether sulfone) with quaternized triptycene groups were synthesized. ► The membranes based on these ionomers have low water uptake and high ion conductivity. ► The membranes were stable in alkaline conditions.
Co-reporter:Jing Wang, Junhua Wang, Suobo Zhang
Journal of Membrane Science 2012 Volumes 415–416() pp:205-212
Publication Date(Web):1 October 2012
DOI:10.1016/j.memsci.2012.04.054
We report an effective and simplified procedure for the synthesis of cross-linked alkaline anion-exchange membranes (AEMs). A new monomer containing two tertiary amine groups on 4,4′-dihydroxydiphenyl ether (DABPE) is used in nucleophilic aromatic substitution step-growth copolymerization with 4,4′-difluorobenzophenone, 2,2′,6,6′-tetramethyl-4,4′-biphenol to obtain the corresponding poly(arylene ether ketone) copolymers containing tertiary amine groups. After partial quaternization, the residual tertiary amine groups of the polymer react with p-xylylene dichloride to produce a cross-linked membrane, which is followed by anion exchange with hydroxide ions. The resulting cross-linked membranes exhibit high hydroxide ion conductivity (above 10−2 S cm−1 at room temperature), good mechanical properties, and reduced water uptake relative to the linear uncross-linked membrane. This facile synthetic approach enables the preparation of cross-linked materials with the potential to meet the demands of hydrogen-powered fuel cells as well as direct methanol fuel cells.graphical abstract.Highlights▸ A novel biphenol monomer containing tertiary amine groups was prepared. ▸ Poly(arylene ether ketone) copolymer containing tertiary amine groups was developed. ▸ Cross-linked quaternized poly(arylene ether ketone)s membranes were synthesized. ▸ The cross-linked membranes exhibit high ion conductivity and low water swelling.
Co-reporter:Qiang Zhang, Suobo Zhang, and Shenghai Li
Macromolecules 2012 Volume 45(Issue 7) pp:2981-2988
Publication Date(Web):March 29, 2012
DOI:10.1021/ma300278d
A quaternary phosphonium and tertiary phosphorus functionalized microporous polymer was obtained via nickel(0)-catalyzed Yamamoto-type cross-coupling reaction. The integration ratio of signals (quaternary phosphonium to tertiary phosphorus atoms) was close to 3:2. The polymer networks were stable toward water, base, and acid, and indeed no change in surface area was observed even after the material was treated with 10 M HCl. The pore size distribution calculated by the Horvath–Kawazoe method indicated the presence of micropores with a mean width of about 0.7 and 1.4 nm. Their apparent BET specific surface areas can be tuned (from 650 to 980 m2 g–1) by changing the counteranions (Br– to F–). It displays high intrinsic catalytic activity for the reaction between epoxide and CO2 (yield: 98%, 1 atm). Pd nanoparticles supported on the polymer networks were also prepared, which exhibits high catalytic activity for cross-coupling reaction between 1-chlorobenzene and phenylboronic acid (yield: >95.8%).
Co-reporter:Huidong Qian, Shenghai Li, Jifu Zheng, and Suobo Zhang
Langmuir 2012 Volume 28(Issue 51) pp:17803-17810
Publication Date(Web):December 2, 2012
DOI:10.1021/la304196q
Ultrathin films of organic networks on various substrates were fabricated through the solution-based molecular layer deposition (MLD) technique. The rigid tetrahedral geometries of polyfunctional amine and acyl chloride involved in the reaction ensure the continuity of the polymerization process. A linear increase in film thickness with respect to cycle number was observed by UV–vis adsorption, ellipsometry, and quartz crystal microbalance. The growth rate per MLD cycle is 1.6 nm, which can be controlled at the single molecular level. For the first time, we develop the MLD method on the top of hydrolyzed PAN substrate, resulting in nanofiltration (NF) membranes. The stepwise growth was monitored via attenuated total reflectance infrared studies. The separation performance of the obtained membrane for various solutes was sensitive to the terminated layers and number of cycles. The rejection of NH2-terminated membranes follows the order of CaCl2 > Na2SO4 > NaCl, while the order for COOH-capped surface is Na2SO4 > CaCl2 > NaCl. The absolute value of zeta potential for the MLD membranes decreases with the addition of deposition layers. The moderate water flux for the resulting membrane is due to the reduced porosity of the support as well as the low roughness and hydrophilicity of the membrane surface. This bottom-up process provides a promising approach for construction of long-term steady NF membranes with nanoscale dimensions.
Co-reporter:Zhuo Zhao, Junhua Wang, Shenghai Li, Suobo Zhang
Journal of Power Sources 2011 Volume 196(Issue 10) pp:4445-4450
Publication Date(Web):15 May 2011
DOI:10.1016/j.jpowsour.2011.01.081
A series of multi-block poly(arylene ether sulfone)s are synthesized via the copolymerization of bis(4-hydroxyphenol) sulfone, 3,3′, 5,5′-tetramethylbiphenol and 4,4′-difluorodiphenyl sulfone. The resulting multi-block copolymers are brominated by using N-bromosuccinmide (NBS) as bromination reagent. The bromomethylated copolymer is solution cast to form clear, creasable films, and subsequent soaking of these films in aqueous trimethylamine to give benzyltrimethylammonium groups. The anion exchange membranes obtained by the solution hydroxide exchange with aqueous sodium hydroxide show varying degrees of ionic conductivity depending on their ion exchange capacity. The highest hydroxide conductivity 0.029 S cm−1 is achieved with the QBPES-40 membrane having IEC value of 1.62 mequiv g−1 at room temperature and 100% RH. The obtained anion exchange membranes also have good mechanical properties and dimensional stability, which greatly facilitates the preparation of a MEA and the cell operation.Research highlights► Multi-block poly(arylene ether sulfone)s were synthesized. ► The block structure improved the performance of polymer electrolyte membrane. ► The membranes have high conductivities with low ion exchange capacity.
Co-reporter:Feixiang Gong, Suobo Zhang
Journal of Power Sources 2011 Volume 196(Issue 23) pp:9876-9883
Publication Date(Web):1 December 2011
DOI:10.1016/j.jpowsour.2011.08.028
Poly(aryl ether sulfone)s containing sulfonated pentiptycene groups SPES-x-PPD are firstly synthesized through nucleophilic aromatic substitution polycondensation by using pentiptycene-6,13-diol, bis(4-hydroxyphenyl) sulfone and 4,4′-difluorodiphenyl sulfone, followed by postsulfonation with concentrated sulfuric acid at room temperature. The structures of SPES-x-PPD are characterized by IR, 1H NMR and 13C NMR spectra. These ionomers generally show high thermal stability. Transmission electron microscopic observations reveal that SPES-x-PPD membranes form well-defined microphase separated structures. SPES-40-PPD with the IEC value 2.36 mmol g−1 shows conductivity of 2.6 × 10−1 S cm−1 which is much higher than that of perfluorinated Nafion 117 membrane (1.1 × 10−1 S cm−1) at 80 °C and 94% RH. At 80 °C and 34% RH, SPES-40-PPD membrane displays the conductivity of 2.7 × 10−3 S cm−1 which is comparable with that of Nafion 117 membrane (3.0 × 10−3 S cm−1).Graphical abstractHighlights► The synthesis of poly(aryl ether sulfone)s containing locally and densely sulfonated pentiptycene groups (SPES-x-PPD) is firstly reported. ► The well-defined micro-phase separated structures is observed for SPES-x-PPD membranes. ► These novel SPES-x-PPD membranes achieved high proton conductivity in a range of 34–94% RH.
Co-reporter:Qiang Zhang, Feixiang Gong, Suobo Zhang, Shenghai Li
Journal of Membrane Science 2011 Volume 367(1–2) pp:166-173
Publication Date(Web):1 February 2011
DOI:10.1016/j.memsci.2010.10.065
A series of cardo poly(aryl ether sulfone) copolymers bearing pendant hydroxyl ethyl groups (−CH2CH2OH) were synthesized from a new biphenol monomer 2-(2-hydroxyethyl)-3,3-bis(4-hydroxyphenyl)isoindolin-1-one (PPH–OH), 4,4′-biphenol(BP), and 4,4′-difluorodiphenylsulfone (DFDPS). Sulfonic acid groups were readily grafted to the copolymers by reaction of the hydroxyl group with 1,3-propanesultone. The resulting sulfonated copolymers SPES-C-X (where X refer to the content of PPH–OH in the bisphenol monomers) contain side chain sulfoalkyl groups (–CH2CH2–O–CH2CH2CH2SO3H). TEM photographs revealed that SPES-C-100 membrane exhibited characteristic hydrophilic/hydrophobic microphase separated morphology with small interconnected and hydrophilic clusters (1.5–2 nm). Such microphase separated morphology renders the membrane high proton conductivity of 0.056 S/cm (IEC = 1.41 mequiv./g), and low dimensional changes of SPES-C-100 at room temperature. SPES-C-X membranes exhibited the methanol permeability in the range of 13.8–5.3 × 10−8 cm2/s, which were much lower than those of SBPES (8.7 × 10−7 cm2/s) and Nafion 117 (2.4 × 10−7 cm2/s).Research highlights▶ Novel side-chain-type sulfonated cardo poly(aryl ether sulfone)s contain side chain sulfoalkyl groups (–CH2CH2–O–CH2CH2CH2SO3H) have been synthesized and characterized. ▶ The side-chain-type sulfonated polymer showed higher proton conductivity than the main-chain-type ionomer with similar IEC value. ▶ The side-chain-type membrane exhibited characteristic hydrophilic/hydrophobic microphase separated morphology with small interconnected and hydrophilic clusters.
Co-reporter:Junhua Wang, Jing Wang, Shenghai Li, Suobo Zhang
Journal of Membrane Science 2011 Volume 368(1–2) pp:246-253
Publication Date(Web):15 February 2011
DOI:10.1016/j.memsci.2010.11.058
A series of quaternized poly(arylene ether sulfone)s containing up to two pendant quaternary ammonium groups per repeat unit was prepared by cesium carbonate mediated direct aromatic nucleophilic substitution polycondensation of 2,2′-dimethylaminemethylene-4,4′-biphenol (DABP), 4,4′-biphenol (BP) and 4,4′-difluorodiphenylsulfone (DFDPS), followed by reaction with iodomethane. The anion exchange membranes formed from these polymers showed conductivities above 10−2 S cm−1 at room temperature with a hydroxide conductivity of 6.5 × 10−2 S cm−1 for QNPS-OH-80. At the test of alkaline stability, these poly(arylene ether sulfone) ionomers were more stable than our previous reported partially fluorinated poly(arylene ether sulfone) ionomers under highly basic conditions.Graphical abstractResearch highlights▶ A modified reaction procedure is developed for the polycondensation of DABP. ▶ QNPS-OHs demonstrate excellent solubility and high ionic conductivity. ▶ QNPS-OHs show more alkaline stable than our previous reported F-QNPS-OHs.
Co-reporter:Qiang Zhang, Suobo Zhang, Shenghai Li
International Journal of Hydrogen Energy 2011 Volume 36(Issue 9) pp:5512-5520
Publication Date(Web):May 2011
DOI:10.1016/j.ijhydene.2011.01.144
A novel series of sulfonated poly(aryl ether sulfone)s with zwitterionic groups ([-CH2CH2CH2N+CH3(CH2CH2SO3−)2]) have been prepared by the copolycondensation of a secondary amine-containing biphenol monomer with 4,4′-biphenol and 4,4′-dichlorodiphenylsulfone, and this was followed by the reaction with sodium 2-bromoethanesulfonate. All the resulting copolymers can form uniform and tough membranes by simple solution casting. The investigation of ion exchange capacity (IEC) values indicated that each ammonium group interacted with one sulfonate group. Because of strong intermolecular interaction, the increased packing density of chain formed that resulted in polymer membranes with lower water uptake and swelling ratio, and better oxidative stability compared with side-chain-type sulfonated poly(aryl ether sulfone)s with the close IEC values. The polymer membranes bearing zwitterionic groups kept intact in Fenton’s reagent at 80 °C for 20 h. Furthermore, these membranes demonstrated higher proton conductivity than the side-chain-type sulfonated polymer membranes at the same measurement conditions.
Co-reporter:Qiang Zhang, Suobo Zhang, Weihui Bi
Polymer 2011 Volume 52(Issue 24) pp:5471-5478
Publication Date(Web):10 November 2011
DOI:10.1016/j.polymer.2011.10.006
A series of comb-type amphiphilic copolymers (PES-g-PEO) with a stiff poly(aryl ether sulfone) backbone and flexible PEO side chains was synthesized via a “grafting onto” technique. By controlling the monomer feed ratios, high molecular weight copolymers with a range of PEO side chain content were prepared and used to form tough and flexible membranes. The PES-g-PEO membranes displayed high thermal stability (Td > 230 °C) and good mechanical properties. The water contact angles of the PES-g-PEO membranes ranged from 60.5° to 66.7°, 20° lower than those of poly(aryl ether sulfone) membranes (82–86°), indicating that the PEO side chains improved the hydrophilicity of the membranes. Wide-angle X-ray diffraction results indicated that the PES-g-PEO membranes possessed an amorphous structure, that is, crystallization of the PEO side chains did not occur. The Li-ion conductivity reached 2.26 × 10−4 S/cm at room temperature, much higher than that of the pure PEO-based system (10−6 S/cm), due to the presence of the amorphous PEO side chains between the PES backbones, which provided an effective Li-ion transport pathway.
Co-reporter:Feixiang Gong, Hongchao Mao, Yuwei Zhang, Suobo Zhang, Wei Xing
Polymer 2011 Volume 52(Issue 8) pp:1738-1747
Publication Date(Web):5 April 2011
DOI:10.1016/j.polymer.2011.02.033
Co-reporter:Nian Gao, Feng Zhang, Suobo Zhang, Jia Liu
Journal of Membrane Science 2011 372(1–2) pp: 49-56
Publication Date(Web):
DOI:10.1016/j.memsci.2011.01.039
Co-reporter:Qifeng Zhang, Haifeng Wang, Suobo Zhang, Lei Dai
Journal of Membrane Science 2011 375(1–2) pp: 191-197
Publication Date(Web):
DOI:10.1016/j.memsci.2011.03.033
Co-reporter:Haifeng Wang, Qifeng Zhang, Suobo Zhang
Journal of Membrane Science 2011 378(1–2) pp: 243-249
Publication Date(Web):
DOI:10.1016/j.memsci.2011.05.015
Co-reporter:Shenghai Li, Yuntao Wu, Junhua Wang, Qiang Zhang, Yongli Kou and Suobo Zhang
Journal of Materials Chemistry A 2010 vol. 20(Issue 21) pp:4379-4384
Publication Date(Web):26 Apr 2010
DOI:10.1039/C0JM00255K
Water-soluble and durable Au nanoclusters, smaller than 4 nm with a narrow size distribution, were supported on a pH- and solvent-responsive water-soluble polyampholyte (SPES). Such synthesized Au@SPES hybrids possessed clear pH- and solvent-sensitive properties, and exhibited precipitation behaviors in response to pH and solvent changes in aqueous solution. Furthermore, the recycled catalyst could be redissolved in water for reuse via simple procedures based on the pH-sensitivity of the polyampholyte. By employing such catalysts, aerobic oxidation of alcohols should be able to be carried out in a homogeneous manner and may thus give rise to similar catalytic activities and selectivities as the homogeneous parent system. The phase separation and sensitivity of the SPES-stabilizing Au nanoclusters permitted a facile separation of the clusters from the reaction mixture without any negative aggregation.
Co-reporter:Qiang Zhang, Shenghai Li and Suobo Zhang
Chemical Communications 2010 vol. 46(Issue 40) pp:7495-7497
Publication Date(Web):16 Sep 2010
DOI:10.1039/C0CC01834A
A novel poly(aryl ether sulfone) ionomer containing hexaalkylguanidinium groups was synthesized, and membranes formed from this polymer displayed large ionic clusters, high hydroxide conductivity, and excellent solubility in low boiling point water-soluble solvents such as ethanol and methanol.
Co-reporter:Haifeng Wang, Lei Li, Xiaosa Zhang, Suobo Zhang
Journal of Membrane Science 2010 Volume 353(1–2) pp:78-84
Publication Date(Web):1 May 2010
DOI:10.1016/j.memsci.2010.02.033
A novel triamine 3,5-diamino-N-(4-aminophenyl) benzamide (DABA) monomer was synthesized and used to prepare thin-film composite (TFC) reverse osmosis (RO) membranes with m-phenylenediamine (MPD) and trimesoyl chloride (TMC). The membranes were characterized on both their top surfaces and cross-sections to determine their permeation properties, chemical composition, hydrophilicity, and membrane morphology. The results of the performance testing showed that the flux of membranes increased from 37.5 to 55.4 l/m2 h as the DABA concentration in amine solution was raised, while the rejection of membranes decreased slightly. Furthermore, the surface structure and chemical composition of the membranes were analyzed by X-ray photoelectronic spectroscopy (XPS), streaming potential measurement, attenuated total reflectance infrared (ATR-IR) spectroscopy, contact angle measurements, scanning electron microscopy (SEM) and atomic force microscopy (AFM) .The results revealed that, as the DABA content in amine solution increased, the membrane surface became more hydrophilic (giving rise to lower contact angles), smoother and thinner. It seemed that all the changes with regard to the membrane surface resulted from the introduction of the DABA into the amine solution.
Co-reporter:Qifeng Zhang, Suobo Zhang, Lei Dai, Xuesi Chen
Journal of Membrane Science 2010 Volume 349(1–2) pp:217-224
Publication Date(Web):1 March 2010
DOI:10.1016/j.memsci.2009.11.048
Two novel cardo poly(arylene ether sulfone)s, one bearing pendant zwitterionic carboxybetaine groups (PES-CB) and the other bearing pendant sulfobetaine groups (PES-SB) were synthesized and used for preparation of asymmetric membranes by the phase inversion method. The chemical structure, thermal, and mechanical properties of the membrane materials were thoroughly characterized. The antifouling effect of the resultant membranes were measured both under static and dynamic protein adsorption experiments. The carboxybetaine poly(arylene ether sulfone) (PES-CB) membrane performed significant resistance to protein adsorption. After three cycles of lysozyme solution filtration, a water flux recovery ratio as high as 95% was achieved for the PES-CB ultrafiltration membrane, whereas only about 25% of water flux recovery ratio was obtained for the conventional poly(arylene ether sulfone) cardo (PES-C) ultrafiltration membrane.
Co-reporter:Feng Zhang, Nanwen Li, Suobo Zhang, Shenghai Li
Journal of Power Sources 2010 Volume 195(Issue 8) pp:2159-2165
Publication Date(Web):15 April 2010
DOI:10.1016/j.jpowsour.2009.10.026
A novel locally and densely sulfonated dianhydride with four sulfonic acid groups, 1,6,7,12-tetra[4-(sulfonic acid)phenoxy]perylene-3,4,9,10-tetracarboxylic dianhydride (SPTDA), was successfully synthesized by direct sulfonation of the parent dianhydride, 1,6,7,12-tetraphenoxyperylene-3,4,9,10-tetracarboxylic dianhydride (PTDA). Sulfonated copolyimides were prepared from SPTDA, nonsulfonated dianhydride 4,4′-binaphthyl-1,1′,8,8′-tetracarboxylic dianydride, 4,4′-diaminodiphenyl ether (a) or dodecane-1,12-diamine (b). The synthesized copolymers, with the –SO3H group on the polymer side chain, possess high molecular weights and high viscosities, and they form tough, flexible membranes. The copolymer membrane with an ion exchange capacity of 2.69 mequiv. g−1 had a proton conductivity of 0.126 S cm−1 at 20 °C and 0.292 S cm−1 at 100 °C; the latter is much higher than that of Nafion® 117 under the same conditions. The mechanical properties of the copolymer membranes were almost unchanged after accelerated water stability testing at 140 °C for 100 h; this indicates excellent hydrolytic stability of the synthesized copolyimides.
Co-reporter:Qiang Zhang, Qifeng Zhang, Suobo Zhang, Shenghai Li
Journal of Membrane Science 2010 Volume 354(1–2) pp:23-31
Publication Date(Web):15 May 2010
DOI:10.1016/j.memsci.2010.02.068
A new biphenol monomer, 2-(2-(dimethylamino)ethyl)-3,3′-bis(4-hydroxyphenyl)isoindolin-1-one (CPPH), was easily prepared by the reaction of phenolphthalein with N,N-dimethylethane-1,2-diamine. Novel polyampholyte, sulfonated poly(aryl ether sulfone)s with pendent alkyl ammonium groups PESQ-x-y, were prepared by copolymerization of CPPH, 4,4′-biphenol, 3,3′-disulfonated-4,4′-dichlorodiphenyl sulfone, and 4,4′-dichlorodiphenyl sulfone, and this was followed by reaction with iodomethane. PESQ-x-y was able to form uniform and tough membranes by simple solution casting. Moreover, the material exhibited a low water uptake as well as a decent dimensional stability in water, even at high temperature (e.g. 100 °C), as a result of the strong electrostatic interactions between the alkyl ammonium and sulfonic acid groups. The PESQ-10-50 copolymer membrane with an ion-exchange capacity (IEC) of 1.65 mequiv./g, displayed a lower water uptake (58.9%), but a higher proton conductivity (0.082 S/cm) than a PES-40 membrane without alkyl ammonium groups (IEC = 1.67 mequiv./g, WU = 85.4%, σ = 0.069 S/cm) at 20 °C.
Co-reporter:Feng Zhang;Nanwen Li;Suobo Zhang
Journal of Applied Polymer Science 2010 Volume 118( Issue 6) pp:3187-3196
Publication Date(Web):
DOI:10.1002/app.32740
Abstract
A series of novel sulfonated poly(arylene-co-naphthalimide)s (SPPIs) were synthesized by Ni(0) catalytic coupling of sodium-(2,5-dichlorobenzoyl)benzenesulfonate and a naphthalimide dichloride comprising benzophenone groups at the meta-position of the imido groups. These materials were to be used as proton exchange membranes. Viscosity measurements revealed that the as-synthesized SPPI copolymers possessed high-molecular weights. Flexible and tough membranes of considerable mechanical strength were obtained by solution casting after which the electrolyte properties of the polymers were intensively investigated. In boiling water, a low water swelling ratio of less than 10% was found, as characterized by dimensional stability testing; a result superior to that for Nafion 117 (i.e., 21.5 %). Hydrolytic testing indicated that the SPPIs displayed an excellent hydrolytic stability, and in addition, their corresponding membranes demonstrated higher proton conductivities than those of Nafion 117, especially at elevated temperatures. The SPPI-80 membrane presented the highest conductivity of 0.302 S cm−1 for an IEC of 2.35 mequiv g−1 at 100°C, which was much higher than the corresponding value of Nafion 117 (0.178 S cm−1, at 100°C). A combination of a low methanol crossover with excellent thermo-oxidative properties indicated that the SPPI membranes were good candidate materials for proton exchange membranes in fuel cell applications. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Co-reporter:Junhua Wang, Shenghai Li and Suobo Zhang
Macromolecules 2010 Volume 43(Issue 8) pp:3890-3896
Publication Date(Web):March 22, 2010
DOI:10.1021/ma100260a
Poly(arylene ether sulfone)s were functionalized with quaternary guanidinium groups in order to investigate their properties as novel polymeric hydroxide exchange membrane materials. The quaternized polymers were synthesized via chloromethylation of poly(arylene ether sulfone)s, followed by reactions with pentamethylguanidine. The resulting quaternized polymers PSGCl-x (where x represents the number of the quaternary guanidinium groups/repeat units) presented an elevated molecular weight and exhibited an outstanding solubility in polar aprotic solvents. Consequently flexible and tough membranes of PSGCl-x with varying ionic content could be prepared by casting from the DMSO solution. Novel anion exchange membranes, PSGOH-x, were obtained by an anion exchange of PSGCl-x with 1 M NaOH at room temperature. The membranes displayed a high ionic conductivity and an excellent chemical stability. The obtained alkaline anion exchange membranes (AEMs) showed conductivities almost above 10−2 S cm−1 at room temperature; the hydroxide conductivity of PSGOH-1.4 was for instance found to be 6.7 × 10−2 S cm−1.
Co-reporter:Shenghai Li Dr.;Junhua Wang;Yongli Kou ;Suobo Zhang
Chemistry - A European Journal 2010 Volume 16( Issue 6) pp:1812-1818
Publication Date(Web):
DOI:10.1002/chem.200902495
Abstract
Novel guanidinium ionic liquid-grafted rigid poly(p-phenylene) (PPPIL) microspheres have been developed for metal scavenging and catalysis. The noble-metal nanoparticles supported on the microspheres surface can be used as efficient heterogeneous catalysts. The combination of nanoparticles and ionic liquid fragments on the microsphere surfaces enhance the activity and durability of the catalyst. The PPPIL⋅Pd0 catalyst has been tested in the Suzuki cross-coupling reaction, and exhibits much higher catalytic activity than Pd catalysts supported on porous polymer matrices. The PPPIL⋅Pd0 catalyst can be recycled at least for nine runs without any significant loss of activity. The present approach may, therefore, have potential applications in transition-metal-nanocatalyzed reactions.
Co-reporter:Qiang Zhang, Qifeng Zhang, Junhua Wang, Suobo Zhang, Shenghai Li
Polymer 2010 Volume 51(Issue 23) pp:5407-5416
Publication Date(Web):29 October 2010
DOI:10.1016/j.polymer.2010.09.049
Novel cardo poly(aryl ether sulfone)s containing pendent –[CH2CH2NMe3]+OH−, or –[CH2CH2CH2NMe3]+OH− groups, and partially fluorinated cardo poly(aryl ether sulfone) containing pendent –[CH2CH2CH2NMe3]+OH− groups were synthesized and examined with the focus of understanding how the polymer chemical structure affects their morphology, ion conductivity and alkaline stability. The resulting quaternized polymers exhibited outstanding solubility in polar aprotic solvents. The partially fluorinated cardo poly(aryl ether sulfone)s (PES-PF-OH) with ion-exchange capacity of 1.44 meq g−1 displayed the highest ion conductivities, varied from 3.0 × 10−2 to 4.1 × 10−2 S cm−1 over the range 20–60 °C. TEM revealed that PES-PF-OH membrane exhibited a distinct phase-separated morphology comprised of interconnected ionic clusters in size of 1–2 nm. The studies on alkaline stability of the membranes revealed that the PES-PF-OH polymer was not stable under strong basic conditions. The quarternized polymers containing pendent –[CH2CH2NMe3]+OH−, or –[CH2CH2CH2NMe3]+OH− groups mainly underwent Hofmann elimination and SN2 substitution reaction.
Co-reporter:Lei Li, Suobo Zhang, Xiaosa Zhang
Journal of Membrane Science 2009 Volume 335(1–2) pp:133-139
Publication Date(Web):15 June 2009
DOI:10.1016/j.memsci.2009.03.011
Most nanofiltration (NF) membranes are composite and have a polyamide thin film prepared by interfacial polymerization. Their performances mainly correlate the structure of the thin film and monomers used for its preparation. In this work, a novel thin-film composite (TFC) nanofiltration membrane was successfully prepared from 3,3′,5,5′-biphenyl tetraacyl chloride (mm-BTEC) and piperazine (PIP) through interfacial polymerization. Attenuated reflectance infrared (ATR-IR) and X-ray photoelectronic spectroscopy (XPS) were used to characterize the chemical composition of the membrane surface. The membrane performance was optimized by studying preparation parameters including monomer concentration, reaction time, and pH of aqueous phase. The resulting NF membrane exhibited significantly enhanced water permeability while maintaining high rejection to salt. The flux and rejection of NF membrane to Na2SO4 (500 ppm) reached to 51.5 L/(m2 h) and 95% under 0.5 MPa. The streaming potential tests indicated that the TFC membrane surface had high charge density and very low isoelectric point which situated between pH 1 and 2.
Co-reporter:Junhua Wang, Nanwen Li, Zhiming Cui, Suobo Zhang, Wei Xing
Journal of Membrane Science 2009 Volume 341(1–2) pp:155-162
Publication Date(Web):30 September 2009
DOI:10.1016/j.memsci.2009.06.002
A new blend system consisting of an amorphous sulfonated poly[bis(benzimidazobenzisoquinolinones)] (SPBIBI) and the semi-crystalline poly(vinylidene fluoride) (PVDF) was prepared for proton exchange membranes. The miscibility behavior of a series of blends of SPBIBI with PVDF at various weight ratios was studied by WXRD, DSC and FTIR. The properties of the blend membranes were investigated, and it was found that the introduction of PVDF in the SPBIBI matrix altered the morphological structure of the blend membranes, which led to the formation of improved connectivity channels. For instance, the conductivity of the blend membrane containing 10 wt% PVDF displayed the highest proton conductivity (i.e., 0.086 S cm−1) at room temperature, a value almost twofold that of the pristine SPBIBI membranes (i.e., 0.054 S cm−1) under identical conditions. The result was thus comparable to the proton conductivity of Nafion 117 (i.e., 0.09 S cm−1). Moreover, the dimensional stability, the elongation at break, the methanol permeability and the oxidative stability were enhanced in various extents by introducing PVDF into the blend membranes.
Co-reporter:Nanwen Li, Zhiming Cui, Shenghai Li, Suobo Zhang, Wei Xing
Journal of Membrane Science 2009 Volume 326(Issue 2) pp:420-428
Publication Date(Web):20 January 2009
DOI:10.1016/j.memsci.2008.10.042
A novel sulfonated tetraamine, di(triethylammonium)-4,4′-bis(3,4-diaminophenoxy)biphenyl-3,3′-disulfonate (BAPBDS), was successfully synthesized by nucleophilic aromatic substitution of 4,4′-dihydroxybiphenyl with 5-chloro-2-nitroaniline, followed by sulfonation and reduction. A high-temperature polycondensation of sulfonated tetraamine, non-sulfonated tetraamine (4,4′-bis(3,4-aminophenoxy)biphenyl) and 1,4,5,8-naphthalenetetracarboxylic dianhydride (a) or 4,4′-binaphthyl-1,1′,8,8′-tetracarboxylic dianydride (b) gave the poly[bis(benzimidazobenzisoquinolinones)] ionomers SPBIBI-a(x) or SPBIBI-b(x), where x refers to the molar percentage of the sulfonated tetraamine monomer. Flexible and tough membranes of high mechanical strength were obtained by solution casting and the electrolyte properties of the polymers were intensively investigated. The ionomer membranes displayed excellent dimensional and hydrolytic stabilities. Moreover, these novel membranes showed proton conductivities comparable to that of Nafion 117, especially at high temperature. In addition, the proton conductivities of the SPBIBI-a ionomer membranes were found to be higher than those of the SPBIBI-b ones due to the weakened acid–base interactions between the pyridinone ring and the sulfonic acid groups. The highest proton conductivity (0.174 S/cm) was obtained for the SPBIBI-a(100) membrane at 100 °C, with an IEC of 2.65 mequiv./g. A combination of excellent dimensional and hydrolytic stabilities indicated that the SPBIBI ionomers were good candidate materials for proton exchange membrane in fuel cell applications.
Co-reporter:Nanwen Li, Shenghai Li, Suobo Zhang, Junhua Wang
Journal of Power Sources 2009 Volume 187(Issue 1) pp:67-73
Publication Date(Web):1 February 2009
DOI:10.1016/j.jpowsour.2008.10.087
Novel water resistant sulfonated poly[bis(benzimidazobenzisoquinolinones)] (SPBIBIs) were synthesized from 6,6′-disulfonic-4,4′-binaphthyl-1,1′,8,8′-tetracarboxylic dianhydride (SBTDA) and various aromatic ether tetraamines. The resulting polymers with IEC in the range of 2.17–2.87 mequiv g−1 have a combination of desired properties such as high solubility in common organic solvents, film-forming ability, and excellent thermal and mechanical properties. Flexible and tough membranes, obtained by casting from m-cresol solution, had tensile strength, elongation at break, and tensile modulus values in the range of 87.6–98.4 MPa, 35.8–52.8%, and 0.94–1.07 GPa. SPBIBI membranes with a high degree of sulfonation displayed high proton conductivity and a good resistance to water swelling as well. SPBIBI-b with IEC of 2.80 mequiv g−1 displayed the conductivity of 1.74 × 10−1 S cm−1 at 100 °C, which was comparable to that of Nafion® 117 (1.78 × 10−1 S cm−1, at 100 °C). However, the water swelling ratio of SPBIBI-b membranes was merely 8% at 100 °C while the Nafion® 117 was 21.5%. The low swelling ratio was attributed to the strong intermolecular interaction including the electrostatic force and hydrogen bond. Moreover, they also exhibited much better hydrolytic stability than other sulfonated aromatic polymers such as polyimides. Consequently, these materials proved to be promising as proton exchange membranes.
Co-reporter:Junhua Wang, Zhuo Zhao, Feixiang Gong, Shenghai Li and Suobo Zhang
Macromolecules 2009 Volume 42(Issue 22) pp:8711-8717
Publication Date(Web):September 10, 2009
DOI:10.1021/ma901606z
A new bisphenol monomer, 2,2′-dimethylaminemethylene-4,4′-biphenol (DABP), was easily prepared by Mannich reaction of dimethylamine and formaldehyde with 4,4′-biphenol. Novel partially fluorinated poly(arylene ether sulfone)s with pendant quaternary ammonium groups were prepared by copolymerization of DABP, 4,4′-biphenol, and 3,3′,4,4′-tetrafluorodiphenylsulfone, followed by reaction with iodomethane. The resulting copolymers PSQNI-x (where x represents the molar fraction of DABP in the feed) with high molecular weight exhibited outstanding solubility in polar aprotic solvents; thus, the flexible and tough membranes of PSQNI-x with varying ionic content could be prepared by casting from the DMAc solution. Novel anion exchange membranes, PSQNOH-x, were obtained by an anion exchange of PSQNI-x with 1 N NaOH. All PSQNOH-x membranes showed conductivities above 10−2 S cm−1 at room temperature, for example, the hydroxide conductivity of PSQNOH-90 achieved to 8.4 × 10−2 S cm−1, which was thus comparable to the proton conductivity of Nafion 117 (i.e., 9.0 × 10−2 S cm−1).
Co-reporter:Junhua Wang, Nanwen Li, Feng Zhang, Suobo Zhang, Jia Liu
Polymer 2009 50(3) pp: 810-816
Publication Date(Web):
DOI:10.1016/j.polymer.2008.12.007
Co-reporter:Nanwen Li, Feng Zhang, Junhua Wang, Shenghai Li, Suobo Zhang
Polymer 2009 50(15) pp: 3600-3608
Publication Date(Web):
DOI:10.1016/j.polymer.2009.05.028
Co-reporter:Nanwen Li, Jia Liu, Zhiming Cui, Suobo Zhang, Wei Xing
Polymer 2009 50(19) pp: 4505-4511
Publication Date(Web):
DOI:10.1016/j.polymer.2009.07.039
Co-reporter:Feixiang Gong, Nanwen Li, Suobo Zhang
Polymer 2009 50(25) pp: 6001-6008
Publication Date(Web):
DOI:10.1016/j.polymer.2009.10.033
Co-reporter:Guang Chen, Guojun Wu, Liming Wang, Suobo Zhang and Zhaohui Su
Chemical Communications 2008 (Issue 15) pp:1741-1743
Publication Date(Web):14 Mar 2008
DOI:10.1039/B801784K
A novel method to produce multilayer films has been developed by layer-by-layer assembly of single-charged ions and a rigid polyampholyte containing unbalanced charges in each of its repeat units.
Co-reporter:Lei Li, Suobo Zhang, Xiaosha Zhang, Guodong Zheng
Journal of Membrane Science 2008 Volume 315(1–2) pp:20-27
Publication Date(Web):1 May 2008
DOI:10.1016/j.memsci.2008.02.022
Three novel of isomeric tetra-functional biphenyl acid chloride: 3,3′,5,5′-biphenyl tetraacyl chloride (mm-BTEC), 2,2′,4,4′-biphenyl tetraacyl chloride (om-BTEC), and 2,2′,5,5′-biphenyl tetraacyl chloride (op-BTEC) were synthesized, and used as new monomers for the preparation of the thin film composite (TFC) reverse osmosis (RO) membranes through interfacial polymerization with m-phenylenediamine (MPDA). The results of membrane performance test showed that membranes prepared from om-BTEC and op-BTEC had higher flux at the expanse of rejection compared with membranes prepared from mm-BTEC. The chemical composition on the active layer was characterized by attenuated total reflectance infrared (ATR-IR) and X-ray photoelectronic spectroscopy (XPS), and the results showed that the content of carboxylic acid on the membrane surface prepared from mm-BTEC are higher than these prepared from op-BTEC and om-BTEC. It seemed that all the difference containing: the membrane performance, the chemical composition on the active layer, hydrophilicity, and the surface morphology might come from the different structure and reactivity of the tetraacyl chloride monomers.
Co-reporter:Wenmu Li, Zhiming Cui, Xiaochun Zhou, Suobo Zhang, Lei Dai, Wei Xing
Journal of Membrane Science 2008 Volume 315(1–2) pp:172-179
Publication Date(Web):1 May 2008
DOI:10.1016/j.memsci.2008.02.026
A novel sulfonated poly(arylene-co-imide)s were synthesized by Ni(0) catalytic copolymerization of sodium 3-(2,5-dichlorobenzoyl)benzenesulfonate and naphthalimide dichloride monomer. The synthesized copolymers with the –SO3H group on the side-chain of polymers possessed high molecular weights revealed by their high viscosity and the formation of tough and flexible membranes. Because of the introduction of electron donating phenoxy groups into naphthalimide moieties, the hydrolysis of the imide rings was depressed. The resulting copolymers exhibited excellent water stability. The copolymer membranes display no apparently change in appearance, flexibility, and toughness after a soaking treatment in pressurized water at 140 °C for 250 h. TEM analysis revealed that these side-chain type membranes have a microphase separated structure composed of hydrophilic side-chain domains and hydrophobic polyimide main chain domains. The proton conductivities of copolymer membranes increased with the increase of IEC and temperature, reaching values above 3.2 × 10−1 S/cm at 80 °C, which are higher than Nafion 117 on the same measurement conditions. The methanol permeability of the copolymer membranes was one order lower than that of Nafion 117. Consequently, these materials proved to be promising as proton exchange membranes.
Co-reporter:Feng Zhang, Nanwen Li, Zhiming Cui, Suobo Zhang, Shenghai Li
Journal of Membrane Science 2008 Volume 314(1–2) pp:24-32
Publication Date(Web):30 April 2008
DOI:10.1016/j.memsci.2008.01.032
The synthesis and characterization of novel acid–base polyimide membranes for the use in polymer electrolyte membrane fuel cell is presented in this paper. The sulfonated polyimides (SPIs) bearing basic triphenylamine groups were easily synthesized using 4,4′-binaphthyl-1,1′,8,8′-tetracarboxylic dianhydride (BTDA), sulfonated diamine of 4,4′-diaminodiphenyl ether-2,2′-disulfonic acid (ODADS), and nonsulfonated diamines of 4,4′-diaminotriphenylamine (DATPA). The effects of the structure of the dianhydride and diamines on the properties of SPI membranes were evaluated through the study of membrane parameters including water sorption, proton conductivity, water stability, dimensional changes, and methanol permeability. It was found that the BTDA-based sulfonated polyimides displayed much better hydrolytic stability than 1,4,5,8-naphthalenecarboxylic dianhydride (NTDA)-based polyimides. This is because the former has a decreased positive charge density in the imido rings compared to the latter ones. Furthermore, the present SPI membranes also displayed much better resistance to swelling than these without DATPA due to the strong interchain interaction through basic triphenylamine functions and sulfonic acid groups. The SPI membrane with IEC value of 2.21 mequiv./g shows the proton conductivity of 0.11 S/cm at 20 °C which is higher than Nafion 117 (0.09 S/cm at 20 °C). Moreover, the SPI membranes exhibited excellent mechanical properties and decreased methanol permeability.
Co-reporter:Nanwen Li, Suobo Zhang, Jia Liu and Feng Zhang
Macromolecules 2008 Volume 41(Issue 12) pp:4165-4172
Publication Date(Web):May 31, 2008
DOI:10.1021/ma800119y
Novel sulfonated poly[bis(benzimidazobenzisoquinolinones)] as hydrolytically and thermooxidatively stable electrolyte for high-temperature fuel cell applications are reported. A series of sulfonated polymers (SPBIBI-x, x refers to molar percentage of sulfonated dianhydride monomer) were synthesized from 6,6′-disulfonic-4,4′-binaphthyl-1,1′,8,8′-tetracarboxylic dianhydride (SBTDA), 4,4-binaphthyl-1,1,8,8-tetracarboxylic dianhydride (BTDA), and 3,3′-diaminobenzidine. The chemical structures of those polymers as well as model compounds synthesized from SBTDA and o-phenylenediamine were confirmed by nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR). The resulting polymers generally showed good solubility in m-cresol and DMSO. Flexible and tough membranes with high mechanical strength were prepared. They show very high thermal, thermooxidative, and hydrolytic stabilities and reduced swelling in water at enhanced temperature compared to other sulfonated aromatic polymers such as sulfonated polyimides. The proton conductivity of SPBIBI was slightly lower than that of the perfluorinated ionomer (Nafion 117) below 100 °C but comparable at higher temperature and 100% RH. The highest conductivity of 1.9 × 10−1 S cm−1 was obtained for SPBIBI-100 at 140 °C.
Co-reporter:Nanwen Li;Zhiming Cui;Suobo Zhang;Shenghai Li
Journal of Polymer Science Part A: Polymer Chemistry 2008 Volume 46( Issue 8) pp:2820-2832
Publication Date(Web):
DOI:10.1002/pola.22616
Abstract
A sulfonated dianhydride monomer, 6,6′-disulfonic-4,4′-binaphthyl-1,1′,8,8′-tetracarboxylic dianhydride (SBTDA), was successfully synthesized by direct sulfonation of the parent dianhydride, 4,4′-binaphthyl-1,1′,8,8′-tetracarboxylic dianhydride (BTDA), using fuming sulfuric acid as the sulfonating reagent. A series of sulfonated homopolyimides were prepared from SBTDA and various common nonsulfonated diamines. The resulting polymer electrolytes, which contain ion conductivity sites on the deactivated positions of the aryl backbone rings, displayed high proton conductivities of 0.25–0.31 S cm−1 at 80 °C. The oxidative stability test indicated that the attachment of the SO3H groups onto the dianhydride units did not deteriorate the oxidative stability of the SPI membranes. The better membranes were achieved by the copolymerization of nonsulfonated diamine, SBTDA, and BTDA. Copolymer membrane synthesized from hexane-1,6-diamine, SBTDA, and BTDA displayed excellent water stability of more than 1000 h at 90 °C, while its proton conductivity was still at a high level (comparable to that of Nafion 117). Furthermore, the novel block copolymer (II-b) displayed higher proton conductivity compared with the random one (II-r) obviously, probably due to the slightly higher water uptake and better microphase separated morphology. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2820–2832, 2008
Co-reporter:Shenghai Li, Suobo Zhang and Xianhong Wang
Langmuir 2008 Volume 24(Issue 10) pp:5585-5590
Publication Date(Web):April 22, 2008
DOI:10.1021/la800157t
An industrial waterproof reagent [(potassium methyl siliconate) (PMS)] was used for fabricating a superhydrophobic surface on a cellulose-based material (cotton fabric or paper) through a solution-immersion method. This method involves a hydrogen bond assembly and a polycondensation process. The silanol, which was formed by a reaction of PMS aqueous solution with CO2, was assembled on the cellulose molecule surface via hydrogen bond interactions. The polymethylsilsesquioxane coatings were prepared by a polycondensation reaction of the hydroxyl between cellulose and silanol. The superhydrophobic cellulose materials were characterized by FTIR spectroscopy, thermogravimetry, and surface analysis (XPS, FESEM, AFM, and contact angle measurements). Analytical characterization revealed that nanoscale roughness protuberances uniformly covered the surface, thus transforming the cellulose from superhydrophilic to superhydrophobic with a water contact angle of 157 °. The superhydrophobic coatings were satisfactory with regard to both chemical and mechanical durability, and because of the transparency of the coatings the native cotton fabric displayed no changes with regard to either morphology or color. The easy availability of the materials and simplicity of this method render it convenient for mass production.
Co-reporter:Shenghai Li, Haibo Xie, Suobo Zhang and Xianhong Wang
Chemical Communications 2007 (Issue 46) pp:4857-4859
Publication Date(Web):21 Sep 2007
DOI:10.1039/B712056G
Superhydrophobic cellulose-based materials coupled with transparent, stable and nanoscale polymethylsiloxane coating have been successfully achieved by a simple process via chemical vapor deposition, followed by hydrolyzation and polymerization.
Co-reporter:Lei Li, Suobo Zhang, Xiaosha Zhang, Guodong Zheng
Journal of Membrane Science 2007 Volume 289(1–2) pp:258-267
Publication Date(Web):15 February 2007
DOI:10.1016/j.memsci.2006.12.007
Two novel of tri- and tetra-functional biphenyl acid chloride: 3,4′,5-biphenyl triacyl chloride (BTRC) and 3,3′,5,5′-biphenyl tetraacyl chloride (BTEC), were synthesized, and used as new monomers for the preparations of the thin film composite (TFC) reverse osmosis (RO) membranes. The TFC RO membranes were prepared on a polysulfone supporting film through interfacial polymerization with the two new monomers and m-phenylenediamine (MPD). The membranes were characterized for the permeation properties, chemical composition, d-space between polymer chains, hydrophilicity, membrane morphology including top surface and cross-section. Permeation experiment was employed to evaluate the membranes performance including salt rejection and water flux. The surface structure and chemical composition of membranes were analyzed by attenuated total reflectance infrared (ATR-IR) and X-ray photoelectronic spectroscopy (XPS). The results revealed that the active layer of membranes was composed of highly cross-linked aromatic polyamide with the functional acylamide (–CONH–) bonds. The TFC membranes prepared from biphenyl acid chloride exhibit higher salt rejection compared with that prepared from trimesoyl chloride (TMC) at the expanse of some flux.
Co-reporter:Nanwen Li, Zhiming Cui, Suobo Zhang, Shenghai Li, Feng Zhang
Journal of Power Sources 2007 Volume 172(Issue 2) pp:511-519
Publication Date(Web):25 October 2007
DOI:10.1016/j.jpowsour.2007.07.069
A series of novel oxidation and water stable sulfonated polyimides (SPIs) were synthesized from 4,4′-binaphthyl-1,1′,8,8′-tetracarboxylic dianhydride (BTDA), and wholly aromatic diamine 2,2′-bis(3-sulfobenzoyl) benzidine (2,2′-BSBB) for proton exchange membrane fuel cells. These polyimides could be cast into flexible and tough membranes from m-cresol solutions. The copolymer membranes exhibited excellent oxidative stability and mechanical properties due to their fully aromatic structure extending through the backbone and pendant groups. Moreover, all BTDA-based SPI membranes exhibited much better water stability than those based on the conventional 1,4,5,8-naphthalenecarboxylic dianhydride. The improved water stability of BTDA-based polyimides was attributed to its unique binaphthalimide structure. The SPI membranes with ion exchange capacity (IEC) of 1.36–1.90 mequiv g−1 had proton conductivity in the range of 0.41 × 10−1 to 1.12 × 10−1 S cm−1 at 20 °C. The membrane with IEC value of 1.90 mequiv g−1 displayed reasonably higher proton conductivity than Nafion® 117 (0.9 × 10−1 S cm−1) under the same test condition and the high conductivity of 0.184 S cm−1 was obtained at 80 °C. Microscopic analyses revealed that well-dispersed hydrophilic domains contribute to better proton conducting properties. These results showed that the synthesized materials might have the potential to be applied as the proton exchange membranes for PEMFCs.
Co-reporter:Wenmu Li;Suobo Zhang;Zhiming Qiu;Zhiming Qiu;Wenmu Li;Suobo Zhang
Journal of Applied Polymer Science 2007 Volume 104(Issue 4) pp:2395-2402
Publication Date(Web):27 FEB 2007
DOI:10.1002/app.25909
A new class of high-performance polymers [poly(phenylene-co-naphthalimide)s] was prepared through the Ni(0) catalytic coupling of N-(4-chloro-2-trifluromethylphenyl)-5-chloro-1,8-naphthalimide and 2,5-dichlorobenzophenone. The resulting copolymers exhibited high molecular weights (high inherent viscosities) and a combination of desirable properties such as good solubility in dipolar aprotic solvents, film-forming capability, and mechanical properties. The glass-transition temperatures of the copolymers ranged from 320 to 403°C and increased as the content of the naphthalimide moiety increased. Tough polymer films, obtained via casting from N-methylpyrrolidone solutions, had tensile strengths of 64–107 MPa and tensile moduli of 3.4–4.7 GPa. The gas permeability coefficients of the copolymers were measured for H2, CO2, O2, CH4, and N2. They showed oxygen permeability coefficients and permeability selectivity of oxygen to nitrogen (permeability coefficient for O2/permeability coefficient for N2) in the ranges of 1.39–4.31 and 4.92–5.38 barrer, respectively. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2395–2402, 2007
Co-reporter:Suobo Zhang;Guang Chen;Xiaosa Zhang;Yonglie Wu;Tianlu Chen
Journal of Applied Polymer Science 2007 Volume 106(Issue 4) pp:2808-2816
Publication Date(Web):2 AUG 2007
DOI:10.1002/app.26930
Novel bisphenol monomers (1a-d) containing phthalimide groups were synthesized by the reaction of phenolphthalein with ammonia, methylamine, aniline, and 4-tert-butylanilne, respectively. A series of cardo poly(arylene ether sulfone)s was synthesized via aromatic nucleophilic substitution of 1a-d with dichlorodiphenylsulfone, and characterized in terms of thermal, mechanical and gas transport properties to H2, O2, N2, and CO2. The polymers showed high glass transition temperature in the range 230–296°C, good solubility in polar solvents as well as excellent thermal stability with 5% weight loss above 410°C. The most permeable membrane studied showed permeability coefficients of 1.78 barrers to O2 and 13.80 barrers to CO2, with ideal selectivity factors of 4.24 for O2/N2 pair and 28.75 for CO2/CH4 pair. Furthermore, the structure–property relationship among these cardo poly(arylene ether sulfone)s had been discussed on solubility, thermal stability, mechanical, and gas permeation properties. The results indicated that introducing 4-tert-butylphenyl group improved the gas permeability of polymers evidently. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Co-reporter:Guang Chen;Xiaosa Zhang;Suobo Zhang;Junhua Wang
Journal of Applied Polymer Science 2007 Volume 106(Issue 5) pp:3179-3184
Publication Date(Web):14 AUG 2007
DOI:10.1002/app.26819
A series of soluble poly(amide-imide)s (PAIs) bearing triethylammonium sulfonate groups were synthesized directly using trimellitic anhydride chloride (TMAC) polycondensation with sulfonated diamine such as 2,2′-benzidinedisulfonic acid (BDSA), 4,4′-diaminodiphenyl ether-2,2′-disulfonic acid (ODADS), and nonsulfonated diamine 4,4-diaminodiphenyl methane in the presence of triethylamine. The resulting copolymers exhibited high molecular weights (high inherent viscosity), and a combination of desirable properties such as good solubility in dipolar aprotic solvents, film-forming capability, and good mechanical properties. Wide-angle X-ray diffraction revealed that the polymers were amorphous. These copolymers showed high permeability coefficients of water vapor because of the presence of the hydrophilic triethylammonium sulfonate groups. The water vapor permeability coefficients (Pw) and permselectivity coefficients of water vapor to nitrogen and methane [α(H2O/N2) and α(H2O/CH4)] of the films increased with increasing the amount of the triethylammonium sulfonated groups. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Co-reporter:Wenmu Li;Suobo Zhang;Guang Chen;Quanyuan Zhang
Macromolecular Chemistry and Physics 2007 Volume 208(Issue 3) pp:307-315
Publication Date(Web):6 FEB 2007
DOI:10.1002/macp.200600461
A new class of high-performance materials, fluorinated poly(phenylene-co-imide)s, were prepared by Ni(0)-catalytic coupling of 2,5-dichlorobenzophenone with fluorinated dichlorophthalimide. The synthesized copolymers have high molecular weights ( = 5.74 × 104–17.3 × 104 g · mol−1), and a combination of desirable properties such as high solubility in common organic solvent, film-forming ability, and excellent mechanical properties. The glass transition temperature (Tgs) of the copolymers was readily tuned to be between 219 and 354 °C via systematic variation of the ratio of the two comonomers. The tough polymer films, obtained by casting from solution, had tensile strength, elongation at break, and tensile modulus values in the range of 66.7–266 MPa, 2.7–13.5%, and 3.13–4.09 GPa, respectively. The oxygen permeability coefficients () and permeability selectivity of oxygen to nitrogen () of these copolymer membranes were in the range of 0.78–3.01 barrer [1 barrer = 10−10 cm3 (STP) cm/(cm2 · s · cmHg)] and 5.09–6.25, respectively. Consequently, these materials have shown promise as engineering plastics and gas-separation membrane materials.
Co-reporter:Wenmu Li;Guang Chen;Suobo Zhang;He Wang;Donghang Yan
Journal of Polymer Science Part A: Polymer Chemistry 2007 Volume 45(Issue 16) pp:3550-3561
Publication Date(Web):21 JUN 2007
DOI:10.1002/pola.22102
New asymmetrical aromatic dichlorophthalimide monomers containing pendant groups (trifluoromethyl or methyl) were conveniently prepared from inexpensive and commercially available compounds. With these monomers, a new class of soluble polyimides with a regioirregular structure within the polymer backbone was obtained by the Ni(0)-catalyzed polymerization method. The structures of the polymers were confirmed by various spectroscopic techniques. The polyimides displayed better solubility and higher thermal stability than the corresponding regular polyimides. In addition, fluorinated polyimides in this study had low dielectric constants ranging from 2.52 to 2.78, low moisture absorptions of less than 0.59%, and low thermal expansion coefficients between 10.6 and 19.7 ppm/°C. The oxygen permeability coefficients and permeability selectivity of oxygen to nitrogen of the films were in the ranges of 2.99–4.20 barrer and 5.55–7.50, respectively. We have demonstrated that the synthetic pathway for polyimides provides a successful approach to increasing the solubility and processability of polyimides without sacrificing their thermal stability. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3550–3561, 2007
Co-reporter:Haibo Xie, Suobo Zhang and Shenghai Li
Green Chemistry 2006 vol. 8(Issue 7) pp:630-633
Publication Date(Web):27 Feb 2006
DOI:10.1039/B517297G
A novel dissolving process for chitin and chitosan has been developed by using the ionic liquid 1-butyl-3-methyl-imidazolium chloride ([Bmim]Cl) as a solvent, and a novel application of chitin and chitosan as substitutes for amino-functionalized synthetic polymers for capturing and releasing CO2 has also been exploited based on this processing strategy.
Co-reporter:Changhe Qi;Suobo Zhang;Jinghun Sun
Applied Organometallic Chemistry 2006 Volume 20(Issue 2) pp:
Publication Date(Web):12 DEC 2005
DOI:10.1002/aoc.1029
Group 4 complexes containing diphosphinoamide ligands [Ph2PNR]2MCl2 (3: R = tBu, M = Ti; 4: R = tBu, M = Zr; 5: R = Ph, M = Ti; 6: R = Ph, M = Zr) were prepared by the reaction of MCl4 (M = Ti; Zr) with the corresponding lithium phosphinoamides in ether or THF. The structure of [Ph2PNtBu]2TiCl2 (3) was determined by X-ray crystallography. The phosphinoamides functioned as η2-coordination ligands in the solid state and the TiN bond length suggests it is a simple single bond. In the presence of modified methylaluminoxane or i-Bu3Al/Ph3BC(C6F5)4, catalytic activity of up to 59.5 kg PE/mol cat h bar was observed. Copyright © 2005 John Wiley & Sons, Ltd.
Co-reporter:Changhe Qi;Suobo Zhang
Applied Organometallic Chemistry 2006 Volume 20(Issue 1) pp:
Publication Date(Web):28 NOV 2005
DOI:10.1002/aoc.1019
A series of titanium and zirconium complexes based on aminoiminophosphorane ligands [Ph2P(Nt-Bu)(NR)]2MCl2 (4, M = Ti, R = Ph; 5, M = Zr, R = Ph; 6, M = Ti, R = SiMe3; 7, M = Zr, R = SiMe3) have been synthesized by the reaction of the ligands with TiCl4 and ZrCl4. The structure of complex 4 has been determined by X-ray crystallography. The observed very weak interaction between Ti and P suggests partial π-electron delocalization through both Ti and P. The complexes 4–7 are inactive for ethylene polymerization in the presence of modified methylaluminoxane (MMAO) or i-Bu3Al–Ph3CB(C6F5)4 under atmospheric pressure, and is probably the result of low monomer ethylene concentration and steric congestion around the central metal. Copyright © 2005 John Wiley & Sons, Ltd.
Co-reporter:Haibo Xie, Shenghai Li and Suobo Zhang
Green Chemistry 2005 vol. 7(Issue 8) pp:606-608
Publication Date(Web):04 Jul 2005
DOI:10.1039/B502547H
1-Butyl-3-methylimidazolium chloride ionic liquid has been developed for the dissolution and regeneration of wool keratin fibers, which can be used to prepare wool keratin/cellulose blended materials directly.
Co-reporter:Haibo Xie, Haifeng Duan, Shenghai Li and Suobo Zhang
New Journal of Chemistry 2005 vol. 29(Issue 9) pp:1199-1203
Publication Date(Web):28 Jul 2005
DOI:10.1039/B504822B
We have described that both homogeneous and a silica-supported hexaalkylguanidinium chloride were effective catalysts for CO2 fixation to carbonate without any solvent under mild reaction conditions (4.5 MPa, 120 °C, 4 h), the silica-supported hexaalkylguanidinium chloride showing the great advantage that it could be recycled easily at least 5 further times without any obvious decrease in its catalytic activity, after simple filtration.
Co-reporter:Changhe Qi, Suobo Zhang, Jinghui Sun
Journal of Organometallic Chemistry 2005 Volume 690(Issue 12) pp:2941-2946
Publication Date(Web):15 June 2005
DOI:10.1016/j.jorganchem.2005.03.016
(Phosphinoamide)(cyclopentadienyl)titanium(IV) complexes of the type Cp*TiCl2(η2-Ph2PNR) [Cp*=C5Me5; R = t-Bu (2a), R = n-Bu (2b), R = Ph (2c)] have been prepared by the reaction of Cp*TiCl3 with the corresponding lithium phosphinoamides. The structure of Cp*TiCl2(η2-Ph2PNtBu) (2a) and Cp*TiCl2(η2-Ph2PNPh) (2c) have been determined by X-ray crystallography. These complexes exhibited moderate catalytic activities for ethylene polymerization in the presence of modified methylaluminoxane (MMAO). Catalytic activity of up to 2.5 × 106 g/(mol Ti h) was observed when activated by i-Bu3Al/Ph3CB(C6F5)4.(Phosphinoamide)(cyclopentadienyl)titanium(IV) complexes of the type Cp*TiCl2(η2-Ph2PNR) have been synthesized and characterized. For polymerization of ethylene, catalytic activity of up to 2.5 × 106 g/(mol Ti h) was observed when activated by i-Bu3Al/Ph3CB(C6F5)4.
Co-reporter:Chang-He Qi, Suo-Bo Zhang, Jing-Hui Sun
Journal of Organometallic Chemistry 2005 Volume 690(Issue 17) pp:3946-3950
Publication Date(Web):1 September 2005
DOI:10.1016/j.jorganchem.2005.05.028
A series of novel phenoxy-phosphinimine ligands (L): L = 2-(Ph2PNR), 4, 6-(CMe3)2-C6H2OH [2, R = SiMe3; 3, R = Ph] have been prepared in the yield of 65–71%. And bis(phenoxy-phosphinimide) group 4 complexes of the type L2MCl2 [4, M = Ti, R = SiMe3; 5, M = Zr, R = SiMe3; 6, M = Ti, R = Ph; 7, M = Zr, R = Ph] have been synthesized by the reaction of the ligands with TiCl4 and ZrCl4. The structure of complex 7 has been determined by X-ray crystallography. The complexes 4–7 showed inactive to ethylene polymerization in the presence of modified methylaluminoxane (MMAO) and i-Bu3Al/Ph3CB(C6 F5)4. These results should be caused by overdoing the steric congestion around central metal.A series of novel phenoxy-phosphinimine ligands have been prepared in the yield of 65–71%. And bis(phenoxy-phosphinimide) group 4 complexes of the type L2MCl2 have been synthesized by the reaction of the ligands with TiCl4 and ZrCl4. The structure of complex 7 has been determined by X-ray crystallography.
Co-reporter:Changlu Gao;Suobo Zhang;Lianxun Gao;Mengxian Ding
Journal of Applied Polymer Science 2004 Volume 92(Issue 4) pp:2415-2419
Publication Date(Web):10 MAR 2004
DOI:10.1002/app.20209
A facile and rapid polycondensation reaction of disodium bisphenol A with bis(chlorophthalimide)s was preformed with a domestic microwave oven in o-dichlorobenzene by phase-transfer catalysis. The polymerization reactions, in comparison with conventional heating polycondensation, proceeded rapidly and were completed within 25 min. The polymerizations gave the corresponding poly(ether imide)s with inherent viscosities of 0.55–0.92 dL g−1. The effects of various factors on the polymerization, such as the amount of the catalyst, the reaction time, and the microwave power were studied. The properties of the polymers were briefly characterized. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2415–2419, 2004
Co-reporter:Shenghai Li, Yuntao Wu, Junhua Wang, Qiang Zhang, Yongli Kou and Suobo Zhang
Journal of Materials Chemistry A 2010 - vol. 20(Issue 21) pp:NaN4384-4384
Publication Date(Web):2010/04/26
DOI:10.1039/C0JM00255K
Water-soluble and durable Au nanoclusters, smaller than 4 nm with a narrow size distribution, were supported on a pH- and solvent-responsive water-soluble polyampholyte (SPES). Such synthesized Au@SPES hybrids possessed clear pH- and solvent-sensitive properties, and exhibited precipitation behaviors in response to pH and solvent changes in aqueous solution. Furthermore, the recycled catalyst could be redissolved in water for reuse via simple procedures based on the pH-sensitivity of the polyampholyte. By employing such catalysts, aerobic oxidation of alcohols should be able to be carried out in a homogeneous manner and may thus give rise to similar catalytic activities and selectivities as the homogeneous parent system. The phase separation and sensitivity of the SPES-stabilizing Au nanoclusters permitted a facile separation of the clusters from the reaction mixture without any negative aggregation.
Co-reporter:Yanqin Yang, Qiang Zhang, Zhiguang Zhang and Suobo Zhang
Journal of Materials Chemistry A 2013 - vol. 1(Issue 35) pp:NaN10374-10374
Publication Date(Web):2013/07/01
DOI:10.1039/C3TA11621B
A series of novel microporous polyimides (SMPIs) were synthesized from 4,4′-binaphthyl-1,1′,8,8′-tetracarboxylic dianhydride (BTDA), 6,6′-disulfonic-4,4′-binaphthyl-1,1′,8,8′-tetracarboxylic dianhydride (SBTDA) and tetrakis(4-aminophenyl)methane (TAPM). The non-sulfonated SMPI-0 (SMPI-x, where “x” is the molar percent of SBTDA) exhibited a BET surface area of 574 m2 g−1 and a CO2 uptake of 2.53 mmol g−1, while sulfonated samples, i.e. SMPI-10, SMPI-50 and SMPI-100, possessed relatively low BET surface areas (from 23 to 112 m2 g−1) but high CO2 capture capacities (from 2.82 to 3.15 mmol g−1) and CO2/N2 selectivities (from 32 to 57). With the increase of sulfonation degree, the polymers were graded from hydrophobic to hydrophilic. Hydrophobic SMPI-0 and SMPI-10 adsorbed a large amount of non-polar benzene (134.7 wt% for SMPI-0 and 104.7 wt% for SMPI-10) and cyclohexane (42.5 wt% for SMPI-0 and 42.8 wt% for SMPI-10) vapor, whereas hydrophilic SMPI-50 and SMPI-100 adsorbed more polar methanol (68.5 wt% for SMPI-50 and 72.2 wt% for SMPI-100).
Co-reporter:Qiang Zhang, Shenghai Li and Suobo Zhang
Chemical Communications 2010 - vol. 46(Issue 40) pp:NaN7497-7497
Publication Date(Web):2010/09/16
DOI:10.1039/C0CC01834A
A novel poly(aryl ether sulfone) ionomer containing hexaalkylguanidinium groups was synthesized, and membranes formed from this polymer displayed large ionic clusters, high hydroxide conductivity, and excellent solubility in low boiling point water-soluble solvents such as ethanol and methanol.
Co-reporter:Shenghai Li, Suobo Zhang, Qifeng Zhang and Guorui Qin
Chemical Communications 2012 - vol. 48(Issue 100) pp:NaN12203-12203
Publication Date(Web):2012/11/12
DOI:10.1039/C2CC36871D
A novel SPES-NH2–GA-Nafion® composite membrane with higher proton conductivity and lower methanol permeability was fabricated by covalent crosslinking layer-by-layer self-assembly of an unbalanced charged polyampholyte (SPES-NH2) and glutaraldehyde (GA) with controllable free sulfonic acid content.
Co-reporter:Guang Chen, Guojun Wu, Liming Wang, Suobo Zhang and Zhaohui Su
Chemical Communications 2008(Issue 15) pp:NaN1743-1743
Publication Date(Web):2008/03/14
DOI:10.1039/B801784K
A novel method to produce multilayer films has been developed by layer-by-layer assembly of single-charged ions and a rigid polyampholyte containing unbalanced charges in each of its repeat units.
Co-reporter:Jing Wang, Jifu Zheng, Zhuo Zhao and Suobo Zhang
Journal of Materials Chemistry A 2012 - vol. 22(Issue 42) pp:NaN22712-22712
Publication Date(Web):2012/09/10
DOI:10.1039/C2JM34417C
A series of poly(arylene ether sulfone) containing pendent imidazole groups (PSf-Im-x) have been successfully synthesized based on a novel monomer 2,2′-bis-(2-methyl-imidazol-1-yl-methyl)-biphenyl-4,4′-diol (MIPO). The pendent imidazole groups along the polymer chain were expected to provide functional sites for the acid–base interaction with the doping phosphoric acid (PA) when they are used as polymer electrolyte membranes for high temperature fuel cell applications. The PA content of the linear PSf-Im-x membranes is about 172.3–235.8% in 85 wt% H3PO4 at room temperature. The volume swelling of these membranes is 114.4–194.0%, lower than that of polybenzimidazole (PBI) with similar PA content. The proton conductivities of the membranes are 0.021–0.053 S cm−1 at 140 °C under absolutely dehydrated state. The low volume swelling and good proton conductivity may be attributed to the “side-chain-type” structures of pendent imidazole groups, which facilitate ion transport. To obtain higher acid doping while maintaining mechanical properties, cross-linked membranes were prepared by the reaction of the imidazole group of the polymer and p-xylene dichloride. The PA content of the membranes with 20% cross-linking is 313.2% in 85 wt% H3PO4 at 80 °C. The stress at breaking and the proton conductivity of the membrane is 3.2 MPa at room temperature and 0.063 S cm−1 at 140 °C in an absolutely dehydrated state.
Co-reporter:Shenghai Li, Haibo Xie, Suobo Zhang and Xianhong Wang
Chemical Communications 2007(Issue 46) pp:NaN4859-4859
Publication Date(Web):2007/09/21
DOI:10.1039/B712056G
Superhydrophobic cellulose-based materials coupled with transparent, stable and nanoscale polymethylsiloxane coating have been successfully achieved by a simple process via chemical vapor deposition, followed by hydrolyzation and polymerization.
![Nonadecacyclo[53.17.3.37,25.313,67.319,37.331,49.343,61.12,6.18,12.114,18.120,
24.126,30.132,36.138,42.144,48.150,54.156,60.162,66.168,72]dohecta-2,4,6(102),8,
10,12(101),14,16,18(100),20,22,24(99),26,28,30(95),32,34,36(94),38,
40,42(90),44,46,48(89),50,52,54(85),56,58,60(84),62,64,66(80),68,70
,72(76)-hexatriacontaene-3,5,9,11,15,17,21,23,27,29,33,35,39,41,45,
47,51,53,57,59,63,65,69,71-tetracosol](http://img.cochemist.com/ccimg/862500/862494-04-0.png)
![Nonadecacyclo[53.17.3.37,25.313,67.319,37.331,49.343,61.12,6.18,12.114,18.120,
24.126,30.132,36.138,42.144,48.150,54.156,60.162,66.168,72]dohecta-2,4,6(102),8,
10,12(101),14,16,18(100),20,22,24(99),26,28,30(95),32,34,36(94),38,
40,42(90),44,46,48(89),50,52,54(85),56,58,60(84),62,64,66(80),68,70
,72(76)-hexatriacontaene-3,5,9,11,15,17,21,23,27,29,33,35,39,41,45,
47,51,53,57,59,63,65,69,71-tetracosol](http://img.cochemist.com/ccimg/862500/862494-04-0_b.png)
![Poly[(3-oxo-1(3H)-isobenzofuranylidene)-1,4-phenyleneoxy-1,4-phenyle
necarbonyl-1,4-phenyleneoxy-1,4-phenylene]](http://img.cochemist.com/ccimg/40900/40883-84-9.png)
![Poly[(3-oxo-1(3H)-isobenzofuranylidene)-1,4-phenyleneoxy-1,4-phenyle
necarbonyl-1,4-phenyleneoxy-1,4-phenylene]](http://img.cochemist.com/ccimg/40900/40883-84-9_b.png)
![Benzonitrile, 2,2'-[1,3-phenylenebis(oxy)]bis[6-[3-[4-(4-chlorobenzoyl)phenoxy]phenoxy]-](/data/chemimg/3779000/1622832-33-0.png)
![Benzonitrile, 2,2'-[1,3-phenylenebis(oxy)]bis[6-[3-[4-(4-chlorobenzoyl)phenoxy]phenoxy]-](/data/chemimg/3779000/1622832-33-0_b.png)
![[1,1'-Biphenyl]-3,3',5,5'-tetracarbonyl tetrachloride](http://img.cochemist.com/ccimg/113800/113797-72-1.png)
![[1,1'-Biphenyl]-3,3',5,5'-tetracarbonyl tetrachloride](http://img.cochemist.com/ccimg/113800/113797-72-1_b.png)
![Benzonitrile, 2,2'-[1,3-phenylenebis(oxy)]bis[6-(3-hydroxyphenoxy)-](/data/chemimg/3779000/1622832-32-9.png)
![Benzonitrile, 2,2'-[1,3-phenylenebis(oxy)]bis[6-(3-hydroxyphenoxy)-](/data/chemimg/3779000/1622832-32-9_b.png)
![Benzonitrile, 2,6-bis[4-(4-chlorobenzoyl)phenoxy]-](/data/chemimg/3780500/1608460-47-4.png)
![Benzonitrile, 2,6-bis[4-(4-chlorobenzoyl)phenoxy]-](/data/chemimg/3780500/1608460-47-4_b.png)
![Benzenamine, 4-[tris[4-(1,1-dimethylethyl)phenyl]methyl]-](http://img.cochemist.com/ccimg/149800/149704-55-2.png)
![Benzenamine, 4-[tris[4-(1,1-dimethylethyl)phenyl]methyl]-](http://img.cochemist.com/ccimg/149800/149704-55-2_b.png)
![9,10-dihydro-9,10-[o]-benzenoanthracene-1,4-diol](/data/chemimg/2263600/5969-70-0.png)
![9,10-dihydro-9,10-[o]-benzenoanthracene-1,4-diol](/data/chemimg/2263600/5969-70-0_b.png)
![1-Hexanaminium, N-[bis(dimethylamino)methylene]-N-hexyl-, bromide](http://img.cochemist.com/ccimg/140000/139996-12-6.png)
![1-Hexanaminium, N-[bis(dimethylamino)methylene]-N-hexyl-, bromide](http://img.cochemist.com/ccimg/140000/139996-12-6_b.png)
![Ethanaminium,N-[bis(diethylamino)methylene]-N-ethyl-, bromide (1:1)](http://img.cochemist.com/ccimg/89700/89610-32-2.png)
![Ethanaminium,N-[bis(diethylamino)methylene]-N-ethyl-, bromide (1:1)](http://img.cochemist.com/ccimg/89700/89610-32-2_b.png)
![Ethanaminium,N-[bis(diethylamino)methylene]-N-ethyl-, chloride (1:1)](http://img.cochemist.com/ccimg/69100/69082-76-4.png)
![Ethanaminium,N-[bis(diethylamino)methylene]-N-ethyl-, chloride (1:1)](http://img.cochemist.com/ccimg/69100/69082-76-4_b.png)
![Poly(oxy[1,1'-biphenyl]-4,4'-diyloxy-1,4-phenylenesulfonyl-1,4-phenylene)](/data/chemimg/1105800/25839-81-0.png)
![Poly(oxy[1,1'-biphenyl]-4,4'-diyloxy-1,4-phenylenesulfonyl-1,4-phenylene)](/data/chemimg/1105800/25839-81-0_b.png)
![Phenol, 4,4'-oxybis[2-[(dimethylamino)methyl]-](/data/chemimg/3779000/17623-26-6.png)
![Phenol, 4,4'-oxybis[2-[(dimethylamino)methyl]-](/data/chemimg/3779000/17623-26-6_b.png)
![[1,1'-Biphenyl]-4,4'-diol, 3,3'-bis[(dimethylamino)methyl]-](/data/chemimg/1474900/10554-73-1.png)
![[1,1'-Biphenyl]-4,4'-diol, 3,3'-bis[(dimethylamino)methyl]-](/data/chemimg/1474900/10554-73-1_b.png)
![9,10[1',2']-Benzenoanthracene-1,4-dione, 9,10-dihydro-](/data/chemimg/24900/3519-82-2.png)
![9,10[1',2']-Benzenoanthracene-1,4-dione, 9,10-dihydro-](/data/chemimg/24900/3519-82-2_b.png)
![POLY[(2,3-DIHYDRO-3-OXO-1H-ISOINDOL-1-YLIDENE)-1,4-PHENYLENEOXY-1,4-PHENYLENESULFONYL-1,4-PHENYLENEOXY-1,4-PHENYLENE]](http://img.cochemist.com/ccimg/40900/40883-79-2.png)
![POLY[(2,3-DIHYDRO-3-OXO-1H-ISOINDOL-1-YLIDENE)-1,4-PHENYLENEOXY-1,4-PHENYLENESULFONYL-1,4-PHENYLENEOXY-1,4-PHENYLENE]](http://img.cochemist.com/ccimg/40900/40883-79-2_b.png)
