Co-reporter:Yujing Zuo;Zhiming Gou;Shengyu Feng
Macromolecular Rapid Communications 2016 Volume 37( Issue 13) pp:1052-1059
Publication Date(Web):
DOI:10.1002/marc.201600155
Co-reporter:Na Cheng, Yuchen Ma, Yongjun Liu, Changqiao Zhang, Chengbu Liu
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2016 Volume 159() pp:262-268
Publication Date(Web):15 April 2016
DOI:10.1016/j.saa.2016.02.003
•The optical properties of BTT-based donor–acceptor copolymers were studied.•The positions of sulfur atoms in BTT units have great influence on the properties.•The maximum shift of main absorption peaks of these polymers can reach ~ 150 nm.In this paper, we have investigated the structures, electronic and optical properties of five conjugated copolymers (BTT1–BTz, BTT2–BTz, BTT3–BTz, BTT4–BTz and BTT5–BTz) featuring benzotrithiophene (BTT) isomers as donor units and benzothiadiazole (BTz) as acceptor units, linked through thiophene spacers, employing many-body perturbation theory (MBPT). We have explored the isomer effects by configuration of the sulfur atoms in BTT units, aimed to get insight into how the structural modifications to the conjugated backbone can influence the molecular structures and electronic properties of conjugated polymers. Using the trimer as the computational model, the calculated low and high energy absorption bands (660 and 413 nm) for BTT1–BTz agree well with the experimental ones (645 and 430 nm) with a small offset of ~ 15 nm. On the basis of our calculations, it is found that the backbones of these polymers display different coplanarities, with the dihedral angles between the two neighboring rings varying from 12.3° to 79.0°. Importantly, both BTT1–BTz and BTT2–BTz exhibit intense adsorption around 660 and 623 nm, indicating their promising application in solar cells, whereas BTT3–BTz and BTT4–BTz display the intense adsorption at 569 and 551 nm, which are also usable in the tandem solar cells. BTT5–BTz has narrow and weak adsorption in the visible and infrared region, implying it is not conducive to the sunlight absorption. The blue shift of about 150 nm from BTT1–BTz to BTT5–BTz is suggested to be originated from the shorter effective conjugation lengths.
Co-reporter:Jinglin Tan, Depeng Ma, Xingrong Sun, Shengyu Feng and Changqiao Zhang
Dalton Transactions 2013 vol. 42(Issue 13) pp:4337-4339
Publication Date(Web):28 Nov 2012
DOI:10.1039/C2DT32645K
Preparation of POSS–min–DS, an octaimidazolium-based polyhedral oligomeric silsesquioxanes (POSS) room temperature ionic liquid, by an ion-exchange reaction between POSS and sodium dodecyl sulfate was reported. Octaimidazolium-based POSS was synthesized with more than 98% yield within 3 h. POSS–min–DS and octaimidazolium-based POSS were confirmed by 1H, 13C, and 29Si NMR, FT-IR and elemental analysis.
Co-reporter:Jinglin Tan;Peijian Zhao;Depeng Ma;Shengyu Feng
Colloid and Polymer Science 2013 Volume 291( Issue 6) pp:1487-1494
Publication Date(Web):2013 June
DOI:10.1007/s00396-012-2885-6
Three cationic silicone surfactants, (2-hydroxyethyl)-N,N-dimethyl-3-[tri-(trimethylsiloxy)]silylpropylammonium chloride (Si4ACl), (2-hydroxyethyl)-N,N-dimethyl-3-[bis(trimethylsiloxy)methyl]silylpropylammonium chloride (Si3ACl), and (2-hydroxyethyl)-N,N-dimethyl-3-[bis(trimethylsilylmethyl)methyl]silylpropyl-ammonium chloride (Si3C2ACl), with the same headgroups and different hydrophobic groups were synthesized. Their aggregation behavior in aqueous solution was investigated by surface tension and electrical conductivity. The results show that all the three cationic silicone surfactants perform admirable surface activity. Because of the effect of the hydrophobic groups, the critical micelle concentration values increase following the order Si3C2ACl < Si4ACl < Si3ACl, and Si3C2ACl packs more compactly at the air/water interface compared with Si4ACl and Si3ACl. Electrical conductivity studies show that all the three cationic silicone surfactants have low degree of counterion binding. Thermodynamic parameters (\( \varDelta\;H_m^0 \), \( \varDelta S_m^0 \), and \( \varDelta G_m^0 \)) of micellization derived from electrical conductivities indicate that the micellization for both Si3C2AC and Si3ACl in aqueous solution is enthalpy-driven, and that for the Si4ACl is entropy-driven. For the heat capacities, \( \varDelta\;c_{m,p}^0 \), values are positive for Si4ACl, indicating that there is an attractive interaction between the nitrogen atom of one surfactant molecule and the oxygen atom of another surfactant molecule for Si4ACl.
Co-reporter:Jinglin Tan, Depeng Ma, Shengyu Feng, Changqiao Zhang
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2013 Volume 417() pp:146-153
Publication Date(Web):20 January 2013
DOI:10.1016/j.colsurfa.2012.10.041
Three cationic silicone surfactants, 1-methyl-3-[tri-(trimethylsiloxy)]silylpropyl-imidazolium chloride (Si4mimCl), (2-hydroxyethyl)-N,N-dimethyl-3-[tri-(trimethylsiloxy)]silylpropylammonium chloride (Si4mam-OHCl), 1-methyl-1-[tri-(trimethylsiloxy)]silylpropylpyrrolidinium chloride (Si4pyCl), with the same hydrophobic group and different headgroups were synthesized. Their aggregation behavior in aqueous solution was systematically investigated by surface tension, electrical conductivity, and steady-state fluorescence. Surface tension of water can be reduced almost to 20 mN m−1 with the addition of the cationic silicone surfactants. This result indicates that all the three surfactants exhibit remarkable surface activity. Because of the effect of the headgroups, the critical micelle concentrations (CMC) values increase following the order Si4pyCl < Si4mimCl < Si4mam-OHCl, and Si4pyCl packs more tightly at the air/water interface compared with Si4mimCl and Si4mam-OHCl. Electrical conductivity measurements show that all the three cationic silicone surfactants have low degree of counterion binding (β) and the β values for Si4pyCl and Si4mam-OHCl increase with increasing the temperature in the investigated temperature range. Thermodynamic parameters (ΔHm0, ΔSm0, and ΔGm0) of micellization indicate that the micellization for Si4mimCl in aqueous is enthalpy-driven, and that for both the Si4pyCl and Si4mam-OHCl entropy-driven.Graphical abstractAggregation behaviors of three novel cationic silicone surfactants are investigated. The figure of β–T for Si4mimCl, Si4pyCl and Si4mam-OHCl shows that the values of β for Si4pyCl and Si4mam-OHCl increase as the temperature increases.Highlights► Cationic silicone surfactants with the same hydrophobic group and different headgroups were synthesized. ► Cationic silicone surfactants have higher surface activity compared with common hydrocarbon surfactants. ► The β values for Si4pyCl and Si4mam-OHCl increase with increasing the temperature in the investigated temperature range.
Co-reporter:Zhizhou Yang, Shuang Han, Rong Zhang, Shengyu Feng, Changqiao Zhang, Shengyou Zhang
Polymer Degradation and Stability 2011 Volume 96(Issue 12) pp:2145-2151
Publication Date(Web):December 2011
DOI:10.1016/j.polymdegradstab.2011.09.014
A series of silicone resins containing silphenylene units were synthesized by a hydrolysis–polycondensation method, with methyltriethoxysilane, dimethyldiethoxysilane and 1,4-bis(ethoxydimethylsilyl)benzene. Their thermal degradation behaviours were studied by thermogravimetric analysis (TGA), differential thermogravimetry (DTG) and Fourier-transform infrared (FTIR) spectroscopy, and the effect of silphenylene units on the thermal stability of silicone resins was also investigated. Results showed that the thermal stability of silicone resins was improved by the introduction of silphenylene units into the backbone. Under nitrogen atmosphere, the temperature for maximum degradation rate of silicone resins with silphenylene units was lower compared to the pure methylsilicone resin. With the increase of silphenylene units, the amount of degradation residues increased under nitrogen atmosphere while it decreased under air atmosphere. Additionally, the short-term and long-term stability of silicone resins were also improved by the introduction of silphenylene units.
Co-reporter:Zhizhou Yang, Lei Feng, Shen Diao, Shengyu Feng, Changqiao Zhang
Thermochimica Acta 2011 Volume 521(1–2) pp:170-175
Publication Date(Web):10 July 2011
DOI:10.1016/j.tca.2011.04.020
Co-reporter:Bing Li;Guilin Dong
Journal of Applied Polymer Science 2011 Volume 122( Issue 2) pp:1450-1456
Publication Date(Web):
DOI:10.1002/app.34272
Abstract
Microcapsules containing α-olefin drag reducing polymer were prepared by in situ and interfacial polymerization with urea, formaldehyde, and styrene as shell materials, respectively. IR spectrums of prepared shells indicated the formations of poly(urea-formaldehyde) and polystyrene in the microencapsulating process. The morphologies of uncoated particles and microcapsules were observed by scanning electron microscopy (SEM) which proved that the α-olefin drag reducing polymer particles were effectively coated. For the purpose of determining the stability of microcapsules in transportation and storage, the static pressure experiment was carried out and lasted for 6 months. In this process, microcapsules with polystyrene as shell material stuck together after 3 months; however, those with poly(urea-formaldehyde) kept the state of particles. The thermal characteristics of uncoated particles (core), poly(urea-formaldehyde) (shell), and microcapsules with that as shell material were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) which proved that thermal stable temperature of microcapsules containing α-olefin drag reducing polymer with poly(urea-formaldehyde) as shell material was below 225°C, and the mean heat absorbed by microcapsules in the temperature increasing process was 1.5–2.0 W/g higher than that by cores. The evaluation of drag reducing rate of microcapsules showed that the microencapsulating process had no influence on the drag reduction of α-olefin drag reducing polymer. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Co-reporter:Shen Diao, Kaikai Jin, Zhizhou Yang, Haifeng Lu, Shengyu Feng, Changqiao Zhang
Materials Chemistry and Physics 2011 Volume 129(1–2) pp:202-208
Publication Date(Web):15 September 2011
DOI:10.1016/j.matchemphys.2011.03.077
Three kinds of treated fumed silica were prepared with methylphenyldimethoxysilane (MPHTS), diphenyldiethoxysilane (DPHTS), and phenyltriethoxysilane (PHTS) as treating agents, respectively, and characterized by N2 adsorption, diffuse reflectance ultraviolet–vis spectra (DRUVS), titration and element analyzer. The results show that compared with untreated silica there are less surface hydroxyl groups retained on the treated silica, and the phenyl groups are introduced onto the silica surface. The treated silica was used as reinforcing filler for silicone rubber to investigate the resistance to irradiation of the silicone rubber obtained thereout. The mechanical properties and the average molecular weight between crosslinking points (Mc) of the silicone rubber were measured before and after irradiation. The dynamical mechanical properties of the silicone rubber were evaluated by dynamic mechanical analysis (DMA) before and after irradiation. It was found that the treated fumed silica cannot only effectively improve the radiation resistance of silicone rubber but also has excellent reinforcing effect on silicone rubber.Highlights► Three kinds of phenyl modified fumed silica are prepared. ► Phenyl modified fumed silica are used as reinforcing filler for silicone rubber. ► This is a novel effective way to improve radiation resistance of silicone rubber.
Co-reporter:Fangna Dai, Shuwen Gong, Peipei Cui, Guoqing Zhang, Xiaoliang Qiu, Fei Ye, Daofeng Sun, Zhijian Pang, Lei Zhang, Guilin Dong and Changqiao Zhang
New Journal of Chemistry 2010 vol. 34(Issue 11) pp:2496-2501
Publication Date(Web):31 Aug 2010
DOI:10.1039/C0NJ00328J
Three flexible bent dicarboxylate ligands, 2,2′-(2,3,5,6-tetramethyl-1,4-phenylene)bis(methylene)bis(sulfanediyl)dibenzoic acid (H2L1), 2,2′-(1,4-phenylenebis(methylene))bis(sulfanediyl)dibenzoic acid (H2L9) and 2,2′-(2,3,5,6-tetramethyl-1,4-phenylene)bis(methylene)bis(oxy)dibenzoic acid (H2L10), have been designed and synthesized. The positions of the functional substituents are in 1,4-positions of the central benzene ring, and all the ligands can adopt syn and anti conformations. By applying these flexible ligands to assemble with thulium ions or zinc ions, three metal–organic supramolecules with metallamacrocycles or 1D chains have been isolated. L1 adopts a syn conformation in complex 1, leading to a 0D metallamacrocycle, L9 in complex 2 adopts an anti conformation to form a 1D “rainbow-like” chain while L10 in complex 3 adopts both syn and anti conformations. L10 in a syn conformation connects Zn4(OH)2(CO2)4 SBU to form a 0D metallamacrocycle, which is further connected by the ligand in an anti conformation to generate a 1D coordination polymer.
Co-reporter:Hui Sun;Dongju Zhang;Chengbu Liu
Chirality 2010 Volume 22( Issue 9) pp:813-819
Publication Date(Web):
DOI:10.1002/chir.20841
Abstract
The Michael addition of cyclohexanone with trans-β-nitrostyrene catalyzed by a chiral ionic liquid (CIL) pyrrolidine-imidazolium bromide, which represents a prototype of CIL-promoted asymmetric syntheses, has been investigated by performing density functional theory calculations. We show the details of the mechanism and energetics, the influence of the acid additive on the reactivity, and the functional role of the CIL in the asymmetric addition. It is found that the reaction proceeds via two stages, i.e., the initial enamine formation, where the imine complex is first created and then isomerizes into the enamine intermediate, and the subsequent Michael addition involving a three-step mechanism. The calculations show that the presence of the acid additive changes the imine formation mechanism and lowers the reaction barrier, as well as, more importantly, makes the reaction become highly thermodynamically favored. It is also suggested that both the anion and cation of the CIL synergically facilitate the reaction, which act as the proton acceptor in the imine-enamine tautomerism and the stabilizer of the negative charge in the CC bond formation process, respectively. The present theoretical study rationalizes the early experimental findings well and provides aid to some extent for the rational design of efficient CIL catalysts. Chirality 2010. © 2010 Wiley-Liss, Inc.
Co-reporter:Fangna Dai, Haiyan He, Dongliang Gao, Fei Ye, Daofeng Sun, Zhijian Pang, Lei Zhang, Guilin Dong, Changqiao Zhang
Inorganica Chimica Acta 2009 Volume 362(Issue 11) pp:3987-3992
Publication Date(Web):15 August 2009
DOI:10.1016/j.ica.2009.05.038
Self-assembly of Zn(NO3)2·6H2O, 5-amino-2,4,6-triiodoisophthalic acid (H2atiip) and 4,4′-bipyridine (bpy) or 1,3-di(4-pyridyl)propane (dpp) gave rise to three unusual zinc metal–organic frameworks, Zn2(bpy)2(atiip)2·3H2O·2dmf (1), Zn8(dpp)8(atiip)8·4H2O (2), Zn(dpp)(atiip)·(dmf)·(H2O) (3). All complexes possess 2D layer frameworks constructed from 1D Zn-carboxylate tubular unit for 1, 1D Zn-carboxylate helical chain for 2 and 3. In 1 and 2, the bpy or dpp act as both bridging and blocking ligands and the blocking ligands play an important role in the formation of the 2D layer frameworks. Both 2 and 3 contain two different large metallomacrocycles. Photoluminescence measurements of 1–3 in the solid state at room temperature show that all complexes exhibit luminescence, which can be assigned to an intraligand π → π∗ transition or ligand-to-metal charge transfer (LMCT).This full paper describes the self-assembly of three 2D zinc metal–organic frameworks based on mixed carboxylate and N-containing ligands. In all complexes, the zinc ion are first connected by the carboxylate ligands to generate a 1D tube or helical chain, which acts as the building unit and is further linked by the N-containing ligand to form the 2D layers.
Co-reporter:Jinglin Tan, Depeng Ma, Xingrong Sun, Shengyu Feng and Changqiao Zhang
Dalton Transactions 2013 - vol. 42(Issue 13) pp:NaN4339-4339
Publication Date(Web):2012/11/28
DOI:10.1039/C2DT32645K
Preparation of POSS–min–DS, an octaimidazolium-based polyhedral oligomeric silsesquioxanes (POSS) room temperature ionic liquid, by an ion-exchange reaction between POSS and sodium dodecyl sulfate was reported. Octaimidazolium-based POSS was synthesized with more than 98% yield within 3 h. POSS–min–DS and octaimidazolium-based POSS were confirmed by 1H, 13C, and 29Si NMR, FT-IR and elemental analysis.
![3',6'-Dihydroxy-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one](http://img.cochemist.com/ccimg/2400/2321-07-5.png)
![3',6'-Dihydroxy-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one](http://img.cochemist.com/ccimg/2400/2321-07-5_b.png)