Co-reporter:Xiquan Cheng, Xu Jiang, Yanqiu Zhang, Cher Hon Lau, Zongli Xie, Derrick Ng, Stefan J. D. Smith, Matthew R. Hill, and Lu Shao
ACS Applied Materials & Interfaces November 8, 2017 Volume 9(Issue 44) pp:38877-38877
Publication Date(Web):October 12, 2017
DOI:10.1021/acsami.7b07373
Membrane separation is a promising technology for extracting temperature-sensitive organic molecules from solvents. However, a lack of membrane materials that are permeable toward organic solvents yet highly selective curtails large-scale membrane applications. To overcome the trade-off between flux and selectivity, additional molecular transportation pathways are constructed in ultrathin polyamide membranes using highly hydrostable metal organic frameworks with diverse functional surface architectures. Additional passageways enhance water permeance by 84% (15.4 L m–2 h–1 bar–1) with nearly 100% rose bengal rejection and 97.6% azithromycin rejection, while showing excellent separation performance in ethyl acetate, ketones, and alcohols. These unique composite membranes remain stable in both aqueous and organic solvent environments. This immediately finds application in the purification of aqueous mixtures containing organic soluble compounds, such as antibiotics, during pharmaceutical manufacturing.Keywords: dye antibiotics removal; high flux; nanofiltration; polyamide; UiO-66;
Co-reporter:Yanchao Xu, Fangjie You, Hongguang Sun, and Lu Shao
ACS Sustainable Chemistry & Engineering June 5, 2017 Volume 5(Issue 6) pp:5520-5520
Publication Date(Web):May 16, 2017
DOI:10.1021/acssuschemeng.7b00871
Herein, a mussel-inspired polydopamine (PDA) coating layer has been first explored as a separating layer for organic solvent nanofiltration (OSN). A PDA based separating layer was constructed on polyimide (PI) support via dopamine coating. The subsequent membrane was then treated with 1,6-hexanediamine for cross-linking on both the PDA layer and PI support. Fourier transform infrared (ATR-FTIR) and X-ray photoelectron (XPS) results indicated the deposition of PDA on support and the cross-linked structures of both PDA and PI. Scanning electron microscopy (SEM), atomic force microscopy (AFM), water contact angle, and surface energy measurements were further employed to characterize the morphologies and surface properties of the composite membranes. After an optimized coating time of 4 h, the resultant membrane showed an EtOH permeance of 0.91 L m–2 h–1 bar–1 and a RB rejection of 99%. More importantly, the composite membrane also exhibited good performance for dyes separation from a wide range of solvents including challenging polar aprotic and strongly swelling solvents, such as dimethylformamide and acetone. In addition to demonstrating a facile and effective OSN membrane fabrication approach, this study may stimulate the bioinspired design of a composite membrane for sustainable applications.Keywords: Cross-linking; Membrane stability; Organic solvent nanofiltration; Polydopamine; Polyimide;
Co-reporter:Xiaobin Yang;Xu Jiang;Yudong Huang;Zhanhu Guo
ACS Applied Materials & Interfaces February 15, 2017 Volume 9(Issue 6) pp:5590-5599
Publication Date(Web):January 19, 2017
DOI:10.1021/acsami.6b15098
The nanoporous metal–organic frameworks (MOFs) “armor” is in situ intergrown onto the surfaces of carbon fibers (CFs) by nitric acid oxidization to supply nucleation sites and serves as a novel interfacial linker between the fiber and polymer matrix and a smart cushion to release interior and exterior applied forces. Simultaneous enhancements of the interfacial and interlaminar shear strength as well as the tensile strength of CFs were achieved. With the aid of an ultrasonic “cleaning” process, the optimized surface energy and tensile strength of CFs with a MOF “armor” are 83.79 mN m–1 and 5.09 GPa, for an increase of 102% and 11.6%, respectively. Our work finds that the template-induced nucleation of 3D MOF onto 1D fibers is a general and promising approach toward advanced composite materials for diverse applications to meet scientific and technical demands.Keywords: 1D fibers; composite materials; metal−organic frameworks; strength; surface modification;
Co-reporter:Yan Chao Xu, Yu Pan Tang, Li Fen Liu, Zhan Hu Guo, Lu Shao
Journal of Membrane Science 2017 Volume 526() pp:32-42
Publication Date(Web):15 March 2017
DOI:10.1016/j.memsci.2016.12.026
•Nanocomposite OSN membranes were prepared by a mussel-inspired co-deposition strategy.•Intramolecular cyclization reaction did do not occur during co-deposition process.•The membrane exhibited good separation performance in a wide range of solvents.Herein, a novel nanocomposite organic solvent nanofiltration (OSN) membrane has been facilely fabricated by a highly-efficient one-step co-deposition of mussel-inspired catechol and octaammonium polyhedral oligomeric silsesquioxane (POSS-NH3+Cl-) onto supports. The basic properties and morphologies of the co-deposited nanocomposite membranes were investigated with various physicochemical characterizations in detail. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectra proved the present of POSS nanoparticles on membrane surface. X-ray photoelectron (XPS) results suggested the optimal ratio of POSS-NH3+Cl- and catechol for co-deposition. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) images demonstrated the formation of a layer on support surface. The optimized nanocomposite membrane exhibited an ethanol (EtOH) permeance of 1.26 L m−2 h−1 bar−1 with a rejection of 99% to Rose Bengal (RB). The novel membrane also exhibited remarkable separation performance for dyes removal from a wide range of solvents including challenging polar aprotic and strongly swelling solvents. Particularly, the nanocomposite membrane demonstrated stable performances during a two-day long term test in DMF for RB concentration. In addition to providing a highly-efficient way to high-performance OSN membrane, this work may stimulate the bio-inspired design of advanced nanocomposite membranes for environmental applications.
Co-reporter:Yan Qiu Zhang;Xiao Bin Yang;Zhen Xing Wang;Jun Long
Journal of Materials Chemistry A 2017 vol. 5(Issue 16) pp:7316-7325
Publication Date(Web):2017/04/18
DOI:10.1039/C6TA11252H
Highly-efficient separating materials, which can simultaneously remove oil from water and adsorb water-soluble contaminants like dyes, are in high demand for wastewater treatment. Herein, a magnetic, multifunctional melamine foam (MF) containing Fe3O4 nanoparticles, poly(sulfobetaine methacrylate) (PSBMA) and polydopamine (PDA) was fabricated via a simple mussel-inspired one-pot process, which not only can separate oil/water mixtures and emulsions but also has cationic-dye selective separation abilities. The addition of poly(sulfobetaine methacrylate) (PSBMA) allows immobilization to bind Fe3O4 nanoparticles tightly on the surface of the melamine foam skeleton so as to endow the 3D foam with superoleophobicity underwater, as well as providing active sites for the adsorption of soluble dyes in water. The special material synergy makes the resultant magnetic MF@Fe3O4@PDA/PSBMA foam quickly absorb cationic dyes and allows for the selective removal (in 2 minutes) of cationic dyes from dye mixtures with high efficiency (>96%), high stability and flexibility even after 10 cycles, when driven by a magnet. Furthermore, the developed 3D magnetic foam is able to separate oil–water mixtures in highly acidic, alkaline, and salty environments. Our strategy may open a new avenue to obtain high-performance 3D magnetic assemblies for wastewater remediation.
Co-reporter:Xiquan Cheng, Shangang Ding, Jiang Guo, Cong Zhang, Zhanhu Guo, Lu Shao
Journal of Membrane Science 2017 Volume 536(Volume 536) pp:
Publication Date(Web):15 August 2017
DOI:10.1016/j.memsci.2017.04.057
•Highly permeable TiO2 incorporated PPy OSN membranes were successfully developed.•The in-situ synthesized TiO2 distributes uniformly in the PPy selective layer.•The novel membrane shows increment of permeances ranging from 475% to 694%.The separation of active organic molecules is the most challenging in pharmaceutical and petrochemical industries due to the intensive energy consumption of traditional distillation and the deactivation of active molecules during phase transition. Although the organic solvent nanofiltration (OSN) with nanoscaled molecular-separation ability is increasingly attractive for active organic molecule separations, the relatively low solvent permeance precludes OSNs from wide applications. Herein, we developed a kind of advanced mixed matrix membranes (MMMs) with both high permeances and high rejection by incorporating TiO2 into polypyrrole (PPy) selective layer through in-situ hydrolysis of Ti(OC4H9)4 precursor on the surface of moisturized substrates. Owing to the uniform dispersion of in-situ formed TiO2 nanoparticles, positive tuning effects of Ti(OC4H9)4 hydrolysis on PPy polymerization and structural characteristics of the hybrid selective layer, the in-situ TiO2 incorporated PPy MMMs demonstrate both high ethanol permeances as 16.2 L m−2 h−1 bar−1 and high brilliant blue rejection (MW=792.85 g mol−1) as 92%. Most importantly, the advanced membrane also demonstrates the ethanol permeance over 8.0 L m−2 h−1 bar−1 during the long-term running test which is even higher than the initial permeances of many organic solvent nanofiltration membranes with similar rejection and high stability.With defect-free and blocking-free selective nanocomposite layer, the in-situ synthesized TiO2/polypyrrole membranes demonstrate above 400% increment of solvent permeances and better dye rejection.Download high-res image (254KB)Download full-size image
Co-reporter:Xu Jiang;Songwei Li
Energy & Environmental Science (2008-Present) 2017 vol. 10(Issue 6) pp:1339-1344
Publication Date(Web):2017/06/14
DOI:10.1039/C6EE03566C
Semi-interpenetrating network (SIPN) membranes with unprecedentedly high CO2 permeability were designed and synthesized simply through one-step, UV-induced radical polymerization. The in situ embedment of linear polyethylene glycol as a “CO2 transport promoter” in membranes can dramatically enhance both CO2 solubility and diffusivity to push SIPN membrane performance beyond Robeson's upper bound line (2008). This extremely facile performance-manipulating strategy establishes our CO2-philic SIPN membranes as an exciting platform for sustainable CO2 separations.
Co-reporter:Zhenxing Wang;Xiaobin Yang;Zhongjun Cheng;Yuyan Liu;Lei Jiang
Materials Horizons (2014-Present) 2017 vol. 4(Issue 4) pp:701-708
Publication Date(Web):2017/07/03
DOI:10.1039/C7MH00216E
A facile strategy for the preparation of multifunctional Janus membranes (JMs) was proposed, and excellent controllability of the multifunctional JMs was demonstrated in water collection, lossless transportation, decontamination, and on-off control. This novel strategy will accelerate the evolution of JMs from a scientific concept to usable materials for the “real” world.
Co-reporter:Fangjie You;Yanchao Xu;Xiaobin Yang;Yanqiu Zhang
Chemical Communications 2017 vol. 53(Issue 45) pp:6128-6131
Publication Date(Web):2017/06/01
DOI:10.1039/C7CC02411H
A novel Ni2+-polyphenol network was designed as an excellent bio-coating by a one-step strategy to obtain nanofiltration membranes, possessing unconventional high water flux up to 56.1 L m−2 h−1 bar−1 with rose bengal (RB) rejection above 95%. This study provides a facile approach to prepare highly-efficient nanofiltration membranes for wastewater remediation.
Co-reporter:Bo Gao, Jing Zhang, Zhenna Hao, Lujie Huo, Ruliang Zhang, Lu Shao
Carbon 2017 Volume 123(Volume 123) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.carbon.2017.08.008
In this study, hyperbranched polyglycerol (HPG) is chemically bound onto carbon fiber (CF) surface by anionic ring-opening polymerization for linking fiber and matrix to release interior and exterior applied forces. To explore the optimal conditions for the successful hyperbranched polymerization of glycidol on the carbon fiber, various characterization techniques were employed. The atomic force microscope quantitative nanomechanical mapping results reveal that the HPG can significantly improve interfacial status between carbon fiber and epoxy matrix. Compared with the mechanical properties of desized fiber based composites, both interfacial shear strength and interlaminar shear strength of HPG grafted fiber/epoxy composites increase by 90.69% and 49.83%, respectively. The adjustable size of HPG grafted on CF endorse the CF modification strategy with the unique characteristic, which can design the optimized interface between CF and resin to meet various scientific and technical demands.Download high-res image (534KB)Download full-size image
Co-reporter:Shuai Quan, Songwei Li, Zhenxing Wang, Xingru Yan, Zhanhu Guo and Lu Shao
Journal of Materials Chemistry A 2015 vol. 3(Issue 26) pp:13758-13766
Publication Date(Web):19 May 2015
DOI:10.1039/C5TA03232F
For the first time, the exciting reaction between the bio-inspired dopamine and the epoxy functional poly(ethylene oxide) (PEO) at elevated temperatures was found and utilized for fabricating dopamine/poly(ethylene oxide) (PEO) network membranes for sustainable gas separation. The gas transport properties of the synthesized novel membrane were investigated aiming at energy (H2) purification and CO2 capture. The membrane was confirmed to be CO2 selective and exhibited relatively high selectivity especially for CO2/N2 separation. Importantly, the flexible incorporation of low-molecular-weight poly(ethylene glycol) dimethyl ether (PEGDME) into the swollen network membrane greatly improved the gas transport performance and the CO2 permeability was increased by 550%. Furthermore, the temperature and upstream pressure dependence of our developed membranes have been examined in detail. Surprisingly, the plasticization phenomena in the membranes at higher upstream pressure can be harnessed to enhance the gas transport performance by increasing both the CO2 permeability and the CO2/other tested gas selectivity mainly due to the network structure and CO2-philic character. This report will expedite the rapid discovery of new materials derived from bio-inspired dopamine for possibly solving energy and environmental issues.
Co-reporter:Zhen-Xing Wang, Cher-Hon Lau, Nai-Qing Zhang, Yong-Ping Bai and Lu Shao
Journal of Materials Chemistry A 2015 vol. 3(Issue 6) pp:2650-2657
Publication Date(Web):01 Dec 2014
DOI:10.1039/C4TA05970K
Novel hybrid coatings with excellent wettability are architecturally constructed on the surfaces of different types of separation membranes via simultaneous polymerization of mussel-inspired dopamine and hydrolysis of commercially available and low-cost silane through a highly efficient one-step approach. After coating with the designed hybrid coatings, the ultrafiltration (UF) membranes possess high hydrophilicity and excellent dry storage ability while the microfiltration (MF) membranes are endorsed with superhydrophilicity and underwater superoleophobicity. Such unique UF and MF membranes can be deployed for treating protein-rich water with drastically enhanced functions and separating oily water (oil-in-water emulsion) under atmospheric conditions with ultrahigh water flux and superior antifouling abilities. This versatile strategy to tailor membrane surface wettability paves the way for separation membranes to be used in harsh water environmental remediation and greatly stimulates the rapid development of mussel-inspired pDA based hybrid materials for advanced applications.
Co-reporter:Zhenxing Wang, Yanchao Xu, Yuyan Liu and Lu Shao
Journal of Materials Chemistry A 2015 vol. 3(Issue 23) pp:12171-12178
Publication Date(Web):30 Apr 2015
DOI:10.1039/C5TA01767J
The current available superhydrophobic modification techniques that utilize mussel-inspired polydopamine (pDA) to construct hierarchical structures require the addition of nanoparticles or the usage of a high concentration of dopamine. These requirements are expensive and therefore lower the application efficiency. Herein, for the first time, a superhydrophobic fabric was prepared by a novel and simple mussel-inspired strategy with a much lower concentration of dopamine without any additional nanoparticles. Folic acid (FA) was first applied to a surface to induce the formation of rough pDA coatings with hierarchical structures. These hierarchical structures can be readily controlled by adjusting FA concentration or coating duration. After octadecylamine (ODA) chemical manipulation, the obtained fabric exhibited water contact and rolling off angles of about 162° and 7°, respectively, indicating that it was endowed with superhydrophobicity. Importantly, the superhydrophobic fabric can withstand continuous and drastic 3.5 wt% NaCl solution rinses and repeated tearing with an adhesive tape more than 30 times, suggesting that it has excellent durability. This novel mussel-inspired strategy can facilely and cost-effectively realize superhydrophobic manipulation and tailoring of materials. Moreover, an energy-saving and highly-efficient mini boat fabricated from our novel superhydrophobic fabric was utilized for self-driven oil spill cleanup. The boat can automatically recycle crude oil spills while floating freely on water with a cleanup rate of crude oil spill up to 97.1%, demonstrating great potential in environmental remediation. The novel strategy designed in this study will inspire the fast development of mussel-inspired superhydrophobic materials for applications in various fields.
Co-reporter:Zhenxing Wang, Jing Guo, Jun Ma and Lu Shao
Journal of Materials Chemistry A 2015 vol. 3(Issue 39) pp:19960-19968
Publication Date(Web):20 Aug 2015
DOI:10.1039/C5TA04840K
Most recently, polydopamine (PDA) and its hybrid nanomaterials have been developed as promising adsorbents to remove organic dyes. However, PDA-based adsorbents are typically limited by a poor alkali resistance, lack of selective adsorption capacity and unsatisfactory recyclability. Herein, novel PDA-based magnetic nanoparticles are fabricated for the first time via the simultaneous incorporation of PDA and poly(ethylenimine) (PEI) on Fe3O4 nanoparticles simply in one step to overcome almost all the disadvantages of “traditional” PDA adsorbents. The constructed PDA-based magnetic nanoparticles have an ultrathin shell layer (only about 3 nm, much thinner than that of other PDA adsorbents) and can withstand strong alkaline solutions (0.1 M NaOH, pH = 13), exhibiting an excellent alkali resistance. Remarkably, the nanoparticles show superior performance in smart and fast selective removal (>95% in just five minutes) of anionic dyes from dye mixtures and can maintain their high efficiency (>90%) even after 10 cycles, indicating the unprecedented selective adsorption capacity and the desirable recyclability. The adsorption process follows pseudo-second order reaction kinetics, as well as the Langmuir isotherm, indicating that anionic dyes are monolayer adsorbed on the hybrid by electrostatic interaction. In particular, the facile regeneration of the novel composite nanoparticles can be accomplished within only several minutes, demonstrating an excellent regeneration ability. Our study can provide new insights into utilizing mussel-inspired materials for environmental remediation and creating advanced magnetic materials for various promising applications.
Co-reporter:Zhenxing Wang, Xu Jiang, Xiquan Cheng, Cher Hon Lau, and Lu Shao
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 18) pp:9534
Publication Date(Web):April 20, 2015
DOI:10.1021/acsami.5b00894
We first report here mussel-inspired, hybrid coatings formed in a facile manner via simultaneous polymerization of mussel-inspired dopamine and hydrolysis of commercial tetraethoxysilane in a single-step process. The hybrid coatings can firmly adhered on hydrophobic polyvinylidene fluoride (PVDF) substrate, and the hydrophilicity of the coating can be tuned by adjusting silane concentration. The reason for the changed hydrophilicity of the coating is disclosed by a series of characterization, and was applied to rationally design optimized hybrid coatings that transform commercial PVDF microfiltration (MF) membrane hydrophobicity into high hydrophilicity with excellent water permeability and underwater superoleophobicity for oil-in-water emulsion separation. The PVDF MF membrane decorated with optimized coatings has ultrahigh water flux (8606 L m–2 h–1 only under 0.9 bar, which is 34 times higher than that of pristine membrane), highly efficient oil-in-water emulsion separation ability at atmospheric pressure (filtrate flux of 140 L m–2 h–1) and excellent antifouling performance. More importantly, these membranes are extremely stable as underwater superoleophobicity are maintained, even after rigorous washings or cryogenic bending, disclosing outstanding stability. The simplicity and versatility of this novel mussel-inspired one-step strategy may bridge the material-induced technology gap between academia and industry, which makes it promising for eco-friendly applications.Keywords: high hydrophilicity; hybrid coating; long-term stability; oil-in-water emulsion separation; underwater superoleophobicity;
Co-reporter:Xi Quan Cheng, Lu Shao, Cher Hon Lau
Journal of Membrane Science 2015 Volume 476() pp:95-104
Publication Date(Web):15 February 2015
DOI:10.1016/j.memsci.2014.11.020
•A novel kind of positive charged TFC composite NF membranes was fabricated.•Factors affecting the performance of NF membranes were investigated in detail.•The high hydrophilicity of the selective layer resulted in the high flux.A hydrophilic thin-film-composite (TFC) nanofiltration (NF) membrane has been developed through the interfacial polymerization (IP) of amino-functional polyethylene glycol (PEG) and trimesoyl chloride. The selective layer is formed on a polyethersulfone (PES) support that is characterized using FTIR, XPS and SEM, and is dependent on monomer immersion duration, and the concentration of monomers and additives. The higher hydrophilicity alongside the larger pore size of the PEG-based selective layer is the key to a high water flux of 66.0 L m−2 h−1 at 5.0 bar. With mean pore radius of 0.42 nm and narrow pore size distribution, the MgSO4 rejections of the PEG based PA TFC NF membranes can reach up to 80.2%. The rejection rates for different salts of the novel membranes are in the order of R(MgCl2)>R(MgSO4)>R(NaCl)>R(Na2SO4); indicating a membrane with positive surface charges. The pore sizes and water permeability of these membranes are tailored by varying the molecular weight and molecular architecture of amino-functional PEG. These newly developed TFC NF membranes show great potential for water softening, wastewater treatment and separation and purification of active, pharmaceutical molecules.
Co-reporter:Shuai Quan;Yu Pan Tang;Zhen Xing Wang;Zai Xing Jiang;Rong Guo Wang;Yu Yan Liu
Macromolecular Rapid Communications 2015 Volume 36( Issue 5) pp:490-495
Publication Date(Web):
DOI:10.1002/marc.201400633
Co-reporter:Shan Gang Ding;Xi Quan Cheng;Zai Xing Jiang;Yong Ping Bai
Journal of Applied Polymer Science 2015 Volume 132( Issue 20) pp:
Publication Date(Web):
DOI:10.1002/app.41991
ABSTRACT
The effects of different solvents (dimethyl formamide: DMF and dimethylsulfoxide: DMSO) on the solubility of polyacrylonitrile (PAN) were investigated by the phase diagrams of H2O/DMF/PAN and H2O/DMSO/PAN ternary systems through cloud-point titration method at low polymer concentration. The influences of polymer concentrations and temperatures on the morphologies of PAN ultrafiltration membranes were elucidated. The morphologies of fabricated UF membranes were characterized by scanning electron microscopy (SEM) and atomic force microscope (AFM), and the basic performance of ultrafiltration including pure water flux and rejection of BSA were explored. At 25°C, the pure water flux of ultrafiltration membranes at the lower PAN content (16 wt % PAN in 84 wt % DMSO) reached 213.8 L/m/bar and the rejection of BSA was 100%. Interestingly, the water flux of UF membranes dramatically decreased to 20.6 L/m/bar (20 wt %) and 2.9 L/m/bar (24 wt %) when increasing PAN concentrations in DMSO. On the other hand, the hydrophilicity of membranes can be enhanced by increasing coagulation temperatures and polymer concentrations which were characterized by static contact angle, fitting well with the variation tendency of roughness. Although there are many works concerning on the effects of phase inversion conditions on the performance of PAN UF membranes, to our best knowledge, there is seldom works focusing on investigating the membrane hydrophilicity trend by adjusting phase inversion conditions. To disclose the reason of the enhanced hydrophilicity, the water and glycol contact angles of various membranes were measured and the surface tensions were presented. The results illustrated that the enhanced hydrophilicity of PAN UF membranes fabricated at higher temperatures or higher polymer concentrations was due to the higher polarity on membrane surface. Since the vast majority of ultrafiltration membranes in labs and in industrial scale have been fabricated by immersion phase inversion method, this work can provide a guidance to obtain hydrophilic PAN UF membranes by adjusting the process of phase inversion. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41991.
Co-reporter:Song Lin Liu, Lu Shao, Mei Ling Chua, Cher Hon Lau, Huan Wang, Shuai Quan
Progress in Polymer Science 2013 Volume 38(Issue 7) pp:1089-1120
Publication Date(Web):July 2013
DOI:10.1016/j.progpolymsci.2013.02.002
Contemporary environmental problems in industrial gas production and purification have driven researchers to search for green, elegant and sustainable technologies to resolve these issues. To this end, membrane technology is a promising and environmentally friendly alternative separation technique for mitigation of carbon dioxide (CO2) emissions in addition to gas purification for energy development (particularly from syngas, natural gas or flue gas streams). Nevertheless, traditional polymeric membranes have demonstrated insufficient capability for CO2 removal because the performance of these membranes is primarily controlled by the diffusion of various gases based on their molecular sizes. Most recently, poly(ethylene oxide) (PEO) membranes have garnered growing interest because their performance for CO2 removal can be elegantly controlled by the solubility of the different gases in the membranes. The PEO membranes have a high affinity towards CO2 and have demonstrated simplicity in membrane fabrication. However, drawbacks such as a high crystallization tendency and a weak mechanical strength have curtailed its industrial application. Various strategies have been considered to overcome these drawbacks using structural design of polymers via copolymerization with additional rigid repeating segments, crosslinking and physical blending with other polymers to produce ultra-permeable PEO-based membranes for CO2 separation. In this review, the state-of-the-art for PEO-containing membranes is evaluated alongside the benefits and shortcomings of various related methodologies. In addition, recent developments are reviewed in the fabrication of PEO-containing asymmetric and composite membranes with a thin separation layer. An assessment of the benefits and drawbacks of various approaches for fabrication of advanced PEO-containing membranes is highlighted, and future research directions in this field are also proposed.
Co-reporter:Cher Hon Lau;Songlin Liu;Donald R. Paul;Jianzhong Xia;Yan-Ching Jean;Hongmin Chen;Tai-Shung Chung
Advanced Energy Materials 2011 Volume 1( Issue 4) pp:634-642
Publication Date(Web):
DOI:10.1002/aenm.201100195
Abstract
An effective separation of CO2 from H2 can be achieved using currently known polyethylene oxide (PEO)-based membranes at low temperatures but the CO2 permeability is inadequate for commerical operations. For commercial-scale CO2/H2 separation, CO2 permeability of these membranes must be significantly enhanced without compromising CO2/H2 selectivity. We report here exceptional CO2/H2 separation properties of a nanohybrid membrane comprising polyethylene glycol methacrylate (PEGMA) grafts on an organic-inorganic membrane (OIM) consisting of a low molecular weight polypropylene oxide (PPO)-PEO-PPO diamine and 3-glycidyloxypropyltrimethoxysilane (GOTMS), an alkoxysilane. The CO2 gas permeability of this nanohybrid membrane can reach 1990 Barrer with a CO2/H2 selectivity of 11 at 35 °C for a mixed gas mixture comprising 50% CO2 - 50% H2 at 3.5 atm. The transformation of the inorganic silica phase from a well-dispersed network of finely defined nanoparticles to rough porous clusters appears to be responsible for this OIM membrane exceeding the performance of other state-of-the-art PEO-based membranes.
Co-reporter:Lu Shao, Yongping Bai, Xu Huang, Zhangfei Gao, Linghui Meng, Yudong Huang, Jun Ma
Materials Chemistry and Physics 2009 Volume 116(2–3) pp:323-326
Publication Date(Web):15 August 2009
DOI:10.1016/j.matchemphys.2009.04.015
For the first time, supercritical ammonia fluid was utilized to simply functionalize multi-walled carbon nanotube (MWCNT) with amino groups. The successful amino functionalization of MWCNTs was proven and the physicochemical properties of MWCNTs before and after supercritical ammonia fluids modifications were characterized using X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), atomic force microscope (AFM) and Raman spectroscopy. The results also indicated that the supercritical ammonia fluids had the visible effects on the nanostructure of carbon nanotubes. Our novel modification approach provides an easy way to modify MWCNTs with amino groups, which is very useful for realizing “carbon nanotube economy” in the near future.
Co-reporter:Song Lin Liu, Lu Shao, Mei Ling Chua, Cher Hon Lau, Huan Wang, Shuai Quan
Progress in Polymer Science (July 2013) Volume 38(Issue 7) pp:1089-1120
Publication Date(Web):1 July 2013
DOI:10.1016/j.progpolymsci.2013.02.002
Contemporary environmental problems in industrial gas production and purification have driven researchers to search for green, elegant and sustainable technologies to resolve these issues. To this end, membrane technology is a promising and environmentally friendly alternative separation technique for mitigation of carbon dioxide (CO2) emissions in addition to gas purification for energy development (particularly from syngas, natural gas or flue gas streams). Nevertheless, traditional polymeric membranes have demonstrated insufficient capability for CO2 removal because the performance of these membranes is primarily controlled by the diffusion of various gases based on their molecular sizes. Most recently, poly(ethylene oxide) (PEO) membranes have garnered growing interest because their performance for CO2 removal can be elegantly controlled by the solubility of the different gases in the membranes. The PEO membranes have a high affinity towards CO2 and have demonstrated simplicity in membrane fabrication. However, drawbacks such as a high crystallization tendency and a weak mechanical strength have curtailed its industrial application. Various strategies have been considered to overcome these drawbacks using structural design of polymers via copolymerization with additional rigid repeating segments, crosslinking and physical blending with other polymers to produce ultra-permeable PEO-based membranes for CO2 separation. In this review, the state-of-the-art for PEO-containing membranes is evaluated alongside the benefits and shortcomings of various related methodologies. In addition, recent developments are reviewed in the fabrication of PEO-containing asymmetric and composite membranes with a thin separation layer. An assessment of the benefits and drawbacks of various approaches for fabrication of advanced PEO-containing membranes is highlighted, and future research directions in this field are also proposed.
Co-reporter:Shuai Quan, Song Wei Li, You Chang Xiao, Lu Shao
International Journal of Greenhouse Gas Control (January 2017) Volume 56() pp:22-29
Publication Date(Web):1 January 2017
DOI:10.1016/j.ijggc.2016.11.010
•GO was firstly incorporated into PEO-based cross-linked membranes for CO2 capture.•The incorporation of GO can enhance gas transport performance of PEO membranes.•GO incorporation restrains molecular chain entanglement to increase FFV of MMMs.•The immersion of PEGDME into MMMs can further increase the CO2 capture ability.In this study, GO was deliberately incorporated into cross-linked poly (ethylene oxide) (PEO) matrix to obtain novel CO2-selective mixed matrix membranes (MMMs) for sustainable CO2 capture. Various characterizations have been carried out to explore the physicochemical properties of cross-linked PEO membranes before and after GO incorporations. The cross-sectional morphologies of MMMs illustrated a favourable polymer-nanofiller interface between GO and PEO matrix. The mechanical tests indicated the enhanced mechanical properties of membranes after GO incorporation. The gas transport performance of MMMs was investigated in detail. Interestingly, the GO incorporation obviously enhanced the gas permeability of pristine cross-linked PEO membrane because GO restrains the molecular chain entanglement and expands the cross-linked network structures, resulting in the increased fractional free volume (FFV). The gas permeabilities of MMMs demonstrate the highest values at 1.0 wt% GO contents. Furthermore, the incorporation of poly(ethylene glycol) dimethyl ether (PEGDME) into MMMs significantly improved the gas transport properties. The improved mechanical properties and excellent CO2 capture performance of GO incorporated PEO network membrane disclosed in this study provide the new opportunity to tackle energy and environmental issues.Download high-res image (158KB)Download full-size image
Co-reporter:Zhenxing Wang, Yanchao Xu, Yuyan Liu and Lu Shao
Journal of Materials Chemistry A 2015 - vol. 3(Issue 23) pp:NaN12178-12178
Publication Date(Web):2015/04/30
DOI:10.1039/C5TA01767J
The current available superhydrophobic modification techniques that utilize mussel-inspired polydopamine (pDA) to construct hierarchical structures require the addition of nanoparticles or the usage of a high concentration of dopamine. These requirements are expensive and therefore lower the application efficiency. Herein, for the first time, a superhydrophobic fabric was prepared by a novel and simple mussel-inspired strategy with a much lower concentration of dopamine without any additional nanoparticles. Folic acid (FA) was first applied to a surface to induce the formation of rough pDA coatings with hierarchical structures. These hierarchical structures can be readily controlled by adjusting FA concentration or coating duration. After octadecylamine (ODA) chemical manipulation, the obtained fabric exhibited water contact and rolling off angles of about 162° and 7°, respectively, indicating that it was endowed with superhydrophobicity. Importantly, the superhydrophobic fabric can withstand continuous and drastic 3.5 wt% NaCl solution rinses and repeated tearing with an adhesive tape more than 30 times, suggesting that it has excellent durability. This novel mussel-inspired strategy can facilely and cost-effectively realize superhydrophobic manipulation and tailoring of materials. Moreover, an energy-saving and highly-efficient mini boat fabricated from our novel superhydrophobic fabric was utilized for self-driven oil spill cleanup. The boat can automatically recycle crude oil spills while floating freely on water with a cleanup rate of crude oil spill up to 97.1%, demonstrating great potential in environmental remediation. The novel strategy designed in this study will inspire the fast development of mussel-inspired superhydrophobic materials for applications in various fields.
Co-reporter:Shuai Quan, Songwei Li, Zhenxing Wang, Xingru Yan, Zhanhu Guo and Lu Shao
Journal of Materials Chemistry A 2015 - vol. 3(Issue 26) pp:NaN13766-13766
Publication Date(Web):2015/05/19
DOI:10.1039/C5TA03232F
For the first time, the exciting reaction between the bio-inspired dopamine and the epoxy functional poly(ethylene oxide) (PEO) at elevated temperatures was found and utilized for fabricating dopamine/poly(ethylene oxide) (PEO) network membranes for sustainable gas separation. The gas transport properties of the synthesized novel membrane were investigated aiming at energy (H2) purification and CO2 capture. The membrane was confirmed to be CO2 selective and exhibited relatively high selectivity especially for CO2/N2 separation. Importantly, the flexible incorporation of low-molecular-weight poly(ethylene glycol) dimethyl ether (PEGDME) into the swollen network membrane greatly improved the gas transport performance and the CO2 permeability was increased by 550%. Furthermore, the temperature and upstream pressure dependence of our developed membranes have been examined in detail. Surprisingly, the plasticization phenomena in the membranes at higher upstream pressure can be harnessed to enhance the gas transport performance by increasing both the CO2 permeability and the CO2/other tested gas selectivity mainly due to the network structure and CO2-philic character. This report will expedite the rapid discovery of new materials derived from bio-inspired dopamine for possibly solving energy and environmental issues.
Co-reporter:Zhen-Xing Wang, Cher-Hon Lau, Nai-Qing Zhang, Yong-Ping Bai and Lu Shao
Journal of Materials Chemistry A 2015 - vol. 3(Issue 6) pp:NaN2657-2657
Publication Date(Web):2014/12/01
DOI:10.1039/C4TA05970K
Novel hybrid coatings with excellent wettability are architecturally constructed on the surfaces of different types of separation membranes via simultaneous polymerization of mussel-inspired dopamine and hydrolysis of commercially available and low-cost silane through a highly efficient one-step approach. After coating with the designed hybrid coatings, the ultrafiltration (UF) membranes possess high hydrophilicity and excellent dry storage ability while the microfiltration (MF) membranes are endorsed with superhydrophilicity and underwater superoleophobicity. Such unique UF and MF membranes can be deployed for treating protein-rich water with drastically enhanced functions and separating oily water (oil-in-water emulsion) under atmospheric conditions with ultrahigh water flux and superior antifouling abilities. This versatile strategy to tailor membrane surface wettability paves the way for separation membranes to be used in harsh water environmental remediation and greatly stimulates the rapid development of mussel-inspired pDA based hybrid materials for advanced applications.
Co-reporter:Zhenxing Wang, Jing Guo, Jun Ma and Lu Shao
Journal of Materials Chemistry A 2015 - vol. 3(Issue 39) pp:NaN19968-19968
Publication Date(Web):2015/08/20
DOI:10.1039/C5TA04840K
Most recently, polydopamine (PDA) and its hybrid nanomaterials have been developed as promising adsorbents to remove organic dyes. However, PDA-based adsorbents are typically limited by a poor alkali resistance, lack of selective adsorption capacity and unsatisfactory recyclability. Herein, novel PDA-based magnetic nanoparticles are fabricated for the first time via the simultaneous incorporation of PDA and poly(ethylenimine) (PEI) on Fe3O4 nanoparticles simply in one step to overcome almost all the disadvantages of “traditional” PDA adsorbents. The constructed PDA-based magnetic nanoparticles have an ultrathin shell layer (only about 3 nm, much thinner than that of other PDA adsorbents) and can withstand strong alkaline solutions (0.1 M NaOH, pH = 13), exhibiting an excellent alkali resistance. Remarkably, the nanoparticles show superior performance in smart and fast selective removal (>95% in just five minutes) of anionic dyes from dye mixtures and can maintain their high efficiency (>90%) even after 10 cycles, indicating the unprecedented selective adsorption capacity and the desirable recyclability. The adsorption process follows pseudo-second order reaction kinetics, as well as the Langmuir isotherm, indicating that anionic dyes are monolayer adsorbed on the hybrid by electrostatic interaction. In particular, the facile regeneration of the novel composite nanoparticles can be accomplished within only several minutes, demonstrating an excellent regeneration ability. Our study can provide new insights into utilizing mussel-inspired materials for environmental remediation and creating advanced magnetic materials for various promising applications.
Co-reporter:Yan Qiu Zhang, Xiao Bin Yang, Zhen Xing Wang, Jun Long and Lu Shao
Journal of Materials Chemistry A 2017 - vol. 5(Issue 16) pp:NaN7325-7325
Publication Date(Web):2017/03/10
DOI:10.1039/C6TA11252H
Highly-efficient separating materials, which can simultaneously remove oil from water and adsorb water-soluble contaminants like dyes, are in high demand for wastewater treatment. Herein, a magnetic, multifunctional melamine foam (MF) containing Fe3O4 nanoparticles, poly(sulfobetaine methacrylate) (PSBMA) and polydopamine (PDA) was fabricated via a simple mussel-inspired one-pot process, which not only can separate oil/water mixtures and emulsions but also has cationic-dye selective separation abilities. The addition of poly(sulfobetaine methacrylate) (PSBMA) allows immobilization to bind Fe3O4 nanoparticles tightly on the surface of the melamine foam skeleton so as to endow the 3D foam with superoleophobicity underwater, as well as providing active sites for the adsorption of soluble dyes in water. The special material synergy makes the resultant magnetic MF@Fe3O4@PDA/PSBMA foam quickly absorb cationic dyes and allows for the selective removal (in 2 minutes) of cationic dyes from dye mixtures with high efficiency (>96%), high stability and flexibility even after 10 cycles, when driven by a magnet. Furthermore, the developed 3D magnetic foam is able to separate oil–water mixtures in highly acidic, alkaline, and salty environments. Our strategy may open a new avenue to obtain high-performance 3D magnetic assemblies for wastewater remediation.
Co-reporter:Fangjie You, Yanchao Xu, Xiaobin Yang, Yanqiu Zhang and Lu Shao
Chemical Communications 2017 - vol. 53(Issue 45) pp:NaN6131-6131
Publication Date(Web):2017/05/08
DOI:10.1039/C7CC02411H
A novel Ni2+-polyphenol network was designed as an excellent bio-coating by a one-step strategy to obtain nanofiltration membranes, possessing unconventional high water flux up to 56.1 L m−2 h−1 bar−1 with rose bengal (RB) rejection above 95%. This study provides a facile approach to prepare highly-efficient nanofiltration membranes for wastewater remediation.
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