INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2015
·
IF 2.587
Song Zhao,Xiaochang Cao,Zijian Ma,Zhi Wang,Zhihua Qiao,Jixiao Wang,Shichang Wang
In this work, imidazolate framework ZIF-8 nanoparticles were synthesized and incorporated into a poly(vinylamine) (PVAm) coating solution. The chemical structure of a PVAm/ZIF-8 film was characterized by X-ray diffraction and attenuated total reflectance Fourier transform infrared spectroscopy techniques. Mixed-matrix membranes (MMMs) were developed by coating the PVAm/ZIF-8 mixed dispersion on a polysulfone (PSf) support membrane. Surface and cross-sectional scanning electron microscopy images of the MMMs were employed to observe the dispersion of nanoparticles in the polymer matrix. The CO2 permeance and CO2/N2 selectivity of the MMMs were evaluated by using a CO2/N2 mixture gas. Optimal preparation parameters for the MMMs were achieved by varying the incorporated ZIF-8 contents in the coating solution and the wet coating thickness. The effect of incorporated ZIF-8 on improving the gas permselectivity was revealed, and the mechanism of CO2-facilitated transport in the PVAm/ZIF-8/PSf membrane was analyzed. The CO2/N2 separation performance of PVAm/ZIF-8/PSf membranes with different wet coating thicknesses was also evaluated at 22–60 °C to analyze the changes of the gas permselectivity with increasing temperature.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2021
·
IF 3.975
Yiran Sun,Qilin Gui,Andong Zhang,Shuxian Shi,Xiaonong Chen
There are huge demands for the development of green, environmentally friendly, and easily prepared cationic adsorbents for treatment of chromium-contaminated water. In this research, we demonstrate the fabrication of a novel polyvinylamine-grafted polypropylene membrane (PPM-PVAm) for Cr(VI) adsorption. Based on a rapid two-step method, polypropylene membrane (PPM) was grafted with high biomedical safety N-vinylformamide (NVF), and then amino groups were generated via hydrolysis of the poly(N-vinylformamide) (PNVF) and these amino groups could be protonated under acidic condition as Cr(VI) adsorbing sites. The effects of both the PNVF grafting rate and its degree of hydrolysis on the adsorption performance of PPM-PVAm were investigated. The membrane with a PNVF grafting rate around 55% (wt) and a degree of hydrolysis around 70–80% exhibits the best performance for Cr(VI) adsorption under the optimal conditions, i.e. pH 2 at about 40 °C. The adsorption of Cr(VI) on PPM-PVAm matches the Langmuir model, showing a maximum Cr(VI) adsorption capacity of 208.3 mg per gram dry membrane. PPM-PVAm could be deprotonated under alkaline condition so the adsorbed Cr(VI) could be easily removed by NaOH/NaCl aqueous solution. The membrane shows excellent recycling performance, and 90.6% of the adsorption capability remains even after 10 cycles of adsorption-desorption test. Combining the unique performance and eco-friendly process in the fabrication of the membrane, PPM-PVAm shows great potential in adsorptive removal of Cr(VI) from water.
研究领域:
环境科学
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材料科学
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化学工程
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Yun Wu,Yiping Nie,Zhu Long,Pengxiang Si,Dan Zhang
Strain-stiffening hydrogels are essential in the development of ionic skin, as human skin possesses a strain-stiffening property for self-protection. Semicrystalline polymers such as poly(vinyl alcohol) (PVA) have been widely investigated to fabricate strain-stiffening hydrogels via freeze–thaw cycling or chemical cross-linking but with limited adjustable properties. Compared with PVA, polyvinylamine (PVAm) has a higher reactive activity, making it easier to achieve multifunctionalities including strain-stiffening in a PVAm hydrogel. However, the amine moieties in the backbone tend to be ionized and form strong ionic hydrogen bonds with water, resulting in difficulties in forming crystalline hydrogels by conventional methods. Herein, a one-pot method to induce crystallinity and achieve multifunctional hydrogel is devised via coacervation of PVAm. Different from a published coacervation method to fabricate hydrogels with various properties via noncovalent interactions between different chemicals, coacervation occurs between PVAm to form aggregated and loose PVAm in our devised system. Such a strategy lowers the amine–water binding energy in the polymer-dense phase to achieve crystallinity and subsequently the strain-stiffening property; meanwhile, self-healability, self-adhesion, and ionic conductivity can be realized in the polymer-loose phase. The obtained hydrogel integrates stretchability (∼1300% elongation), toughness (227 kPa), the strain-stiffening property (∼10 times increase), self-adhesion (90 J m–2), self-healability (∼80% healing efficiency in toughness), and ionic conductivity (0.22 mS m–1). This convenient strategy will open a new horizon to design multifunctional skin-mimic materials.
研究领域:
材料科学
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生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 32
·16746-16761
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IF 7.443
Jiayou Liao,Zhi Wang,Chengyun Gao,Ming Wang,Kai Yan,Xianmei Xie,Song Zhao,Jixiao Wang,Shichang Wang
A PVAm–HT membrane is fabricated by establishing a hydrotalcite (HT) channel in a polyvinylamine (PVAm) fixed carrier membrane. The flexible PVAm fixed carrier membrane material as a matrix membrane is beneficial to get high permeance. Simultaneously, the HT channels can be used as high-speed facilitated transport channels, in which the movable carbonate can actively meet CO2 and help to increase the CO2/N2 selectivity of membranes as in liquid membranes or in ion exchange membranes. Moreover, the unobstructed HT channels are conducive to transport CO2 rapidly and they can increase the chain spacing of polymers; these are beneficial to further enhance the permeance of membranes. In addition, the charged layers of HT provide necessary stability for movable carriers due to the electrostatic attraction. Thus, the PVAm–HT membrane obtains high permeance and high selectivity, as well as good stability. The CO2 permeance of the PVAm–HT membrane reaches 3187 GPU and the CO2/N2 selectivity of the PVAm–HT membrane reaches 296 at 0.11 MPa.
研究领域:
材料科学
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环境工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2015
·
IF 5.056
Junhui Wu,Zhi Wang,Yao Wang,Wentao Yan,Jixiao Wang,Shichang Wang
It is known that some commercially antifouling reverse osmosis (RO) membranes are coated with polyvinyl alcohol (PVA) layers. In this work, a new antifouling RO membrane was prepared by surface grafting of a commercial RO membrane (RE4021-TE from Woongjin, without a PVA layer) with the positively charged and hydrophilic polyvinylamine (PVAm) which was synthesized in lab. To determine the similarities and differences between the PVAm-grafted and PVA-coated membranes, one lab-prepared PVA-coated membrane (also coating on the TE membrane) and two typical commercially antifouling RO membranes with PVA coating layers (BW30FR from Filmtec and LFC3 from Hydranautics) were used for comparisons. Successful synthesis of PVAm was confirmed by the results of the ATR-FTIR and 1 H-NMR analyses. ATR-FTIR, XPS and zeta potential measurements of the membranes together indicated that the PVAm was successfully grafted onto the TE membrane surface. The membrane surface became more hydrophilic and smoother after the PVAm grafting. More importantly, for the TE membrane, the membrane surface charge climbed from negative to positive values after the grafting of PVAm with increasing concentrations, while the surface was still negatively charged after the PVA coating though the charge density was reduced. Besides, the PVAm grafting had smaller influence on the membrane permselectivity than the PVA coating: after the PVAm grafting (with a concentration of 0.20 w/v%) the salt rejection was slightly increased and the water flux decreased by 12.4%, but after the PVA coating the salt rejection was slightly declined and the water flux decreased by 35.4%. Fouling behaviors of the membrane grafted with 0.20 w/v% PVAm and the other three membranes with PVA coating layers were investigated and compared using two proteins (bovine serum albumin (BSA) and lysozyme), one polysaccharide (sodium alginate, SA), one surfactant (dodecyltrimethylammonium bromide, DTAB) and one colloid (colloidal ferric hydroxide, Fe(OH) 3 ) as model foulants. The results showed that the PVAm-grafted membrane exhibited better antifouling property than the two commercially antifouling RO membranes with PVA coating layers. In addition, fouling behavior of the lab-prepared PVA-coated membrane indicated that lower initial water flux resulted in less initial flux decline in the fouling process. This work provides a new potential strategy for improvement of antifouling property of commercial RO membranes besides the traditional PVA coating process .
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2023
·
IF 9.5
Weifan Wang,Ye Yuan,Fei Shi,Qinghua Li,Song Zhao,Jixiao Wang,Menglong Sheng,Zhi Wang
Mixed matrix membrane (MMM) is now emerging as a viable and promising option for industrial separation processes due to its combination of the benefits of polymers and porous nanofillers. However, the aggregation of nanofillers at high concentrations hinders the development of MMM. Here, we introduce a simple polymeric surface post-modification method by covalently bonding polyvinylamine (PVAm) to prepare polymer-modified Schiff base network-1 (SNW-1) called SNW-P. Adjusting the post-modification time improved the dispersibility of SNW-P. Compared to SNW-1, MMMs with SNW-P 4H as nanofiller achieved a significantly high CO 2 permeance of 3092 GPU as well as the CO 2 /N 2 selectivity of 184 at the feed gas pressure of 0.2 MPa, which obviously surpasses the current limit enumerated by 2019. Additionally, for CO 2 /CH 4 and CO 2 /H 2 separation, the optimized membrane also exhibits excellent CO 2 permeance. With low-cost raw materials and superior properties, the membrane created in our research has good potential for large-scale applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Carbon Capture Science & Technology
·
2023
·
IF 0
Chaoqi Ge,Menglong Sheng,Ye Yuan,Fei Shi,Yi Yang,Song Zhao,Jixiao Wang,Zhi Wang
Mixed matrix composite membranes (MMCMs) are considered as one of the potential directions for the development of CO 2 capture membranes. Nevertheless, the high cost and the challenging nature of improving separation performance are significant obstacles that prevent MMCMs from being widely applied in practice. In this study, we developed a cost-effective modified pore-optimized MOF-808 (MOF-808@PVAm) and utilized it to fabricate high-performance CO 2 capture MMCMs. Specifically, MOF-808 and polyvinylamine (PVAm) were cross-linked by γ-(2,3-epoxypropoxy) propytrimethoxysilane (KH-560), which improved the pore structure characteristics of MOF-808 and led to high-performance MMCMs. For 2 bar feed gas (CO 2 /N 2 , 15/85), the MMCM with 33.33 wt.% MOF-808@PVAm loading displayed remarkable CO 2 permeance of 2753 GPU and selectivity of 181. The prepared MMCM demonstrated good operational stability in simulated flue gas and exhibited potential for application in various gas purification fields (CO 2 /CH 4 , CO 2 /H 2 ) through gas permeation tests.
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2022
·
IF 3.898
Ye Yuan,Yurui Pan,Menglong Sheng,Guangyu Xing,Ming Wang,Jixiao Wang,Zhi Wang
Membrane technology features inspiring excellence from numerous separation technologies for CO 2 capture from post-combustion gas. Polyvinylamine (PVAm)-based facilitated transport membranes show significantly high separation performance, which has been proven promising for industrial scale-up. However, commercialized PVAm with low molecular weight and excessive crystallinity is not available to prepare high-performance membranes. Herein, the synthesis process of PVAm was optimized by regulating polymerization and acidic hydrolytic conditions. The membranes based on PVAm with a molecular weight of 154 kDa and crystallinity of 11.37% display high CO 2 permeance of 726 GPU and CO 2 /N 2 selectivity of 55 at a feed gas pressure of 0.50 MPa. Furthermore, we established a PVAm synthesis reactor with an annual PVAm solution (1%(mass)) capacity of over 7000 kg and realized the scaled-up manufacture of both PVAm and composite membranes.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Ye Yuan,Yi Yang,Fei Shi,Chenyang Song,Bo Wang,Menglong Sheng,Zhi Wang
Advanced CO 2 separation technology is one of the key technologies for reducing carbon emissions and can make significant contributions to reducing the negative impact of the greenhouse effect on human survival. Membrane separation technology is regarded as a new generation of carbon capture technology because of its great potential to reduce carbon capture energy consumption and improve net carbon capture efficiency. Mixed matrix membranes (MMMs) can break through the performance limit of traditional polymer membranes, but the influence of bridging agents for post-modifying nanofillers on membrane structure and properties needs further systematic investigation. In this work, four types of ligands were selected for synthesizing polymer-modified nanofillers and then incorporated into poly (vinylamine) (PVAm) to prepare MMMs. The comparative analysis results indicate that bridging ligands with superior flexibility are conducive to enhancing the gas permeability within the pores by diminishing the compactness of the polymer shell. The constructed phase interface transition area with uniformly enhanced mechanical strength demonstrates the improved interface compatibility between the matrix and nanofillers bridged via the flexible ligand. Techno-economic evaluation verifies the industrial application potential of the optimal MMMs targeting CO 2 capture from post-combustion gas.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Water Process Engineering
·
2024
·
IF 6.3
Jian Dong,Yi Wang,Liangliang Dong,Tatsuo Kaneko,Weifu Dong,Dongjian Shi,Mingqing Chen
To address the membrane challenges such as the trade-off effect between water permeance and separation selectivity, development of a desirable nanofiltration membrane structure is crucial. And, it is important to design a positively charged surface to enhance charge repulsion force between membrane surface and ions due to lithium (Li) extraction problem as the close hydration diameter of magnesium (Mg) and lithium ions. Herein, a strategy that involves regulating membrane structure to create a loose and dense double-layer structure via bi-directional interfacial polymerization has been proposed to form selectivity-enhanced nanofiltration membranes for Li + /Mg 2+ separation. The incorporation of dopamine (DA) and trimesoyl chloride (TMC) in first loose layer could improve the membrane stability, while the amine groups from polyethyleneimine (PEI) or polyvinylamine (PVAm) in the second dense layer surface, provided by rich amine polymers, could improve the rejection of divalent magnesium ion. The as-fabricated membrane DA-TMC-PEI shows enhanced permeance (around 15.4 L m −2 h −1 bar −1 ) and the membrane DA-TMC-PVAm demonstrates outstanding ion selectivity with Li + /Mg 2+ separation factor of 30. Moreover, the DA-TMC-PEI and DA-TMC-PVAm membranes could efficiently purify the ratio of Mg 2+ /Li + solution from 50 to 0.43. We believe the strategy could provide a promising potential in lithium extraction.
研究领域:
材料科学
·
环境工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2020
·
IF 7.183
Xiaochang Cao,Haoqing Xu,Songlin Dong,Jiayou Xu,Zhihua Qiao,Song Zhao,Jixiao Wang,Zhi Wang
In this work, we proposed a simple method to prepare high-performance and pressure-resistant mixed matrix membranes (MMMs) for CO 2 /H 2 separation. The groups or segments of poly-(vinylamine) (PVAm) were used to modify covalent organic frameworks (COFs), and COFs with similar frameworks but different surfaces were obtained. Then, modified COFs were mixed with PVAm matrix and used to coat the modified-polysulfone (mPSf) to prepare MMMs for CO 2 /H 2 separation. Modified COFs and the PVAm matrix were highly compatible because COF surfaces possessed the same groups or segments as PVAm. Meanwhile, in the coating solution, COF surfaces were found to induce penetration of PVAm molecules into COF pores, narrowing the pore size of the COFs and providing an amino environment for CO 2 preferential absorption and transport. The penetration degree was affected by the hydrogen bond between COF surfaces and the PVAm molecules. In addition, the incorporated COFs effectively restricted the mobility of the PVAm matrix, increasing the pressure resistance for MMMs under high pressure. In the gas permeation test, the optimal MMMs could achieve a CO 2 permeance of 957 GPU and a CO 2 /H 2 selectivity of 17.1 at 2.0 MPa because of the high compatibility and size of the channels (0.94 nm).
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2014
·
IF 4.908
Zhihua Qiao,Zhi Wang,Shuangjie Yuan,Jixiao Wang,Shichang Wang
Small molecular amines (SMAs) (ethanediamine (EDA), piperazine (PIP), monoethanolamine (MEA) and diethanol amine (DEA)) were separately used to modify the polyvinylamine (PVAm). ATR-FTIR, elemental analyzer, XRD and SEM were employed to characterize the SMA interacted PVAm. The PVAm–SMA/polysulfone (PS) membranes were developed by coating PVAm–SMA mixed solutions on the PS ultrafiltration membrane. CO 2 permeance and CO 2 /H 2 selectivity of the PVAm–SMA/PS membranes were investigated. Among different PVAm–SMA/PS membranes, the PVAm–MEA/PS membrane shows the highest CO 2 /H 2 separation performance. Moreover, the effect of the selective layer thickness on the CO 2 /H 2 separation performance of the PVAm–MEA/PS membrane was studied. With increasing the PVAm–MEA selective layer thickness, the CO 2 /H 2 separation performance of the membrane apparently decreases. Finally, the CO 2 /H 2 separation performance stability of the PVAm–MEA/PS membranes was investigated and no deterioration in the membrane permselectivity was observed.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）