Polymers
·
2021
·Vol. 13
·期 21
·3778
·
IF 4.329
Siqi Chen,Hao Yang,Kui Huang,Xiaolong Ge,Hanpeng Yao,Junxiang Tang,Junxue Ren,Shixue Ren,Yanli Ma
In recent years, inverse gas chromatography (IGC) and molecular dynamics simulation methods have been used to characterize the solubility parameters and surface parameters of polymers, which can provide quantitative reference for the further study of the surface and interface compatibility of polymer components in the future. In this paper, the solubility parameters and surface parameters of two kinds of common alcoholysis, PVA88and PVA99, are studied by using the IGC method. The accuracy of the solubility parameters obtained by the IGC experiment is verified by molecular dynamics simulation. On the basis of this, the influence of repeated units of polyvinyl alcohol (PVA) on solubility parameters is studied, so as to determine the appropriate chain length of the PVA for simulation verification calculation. The results show that the solubility parameters are not much different when the PVA chain length is 30 and above; the numerical trends of the solubility parameters of PVA88and PVA99at room temperature are the same as the results of molecular dynamics simulation; the dispersive surface energyγsdand the specific surface energyγsspare scattered with the temperature distribution and have a small dependence on temperature. On the whole, the surface energy of PVA99with a higher alcoholysis degree is higher than that of PVA88with a lower alcoholysis degree. The surface specific adsorption free energy (ΔGsp) indicates that both PVA88and PVA99are amphoteric meta-acid materials, and the acidity of PVA99is stronger.Keywords:PVA;solubility parameter;IGC;alcoholicity;molecular dynamics simulation;surface properties
研究领域:
材料科学
·
化学工程
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DOI
PubMed
高影响因子
MACROMOLECULAR MATERIALS AND ENGINEERING
·
2020
·Vol. 305
·期 8
·2000239
·
IF 3.853
Ke Li,Chuanming Li,Huafeng Tian,Li Yuan,Aimin Xiang,Chaoyang Wang,Jinlong Li,A. Varada Rajulu
Nanofibers prepared by electrospinning technology possess large specific surface area and adjustable fiber diameter. Zein is a hydrophobic plant protein that can interact with pollutants in the air. In this work, using polyvinyl alcohol (PVA) as the auxiliary spinning polymer, zein based nanofiber materials are prepared for air filtration by varying zein/PVA ratio as well as the alcoholysis degree. With the increase of zein content, the diameter of nanofibers decreases gradually, and the nanofibers prepared by PVA with low alcoholysis degree exhibit better micromorphology. The zein based nanofibers prepared after denaturation of zein protein can interact with different types of pollutants. In addition, for the nanofibers prepared by PVA with different alcoholysis degree, the filtration efficiency increases with the increase of zein content when absorbing air pollution particles with different particle sizes and the alcoholysis degree affects the air filtration efficiency. Thus, through controlling zein content and alcoholysis degree, the filtration efficiency of nanofibers is promoted availably. These results indicate that the natural nanofilter prepared with zein and PVA can be used a multifunctional and efficient material for air filtration.
研究领域:
材料科学
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环境工程
·
纳米技术
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Xuewu Zhu,Zhongyue Sun,Jingtao Xu,Sisi Xu,Xinsheng Luo,Fengxun Tan,Xiaolong Lu,Daoji Wu,Heng Liang,Xiaoxiang Cheng
Poly(vinyl alcohol) (PVA)-based polyester loose nanofiltration (LNF) membranes present an ideal material for achieving dye/salt separation from dye/salt mixtures. Owing to the intrinsic features of the material, PVA with varying degrees of alcoholysis may exhibit different roles and functions, allowing for performance tailoring in PVA-based LNF membranes. In this work, we have demonstrated a facile approach for regulating the performance of polyester (PE) LNF membranes by tailoring the degree of alcoholysis. Stopped-flow mass spectrometry and various characterization techniques showed that an increase in the degree of alcoholysis accelerates reaction rates, increases reaction heat release, and boosts nanobubble formation during interfacial polymerization. The resulting LNF membrane featuring folds and a dense PE film demonstrated a permeance of 44.9 L m -2 h −1 bar −1 and a CR/Na 2 SO 4 selectivity of 240, as well as satisfactory stability, showing dye/salt separation performance superior to that of other LNF membranes. This work provides novel insights into tailoring high-performance LNF membranes for selective salt/dye separation.
研究领域:
材料科学
·
化学工程
·
膜技术
·
环境科学
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产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2024
·
IF 6.7
Qingxin Yang,Zhiming Yang,Fengniu Lu,Hanbing Ge,Yi Du,Ding Cao,Zhiqin Yuan,Chao Lu
Polyvinyl alcohol (PVA) with abundant hydroxyl groups (−OH) has been widely used for membranes, hydrogels, and films, and its function is largely affected by the alcoholysis degree. Therefore, the development of rapid and accurate methods for alcoholysis degree determination in PVAs is important. In this contribution, we have proposed a novel fluorescence-based platform for probing the alcoholysis degree of PVA by using the (E)-N-(4-methoxyphenyl)-1-(quinolin-2-yl)methanimine (QPM)-Zn2+ complex as the reporter. The mechanism study disclosed that the strong coordination between −OH and Zn2+ induced the capture of the QPM-Zn2+ complex and promoted its subsequent immobilization into the noncrystalline area. The immobilization of the QPM-Zn2+ complex restricted its molecular rotation and reduced the nonirradiative transition, thus yielding bright emissions. In addition, the practical applications of this proposed method were further validated by the accurate alcoholysis degree determination of blind PVA samples with the confirmation of the National Standard protocol. It is expected that the developed fluorescence approach in this work might become an admissive strategy for screening the alcoholysis degree of PVA.
研究领域:
材料科学
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分析化学
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高分子化学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）