Microstructure-related performances of poly(vinyl alcohol)-silica hybrid membranes: a molecular dynamics simulation study
Microstructure-related performances of poly(vinyl alcohol)-silica hybrid membranes: a molecular dynamics simulation study
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DOI：
10.1039/c2jm30653k
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发表时间：
2012-05
影响因子：
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通讯作者：
Q. Zhang;Q. Liu;S. Huang;Wei Hu;A. Zhu
中科院分区：
文献类型：
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作者：
Q. Zhang;Q. Liu;S. Huang;Wei Hu;A. Zhu
采用分子动力学模拟方法研究了硅醇R-Si（OH）3杂化PVA-SiO2杂化膜的微观结构与性能之间的关系。本文首先研究了含-CnH 2n +1的硅烷醇杂化PVA膜，考察了硅烷醇的尺寸对杂化膜的结构和性能的影响，然后研究了由APTEOS水解得到的H2 N（CH 2）3-Si（OH）3（APTS）杂化膜。SiO2杂化显著降低了PVA分子链的迁移率，增加了PVA基体中的无定形区，调整了膜的微观结构。硅醇R-Si（OH）3中的R基团对杂化膜的结构和性能有很大的影响。随着R基团尺寸的增大，自由体积小空穴减少，PVA链间间距和大空穴增大。此外，MD模拟揭示了PVA/APTS杂化膜的微观结构和性能之间的关系。研究结果可为新型功能性硅基杂化膜的设计提供指导。
Molecular dynamics (MD) simulations were used to reveal the relationship between the microstructure and performance of PVA–silica hybrid membranes from the hybridization of silanols, R–Si(OH)3. We first studied the PVA membranes hybridized by silanols with the linear alkyl group of –CnH2n+1 to investigate the effect of their size on the microstructure and properties of the hybrid membranes, then studied hybridization of H2N(CH2)3–Si(OH)3 (APTS) from the hydrolysis of APTEOS. Silica hybridization reduced the mobility of PVA chains remarkably, raised the amorphous region in the PVA matrix, and adjusted the membrane microstructure. Group R in the silanol R–Si(OH)3 has a prodigious effect on the microstructure and performances of the hybrid membranes. Small free volume cavities decreased, and the interchain spacing of PVA chains and big cavities increased with increasing size of group R. Furthermore, MD simulations revealed a relationship between the microstructure and performances of the PVA/APTS hybrid membranes. The results could provide guidance for designing novel functional silica-based hybrid membranes.