膜
界面聚合
薄膜复合膜
聚砜
化学工程
聚合物
聚合
磁导率
膜结构
化学
高分子化学
材料科学
反渗透
单体
有机化学
工程类
生物化学
作者
Yujun Song,Pengfei Sun,L. L. Henry,Bingbing Sun
标识
DOI:10.1016/j.memsci.2004.10.042
摘要
Kinetics and mechanisms involved in the formation of crosslinked polyamide (PA) membrane from p-phenylenediamine (PPD) and trimesoyl chloride (TMC) grown within a porous polysulfone substrate via interfacial polymerization (IP) process were studied through weight gain, permeability and selectivity of the membrane. A modified diffusion- and reaction-controlled model was derived, in which membrane structural parameters including apparent wet membrane density (ρ), dry polymer density (ρp), the number of functional groups on polymer chains (NCOCl) and polymer molecular weight (Mw), were correlated with the kinetics of thin film composite (TFC) membrane formation. According to the change of the main inhibition reaction rate constant as function of these four variables, a multi-stage membrane formation mechanism was developed. It elucidated many unique phenomena induced by this IP process, such as the primary membrane formation caused by polymer precipitation, the membrane perpendicular growth along water–oil interface, the crosslinking reaction, the “self-limiting” tendency and the limited membrane thickness. Effects of these phenomena and post-treatment on membrane structure and performance were discussed. It was shown that the permeability and selectivity of PA membrane can be effectively controlled by reaction time and the TMC and PPD concentrations. This study extended existing theories and techniques regarding IP process and structure–performance control of TFC membrane.
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