Amorphous Teflons AF as organophilic pervaporation materials transport of individual components
Amorphous Teflons AF as organophilic pervaporation materials transport of individual components
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DOI：
10.1016/s0376-7388(03)00077-2
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发表时间：
2003-05-01
影响因子：
9.5
通讯作者：
Yampolskii, YP
中科院分区：
文献类型：
--
作者：
Polyakov, AM;Starannikova, LE;Yampolskii, YP
各种有机液体（氯化烃、低级醇、烃等）的渗透和吸附在5-95 ℃的温度范围内研究了2，2-双-三氟甲基-4，5-二氟-1，3-二氧杂环戊烯和无定形聚四氟乙烯AF的无定形共聚物。根据渗透速率和溶解度系数，估算了有机渗透剂在AF共聚物中的扩散系数。结果表明，具有较高含量（87%）的间二氧杂环戊烯组分（AF 2400）的共聚物（以较大的自由体积为特征）比含有65%间二氧杂环戊烯共聚单体的共聚物AF 1600对液体的渗透性大得多。相反，有机化合物在两种共聚物中的溶解度几乎不受其组成的影响。分析了临界体积（V-c）和临界温度（T-c）等渗透参数对渗透性能的影响。通过这些材料的液体和气体的渗透速率的变化是一致的流动性（扩散）控制的传质机制。渗透蒸发的渗透性和范特霍夫参数的Arkenius参数之间的权衡证明。在此基础上，获得了新的关联式，使得能够从渗透系数（P）和溶解度（S）确定渗透活化能E-p和吸附焓H-S。长期试验（长达12个月）显示出优异的时间稳定性的传输参数，一个属性意想不到的高通量，高自由体积的渗透蒸发材料是非常重要的。(C)2003 Elsevier Science B. V.保留所有权利。
Permeation and sorption of various organic liquids (chlorinated hydrocarbons, lower alcohols, hydrocarbons, etc.) in amorphous copolymers of 2,2-bis-trifluoromethyl-4,5-difluoro-1,3-dioxole and tetrafluoroethylene (amorphous Teflons AF) were studied in the temperature range 5-95 degreesC. Based on permeation rate and solubility coefficients, the diffusion coefficients of organic penetrants in AF copolymers AF were estimated. It was shown that the copolymer with a higher content (87%) of the dioxole component (AF2400), as distinguished by a larger free volume, is much more permeable to liquids than the copolymer AF1600 containing 65% of the dioxole comonomer. In contrast, solubility of organic compounds in both copolymers is hardly affected by their composition. The effects of penetrant parameters, such as critical volume (V-c) and critical temperature (T-c) were analyzed. The variation in permeation rates of liquids and gases through these materials are consistent with a mobility (diffusion) controlled mechanism for mass transfer. A trade-off between the Arrhenius parameters for permeability and the van't Hoff parameters for solubility is demonstrated for pervaporation. On this basis, novel correlations are obtained that enable a determination of the activation energy for permeation E-p and the enthalpy of sorption H-S from the permeability (P) and solubility (S) coefficients. Long term tests (up to 12 months) showed excellent time stability of the transport parameters, a property unexpected and quite important for a high flux, high free volume pervaporation material. (C) 2003 Elsevier Science B.V. All rights reserved.