Choudhari Santosh K, Kariduraganavar Mahadevappa Y
Center of Excellence in Polymer Science and Department of Chemistry, Karnatak University, Dharwad 580 003, India.
J Colloid Interface Sci. 2009 Oct 1;338(1):111-20. doi: 10.1016/j.jcis.2009.05.071. Epub 2009 Jun 3.
Novel polymer-clay-based composite membranes were prepared by incorporating sodium montmorillonite (Na(+)-MMT) clay into quaternized chitosan. The resulting membranes were characterized by Fourier transform infrared spectroscopy (FTIR), wide-angle X-ray diffraction (WXAD), and thermogravimetric analysis (TGA). The effect of membrane swelling was studied by varying the water concentration in the feed. The membranes were employed for the pervaporation dehydration of isopropanol in terms of feed composition and Na(+)-MMT clay loading. The experimental results demonstrated that membrane containing 10 mass% of Na(+)-MMT clay showed the highest separation selectivity of 14,992 with a flux of 14.23x10(-2) kg/m(2) h at 30 degrees C for 10 mass% of water in the feed. The total flux and flux of water are found to be overlapping each other particularly for clay-incorporated membranes, signifying that the composite membranes developed in the present study involving quaternized chitosan and Na(+)-MMT clay are highly selective toward water. From the temperature-dependent diffusion and permeation values, the Arrhenius activation parameters were estimated. The resulting activation energy values obtained for water permeation (E(pw)) are much lower than those of isopropanol permeation (E(pIPA)), suggesting that the developed composite membranes have higher separation efficiency for the water-isopropanol system. The estimated E(p) and E(D) values ranged between 8.97 and 11.89, and 7.56 and 9.88 kJ/mol, respectively. The positive heat of sorption (DeltaH(s)) values were obtained for all the membranes, suggesting that Henry's mode of sorption is predominant in the process.
通过将钠蒙脱石（Na(+)-MMT）粘土掺入季铵化壳聚糖中来制备新型聚合物-粘土基复合膜。通过傅里叶变换红外光谱（FTIR）、广角X射线衍射（WXAD）和热重分析（TGA）对所得膜进行表征。通过改变进料中的水浓度来研究膜溶胀的影响。根据进料组成和Na(+)-MMT粘土负载量，将这些膜用于异丙醇的渗透汽化脱水。实验结果表明，含有10质量% Na(+)-MMT粘土的膜在30℃下对进料中10质量%的水表现出最高的分离选择性为14992，通量为14.23×10(-2) kg/m(2) h。发现总通量和水通量相互重叠，特别是对于掺入粘土的膜，这表明本研究中开发的涉及季铵化壳聚糖和Na(+)-MMT粘土的复合膜对水具有高度选择性。根据温度依赖性扩散和渗透值，估算了阿伦尼乌斯活化参数。水渗透（E(pw)）获得的活化能值远低于异丙醇渗透（E(pIPA)）的活化能值，这表明所开发的复合膜对水-异丙醇体系具有更高的分离效率。估算的E(p)和E(D)值分别在8.97至11.89 kJ/mol和7.56至9.88 kJ/mol之间。所有膜均获得正吸附热（DeltaH(s)）值，表明该过程中亨利吸附模式占主导。
