کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
612042 880690 2007 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Composite hybrid membrane of chitosan–silica in pervaporation separation of MeOH/DMC mixtures
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی شیمی کلوئیدی و سطحی
پیش نمایش صفحه اول مقاله
Composite hybrid membrane of chitosan–silica in pervaporation separation of MeOH/DMC mixtures
چکیده انگلیسی

Chitosan–silica hybrid membranes (CSHMs) were prepared by cross-linking chitosan (CS) with 3-aminopropyl-triethoxysilane (APTEOS). The dynamic behaviors of the CS membrane and the CSHM were investigated in pervaporation (PV) of methanol/dimethyl carbonate (MeOH/DMC) mixtures. The membranes were characterized by X-ray diffraction (XRD), contact angle meter, scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The transition state of PV processes were studied. During the PV processes, the amorphous region of the membranes increases and the contact angle between MeOH and the membrane decreases within a range of operating time and then remains almost constant implying a reconstruction occurred on the membrane surface. The silica is well distributed in the CSHM matrix and the thermal stability of the CSHM is enhanced. The time for a PV process to reach a steady state decreases with increasing MeOH concentration or feed temperature, and it is longer for the CSHM than the CS membrane under the same operating condition. Swelling experiments show that the degree of swelling (DS) is greatly depressed by cross-linking CS with APTEOS. Sorption data indicate that the selectivity of solubility and diffusion of the CSHM are greatly improved over the CS membrane. The CSHM presents superior separation behaviors over other membranes with a flux of 1265 g/(hm2) and separation factor of 30.1 in PV separation of 70 wt% MeOH in feed at 50 °C.

Contact angle between MeOH and the CSHMs as a function of time immersed in MeOH/DMC mixtures with 30 wt% MeOH mass fraction at the temperature range of 30–50 °C.Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Colloid and Interface Science - Volume 316, Issue 2, 15 December 2007, Pages 580–588
نویسندگان
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