Dehydration of an Ethanol/Water Azeotrope by Novel Organic−Inorganic Hybrid Membranes Based on Quaternized Chitosan and Tetraethoxysilane

Abstract

To control swelling of quaternized chitosan (q-Chito) membranes, mixtures of q-Chito as an organic component and tetraethoxysilane (TEOS) as an inorganic component were prepared using the sol-gel reaction, and novel q-Chito/TEOS hybrid membranes were formed. In the separation of an ethanol/water azeotrope by pervaporation, the effect of TEOS content on the water/ethanol selectivity of q-Chito/TEOS hybrid membranes was investigated. Hybrid membranes containing up to 45 mol % TEOS exhibited higher water/ethanol selectivity than the q-Chito membrane. This resulted from depressed swelling of the membranes by formation of a cross-linked structure. However, introduction of excess TEOS led to greater swelling of the hybrid membranes. Therefore, the water/ethanol selectivity of the hybrid membranes containing more than 45 mol % TEOS was lower than that of the q-Chito membrane. The relationship between the structure of q-Chito/TEOS hybrid membranes and their permeation and separation characteristics during pervaporation of an ethanol/water azeotrope is discussed in detail.

Anhydrous proton conductor consisting of pectin–inorganic composite material

“…Similar results, such as the increase in the physical property by the addition of an inorganic component into a biopolymer, have been reported for various organic-inorganic hybrid materials. [31][32][33]39 Thermal Stability of Pectin/Ti/Im Composite Material Figure 5(a,b) shows the thermogravimetric (TG) and differential thermal analyses (DTA) of (1) pectin without the composite, (2) pectin after the heat treatment at 1808C for 3 h, and (3) Im molecules, respectively. The pectin without the composite (line (1) in Figure 5) showed the TG weight loss of approximately .…”

“…On the other hand, the polymer-inorganic composite material by mixing the polymer and inorganic component, such as silica or titanate, shows a water insolubilization, a thermal stabilization, and a high mechanical strength. [31][32][33] Therefore, the addition of an inorganic component to the biopolymer can improve these weak characteristics of the biopolymer. The preparations of the biopolymer-inorganic composite materials as anhydrous proton conductor are novel and important for the development of future PEFC technologies.…”

Chitosan Hydrogel‐Capped Porous SiO2 as a pH Responsive Nano‐Valve for Triggered Release of Insulin

“…Chitosan-based organic-inorganic hybrid materials have been prepared in the form of xerogels, thin films, and freestanding membranes. [36][37][38][39] Compared with singlecomponent chitosan materials, incorporation of chitosan into a crosslinked inorganic network can provide improved characteristics. For example, Liu reported in situ formation of chitosansilica hybrid membranes using glycidoxypropyltrimethoxysilane (GPTMS) as a crosslinking agent, which provides a convenient means to combine two distinct features of crosslinking and organic-inorganic hybridization in a one-pot process.…”

Chitosan Based Membranes for Separation, Pervaporation and Fuel Cell Applications: Recent Developments

“…The commercialization of the pervaporation technique is, to a large extent, attributed to the engineering approach of making thin membranes in asymmetric and composite forms. When the separation factor is unity, no separation occurs [146]. The silica CS membrane modified with functionalized silica (CSM-5 and CSM-10) were more suitable for the pervaporation and dehydration of ethanol/ aqueous mixture solution.…”