Characterization of sodium alginate membrane crosslinked with glutaraldehyde in pervaporation separation

Abstract

Dense sodium alginate (SA) membranes crosslinked with glutaraldehyde (GA) have been prepared by the solution method, wherein a nonsolvent of SA (acetone) was used in a reaction solution instead of an aqueous salt solution. Through infrared radation, X-ray diffractometry, and the swelling measurement, the crosslinking reaction between the hydroxyl groups of SA and the aldehyde groups of GA was characterized. To investigate the selective sorption behavior of the crosslinked SA membranes, swelling measurements of the membranes in ethanol-water mixtures of 70-90 wt % ethanol contents were conducted by equipment that was able to measure precisely the concentration and amount of the liquid absorbed in the membranes. It was observed that the crosslinking could reduce both the solubility of water in the resulting membrane and the permselectivity of the membrane toward water at the expense of membrane stability against water. The pervaporation separation of a ethanol-water mixture was conducted with the membranes prepared at different GA contents in the reaction solution. When the membrane was prepared at a higher GA content, both flux and separation factor to water were found to be reduced, thus resulting from the more crosslinking structure in it. The pervaporation separations of ethanol-water mixtures were also performed at different feed compositions and temperatures ranging from 40 to 80ЊC. A decline in the pervaporative performance was observed due to the relaxation of polymeric chains taking place during pervaporation, depending on operating temperature and feed composition. The relaxational phenomena were also elucidated through an analysis on experimental data of the membrane performance measured by repeating the operation in the given temperature range.

Post-crosslinking towards stimuli-responsive sodium alginate beads for the removal of dye and heavy metals

“…The air gap from the syringe needle to the coagulating bath was 15 cm and the air pressure was controlled at 0.1 MPa. The coagulating agent was composed of acetone, GA and HAc/HCl (Chan, Whitney & Neufeld, 2008;Yeom & Lee, 1998), and the detailed compositions were listed in Table 1. Since SA is soluble in water and insoluble in the coagulation agent, the SA beads were formed due to liquid-liquid phase separation.…”

“…Glutaraldehyde (GA) is commonly utilized to crosslink alginates for different applications. Yeom et al (Yeom & Lee, 1998) used GA cross-linked SA membranes for dehydration of ethanol-water mixtures. Neufeld et al (Chan, Whitney & Neufeld, 2009) studied the semi-synthesis of a controlled stimuliresponsive alginate hydrogel with GA. GA was also used to cross-link humic acidimmobilized SA adsorbent for the adsorption of Cu 2+ ions (Chen, Liu, Hu, Ni & He, 2011).…”

Influência da adição de plastificante do processo de reticulação na morfologia, absorção de aguá e propriedades mecânicas de filmes de alginato de sódio

“…Entretanto, a reticulação dos filmes foi confirmada pela presença da banda em 1250 cm -1 , que foi atribuída à formação de ligação acetal resultante da reação entre os grupos hidroxilas do alginato de sódio e os grupos aldeído do formaldeído. Esta conclusão concorda com o mecanismo de formação de anel acetal entre os gru-pos aldeído do glutaraldeído com os grupos hidroxilas do alginato de sódio 16 , ácido hialurônico 37 e poli (álcool vinílico) 33 , descrito na literatura. No presente trabalho, na reação entre alginato e formaldeído ocorre a formação da ligação acetal, sem, no entanto, ocorrer a formação de anel acetal como mencionado acima.…”

Separation Performance of Sodium Alginate/Poly Vinyl Pyrrolidone Membranes for Aqueous/Dimethylformamide Mixtures by Vapor Permeation and Vapor Permeation with Temperature Difference Methods

“…It has widespread applications as a membrane material because of its high hydrophilicity [4][5][6][7]. Although alginic acid can hardly dissolve in commercially available solvents, its alkali metal salt form (alginate), obtained by neutralizing the acidic functional groups with strong alkalis, is well soluble in water.…”