Blend membranes from carboxymethylated chitosan/alginate in aqueous solution

✍ Scribed by Lina Zhang; Ji Guo; Jinping Zhou; Guang Yang; Yumin Du

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 239 KB
• Volume: 77
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(20000718)77:3<610::aid-app16>3.0.co;2-b

✦ Synopsis

The blend membranes were satisfactorily prepared by coagulating a mixture of O-carboxymethylated chitosan (CM-chitosan) and alginate in aqueous solution with 5 wt % CaCl 2 , and then by treating with 1 wt % HCl aqueous solution. Their structure and miscibility were characterized by scanning electron micrograph, X-ray diffraction, infrared spectra, differential thermal analysis, and atomic absorption spectrophotometer. The results indicated that the blends were miscible, when the weight ratio of CM-chitosan to alginate was in the range from 1 : 1 to 1 : 5. The polymers interpenetration including a Ca 2ϩ crosslinked bridge occurred in the blend membrane, and leads to high separation factor for pervaporation separation of alcohol/water and low permeation. The tensile strength in the wet state ( b ϭ 192 kg cm Ϫ2 for CMchitosan/alginate 1 : 1) and thermostability of the blend membranes were significantly superior to that of alginic acid membrane, and cellulose/alginate blend membranes, owing to a strong electrostatic interaction caused by -NH 2 groups of CM-chitosan with -COOH groups of algic acid.