Poly(vinyl alcohol) Membrane with Surface Immobilized β-cyclodextrin Synthesis via Glutaraldehyde

摘要

A novel cyclodextrin (CD) grafted polyvinyl alcohol (PVA) material has been synthesized. Beta-cyclodextrin (βCD) is chemically grafted into PVA via glutaraldehyde (GA) in acidic medium (HCl). The reaction mechanism and the membrane surface grafting are confirmed by Fourier Transform Infrared Spectroscopy (FTIR), modulus of elasticity and contact angle determination. An amount of PVA and βCD are dissolved in a pH 3 HCl solution at 90°C with continuous stirring. Glutaraldehyde was slowly added into the clear solution to effect grafting and crosslinking between the PVA and βCD. It was cooled and allowed to stand overnight to eliminate bubbles formed. The clear PVA-GA-βCD material is casted on a glass plate to form membranes which are peeled off after subsequent drying. The grafted and crosslinked membrane showed peaks in the IR spectra confirming the chemical bonding between PVA, GA and βCD. PVA-GA-βCD membrane is 6% stronger than the physically blended membrane as shown by the increase of its modulus of elasticity. Likewise, a reduction in the hydrophilicity is observed by the newly synthesized membrane as shown by the increase of the membrane's contact angle. This newly developed material with immobilized βCD may significantly improve the performance of PVA-CD pervaporation membranes by reducing the phase separation phenomenon due to agglomeration of CD in high concentrations as well as preventing βCD from dissolving in aqueous feed. Moreover, this may open new perspective for the development of high performance nanofibers and other nanomaterials such as drug delivery system materials and inclusion complexes.