Mechanical, swelling and adsorptive properties of dry-wet spun chitosan hollow fibers crosslinked with glutaraldehyde

Chitosan (CS) hollow fiber (HF) membranes were successfully prepared according to the dry-wet spinning technique. A post-treatment with glutaraldehyde (GA) aqueous solution was carried out to perform the cross-linking reaction. The effect of GA concentration in the range 50-1000 mg l-1 on the swelling, mechanical and adsorptive properties was investigated. The morphology and chemical structure of the fibers were examined by means of SEM and FTIR. The degree of swelling and adsorption capacity decreased as the GA concentration increased. CS hollow fibers swelled the most in acidic solution as compared with distilled water and saline solution. The adsorption capacity of CS HFs increased while decreasing of initial pH from 7.5 to 3.5. Desorption experiments showed that CS HFs were reusable as adsorbent. Mechanical properties were strongly affected by GA post-treatment: tensile strength and elastic modulus increased at low GA concentration (50 mg l -1), to sharply decrease when concentration was >=500 mg l -1. Breaking elongation decreased with increasing GA concentration.