Adsorption of neutral proteinase on chitosan nano-particles

Abstract

The sorption kinetics and sorption mechanism for neutral proteinase on chitosan nano-particles were studied in the paper. The effect factors of adsorption kinetics were investigated, such as neutral proteinase concentration, chitosan nano-particles solution concentration, adsorption temperature, size of chitosan nano-particles, stirring rate, solution pH et al. Adsorption of neutral proteinase with chitosan nano-particles was fitted into Lagergren first-order equation at initial neutral proteinase of 3.0 mg/ml (pH 7.0). The first-order constant for neutral proteinase was 23.65 h−1. When neutral proteinase concentration was controlled under certain region, it was fitted into Freundlich isothermal linear equation. Mechanism of adsorption for neutral proteinase was presumed by analyzing IR spectra. The hydrogen in the carboxyl group was connected with electronegative oxygen. Electron pair was attractive to oxygen, so hydrogen atom became cation and proton. When electronegative neutral proteinase was closed to chitosan nano-particle, the hydrogen bond might be formed. It was the main force between hydroxyl group, NH2 group and neutral proteinase. © 2007 Taylor and Francis Group, LLC.