Development And Performance Evaluation Of Chitosan Modified By Quaternary Ammonium Salt And Its Composite Film

N-[(2-hydroxy-3-trimethylammonium) propyl]chloride chitosan (HTCC) with different substitution degrees were prepared by heterogeneous grafting glycidyltrimethyl-ammonium chloride (GTMAC) onto chitosan (CTS). Blending method was used to form a new organic-inorganic HTCC/TiO2 hybrid membrane by introducing TiO2 nanopartical to chitosan solution which was reacting with GTMAC. The prepared HTCC and HTCC/TiO2 hybrid membrane were characterized by Fourier Transform Infrared Spectroscopy (FTIR),1H-NMR spectroscopy, X-ray Diffraction (XRD), Thermal Gravimetric Analysis (TG-DTA) and Scanning Electron Microscopy (SEM). Additionally, the antibacterial property of HTCC was compared with CTS, as well as antibacterial properties and mechanical properties of HTCC/TiO2 hybrid membrane, CTS membrane and HTCC membrane were compared with each other.The results demonstrated the active amino groups of CTS were substituted by GTMAC partly. The obtained HTCC is superior to CTS powder in terms of antibacterial activity, acid resistance as well as water-solubility along with the increasing substitution degree. Meanwhile, HTCC/TiO2 hybrid membranes with good dispersion have been obtained, and its optimum preparation conditions were determined as follows:concentration of CTS casting solution 2.0wt%, pH 3.5, mole ratio of material nCTS:nGTMAC 1:0.5, drying temperature 60℃and mass fraction of TiO2 1.0 wt%. The prepared HTCC/TiO2 hybrid membrane in this condition has high mechanical strength (78.33MPa), elongation at break (139.72%) and low water uptake(135.53%). The antibacterial assays indicated that antibacterial properties of the tested membranes against E. coli and Bacillus as follows:HTCC/TiO2 hybrid membrane > HTCC membrane> CTS membrane, and these membranes showed the greater antibacterial activity against E. coli than Bacillus. In addition, water vapor permeability and ion exchange capacity (IEC) of HTCC/TiO2 hybrid membrane and HTCC membrane were higher than CTS membrane, but content of TiO2 had slightly effect on water vapor permeability as well as IEC.