Chitosan-N-2-hydroxypropyl trimethyl ammonium chloride (QTS) was prepared by reaction of chitosan with glycidyl trimethylammonium chloride, which was characterized by FTIR. QTS with different molecular weights (Mw 41.55 × 104, 9.02 × 104, 3.57 × 104, and 0.17 × 104) showed biocidal activity on Staphylococcua aureus, Bacillus subtilis, Staphylococcua epidermidis, and Candida albicans. QTS with high molecular weight had high biocidal activity on the gram-positive bacteria, and the biocidal effect of QTS decreased with decreasing molecular wei...
