Study on Evaluation of Various Factors Affecting Antibacter Activities of Textile Products

To evaluate the effect of environmental factors on the antimicrobial activity of antimicrobial textile products, the antibacterial activities of chitosan fibre were tested under various conditions (pH, temperature and coexisting substances). Shaking flask method based on "National Standard GB/T20944-2008" and "Disinfection Technical Guidelines, 2002 ed. (Ministry of Public Health of the People's Republic of China) " was used for testing. The results indicated that the antibacterial activities were affected by environmental factors enormously. At pH6.5 and 45 degrees C, the bacteriostasis rates of chitosan fibre against E.coli 8099 were 86.6% and 36.3 % higher than that at pH 7.5 and 20 degrees C respectively. The antibacterial activity of chitosan fibre against E.coli 8099 in 0.1 mol.L-1 artificial perspiration (NaCl 5.0%, L-histidine hydrochloride 0.5% and NaH2PO4 2.2%) showed 37.6% lower than that in standard test condition (0.03 mol.L-1 phosphoric acid buffer solution). In the testing environment containing 0.5% peptone, 68.8% of the antibacterial activity of chitosan fiber against E.coli 8099 was inhibited. Based on the test results above, it was suggested that the actual antibacterial effect of antibacterial products depends closely on environmental conditions in which they are used. In order to evaluate their antibacterial effect objectively it was most important to establish an evaluating system that well agreed with the environmental conditions in which antibacterial materials were applied.