Synthesis, Stability and Antimicrobial Properties of Silver Nanoparticle/Clay Hybrids

• Main Authors: Yi-Ting Wang, 王怡婷
• Other Authors: 林江珍
• Format: Others
• Language: en_US
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/91107696980353659349

碩士 === 國立臺灣大學 === 高分子科學與工程學研究所 === 100 === The hybrids of silver nanoparticles (AgNP) on clay silicate platelets (NSP) were synthesized and analyzed to have precise controls in particle size and high stability against thermal, ultraviolet, ultrasonic and air oxidative deterioration. Various hybrids of the composition (weight ratio of Ag/silicate) in corresponding to the Ag particle size of 3.6 to 16.8 nm in diameter were tailored by changing the starting material ratio of NSP and silver nitrate under reduction conditions. The stability of the AgNP was investigated by examining the absorption peak shifts of UV–visible spectra and compared with the AgNP stabilized by the polymers and the pristine clays. The presence of NSP could largely contribute the high stability of the AgNP due to the intensive interaction between Ag nanoparticles and NSP of high surface area and ionic charges. The Ag particle coalescence, aggregation to larger particles and air oxidation to Ag2O were totally subsided by NSP. By comparison, the conventional AgNP materials with the common organic stabilizers were generally unstable and deteriorating under the same tests of heat, UV and air. The unique characteristics of the clay species with high−aspect−ratio and ion charged surface are essential for stabilizing the Ag0 particles. We further investigate the bactericidal efficacy of the AgNP/NSP nanohybrids. The antimicrobial tests were performed on Escherichia coli and Staphylococcus aureus. The antibacterial effect was enhanced by the presence of NSP which facilitates the nanohybrids adhesion onto the bacterial surface and consequently achieves the high efficacy. It was found that the close attachment could prevent the AgNP entering into the cell body and avoid the possible damage on DNA. It is an advantage for the hybrid to fulfill its antimicrobial function without the adversity of accumulation in normal cell and harmfulness to the health.