Preparation and Characterization of Nanoscale Silver Particle by Chitosan

• Main Authors: Yu-Wan Chen, 陳鈺婉
• Other Authors: Yawo-Kuo Twu
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/85926791536876150329

碩士 === 大葉大學 === 生物產業科技學系 === 93 === Chitosan suspension of pH=11 and pH=13 were prepared by dropping chitosan acetate solution into 0.05N and 0.1N NaOH(aq) with high-speed homogenizing, respectively. Alkaline chitosan-Ag composite suspensions were synthesized by mixing of silver nitrate aqueous solution with chitosan suspension. The ratios of chitosan repeat unit number to Ag+ number were 1:1(C1Ag), 3:1(C3Ag) and 5:1(C5Ag). Dialysis was used to remove free ions from the alkaline composite suspensions and then pyrolysis or hydrolysis was used to decompose chitosan and to gain silver nanoparticles. UV-visible molecular absorption spectrometry revealed that the alkaline chitosan suspensions were capable of reducing silver ion to silver. Analytical electron microscope (AEM) images of the suspensions showed that chitosan particle mean diameter was in the range of 20~50 nm and the mean diameter of silver particle in the composite was in the range of 5 ~15 nm. The silver particle size decreased with the concentration of chitosan increased. In addition, thermogravimetric analysis (TGA) showed that chitosan was degraded completely at 600℃. The field emission scanning microscope (FESEM) micrographs of silver nanoparticles obtained by prolysis and by hydrolysis showed that the mean sizes were smaller than 80 nm and approximately 83 nm, respectively.