金纳米晶体的生长动力学：小角X射线散射与量热法联合研究

Growth kinetics of gold nanocrystals: a combined small-angle X-ray scattering and calorimetric study.

作者信息

Biswas Kanishka, Varghese Neenu, Rao Chintamani N R

机构信息

Chemistry and Physics of Materials Unit, DST nanoscience unit and CSIR Centre of Excellence in Chemistry, Jawaharlal Nehru Centre for Advanced Scientific Research Jakkur P. O., Bangalore 560064, India.

出版信息

Small. 2008 May;4(5):649-55. doi: 10.1002/smll.200700937.

DOI:10.1002/smll.200700937

PMID:18398923

Abstract

The growth of gold nanocrystals prepared by the reduction of tetrachloroauric acid by tetrakis(hydroxymethyl)phosphonium chloride, which allows slow reduction, is investigated by small-angle X-ray scattering and isothermal titration calorimetry in combination with transmission electron microscopy. The growth of the nanocrystals does not follow the diffusion-limited Ostwald ripening but instead follows a sigmoidal rate curve. The activation energy obtained from the temperature-dependent growth study is very small. The heat change associated with the growth is determined for the first time as approximately 10 kcal mol(-1) per 1 nm increase in the nanocrystals' diameter.

摘要

通过氯化四羟甲基鏻还原氯金酸制备金纳米晶体，这种方法可实现缓慢还原。采用小角X射线散射、等温滴定量热法并结合透射电子显微镜对其生长过程进行了研究。纳米晶体的生长并不遵循扩散限制的奥斯特瓦尔德熟化，而是呈现出S形速率曲线。通过与温度相关的生长研究获得的活化能非常小。首次确定与生长相关的热变化约为每纳米晶体直径增加1纳米 10千卡摩尔（-1）。