液相纳米化学

Liguid Phase Nanochemistry

纳米化学是当代化学中最富有挑战性的分支之一。它以纳米粒子或团簇的合成、表征及其化性质为主要研究对象。在液相中组装纳米粒子或团簇，使我们有可能控制其颗粒度及结构，以期获得具有一定大小及结构的人造功能分子。本文首先介绍几种常见的化学合成纳米粒子的方法。紧接着详细阐述辐射合成和光化学合成方法，包括合成原理、最佳条件及优点等，着重介绍如何通过调节介质的组成（物料、浓度等）及介质的性质（pH值等）来控制纳米粒子的大小，并探讨控制纳米粒子结构的可能途径。另外，我们还介绍如何利用脉冲式辐照（脉冲辐解技术）研究液相中金属纳米粒子形成的化学反应机理，它能够对稀水溶液中金属离子的还原、金属原子的聚集直至纳米粒子或团簇形成的动力学过程进行深入的基础研究。

Nanochemistry is one of the most challenging branches in modern chemistry. It takes the synthesis,the characterization and the study of the properties of nanoaggregates or clusters,as its principal objects of study. The assembly of nanoaggregates or clusters in liquid phase permits us to control the particle's sizes and structure,so that we may hopefully obtain some artificial functional molecules. In this review, we present firstly several chemical synthetic routes of metallic nanoaggregates. Then we describe in detail the methods of the radiolytic synthesis and photochemical synthesis of metallic nanoaggregates, including their princip1e of synthesis, optimal conditions and advantages. Special attention has been paid to the control of the size of nanoaggregates by adjusting the compositions (e. g,chernical compounds,concentrations)and the properties of the medium (e. g,the pH value ), and the possible synthetic routes to conlrol the structure of the nanoaggregates is also discussed. Moreover,the study of the reaction mechanism of the formation of the metallic nanoaggregates by the technique of pulse radiolysis is presented. This powerful technique permits us to study profoundly the kinetics of the reduction of the metallic ions,the coalescence of the atoms and the formation of the aggregates of clusters in aqueous solution.