Samoilova Nadezhda, Kurskaya Elena, Krayukhina Maria, Askadsky Andrey, Yamskov Igor
AN Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow, Russian Federation.
J Phys Chem B. 2009 Mar 19;113(11):3395-403. doi: 10.1021/jp806683m.
Silver nanoparticles were prepared by reduction of the corresponding metal salt with NaBH(4) in the presence of appropriate dispersing agents, namely, copolymers of maleic acid: poly(N-vinyl-2-pyrrolidone-alt-maleic acid), poly(ethylene-alt-maleic acid), poly(styrene-alt-maleic acid) or their amphyphilic derivatives. A thorough study of the whole process of silver nanoparticles production including formation of polymeric silver salt and stabilization of nanoparticles has been carried out. The degree of cooperativity of copolymer silver ions binding process and binding capacity of copolymers with respect to silver ions was calculated. To estimate the effect of silver binding on dimension of copolymers particles in solutions viscometric method and atomic force microscopy were used. The most stable and highly silver-"loaded" colloids, identified with optical absorption spectroscopy and transmission electron microscopy, were prepared at biphilic copolymers concentrations lower than their critical aggregation concentrations and copolymer/Ag(+) molar ratio was equal to unity. Under optimal reduction conditions, the final morphology of Ag nanoparticles is governed by structural similarity (strict alternation of monomer units) and similar polymer chains length of all copolymers; hydrophobic ligands only assist in stabilization of nanoparticles. A simple method for evaluating the thickness of polymer protective layer based on atomic force microscopy and transmission electron microscopy data is proposed.
通过在适当的分散剂（即马来酸共聚物：聚（N-乙烯基-2-吡咯烷酮-alt-马来酸）、聚（乙烯-alt-马来酸）、聚（苯乙烯-alt-马来酸）或其两亲衍生物）存在下用硼氢化钠还原相应的金属盐来制备银纳米颗粒。对银纳米颗粒生产的整个过程进行了深入研究，包括聚合物银盐的形成和纳米颗粒的稳定化。计算了共聚物银离子结合过程的协同程度以及共聚物对银离子的结合能力。为了评估银结合对溶液中共聚物颗粒尺寸的影响，使用了粘度法和原子力显微镜。通过光学吸收光谱和透射电子显微镜鉴定出最稳定且银“负载”量高的胶体是在两亲共聚物浓度低于其临界聚集浓度且共聚物/银离子摩尔比等于1的条件下制备的。在最佳还原条件下，银纳米颗粒的最终形态由所有共聚物的结构相似性（单体单元的严格交替）和相似的聚合物链长度决定；疏水性配体仅有助于纳米颗粒的稳定化。提出了一种基于原子力显微镜和透射电子显微镜数据评估聚合物保护层厚度的简单方法。
