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在十二烷基苯磺酸钠(SDBS)和聚乙烯吡咯烷酮(PVP)的混合水溶液中,通过水合肼还原硝酸银制备了分布均匀、粒度可控的纳米片状银。使用紫外可见光谱(UV-vis)对不同反应时间的溶胶进行分析,结合扫描电子显微镜(SEM)的表征结果,探讨了SDBS/PVP复合体系中,纳米银溶胶的光谱特征以及银纳米片的形成过程。研究结果表明,随着反应时间的延长,5 min内将获得长、宽、厚度都小于100 nm的片状粒子,60 min时得到的是长、宽超过400 nm,分布均匀的片状银粒子。片状纳米银的形成过程中,SDBS中的磺酸基被吸附到PVP的内酰胺基链上,通过对Ag+的吸附缔合作用,首先会形成粒径较小的单晶银粒子,进一步生长聚合成大尺度的多边形片状银粉,形成的银溶胶呈现出多个表面等离子共振(SPR)吸收峰。
In a mixed aqueous solution of sodium dodecylbenzenesulfonate (SDBS) and polyvinylpyrrolidone (PVP), nano-silver flake with uniform distribution and controlled particle size was prepared by reducing silver nitrate with hydrazine hydrate. The sols with different reaction time were analyzed by UV-vis. Combined with the characterization results of scanning electron microscopy (SEM), the spectral characteristics of nano-silver sol and the formation of silver nanosheets in SDBS / PVP composite system process. The results show that, with the extension of the reaction time, the flaky particles with the length, width and thickness less than 100 nm will be obtained within 5 min, and the flaky silver particles with the length and width over 400 nm are obtained at 60 min . During the formation of flaky nanosilver, the sulfonic acid groups in SDBS are adsorbed to the lactam-based chain of PVP. Through the adsorption and association of Ag +, firstly, single-crystal silver particles with smaller particle size will be formed and further grow Polymerization into large-scale polygonal flaky silver powder, the formation of silver sol presents a number of surface plasmon resonance (SPR) absorption peak.