CAJ | 학술논문

在水相体系中以柠檬酸钠和硝酸银为反应物,利用可见光诱导的还原过程在室温下制备盘状的银纳米粒子,通过紫外-可见光谱监控了不同反应条件下银纳米粒子的生长过程及体系的稳定性.吸收光谱随时间的变化表明,在一定的反应条件下早期的产物为球形粒子;随着反应时间延长盘状产物开始逐渐生成并长大,球形粒子数也进一步增加;而到了后期盘状粒子则通过粒子间的Ostwald熟化过程进一步长大.研究还发现,过量的柠檬酸根离子无助于稳定胶态体系,而适量的PVP(聚乙烯吡咯烷酮)的加入则能起到有效的稳定作用;严格控制的搅拌对于保证体系良好的分散稳定性不可缺少.进一步的研究还表明,在反应体系中引入大量的氢氧根离子能大大的加快反应速度.
재수상체계중이저몽산납화초산은위반응물,이용가견광유도적환원과정재실온하제비반상적은납미입자,통과자외-가견광보감공료불동반응조건하은납미입자적생장과정급체계적은정성.흡수광보수시간적변화표명,재일정적반응조건하조기적산물위구형입자;수착반응시간연장반상산물개시축점생성병장대,구형입자수야진일보증가;이도료후기반상입자칙통과입자간적Ostwald숙화과정진일보장대.연구환발현,과량적저몽산근리자무조우은정효태체계,이괄량적PVP(취을희필각완동)적가입칙능기도유효적은정작용;엄격공제적교반대우보증체계량호적분산은정성불가결소.진일보적연구환표명,재반응체계중인입대량적경양근리자능대대적가쾌반응속도.
Sliver nanoplates were prepared through a visible light induced reduction process by a reaction between sodium citrate and silver nitrate in an aqueous solvent at room temperature. UV-Vis spectra were employed to monitor the growth of the silver nanoplates. The resulting spectra indicated that, at an early stage,the products were spherical particles with planar nanoparticles appearing and growing subsequently. In the last stages of the process, some spherical particles were consumed by the growth of the nanoparticles,through an Ostwald ripening mechanism. Furthermore, it was found that the addition of either Poly(Vinyl Pyrrolidone) (PVP) or excessive citrate could stabilize the colloidal system effectively, and that rigorous stirring was necessary for the anticipant products. Introduction of a large quantities of sodium hydroxide can dramatically accelerate the reactive rate of the photoreduction process.