不同制备因素对纳米金尺寸的影响

通过化学还原法制备出不同粒径的纳米金(GNPs).利用紫外-可见分光光度计(UVVis)和透射电子显微镜(TEM)对GNPs的形貌及尺寸进行表征.讨论了还原剂种类、还原剂用量、保护剂等因素对GNPs形貌、粒径、稳定性和分散性的影响.结果表明:还原剂柠檬酸钠的用量直接影响GNPs的尺寸大小,但当柠檬酸钠用量超过3 mL时,制得GNPs的尺寸不再变化,以柠檬酸钠为还原剂制得GNPs粒径在13~50 nm之间,分散性好且尺寸较均匀,此时,保护剂PVP对大尺寸GNPs的制备影响不大;以硼氢化钠为还原剂,可制得GNPs粒径在2~3 nm之间,分散性好,此时保护剂PVP对于制备的影响较显著,但不影响GNPs的可控制备.

Effects of different preparation factors on the size of gold nanoparticles

Gold nanoparticles( GNPs) with different particle sizes were synthesized by the chemical reduction method. The morphology and sizes of gold nanoparticles( GNPs) were characterized by the ultraviolet-visible spectrophotometer( UV-Vi S) and transmission electron microscopy( TEM). The effects of the dosage and types of reducing-agents,and the protective agent on the morphology,particle sizes,stability and dispersion of gold nanoparticles( GNPs) were discussed. The results showed that the amount of the reducing agent directly affected the size of gold nanoparticles( GNPs). When the amount of the sodium citrate exceeded 3ml,the size of the GNPs was no longer changed. Gold nanoparticles( GNPs) with the diameters of 13—50 nm were synthesized by the reducing agent of sodium citrate,with good dispersion and similar sizes; at this moment,the protective agent PVP has little effect on the preparation of large-size GNPs; with sodium borohydride as the reducing agent,gold nanoparticles( GNPs) with the diameters of 2—3 nm were synthesized,with good dispersion: at this time,the protective agent PVP has obvious effects on the preparation,but will not affect the controllable preparation of gold nanoparticles( GNPs).