Ranoszek-Soliwoda Katarzyna, Tomaszewska Emilia, Socha Ewelina, Krzyczmonik Pawel, Ignaczak Anna, Orlowski Piotr, Krzyzowska Małgorzata, Celichowski Grzegorz, Grobelny Jaroslaw
Department of Materials Technology and Chemistry, Faculty of Chemistry, University of Lodz, Pomorska 163, 90-236 Lodz, Poland.
Department of Inorganic and Analytical Chemistry, Faculty of Chemistry, University of Lodz, Tamka, 91-403 Lodz, Poland.
J Nanopart Res. 2017;19(8):273. doi: 10.1007/s11051-017-3973-9. Epub 2017 Aug 4.
We describe herein the significance of a sodium citrate and tannic acid mixture in the synthesis of spherical silver nanoparticles (AgNPs). Monodisperse AgNPs were synthesized via reduction of silver nitrate using a mixture of two chemical agents: sodium citrate and tannic acid. The shape, size and size distribution of silver particles were determined by UV-Vis spectroscopy, dynamic light scattering (DLS) and scanning transmission electron microscopy (STEM). Special attention is given to understanding and experimentally confirming the exact role of the reagents (sodium citrate and tannic acid present in the reaction mixture) in AgNP synthesis. The oxidation and reduction potentials of silver, tannic acid and sodium citrate in their mixtures were determined using cyclic voltammetry. Possible structures of tannic acid and its adducts with citric acid were investigated in aqueous solution by performing computer simulations in conjunction with the semi-empirical PM7 method. The lowest energy structures found from the preliminary conformational search are shown, and the strength of the interaction between the two molecules was calculated. The compounds present on the surface of the AgNPs were identified using FT-IR spectroscopy, and the results are compared with the IR spectrum of tannic acid theoretically calculated using PM6 and PM7 methods. The obtained results clearly indicate that the combined use of sodium citrate and tannic acid produces monodisperse spherical AgNPs, as it allows control of the nucleation, growth and stabilization of the synthesis process. Graphical abstractᅟ.
我们在此描述柠檬酸钠和单宁酸混合物在球形银纳米颗粒（AgNPs）合成中的重要性。通过使用两种化学试剂（柠檬酸钠和单宁酸）的混合物还原硝酸银来合成单分散的AgNPs。通过紫外-可见光谱、动态光散射（DLS）和扫描透射电子显微镜（STEM）确定银颗粒的形状、尺寸和尺寸分布。特别关注理解并通过实验证实反应混合物中试剂（柠檬酸钠和单宁酸）在AgNP合成中的确切作用。使用循环伏安法测定银、单宁酸和柠檬酸钠在其混合物中的氧化和还原电位。通过结合半经验PM7方法进行计算机模拟，研究了单宁酸及其与柠檬酸加合物在水溶液中的可能结构。展示了从初步构象搜索中找到的最低能量结构，并计算了两个分子之间相互作用的强度。使用傅里叶变换红外光谱（FT-IR）鉴定了AgNPs表面存在的化合物，并将结果与使用PM6和PM7方法理论计算的单宁酸红外光谱进行了比较。所得结果清楚地表明，柠檬酸钠和单宁酸的联合使用可产生单分散的球形AgNPs，因为它允许控制合成过程的成核、生长和稳定。图形摘要ᅟ。
