Pang Bo, Köhler Robert, Roddatis Vladimir, Liu Huan, Wang Xiaohui, Viöl Wolfgang, Zhang Kai
Wood Technology and Wood Chemistry, Georg-August-University of Goettingen, Büsgenweg 4, 37077 Göttingen, Germany.
Laboratory of Laser and Plasma Technologies, University of Applied Sciences and Arts Hildesheim/Holzminden/Goettingen, Von-Ossietzky-Str. 99, 37085 Göttingen, Germany.
ACS Omega. 2018 Jun 25;3(6):6841-6848. doi: 10.1021/acsomega.8b00833. eCollection 2018 Jun 30.
Polymers or small molecules with functional groups were always employed to synthesize two-dimensional (2D) silver nanostructures, but the polysaccharides and derivatives have rarely been used for their preparation, let alone of uniform quadrilateral shapes. Herein, amylopectin derivatives containing concentrated carboxyl groups were first used for the synthesis of uniform 2D quadrilateral silver nanoplates (QAgNPs) with lamellar structure. As a native hyperbranched polysaccharide, amylopectin was esterified with 10-undecenoyl chloride and then modified via thiol-ene click chemistry to introduce high amount and high density of carboxyl groups. Then, QAgNPs were synthesized via UV photoreduction in the presence of the resultant amylopectin 11-((3-carboxyl)ethylthio)undecanoate (APUE-MPA) in water-tetrahydrofuran binary system. QAgNPs showed novel uniform quadrilateral shapes with lamellar structure, as verified by their wide-angle X-ray scattering patterns. The average interlayer distance was around 1.3 nm, whereas the average edge lengths of QAgNPs varied between 0.29 ± 0.07 and 1.09 ± 0.25 μm. The concentration of APUE-MPA and the amount of water in the reaction system strongly affected the shapes of QAgNPs. Thus, the reaction system and the arrangement of numerous carboxyl groups were the key factors for the formation of lamellar-structured QAgNPs.
带有官能团的聚合物或小分子常被用于合成二维（2D）银纳米结构，但多糖及其衍生物很少用于其制备，更不用说制备出均匀的四边形形状了。在此，首次使用含有浓缩羧基的支链淀粉衍生物来合成具有层状结构的均匀二维四边形银纳米片（QAgNPs）。作为一种天然的超支化多糖，支链淀粉用10-十一碳烯酰氯进行酯化，然后通过硫醇-烯点击化学进行改性，以引入大量且高密度的羧基。然后，在水-四氢呋喃二元体系中，在所得的支链淀粉11-((3-羧基)乙硫基)十一烷酸酯（APUE-MPA）存在下，通过紫外光还原合成了QAgNPs。QAgNPs呈现出具有层状结构的新型均匀四边形形状，这通过其广角X射线散射图谱得到了验证。平均层间距约为1.3 nm，而QAgNPs的平均边长在0.29±0.07至1.09±0.25μm之间变化。反应体系中APUE-MPA的浓度和水量对QAgNPs的形状有很大影响。因此，反应体系和众多羧基的排列是形成层状结构QAgNPs的关键因素。
