title: Investigating the multiple roles of polyvinylpyrrolidone for a general methodology of oxide encapsulation.
abstract: Growing oxide shells on seed nanoparticles requires the control of several processes: (a) the nucleation and growth of the shell material; (b) the "wetting" of the shell material on the seeds; and (c) the aggregation of the nanoparticles. These processes are influenced by a number of factors, many of which are related. Without understanding the interdependence of these contributing factors, it is difficult to circumvent problems and achieve rational synthesis. We first did a case study on encapsulating Au nanoparticles with ZnO to understand the multiple roles of polyvinylpyrrolidone (PVP) and their dependence on other factors. We developed a general method for coating ZnO on a variety of seeds, including metals, oxides, polymer nanoparticles, graphene oxide, and carbon nanotube. This method can be further extended to include Fe3O4, MnO, Co2O3, TiO2, Eu2O3, Tb2O3, Gd2O3, β-Ni(OH)2, ZnS, and CdS as the shell materials. The understanding obtained in this systematic study will aid rational design and synthesis of other core-shell nanostructures.
authors.affiliation: Division of Chemistry and Biological Chemistry, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
authors.forename: Hang
authors.initials: H
authors.lastname: Sun
authors.forename: Jiating
authors.initials: J
authors.lastname: He
authors.forename: Jiangyan
authors.initials: J
authors.lastname: Wang
authors.forename: Shuang-Yuan
authors.initials: SY
authors.lastname: Zhang
authors.forename: Cuicui
authors.initials: C
authors.lastname: Liu
authors.forename: Thirumany
authors.initials: T
authors.lastname: Sritharan
authors.forename: Subodh
authors.initials: S
authors.lastname: Mhaisalkar
authors.forename: Ming-Yong
authors.initials: MY
authors.lastname: Han
authors.forename: Dan
authors.initials: D
authors.lastname: Wang
authors.forename: Hongyu
authors.initials: H
authors.lastname: Chen