Seed‐Assisted Synthesis of BaCrO4 Nanoparticles and Nanostructures in Water‐in‐Oil Microemulsions
Seed‐Assisted Synthesis of BaCrO4 Nanoparticles and Nanostructures in Water‐in‐Oil Microemulsions
复制标题
油包水微乳液中 BaCrO4 纳米颗粒和纳米结构的种子辅助合成
DOI：
10.1002/adfm.200400197
复制
发表时间：
2004
影响因子：
19
通讯作者：
S. Mann
中科院分区：
文献类型：
--
作者：
C. J. Johnson;Mei Li;S. Mann
Isooctane dispersions of discrete isometric BaCrO4 nanoparticles or self‐assembled linear chains of prismatic BaCrO4 nanoparticles were added as surfactant‐coated seed crystals/nanostructures to Na2CrO4/NaAOT/Ba(AOT)2/isooctane microemulsion reaction solutions prepared at w = 10 with molar ratios favoring the de novo synthesis of either nanoparticle chains ([Ba2+]/ [CrO42–] = 1:1) or isolated nanoparticles ([Ba2+]/[CrO42–] = 1:5.5). Addition of BaCrO4 nanoparticles or chains under particle‐ or chain‐producing conditions, respectively, resulted in preferential growth of the seeds with retention of particle morphology and nanostructure architecture. In contrast, addition of linear chains to microemulsion reaction solutions under particle‐producing conditions resulted in disruption of the seed nanostructure and overgrowth of the released prismatic nanoparticles to produce discrete oval‐shaped or cuboidal nanocrystals depending on the seed concentration used. Discrete faceted nanoparticles were also produced by seed‐assisted synthesis when isometric nanoparticles were added at relatively high concentrations to chain‐producing microemulsion reaction solutions; however, decreasing the seed population resulted in intact self‐assembled linear chains and superlattices that consisted of interlinked prismatic nanoparticles with end‐capped pseudo‐hexagonal morphology. Growth of the seeds and their assembly/disassembly was consistent with a model of coupled synthesis and self‐organization based on the strength of electrostatic interactions at the surfactant‐crystal interface. The results suggest that microemulsion‐based processes could be of general importance for controlling the secondary growth of pre‐organized nanoparticle‐based superstructures, as well as the morphological refinement of their constituent building blocks.
