Synthesis of Hollow Silica Spheres with Hierarchical Shell Structure by the Dual Action of Liquid Indium Microbeads in Vapor–Liquid–Solid Growth

• Published in: Langmuir 2011-07, Vol.27 (13), p.7996-7999
• Main Authors: Wang, Jian-Tao, Wang, Hui, Ou, Xue-Mei, Lee, Chun-Sing, Zhang, Xiao-Hong
• Format: Article
• Language: English
• Subjects: Adsorption; Catalysis; Chemistry; Exact sciences and technology; General and physical chemistry; Indium - chemistry; Microspheres; Molecular Structure; Particle Size; Porosity; Silicon Dioxide - chemical synthesis; Silicon Dioxide - chemistry; Surface Properties; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Volatilization
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la201451x

Geometry-based adhesion arising from hierarchical surface structure enables microspheres to adhere to cells strongly, which is essential for inorganic microcapsules that function as drug delivery or diagnostic imaging agents. However, constructing a hierarchical structure on the outer shell of the products via the current microcapsule synthesis method is difficult. This work presents a novel approach to fabricating hollow microspheres with a hierarchical shell structure through the vapor–liquid–solid (VLS) process in which liquid indium droplets act as both templates for the formation of silica capsules and catalysts for the growth of hierarchical shell structure. This hierarchical shell structure offers the hollow microsphere an enhanced geometry-based adhesion. The results provide a facile method for fabricating hollow spheres and enriching their function through tailoring the geometry of their outer shells.