Colloidal particles with multifunctionality have long been considered as a new component for building blocks for novel structures and biological applications such as drug delivery and bio molecular detection. In addition to the preparation of multifunctional colloidal particles, the assembly of colloidal sphere in an ordered structure has been at the center of intensive study. Ordering of colloidal particles is essential to use them in practical industrial applications such as photonic crystals, monolayer coating, and biological devices. Various methods have been developed to assemble colloidal particles in controlled fashions including sedimentation, assembly in confined space, columbic assembly, and etc. Functionalities on the surface of spherical particles could provide directional properties on ordered assembly with a structural rigidity. In addition, assembled structural units still possess extra functional groups for further modification such as chemical reaction, targeting for biomolecules, catalytic reaction, and dye tagging.

Here we describe the monolayer film formation of multifunctional hybrid silica particles at the liquid-liquid interface and generation of Janus particles using asymmetric synthesis. Ordered monolayer of MHS particles was prepared using self assembly process at a hexane/water interface. When MHS particles with methacrylate functional groups were used, post curing by UV light produced a rigid monolayer films with a side-by-side connection, while MHS particles without methacrylate functional groups were used, the addition of methyl methacrylate monomer to hexane layer produced monolayer covered with rather thick film of PMMA after UV curing. This network was strong enough to maintain the morphology of monolayer film with small disturbance such as stirring or agitating. Monolayer films with a rigid network can be used as a template for Janus particles. Different types of Janus particles such as organic-inorganic and organic-metallic biphasic colloidal particles are prepared by an asymmetric chemical modification of MHS particles at the liquid-liquid interface and characterized by SEM and TEM.