Well-defined hollow nanochanneled-silica nanospheres prepared with the aid of sacrificial copolymer nanospheres and surfactant nanocylinders.

A new approach for synthesizing well-defined hollow nanochanneled-silica nanosphere particles is demonstrated, and the structural details of these particles are described for the first time. Positively charged styrene copolymer nanospheres with a clean, smooth surface and a very narrow size distribution are synthesized by surfactant-free emulsion copolymerization and used as a thermal sacrificial core template for the production of core-shell nanoparticles. A surfactant/silica composite shell with a uniform thickness is successfully produced and deposited onto the polymeric core template by charge density matching between the polymer nanosphere template surface and the negatively charged silica precursors and then followed by selective thermal decomposition of the polymeric core and the surfactant cylinder domains in the shell, producing the hollow nanochanneled-silica nanospheres.

Core-shell-structured monodisperse copolymer/silica particle suspension and its electrorheological response.

Monodisperse core-shell-structured poly(styrene-co-butyl acrylate-co-[2-(methacryloxy)ethyl] trimethylammonium chloride)/silica (PSBM/SiO2) nanoparticles were applied as new electrorheological (ER) materials in which the particles were dispersed in an insulating oil. These nanoparticles were prepared by the consecutive precipitation of cetyltrimethylammonium bromide and negatively charged tetraethylorthosilicate onto the cationic surfaces of PSBM colloidal particles. The successful deposition of the shell phase of the particles and their morphology was examined by transmission and scanning electron microscopy.

Commensurability effect in diblock copolymer lamellar phase under d-dimensional nanoconfinement.

We theoretically consider the commensurability problem of AB diblock lamellar phase confined between parallel plates, in cylinder, and in sphere calculating the free energy of confined lamellar phase which is generalized in terms of dimensionality of confinement (d) and conformational asymmetry (ɛ). We find that the first-order layer-addition transition of lamellar layers parallel to the confining surface (L(∥)) becomes suppressed as the dimensionality of confinement increases. For lamellae confined in curved space, the conformational asymmetry alters the location of layer-addition transition point and the stability of L(∥) against nonconcentric layers.

Preparation and characterization of colored electronic ink nanoparticles by high temperature-assisted dyeing for electrophoretic displays.

The charged polymer nanoparticles of poly(methyl methacrylate-co-ethylene glycol dimethacrylate) were prepared by emulsifier-free emulsion copolymerization and aminolysis. Coloring on the nanoparticles was achieved by high temperature-assisted disperse dyeing. In the presence of a charge control and stabilizing agent, the colored PMMA nanoparticles showed the electrophoretic mobility because of the amine groups on their surfaces.

Synthesis of a nanostructured star block copolymer with a cyclotriphosphazene core.

An amphiphilic star block copolymer of poly(L-lactic acid)-b-poly(ethylene glycol) (PLLA-b-PEG) was synthesized using a hexachlorocyclotriphosphazene ring (N3P3Cl6) as a core. N3P3(OC6H4-p-CHO)6 was prepared by the reaction between the hexachlorocyclotriphosphazene core and 4-hydroxybenzaldehyde sodium salt. N3P3(OC6H4-p-CH2OH)6 was then obtained by reduction of N3P3(OC6H4-p-CHO)6.

Monodisperse hollow titania nanospheres prepared using a cationic colloidal template.

Titania-coated polymeric nanoparticles were synthesized based on the cationic colloidal particles which were prepared by surfactant-free emulsion copolymerization of styrene and butylacrylate in the presence of a cationic monomer, methacryloxyethyltrimethyl ammonium chloride (MOTAC) using azobis(isobutylamidine)hydrochloride (AIBA) as an initiator. These cationic particles were stabilized by poly(vinylpyrrolidone) (PVP). Then, these particles were dispersed in ethanol and mixed with titanium(IV) butoxide.