title: Toward coordinated colloids: site-selective growth of titania on patchy silica particles.
abstract: Rational synthesis of coordinated spherical colloids is reported by site-selective growth of secondary hemispherical patches on primary spherical particles with quasi-defined coordination numbers and positions. We clarify the importance of mass transport phenomena on the site-specific secondary nucleation/growth in nanoparticulate colloidal systems. By comparing ultrasonic and conventional agitation during patch growth, we found that enhanced mass transfer is the key to controlled, homogeneous transport of the molecular precursors in a solvent onto the nanoparticles. With chemically defined nucleation sites, the surfaces of spherical silica particles were modified for use as a new kind of colloid with patches at desired coordination positions. Our observations represent a significant breakthrough in colloidal chemistry and self-assembly.
authors: 1] Department of Energy Science, Sungkyunkwan University, Suwon 440-746, South Korea [2] Integrated Energy Center for Fostering Global Creative Researcher (BK 21 plus), Sungkyunkwan University, Suwon 440-746, South Korea.
authors: Changdeuck
authors: C
authors: Bae
authors: Department of Energy Science, Sungkyunkwan University, Suwon 440-746, South Korea.
authors: Hyunchul
authors: H
authors: Kim
authors: Institute of Applied Physics, University of Hamburg, Jungiusstrasse 11, Hamburg 20355, Germany.
authors: Josep M
authors: JM
authors: Montero Moreno
authors: Department of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, South Korea.
authors: Gi-Ra
authors: GR
authors: Yi
authors: Department of Energy Science, Sungkyunkwan University, Suwon 440-746, South Korea.
authors: Hyunjung
authors: H
authors: Shin