Colloidal crystallization on tilted substrates under gravitational fields

We show usefulness of a side wall of a tilted growth container during continuous growth of colloidal crystals under gravitational fields. The side wall works as an effective substrate which enables both enlargement of grains of colloidal crystals and control of crystallographic orientations of the grains. We successfully fabricated large grains of polystyrene face-centered cubic colloidal crystals which align with their {111} planes parallel to a side wall by tilting a growth container during centrifugation. Although, without tilting a growth container, widths and crystallographic orientations of grains remained unchanged once the widths become asymptotic values, we could increase both widths of grains and population of the grains which aligned with their {111} planes parallel to a side wall with terminating grains of the other orientations by tilting the container. (C) 2014 Elsevier B.V. All rights reserved.