title: Controlling Gaussian and mean curvatures at microscale by sublimation and condensation of smectic liquid crystals.
abstract: Soft materials with layered structure such as membranes, block copolymers and smectics exhibit intriguing morphologies with nontrivial curvatures. Here, we report restructuring the Gaussian and mean curvatures of smectic A films with free surface in the process of sintering, that is, reshaping at elevated temperatures. The pattern of alternating patches of negative, zero and positive mean curvature of the air-smectic interface has a profound effect on the rate of sublimation. As a result of sublimation, condensation and restructuring, initially equilibrium smectic films with negative and zero Gaussian curvature are transformed into structures with pronounced positive Gaussian curvature of layers packing, which are rare in the samples obtained by cooling from the isotropic melt. The observed relationship between the curvatures, bulk elastic behaviour and interfacial geometries in sintering of smectic liquid crystals might pave the way for new approaches to control soft morphologies at micron and submicron scales.
authors.affiliation: Graduate School of Nanoscience and Technology and KINC, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
authors.forename: Dae Seok
authors.initials: DS
authors.lastname: Kim
authors.affiliation: Graduate School of Nanoscience and Technology and KINC, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
authors.forename: Yun Jeong
authors.initials: YJ
authors.lastname: Cha
authors.affiliation: Department of Polymer Engineering, Pukyong National University, Busan 608-739, Korea.
authors.forename: Mun Ho
authors.initials: MH
authors.lastname: Kim
authors.affiliation: Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University, Kent, Ohio 44242, USA.
authors.forename: Oleg D
authors.initials: OD
authors.lastname: Lavrentovich
authors.affiliation: Graduate School of Nanoscience and Technology and KINC, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
authors.forename: Dong Ki
authors.initials: DK
authors.lastname: Yoon