title: Light-Induced Surface Patterning of Silica.
abstract: Manipulating the size and shape of silica precursor patterns using simple far-field light irradiation and transforming such reconfigured structures into inorganic silica patterns by pyrolytic conversion are demonstrated. The key concept of our work is the use of an azobenzene incorporated silica precursor (herein, we refer to this material as azo-silane composite) as ink in a micromolding process. The moving direction of azo-silane composite is parallel to light polarization direction; in addition, the amount of azo-silane composite movement can be precisely determined by controlling light irradiation time. By exploiting this peculiar phenomenon, azo-silane composite patterns produced using the micromolding technique are arbitrarily manipulated to obtain various structural features including high-resolution size or sophisticated shape. The photoreconfigured patterns formed with azo-silane composites are then converted into pure silica patterns through pyrolytic conversion. The pyrolytic converted silica patterns are uniformly formed over a large area, ensuring crack-free formation and providing high structural fidelity. Therefore, this optical manipulation technique, in conjunction with the pyrolytic conversion process, opens a promising route to the design of silica patterns with finely tuned structural features in terms of size and shape. This platform for designing silica structures has significant value in various nanotechnology fields including micro/nanofluidic channel for lab-on-a-chip devices, transparent superhydrophobic surfaces, and optoelectronic devices.
authors.forename: Hong Suk
authors.initials: HS
authors.lastname: Kang
authors.affiliation: SKKU Advanced Institute of Nanotechnology (SAINT) & School of Chemical Engineering, Sungkyunkwan University (SKKU) , Suwon, 440-746 Korea.
authors.forename: Seungwoo
authors.initials: S
authors.lastname: Lee
authors.forename: Jaeho
authors.initials: J
authors.lastname: Choi
authors.forename: Hongkyung
authors.initials: H
authors.lastname: Lee
authors.forename: Jung-Ki
authors.initials: JK
authors.lastname: Park
authors.forename: Hee-Tak
authors.initials: HT
authors.lastname: Kim
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D062028:Bioprinting; D004867:Equipment Design; D056656:Lab-On-A-Chip Devices; D008027:Light; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology; D012821:Silanes / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D001391:Azo Compounds; D012821:Silanes; D012822:Silicon Dioxide; C009850:azobenzene
keywords: azobenzene materials; micro/nano silica patterning; photofluidization; pyrolytic conversion; silica precursor