• Media type: E-Article
  • Title: Spontaneous Formation of Vertically Aligned Lamellae in Thin Films of Block Copolymer–Silica Hybrid Material
  • Contributor: Hara, Mitsuo; Nagano, Shusaku; Seki, Takahiro
  • Published: Oxford University Press (OUP), 2013
  • Published in: Bulletin of the Chemical Society of Japan, 86 (2013) 10, Seite 1151-1157
  • Language: English
  • DOI: 10.1246/bcsj.20130172
  • ISSN: 0009-2673; 1348-0634
  • Keywords: General Chemistry
  • Origination:
  • Footnote:
  • Description: <jats:title>Abstract</jats:title> <jats:p>Vertical alignment of mesoscaled and phase-separated structures in organic–inorganic hybrid materials has significant potential for various applications. However, particular procedures and treatments are required to generate such pattern geometries. We demonstrate herein a simple and spontaneous process for vertical alignment of mesoscopic phase-separated structures in a hybrid material consisting of an amphiphilic block copolymer that possesses a thermotropic liquid crystal framework and silicate sol. By combining the thermotropic and lyotropic liquid crystal properties, the sol–gel condensation in this system spontaneously leads to the vertical alignment of mesoscopic lamellae. Most likely, the vertical molecular orientation formed in the thermotropic smectic liquid crystal domains promotes the vertical alignment of the mesoscaled lyotropic liquid crystalline structure of the hybrid film. The organic block components in the film could be selectively etched by ultraviolet light/ozone treatment and, consequently, provide a topologically undulated silica film that retains the vertical lamella structure of the precursor hybrid film. This approach via the hybridization with a metal oxide sol solution is advantageous in tuning the lateral pitch of the structure simply by adjusting the volume fraction of precursor sol content.</jats:p>