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Optical and topographic changes in water-responsive patterned cholesteric liquid crystalline polymer coatings

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Details

Original languageEnglish
Title of host publicationProceedings of SPIE
Subtitle of host publicationOrganic Photonics VI
PublisherSPIE
Volume9137
ISBN (Print)9781628410853
DOIs
Publication statusPublished - 2014
Externally publishedYes
Publication typeA4 Article in a conference publication
EventOrganic Photonics VI - Brussels, Belgium
Duration: 15 Apr 201416 Apr 2014

Publication series

NameProceedings of SPIE: the International Society for Optical Engineering
PublisherSPIE
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X

Conference

ConferenceOrganic Photonics VI
CountryBelgium
CityBrussels
Period15/04/1416/04/14

Abstract

In this work, we present patterned water-responsive coatings, which alter both their topological and optical properties. The polymer coatings are based on a hydrogen-bonded cholesteric liquid crystalline polymer network. A two-step photopolymerization procedure leads to a patterned coating with repeating liquid crystalline and isotropic areas. The cholesteric liquid crystalline areas reflect green light, whilst the isotropic areas are transparent for visible light. Treatment with alkaline solution results in a hygroscopic polymer salt coating. When placed in demineralized water, the polymer films swells, leading to an enhancement of the surface topography structure in which the liquid crystalline areas swell more. Moreover, the pitch of the helical organization in the cholesteric areas increases due to this swelling leading to a color change from green to red.

Keywords

  • cholesteric liquid crystals, patterned surfaces, responsive optical coatings, responsive surface topographies, water-responsive