Abstract
Thin coatings based on liquid crystal networks (LCNs) modified with azobenzene moieties are able to create dynamic surface topographies in the micrometre range by exposure with UV light. The surface corrugations can be erased and restored by switching ‘off’ and ‘on’ the UV illumination. Various configurations were presented. The formation of the protrusions was proven to be induced mainly by excessive volume formation when the order in the LCNs is reduced. It is suggested that this extra volume formation can be further enhanced by stimulating the oscillatory dynamics of trans-cis and cis-trans isomerisation. Therefore, dual-wavelength exposure not only exciting the trans state of azobenzene by 365 nm UV light but simultaneously also the cis state by 455 nm blue light was shown to enhance the effect.
| Original language | English |
|---|---|
| Pages (from-to) | 2136-2143 |
| Number of pages | 8 |
| Journal | Liquid Crystals |
| Volume | 43 |
| Issue number | 13-15 |
| DOIs | |
| Publication status | Published - 7 Dec 2016 |
Keywords
- azobenzene
- Dynamic surface topographies
- liquid crystal networks
- volume increase