Nitroxide radicals reduce shrinkage in acrylate-based holographic gratings
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- 作者：Riccardo Castagna ; Francesco Vita ; Daniele E. Lucchetta ; Luigino Criante ; Lucedio Greci ; Paolo Ferraris ; Francesco Simoni
- 关键词：Photo-polymerization ; Nitroxide radicals ; Holographic gratings ; Polymer shrinkage ; Acrylates
- 刊名：Optical Materials
- 出版年：2007
- 出版时间：December 2007
- 年：2007
- 卷：30
- 期：4
- 页码：539-544
- 全文大小：281 K
文摘
High resolution holographic polymer dispersed liquid crystal gratings are photo-induced periodic structures commonly affected by shrinkage. This phenomenon represents a problem in several application fields such as in high density optical storage. In this work we observed that, by directly monitoring the blue-shift of the reflection peak of the periodic structure, an evident shrinkage reduction occurs using the nitroxide radical Tinuvin770-N-yloxy [(bis(2,2,6,6-tetramethyl-piperidine-1-yloxy-4-yl)-sebacate] as inhibitor of polymerization. This compound is a stable hindered amine light stabilizer-derived free radical, which plays a significant role in the photo-polymerization dynamics.