Structure and stability of molecular layers of a photosensitive azo-polyacrylate by X-rays reflectivity and GID

被引:5
作者
Cristofolini, L
Berzina, T
Fontana, MP
Konovalov, O
机构
[1] Univ Parma, Dipartimento Fis, I-43100 Parma, Italy
[2] Univ Parma, INFM, I-43100 Parma, Italy
[3] ESRF, Grenoble, France
关键词
polymeric liquid crystals; photoinduced effects; x-ray reflectivity;
D O I
10.1080/10587250210586
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
We report on the modifications in morphology and microscopic structure induced by photoexcitation of homo- and heterostructures of a side chain liquid crystalline polymer, namely a polyacrylate with an azobenzene moiety in the side chain. The structures were molecular mono- and multilayers deposited with the Langmuir-Schaefer technique. The structural and morphological determinations were performed with synchrotron radiation Xray reflectometry and Grazing Incidence Diffraction (GID). We observe extensive photoinduced effects on the nanoscale: expansion of the multilayers independently of number of layers, reduction of surface toughness, and destruction of order to yield a glasslike phase. The study of superlattices composed of alternate layers of barium behenate and our polymer indicates a general reduction of photoinduced structural effects on the polymer multilayer. Finally, we discuss these effects as a function of temperature from the range of the glass transition to the clearing point.
引用
收藏
页码:689 / 699
页数:11
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