Photo‐Triggered Surface Relief Grating Formation in Supramolecular Liquid Crystalline Polymer Systems with Detachable Azobenzene Unit
Photo‐Triggered Surface Relief Grating Formation in Supramolecular Liquid Crystalline Polymer Systems with Detachable Azobenzene Unit
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DOI：
10.1002/adma.200701110
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发表时间：
2008-02
影响因子：
29.4
通讯作者：
N. Zettsu;Toshinobu Ogasawara;Norihiro Mizoshita;Shusaku Nagano;T. Seki
中科院分区：
文献类型：
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作者：
N. Zettsu;Toshinobu Ogasawara;Norihiro Mizoshita;Shusaku Nagano;T. Seki
偶氮苯官能化聚合物已被广泛探索，在各种技术应用中具有潜在用途，例如光学信息存储、光学开关、衍射光学元件等。[1-9]所有这些应用都基于聚合物链中偶氮苯基团的高效光致异构化和光致重取向。在用适当波长的偏振光照射时，偶氮苯部分通过可逆的反式（cid：1）顺式光异构化进行光诱导重取向。在干涉激光照射下的这种异构化循环经常导致通常在微米级的质量传输过程，导致在膜上形成表面浮雕光栅（SRG）。所得到的浮雕对应于包括强度和偏振的入射光调制的图案。[1，9 -15]已经用各种偶氮苯官能化聚合物研究了这种现象。侧链型聚合物已被有利地用于获得高效的光驱动质量传输。已经有一些尝试在主-客体体系中制备SRG，其中偶氮染料分子仅嵌入聚合物膜中。[16]然而，在这样的系统中，即使顺式/反式光异构化进行，所得的表面起伏也很小（< 10 nm）。染料的浓度与形成SRG结构的能力密切相关，并且应将大量染料（高达30%）掺入聚合物中以产生这种效果。Fukuda等人声称，以如此高的百分比掺入染料仅可通过使用官能化的侧链聚合物来实现，
Azobenzene-functionalized polymers have been extensively explored for potential uses in various technological applications, such as optical information storage, optical switching, diffractive optical elements, and so on. [1–9] All of these applications are based on the efficient photoisomerization and photoinduced reorientation of azobenzene groups in the polymer chains. Upon irradiation with polarized light at an appropriate wavelength, azobenzene moieties undergo a photoinduced reorientation through the reversible trans (cid:1) cis photoisomerization. This isomerization cycle under an interference laser illumination frequently leads to mass transport processes at typically micrometer levels, resulting in the formation of surface relief gratings (SRG) on the film. The resultant reliefs correspond to the patterns of incident light modulations including both intensity and polarization. [1,9–15] Such phenomena have been investigated with a variety of azobenzene functionalized polymers. The side-chain type polymers have been favorably employed to attain the efficient light driven mass transport. There have been some attempts to produce SRG in the host-guest system in which azo dye molecules are just embedded in the polymer films. [16] In such systems, however, the resulting surface undulation is small (< 10 nm) even though the cis / trans photoisomerization proceeds. The concentration of the dye is closely linked to the ability to form SRG structures, and the high amount of dye (up to 30 %) should be incorporated into the polymer to make this effect. Fukuda et al. claimed that the dye incorporation at such a high percentage can be possible only by using functionalized side-chain polymers with