Shintate Morio, Inadomi Takumi, Yamamoto Shinya, Kuboyama Yusuke, Ohsedo Yutaka, Arimura Takashi, Nakazumi Tomoka, Hara Yusuke, Miyamoto Nobuyoshi
Department of Life, Environment and Materials Science , Fukuoka Institute of Technology , 3-30-1, Wajirohigashi , Higashiku, Fukuoka 811-0295 , Japan.
Research Institute for Sustainable Chemistry , National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba Central 5, 1-1-1 Higashi, Tsukuba , Ibaraki 305-8565 , Japan.
J Phys Chem B. 2018 Mar 22;122(11):2957-2961. doi: 10.1021/acs.jpcb.7b11631. Epub 2018 Mar 8.
Anisotropic chemical wave propagation of self-oscillating Belousov-Zhabotinsky (BZ) reaction was demonstrated in the poly( N-isopropylacrylamide) gel films embedded with macroscopically aligned liquid crystalline inorganic nanosheets. Although the average propagation rate of chemical wave v̅ was 3.56 mm min in the gels without nanosheets, the propagation was retarded in the gels with 1 wt % of nanosheets: [Formula: see text] = 1.89 mm min and [Formula: see text] = 1.33 mm min along the direction parallel and perpendicular to the nanosheet planes, respectively. Thus, the wave propagation is anisotropic with the anisotropy ratio [Formula: see text] = 1.42 in these gels and the periodic patterns formed by the BZ reaction were concentric ellipses, different from circles seen in isotropic gels. Furthermore, the propagation rate and degree of anisotropy were controllable by nanosheet concentration. These phenomena can be explained that the diffusion of molecules inside the gel is effectively hindered along the direction perpendicular to the nanosheet planes due to the very large aspect ratio of the aligned nanosheets. The present systems will be applicable for anisotropic self-oscillating soft actuators with one-dimensional motions as well as for ideal model system of BZ reactions.
在嵌入宏观取向液晶无机纳米片的聚（N - 异丙基丙烯酰胺）凝胶薄膜中，展示了自振荡的贝洛索夫 - 扎博廷斯基（BZ）反应的各向异性化学波传播。尽管在没有纳米片的凝胶中化学波的平均传播速率(\bar{v})为3.56毫米/分钟，但在含有1重量％纳米片的凝胶中传播受到阻碍：沿平行于纳米片平面的方向([公式：见原文] = 1.89)毫米/分钟，沿垂直于纳米片平面的方向([公式：见原文] = 1.33)毫米/分钟。因此，在这些凝胶中波传播是各向异性的，各向异性比([公式：见原文] = 1.42)，并且由BZ反应形成的周期性图案是同心椭圆，不同于在各向同性凝胶中看到的圆形。此外，传播速率和各向异性程度可通过纳米片浓度控制。这些现象可以解释为，由于取向纳米片的非常大的纵横比，凝胶内部分子的扩散在垂直于纳米片平面的方向上受到有效阻碍。本系统将适用于具有一维运动的各向异性自振荡软致动器以及BZ反应的理想模型系统。
