Hirano Takayuki, Mitsuzawa Kana, Ishioka Shun, Daicho Kazuho, Soeta Hiroto, Zhao Mengchen, Takeda Masaaki, Takai Yoshihiro, Fujisawa Shuji, Saito Tsuguyuki
Material Characterization Laboratories, Toray Research Center, Otsu, Japan.
Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.
Front Chem. 2020 Feb 7;8:68. doi: 10.3389/fchem.2020.00068. eCollection 2020.
We report the anisotropic thermal expansion of a transparent nanopaper structure comprising cellulose nanofibers (CNFs). The coefficient of thermal expansion (CTE) of the nanopaper in the out-of-plane direction was 44.6 ppm/°C in the temperature range of 25-100°C, which is approximately five times larger than its CTE in the in-plane direction in the same temperature range (8.3 ppm/°C). Such a strong anisotropy in thermal expansion is mainly attributable to the anisotropic CTE values of single CNFs in the fiber axis and cross-sectional directions. We observed anisotropic thermal expansion even in a bioplastic composite containing only 2.5% w/w CNFs.
我们报道了一种由纤维素纳米纤维（CNFs）组成的透明纳米纸结构的各向异性热膨胀。在25 - 100°C的温度范围内，纳米纸在面外方向的热膨胀系数（CTE）为44.6 ppm/°C，这大约是其在相同温度范围内面内方向CTE（8.3 ppm/°C）的五倍。这种热膨胀的强各向异性主要归因于单个CNF在纤维轴方向和横截面方向上不同的CTE值。我们甚至在仅含有2.5% w/w CNFs的生物塑料复合材料中也观察到了各向异性热膨胀。
