Inhomogeneous nematic-isotropic phase transition of a thermotropic liquid crystal doped with iron oxide nanoparticles
Inhomogeneous nematic-isotropic phase transition of a thermotropic liquid crystal doped with iron oxide nanoparticles
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DOI：
10.1016/j.physleta.2020.126927
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发表时间：
2020-12-30
影响因子：
2.6
通讯作者：
Abelmann, Leon
中科院分区：
文献类型：
--
作者：
Sung, Baeckkyoung;Yan, Huan;Abelmann, Leon
利用原位低温透射电子显微镜和偏振光显微镜，研究了氧化铁纳米粒子（直径6 nm）在4-氰基-4 '-戊基联苯液晶（LC）基质中的局部分布和聚集结构.我们发现，几十个IONP聚集成一个球形的形态，和聚集体联合收割机成细长的集群与数百nm的长度。与IONP掺杂的液晶矩阵局限于一个薄的玻璃细胞，我们研究了向列-各向同性（N-I）相变，并建议在偏光显微镜中看到的液晶织构的局部异质性是由IONP聚集团簇的存在所造成的。这些团簇还充当加热时形成各向同性畴的核。(C)2020 Elsevier B. V.保留所有权利。
We elucidate the local distribution and aggregated structure of iron oxide nanoparticles (IONPs; 6 nm in diameter) doped in the matrix of a nematic liquid crystal (LC), 4-cyano-4'-pentylbiphenyl, utilizing in situ cryogenic transmission electron microscopy and polarized light microscopy. We show that tens of IONPs aggregate into a sphere-like morphology, and the aggregates combine into elongated clusters with a length of hundreds of nm. With the IONP-doped LC matrix confined to a thin glass cell, we study the nematic-isotropic (N-I) phase transition, and suggest that local heterogeneity of LC textures as seen in polarized microscopy is caused by the existence of IONP aggregate clusters. These clusters act also as nuclei for the formation of isotropic domains upon heating. (C) 2020 Elsevier B.V. All rights reserved.