ABSTRACT

In the present work, we have dispersed diamond nanoparticles (DNPs) in nematic liquid crystal 4-(Trans-4ʹ-n-Pentylcyclohexyl) Benzonitrile (PCH5) and studied the dielectric and optical properties of pure and DNPs dispersed nematic systems. We have investigated the effect of dispersion of DNPs (concentrations 0.5 and 1.0 wt%) in nematic liquid crystals (NLC) PCH5 on the dielectric permittivity, dielectric loss, dielectric anisotropy, photoluminescence, UV-Vis absorbance. It has been found that these properties are influenced by the dispersion of DNPs in nematic PCH5 system and applied electric field. Due to the dispersion of DNPs (1.0 wt% concentration) in PCH5, a significant decrease in the relative permittivity occurs. The relaxation peaks of dielectric loss shifts towards higher frequency side for NLC-DNPs composites. The dielectric anisotropy has been found to decrease with the dispersion of DNPs into pure NLC. The PL emission and UV-Vis absorbance for the dispersed systems have been decreased. An effort has been made to explain the observed results on the basis of interaction between nematic molecules and diamond NPs. The possible applications have also been suggested for the dispersed systems in this study.

摘要

在目前的工作中，我们将金刚石纳米颗粒 (DNP) 分散在向列液晶 4-(Trans-4ʹ-n-Pentylcyclohexyl) 苯甲腈 (PCH5) 中，并研究了纯 DNP 和分散向列系统的介电和光学特性。我们研究了 DNP（浓度为 0.5 和 1.0 wt%）在向列液晶 (NLC) PCH5 中的分散对介电常数、介电损耗、介电各向异性、光致发光、UV-Vis 吸光度的影响。已经发现，这些特性受 DNP 在向列 PCH5 系统中的分散和外加电场的影响。由于 DNP（浓度为 1.0 wt%）在 PCH5 中的分散，相对介电常数会显着降低。对于 NLC-DNPs 复合材料，介电损耗的弛豫峰向高频侧移动。已发现介电各向异性随着 DNP 分散到纯 NLC 中而降低。分散系统的 PL 发射和 UV-Vis 吸收已经降低。已努力根据向列分子和金刚石 NP 之间的相互作用来解释观察到的结果。在本研究中还建议了分散系统的可能应用。