Thermodynamic and Spectroscopic, Characterization of A Weakly Polar Liquid Crystalline Compound Influenced Polyvinyl Pyrrolidone Capped Gold Nanoparticles Volume 5 - Issue 3

Bhupendra Pratap Singh¹, Samiksha Sikarwar², Shivangi Tripathi¹, Rajiv Manohar¹* and Kamal Kumar Pandey³*

• ¹Liquid Crystal Research Laboratory, Department of Physics, University of Lucknow, India
• ²School of Physical and Decision Sciences, Babasaheb Bhimrao Ambedkar University, India
• ³Shri JNMPG College, India

Received:June 24, 2021   Published:July 23, 2021

*Corresponding author:Kamal Kumar Pandey, Rajiv Manohar, Shri JNMPG College, India. Liquid Crystal Research Laboratory, Department of Physics, University of Lucknow, India

DOI: 10.32474/AOICS.2021.05.000214

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Abstract

The dispersion of colloidal polyvinyl pyrrolidone (PVP) capped gold nanoparticles (GNPs) in an azoxybenzene-based nematic liquid crystal (NLC), namely 4,4’- di pentyl azoxy benzene (D₅AOB) has been studied. The present study reported the differential scanning calorimetry (DSC), polarized light microscopy, UV-Vis’s absorption spectroscopy, photoluminescence (PL) and Fouriertransform infrared spectroscopy (FTIR) of GNPs doped NLCs. Three different concentrations of GNPs have been dispersed in pure D₅AOB viz 0.25, 0.5, and 1.0 wt%. It has been observed that, with the increase the GNPs concentration, crystal to nematic phase (Cr-Ne) transition temperature does not change sufficiently but nematic to isotropic temperature decrease significantly. This study reported that the 76% and 46% enhancement of UV-Vis’s absorbance and photoluminescence (PL) intensity respectively with the suitable amount of GNPs dispersion in D₅AOB. The increase in the surface area of GNPs has been attributed to increase in the PL intensity, resulting in increased emissions due to increased scattering of excitation.

Keywords:Colloidal gold nanoparticles; Nematic liquid crystals; Differential Scanning Calorimetry (DSC); UV-Vis’s absorbance; Photoluminescence; Fourier Transform Infrared Spectroscopy (FTIR).

Abstract| Introduction| Experimental Section| Results and Discussion| Conclusion| Acknowledgments| References|