Materials Chemistry and Physics

Volume 148, Issue 3, 15 December 2014, Pages 1013-1021

Azobenzene mesogen-passivated gold nanoparticles: Controlled preparation, self-organized superstructures, thermal behavior and photoisomerization

Junfei Duan Meng Wang Huafeng Bian Yang Zhou Jie Ma Chengjie Liu Dongzhong Chen

https://doi.org/10.1016/j.matchemphys.2014.09.012

Abstract

Liquid crystal nanoscience has aroused intensive interests mainly due to their unique and collective properties and a variety of potential applications. In this paper, gold nanoparticles (GNPs) coated with alkoxy azobenzene mesogenic thiol ligands of different length polymethylene spacer and linear alkyl thiol co-ligands have been prepared. The thermal properties, phase behavior of thus obtained hybrid GNPs and photophysical properties of their solid-state films have been investigated by differential scanning calorimetry (DSC), variable-temperature small and wide angle X-ray scattering (SAXS/WAXS) and UV–vis spectroscopy. The hybrid GNPs exclusively passivated with azobenzene mesogenic ligands showed lamellar structure while those with mixed ligands exhibited hexagonal columnar superstructure, and the latter complex hybrid GNPs exhibited noticeably improved thermolysis resistance. Moreover, it is very interesting that the solid-state films of the hybrid GNPs displayed reversible photoresponse owing to the trans–cis transformation of azobenzene mesogenic ligands, and compared with the hybrid GNPs coated with mesogenic ligands only, those with mixed ligands exhibited faster photoisomerization rate upon alternate UV and visible light irradiation, which may have some promising applications.