The synthesis and enhanced thermal-optical properties of nanocomposites fabricated from gold nanoclusters ([Au25(SC12H25)18]TOA) and non-linear S-shaped liquid crystalline materials

Abstract

A series of new gold nanocomposite materials, GNC_LCx (x = 6–11), was obtained from a series of non-linear liquid crystal oligomers, LCx (x = 6–11), with a gold nanocluster (GNC) possessing a formulation of [Au₂₅(SC₁₂H₂₅)₁₈]TOA, which is represented as Au₂₅. The oligomers consist of a central disulphide (S–S) linkage wherein the length of the inner alkyl spacer n₁ varied from 6 to 11, whilst the outer alkyl length n₂ was fixed at 6. The synthesis of Au₂₅ was verified using UV-vis and TEM, whereas the properties of Au₂₅, LCx, and GNC_LCx were validated using UV-vis, PL, DLS, and TEM. However, the fundamental results of GNC_LCX suggest the possibility of core alteration, indicating that the GNC in GNC_LCx may no longer be the same Au₂₅. The occurrence of some kind of complexation or more than one intermolecular interaction (other than hydrophobic interaction) is proposed that might contribute to the exisiting outcome. The primary findings implied that the synthesis of the nanocomposites was successful and the enhancement of the thermal stability of the transition temperatures of crystal–isotropic (T_Cr–I) and isotropic–nematic (T_I–N) transitions along with the photoluminescence property were observed.