Probing Optical Nonlinearities of Unconventional Glass Nanocomposites Made of Ionic Liquid Crystals and Bimetallic Nanoparticles.

In this paper, we report the synthesis and characterization of unconventional nanocomposites made of bimetallic nanoparticles dispersed in a liquid crystal glass. Core-shell bimetallic nanoparticles (Ag/Au or Au/Ag) and Ag-Au bimetallic nanoalloys are synthesized using cadmium alkanoate glass-forming liquid crystals as nanoreactors. Optical spectra of the produced glassy nanocomposites exhibit a distinctive absorption peak due to a surface plasmon resonance. In addition, these unusual materials demonstrate a strong nonlinear-optical response probed by means of the Z-scan technique. The use of near-infrared (1064 nm) and visible (532 nm) nanosecond laser pulses reveal a variety of nonlinear-optical mechanisms that depend on the composition of the studied nanocomposites. Our results indicate that metal alkanoate-based glass-forming ionic liquid crystals with embedded plasmonic nanoparticles are promising, yet they are overlooked photonic nanomaterials suitable for optical and nonlinear-optical applications.

Influence of semiconductor and metal nanoparticles on the dielectric properties of ionic matrix cadmium octanoate.

Dielectric properties of ionic composites consisted of cadmium octanoate matrix and semiconductor or metal nanoparticles have been investigated. The nanoparticles of different nature (semiconductor CdS, metal Au, and metal core-semiconductor shell Au-CdS) were chemically synthesized in the smectic A phase of (Cd(+2)(C7H15COO)(-2), CdC8) that was used as a nanoreactor. These nanocomposites are very stable and well ordered; the size and shape of the nanoparticles (NPs) are well controlled during the synthesis. The main aim of the research was to examine the influence of nanoparticles on the dielectric properties of ionic matrix, which has smectic A ordered structure. Electrical characteristics were investigated at different temperatures, which correspond to different phases of the material. The conductivity of nanocomposites has an activation nature. The electrical conductivity anisotropy confirms the structural anisotropy of the nanocomposites. The conductivity of the nanocomposite along the cation-anion layers is higher by 2 orders of magnitude than that across the cation-anion layers. Basing on the experimental data, we proposed the simple model of the charge carriage process.