Temperature Effects on Molecular Alignments at the Surface of Ultrathin Films Studied by SHG and Fluorescence Techniques.

Abstract

Poly(methyl methacrylate) (PMMA) thin films incorporating amphiphilic dyes, ruthenium tris(2,2-bipyridine)-type complexes, were prepared by water casting. Films fabricated in this manner are peculiar with their well lined-up molecular orientations at the surface and thus are highly nonlinear effective. Unfortunately, like most other nonlinear materials, the surface orders of the dye molecules tend to collapse once exposed to heat. This work presents our recent studies on heat-induced molecular reorientation by probing SHG and fluorescence spectra. It shows that, in the course of heating between 20 °C and 80°C, the secondary glass transition of PMMA molecules is responsible for both the randomization of the surface alignments of the Ru complex molecules and the migration of these molecules into the body of the PMMA layer.

In Situ Preparation and Luminescent Properties of CeF3 and CeF3:Tb3+ Nanoparticles and Transparent CeF3:Tb3+/PMMA Nanocomposites in the Visible Spectral Range

“…Moreover, since PMMA is nontoxic, it could be also useful in dentures, medicine dispensers, food handling equipments, throat lamps, and lenses. PMMA embeddedd with inorganic or organically modified inorganic particles has been cast into films to yield enhanced functional properties such as electrical conductivity, 13 photoconductivity, 14 photoinduced chargetransfer, 15 nonlinear optical properties, 16 photoluminescence, 11a,bd,17 mechanical, 2b,12a,18 and magnetic properties. 19 Compared with conventional oxide-based luminescent materials, fluorides have advantages as fluorescent host materials owing to their low vibrational energies and the subsequent minimization of the quenching of the excited-state of the rareearth ions.…”

“…Moreover, since PMMA is nontoxic, it could be also useful in dentures, medicine dispensers, food handling equipments, throat lamps, and lenses. PMMA embeddedd with inorganic or organically modified inorganic particles has been cast into films to yield enhanced functional properties such as electrical conductivity, photoconductivity, photoinduced charge-transfer, nonlinear optical properties, photoluminescence, , d, mechanical, ,, and magnetic properties …”

Tuning of Dielectric Properties of Polymers by Composite Formation: The Effect of Inorganic Fillers Addition

“…Their excellent optical property due to transparency in the visible region is another feature which makes this polymer popular in many technological and productive fields. PMMA embedded with inorganic or organic materials, cast into films, have been broadly used to yield satisfying properties such as photoconductivity, nonlinear optical properties and photoluminescence, etc., [20][21][22].…”

“…The present manuscript highlights the dielectric properties and electrical behavior of PMMA doped with different inorganic fillers in different weight ratios, to obtain suitable results of dielectric properties. Their final consequences revealed the dependence of dielectric behavior on the dispersion factor of the polymer matrix and fillers, the content of the fillers, the shape and size of the fillers and porosity [20,21].…”

Gd2O3:Eu3+/PMMA Composite: Thermal and Luminescence Properties

“…A further advantage of PMMA relies on its large availability and easy preparation [5]. PMMA embedding inorganic or organically modified inorganic particles has been cast into films to yield enhanced functional properties such as photoconductivity [6], photoinduced charge-transfer [7], nonlinear optical properties [8], photoluminescence [9,10], mechanical [11] and magnetic properties [12].…”