Fabrication of size-controlled Alq3 nanoparticles within PMMA matrix in the form of nanocomposite sheet for potential use as UV dosimeter

Abstract

Tri (8-hydroxyquinoline) aluminum (Alq3) is a metal organic light emitting material and has a high sensitivity to ultraviolet (UV) light, however, no study has considered its potential use in UV dosimetry. Moreover, the nanostructures of Alq3 were reported to have enhanced light emission. It is therefore, of great importance to evaluate the optical response of Alq3 nanoparticles to UV light. In this work polymethyl methacrylate (PMMA) matrix has been chosen as transparent matrix for the formation of Alq3 nanoparticles in the form of a nanocomposite sheet. The PMMA is found to function as a surfactant/capping agent for controlling the particle size growth of Alq3. These nanocomposite sheets were fabricated using chloroform as a suitable solvent at different ratios of Alq3 to PMMA polymer. The resultant nanocomposite sheets revealed ultrafine nanoparticles of Alq3 with excellent uniformity. The particle size changed from around 77 nm to approximately 10 nm by changing the Alq3:PMMA ratio from 1:0.1 to 1:0.5, respectively. These nanocomposite sheets exposed to UVB light source for different exposure time. The crystalline structure, molecular fingerprint and optical properties of both pristine and irradiated nanocomposite sheets were investigated. A linear variation of UV dose with Raman signals, in addition to exponentially fitted PL signals are inspiring. Therefore, these recorded linear variations, in addition to linear stability and systematic fading of PL intensity over time might serve as basis for further evaluation of these nanocomposite sheets for possible use in UV dosimetry.