Electronic Thesis and Dissertation Repository

Degree

Master of Engineering Science

Program

Chemical and Biochemical Engineering

Supervisor

Dr. Jin Zhang

Abstract

Different methods have been applied to deposit hybrid nanocomposites which can be applied in various fields due to their light weight and multifunctional properties. Here, matrix assisted pulsed laser evaporation (MAPLE) equipment with 532 nm Nd:YAG laser is applied to fabricate three types of hybrid nanocomposites on different substrates.

Chemical synthesized FeCo nanoparticles were deposited on graphene sheets by MAPLE technique (laser fluence: 300 mJ/cm2). The effects of deposition time (t) on particle amount, shape and size have been investigated. Yttrium barium copper oxide (YBCO) materials are one type of high-temperature superconductive materials and could be applied in transportation. To fabricate superconductive materials/graphene hybrid nanocomposites, YBCO nanoparticles were deposited on graphene sheets by MAPLE techniques with a laser fluence at 150 mJ/cm2. The microstructures in terms of particle size, size distribution, and particle shape are studied as functions of the deposition time (t). In addition, up-conversion nanoparticles (NaGdF4: Yb3+, Er3+) which are able to be excited by low energy photons (λex = 980 nm) and emit high energy photons were deposited through MAPLE technique. Results indicate that 2 hours’ deposition can result in high-quality samples in terms of particle size and particle amount. No toxic effect is imposed on the cells by the deposited up-conversion nanoparticles with/without protein modification.

Our results indicate that the MAPLE deposition technique demonstrates the good versatility of depositing different nanoparticles and preserving their chemical composition.