Advanced analysis of nanoparticle composites - a means toward increasing the efficiency of functional materials

摘要

The applications of functional materials containing nanoparticles are rapidly increasing. This area is especially relevant to the healthcare industry and the design of new light activated antimicrobials. Wider application of these materials will require quantification of localised nanoparticle concentration, which is currently only available through indirect estimates ( including functional testing and bulk spectroscopy). The work presented uses direct visualisation of embedded cadmium selenide quantum dots (empty set 13.1 nm) using fluorescence lifetime imaging. The nanoparticles used in this study are embedded into a polydimethylsiloxane host matrix via swell encapsulation. The swell encapsulation of the particles is shown to achieve the highest concentration of material at the polymers surface, while a lower concentration is found in the bulk. Fluorescence imaging provides direct comparison of nanoparticle concentration between samples. A comparative swell encapsulation of titanium dioxide nanoparticles (empty set - 12.6 nm) provides further analysis, including photocatalytic dye degradation, water contact angle measurement and energy-dispersive X-ray analysis. The techniques demonstrated allow quantification of nanoparticle concentration within a host matrix, both the functional nanoparticles at the materials' surface and the redundant particles within the bulk.