Improved Optical Degradation Characteristics of Eu Complex Encapsulated by High-Pressure Annealing

Abstract

In this study, we explored the use of rice-husk-derived nanosilica (nSiO 2 ) as fillers in epoxy resins. The nSiO 2 was irradiated with a capacitively coupled 13.56 MHz radio frequency (RF) plasma using an admixture of argon (Ar) and hexamethyldisiloxane (HMDSO) or 1,7-octadiene (OD) monomers. The plasma-polymerized nSiO 2 was loaded at various concentrations (1-5%) into the epoxy matrix. Surface hydrophobicity of the plasma-treated nSiO 2 -filled composites increased, which is attributed to the attachment of functional groups from the monomer gases on the silica surface. Microhardness increased by at least 10% upon the inclusion of plasma-modified nSiO 2 compared with pristine nSiO 2 -epoxy composites. Likewise, hardness increased with increasing loading volume, with the HMDSO-treated silica composite recording the highest increase. Elastic moduli of the composites also showed an increase of at least 14% compared with untreated nSiO 2 -filled composites. This work demonstrated the use of rice husk, an agricultural waste, as a nSiO 2 source for epoxy resin fillers.