Surface modification of particles in a photochemical fluidized bed

Abstract

Different techniques have been recently studied to promote the surface modification of materials. Surface modifications are used to improve the performance of materials in diverse areas, such as chemical processes, pharmaceutical industry and agriculture. Despite the considerable work in the literature on the subject, the experiments carried out were always conducted with small samples of the materials, and the performance of the treatment on a larger scale has yet to be evaluated. This work aimed to make the surface modification of particles of different materials by UV-assisted treatment in a photochemical fluidized bed. The purpose was to verify the feasibility of treating particles with UV radiation on a larger scale, something not yet found in the literature. The analyzed materials were two polymers and four types of forage seeds. The effect of UV radiation on the surface was checked using the water contact angle (WCA) and FTIR analysis. The treated seeds were also submitted to the Standard Germination Test (SGT) to verify eventual physiological damages and possible beneficial effects of the treatment. The results indicated a significant decrease in the contact angle of the treated particles of all materials because of the incorporation of oxygenated groups on their surface. In turn, the SGT pointed out not only that the seeds were not damaged by radiation but also that there was a significant increase in the agronomic index for two of the species studied. The data obtained in this work showed that the photochemical fluidized bed proved a viable way to carry out the surface treatment of particles with UV radiation, making it possible to conduct the process on a larger scale.