masterThesis
Preparo, caracterização e análise de nanocompósitos de Diatomita e Nanocelulose Cristalina para aplicação como biomembranas
Fecha
2020-11-06Registro en:
SILVA, Joyce Cavalcante da. Preparo, caracterização e análise de nanocompósitos de Diatomita e Nanocelulose Cristalina para aplicação como biomembranas. 2020. 80f. Dissertação (Mestrado em Ciência e Engenharia de Materiais) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2020.
Autor
Silva, Joyce Cavalcante da
Resumen
Diatomite nanocomposites have become the subject of significant interest in
the research and development of reliable filter materials which can enable the
democratic access to freshwater with fair quality. This holds true due to the safe
chemical composition and the naturally standardized porous microstructure of this
unique material. In this study, the White Diatomite Ceramic Powder was used in the
fabrication of biomembranes with controlled porosity. Ceramic laminates (with 3 and
4 layers of tape-casted tapes) were subjected to warm pressing followed by binder
removal and sintering. The White Diatomite powder was characterized via Laser
Diffraction Particle Size Analysis, XRF, XRD and FE-SEM. The determination of the
viscosimetric behavior of the ceramic suspension used on the tape casting process,
fabricated with the addition of the Diatomite powder, was carried out with rheological
tests on a cone-plate system. TG/DT analysis were performed to investigate the
thermogravimetric behavior of tape-casted Diatomite tapes. The thermal treatment
route implemented in this work fostered the observation, via XRD, of the
transformation of biogenic amorphous silica into tetragonal cristobalite and low quartz
with hexagonal symmetry. Thus, polymeric nanoparticles of NCC were applied, via
Silk Screen Coating, onto the surface of Diatomite sintered laminates, leading to the
final nanocomposite obtained in this study: Diatomite biomembranes superficially
coated with NCC. Subsequently, FE-SEM analysis signaled the partial reduction on
the pore size distribution near the surface of the produced biomembranes, on
account of the identification the NCC nanoparticles on the interior of the Diatomitematrix’s pores.