LUIZ GUSTAVO HIROKI KOMATSU

LUIZ GUSTAVO HIROKI KOMATSU

Página do item completo

Resultados de Busca

Agora exibindo 1 - 7 de 7

Fabrication of polypropylene/silver nanocomposites for biocidal applications
2017 - OLIANI, WASHINGTON L.; PARRA, DUCLERC F.; KOMATSU, LUIZ G.H.; LINCOPAN, NILTON; RANGARI, VIJAYA K.; LUGAO, ADEMAR B.
This paper presents a study on biocidal effect of polymer nanocomposite films of gamma irradiated polypropylene (PP) and silver nanoparticles. The modified polypropylene was obtained from isotactic polypropylene (iPP) in pellets form by irradiation with gamma rays in the presence of acetylene. A new morphology with long chain branching of PP and distinct rheology is obtained by this process. The blend of 50/50 wt neat PP and PP modified by gamma radiation were further mixed using a twin screw extruder. The AgNPs were infused into this polymer blend at different concentrations of: 0.1%; 0.25%; 05%; 1.0%; 1.0% (PVP), 2.0% and 4.0% by wt%. These polymer nanocomposites were characterized by Raman spectroscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), thermogravimetric analysis (TG), differential scanning calorimetry (DSC), X-ray diffraction (XRD), transmission electron microscopy (TEM), cytotoxicity test and Kirby-Bauer disk diffusion techniques. The bactericidal effect of Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) were assessed in detail.
Nanocomposites based on polypropylene with nanosilver particles and antibacterial behavior – a review
2016 - OLIANI, W.L.; PARRA, D.F.; KOMATSU, L.G.H.; LINCOPAN, N.; RANGARI, V.K.; LUGAO, A.B.
This paper presents a study of polypropylene (PP) films modified by gamma irradiation with insertion of silver nanoparticles (AgNPs) and montmorillonite (MMT) aiming bactericide effect. The use of silver (Ag) gives important antibacterial property since silver is highly toxic for bacteria. The PP matrix was processed in a twin screw extruder and polypropylene nanocomposites (PPNC) were obtained in different concentrations of 0.25%; 0.5%; 1.0%; 2.0% and 4.0% in wt% and 1% of MMT. The material was characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), field emission scanning electron microscopy (FESEM), X-ray diffraction spectroscopy (XRD), cytotoxicity assay and reduction colony-forming-unit (CFU). The analyzed films showed spherical clusters and homogeneous regions with good distribution of the silver nanoparticles. Furthermore, the PP@AgNPs films exhibited a strong antibacterial efficiency against S. aureus, E. coli and P. aeruginosa due to the presence of the biocidal silver nanoparticles.
Análise da degradação dos nanocompósitos de polipropileno modificado sob condições de envelhecimento acelerado em estufa e natural
2016 - KOMATSU, L.G.H.; OLIANI, W.L.; LUGAO, A.B.; PARRA, D.F.
O entendimento dos mecanismos de degradação que agem sob os nanocompósitos polimericos frente ao intemperismo (luz UV, calor, chuva ácida e entre outros), é o ponto chave para o desenvolvimento de novos aditivos. Para esta análise, as amostras de nanocompósitos de polipropileno modificado por radiação gamma foram obtidos por meio de processamento em extrusora de dupla rosca. Posteriormente estas amostras foram submetidas a ensaios de envelhecimento acelerado em estufa e envelhecimento natural. Os efeitos dos ensaios de envelhecimento foram avaliados por meio das técnicas de, Calorimetria Exploratória Diferencial (DSC), Espectroscopia de Infravermelho pela Transformada de Fourier (FT-IR), Índice Carbonila (IC), Índice de Fluidez (IF), Espectroscopia de Energia Dispersiva (EDS) e Microscopia Eletrônica de Varredura (MEV). Com o decorrer do ensaio de envelhecimento foi possível realizar uma correlação entre o índice de carbonila e índice de fluidez durante o processo degradativo.
Degradation study of High Melt Sterngt Polypropylene/Clay nanocomposites in environmental and accelerated conditions
2016 - KOMATSU, LUIZ G.H.; PARRA, DUCLERC F.; OLIANI, WASHINGTON L.; LUGAO, ADEMAR B.; RANGARI, VIJAYA K.
Estudo da foto-oxidação de nanocompósitos de polipropileno com cloisite 20 A
2013 - KOMATSU, LUIZ G.H.; OLIANI, WASHINGTON L.; PARRA, DUCLERC F.
Estudo da degradação ambiental de nanocompósitos de polipropileno com cloisite 20 A
2011 - KOMATSU, LUIZ G.H.; OLIANI, WASHINGTON L.; PARRA, DUCLERC F.
Thermal analysis of polypropylene modified by gamma irradiation composites under outdoor conditions
2015 - KOMATSU, LUIZ G.H.; OLIANI, WASHINGTON L.; LUGAO, ADEMAR B.; PARRA, DUCLERC F.