LUIZ GUSTAVO HIROKI KOMATSU
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Capítulo IPEN-doc 25878 Application of natural nanoparticles in polymeric blend of HMSPP/SEBS for biocide activity2019 - KOMATSU, L.G.H.; ZAFALON, A.T.; SANTOS, V.J.; LINCOPAN, N.; RANGARI, V.K.; PARRA, D.F.The natural nanoparticles of CaCO3, from eggshell and CaCO3/Ag, were investigated as candidates for biocide nanoparticles in a blend of thermoplastic elastomer, styrene–ethylene/butadiene–styrene (SEBS), and polyolefin, high-meltstrength polypropylene (HMSPP). The nanoparticles with silver (Ag) were synthesized by metal precursor method, and before the application in the polymer matrix, the nanoparticles were analyzed on dynamic lighting scattering (DLS) and Raman spectroscopy. After DLS and Raman analyses, the nanoparticles were evaluated in biocide tests against P. aeruginosa and S. auerus. The aim of this investigation was the blending and the injection molding in dumbbell samples with the nanoparticles. The characterizations were carried out by differential scanning calorimetry (DSC), thermogravimetry analysis,mechanical tests, X-ray diffraction, Raman spectroscopy, scanning electronmicroscopy, and energy-dispersive scanning and biocide tests. Correlation between size and particle distribution on the polymerwas founded. However, samples at higher concentrations (>1 wt%) do not show biocide activity.Capítulo IPEN-doc 25620 Synthesis and characterization of PVP/CaCO3-Ag blend hydrogel by gamma irradiation2019 - ZAFALON, ANGELICA T.; JUVINO, VINICIUS dos S.; KOMATSU, LUIZ G.H.; PARRA, DUCLERC F.; LUGAO, ADEMAR; SAMUEL, TEMESGEN; RANGARI, VIJAYAChronic wounds are skin injuries with failed healing. They have become a public health problem that affects more than 2% of the population and the presence of bacteria resistances difficult of treatment. Pseudomonas aeruginosa is opportunist pathogens and the treatment is difficult and requires a long period of treatment. Hydrogels are structure polymeric tridimensional and biocompatible. They have been used as a controlled delivery system for treatment of topic infection. Studies have reported calcium carbonate and silver ion can improve the mechanical properties and biocide activity of hydrogel. Here in this study, hydrogels loaded CaCO3-Ag were prepared using poly (N-vinyl-2-pyrrolidone), poly (ethylene glycol), agar, calcium carbonate, silver nitrate followed gamma irradiation with 25 kGy dose. The gel fraction, behavior swelling and biocide action against P. aeruginosawas investigated. The degree of swelling of the hydrogel loaded CaCO3-Ag was 12% higher than the unloaded and exhibited antibacterial effects against P. aeruginosa and biofilm.Artigo IPEN-doc 22128 Fabrication of gamma-irradiated polypropylene and AgNPs nanocomposite films and their antimicrobial activity2016 - BERENGUER, ISABELLE O.; OLIANI, WASHINGTON L.; PARRA, DUCLERC F.; KOMATSU, LUIZ G.H.; SANTOS, VINICIUS J.; LINCOPAN, NILTON; LUGAO, ADEMAR B.; RANGARI, VIJAYA K.