A5058494919- Polymer Surface Interaction Studies
- Surfactants and Colloidal Systems
- biodegradable polymer synthesis and properties
- Advanced Cellulose Research Studies
- Hydrogels: synthesis, properties, applications
- Polysaccharides Composition and Applications
- Polysaccharides and Plant Cell Walls
- Electrospun Nanofibers in Biomedical Applications
- Electrostatics and Colloid Interactions
- Antimicrobial agents and applications
- Adsorption and biosorption for pollutant removal
- Surface Modification and Superhydrophobicity
- Proteins in Food Systems
- Agricultural and Food Sciences
- Biofuel production and bioconversion
- Nanocomposite Films for Food Packaging
- Advanced Drug Delivery Systems
- Fluid Dynamics and Thin Films
- Microplastics and Plastic Pollution
- Polymer Nanocomposites and Properties
- Microfluidic and Capillary Electrophoresis Applications
- Advanced Polymer Synthesis and Characterization
- Force Microscopy Techniques and Applications
- Chemistry Education and Research
- Analytical chemistry methods development
Universidade de São Paulo
2015-2024
Instituto Butantan
2015
Universidade de Ribeirão Preto
2010
Max Planck Institute for Polymer Research
2006-2007
Petrobras (Brazil)
2007
Universidade Federal do Rio de Janeiro
2007
Karlsruhe Institute of Technology
1999-2006
Instituto de Botânica
2005
Universidade Estadual de Maringá
2003
Karlsruhe University of Education
2000
ABSTRACT Xanthan gum is an extracellular polymer produced mainly by the bacterium Xanthomonas campestris . Traditionally it plays important role in industrial applications as thickener, emulsion stabilizer and has been added to water‐based drilling fluids due its pseudoplastic behavior thermal stability. The structural properties of xanthan solution can be tuned temperature ionic strength; under high strength or low temperature, chains are arranged helical conformation, whereas coiled....
In this work xanthan chains were crosslinked by esterification reaction at 165 °C either in the absence or presence of citric acid. Higher crosslinking density was obtained using acid, as evidenced its lower swelling degree. Tensiometry, a very precise and sensitive technique, applied to study rates diffusion mechanisms water, which initially quasi-Fickian, controlled wicking properties, changing Fickian Anomalous, depending on hydrogel composition. Hydrogels degree increased high pH values,...
Amino-terminated self-assembled monolayers on SiO2 surfaces were obtained by means of a simple silylation method. The thickness the was measured with ellipsometry. Washing tests strong solvents indicated that amino-silane is covalently bonded to silica surface. are very flat and homogeneous, as shown atomic force microscopy. Contact angle measurements showed such interact quickly air impurities should be used just after silylation. adhesion between amino-terminated surface gold evidenced...
The effect of CaCl2, Ca(NO3)2, CaSO4, CaCO3 and Ca3(PO4)2 on the flow behavior xanthan gum solutions was investigated. Regardless concentration type calcium salt used, presented pseudoplastic behavior. soluble salts (CaCl2 Ca(NO3)2) induced disordered state in chains at 1.0 g/L or 10 g/L, decreasing consistency index (K) values. At 100 K values were similar to those found for pure solutions, whereas same insoluble particles increased 20%. adsorption onto Si/SiO2 surfaces presence...
BIOMASS ENZYMATIC HYDROLYSIS.Production of ethanol from biomass fermentation has gained much attention recently.Biomass cellulosic material is first converted into glucose either by chemical or enzymatic process, and then fermented to ethanol.Considering the current scenario, where many efforts are devoted for search green routes obtaining renewable sources, this review presents relationship between structure properties material, pre-treatments hydrolysis function cellulase enzyme complex.
Ellipsometry was used to investigate the influence of ionic strength (I) and pH on adsorption bovine serum albumin (BSA) or beta-lactoglobulin (BLG) onto preabsorbed layers two polycations: poly(diallyldimethylammonium chloride) (PDADMAC) poly(4-vinylpyridine bromide) quaternized with linear aliphatic chains (QPVP-C2) five (QPVP-C5) carbons. Comparisons among results for three polycations reveal hydrophobic interactions, while comparisons between BSA BLG-proteins very similar isoelectric...
In this article the molecular conformation of xanthan chains in hydrogel films was investigated by means circular dichroism, showing substantial differences between prepared absence (XNT) and presence citric acid (XCA). The XNT hydrogels presented ordered (helixes), while XCA they were disordered (coils), exposing a larger number carboxylate groups than XNT. large charge density evidenced their behavior under variable ionic strength. Studies about application for loading delivering bovine...
Several cationic polymers exhibit a useful antimicrobial property, however the structure–activity relationship still requires more complete investigation. The main objective of this work is comparison between activity and toxicity free immobilized poly (diallyldimethylammonium) chloride (PDDA) in biocompatible (methylmethacrylate) (PMMA) nanoparticles (NPs). NPs synthesis by emulsion polymerization performed over range [PDDA] at two methylmethacrylate (MMA) concentrations. PMMA/PDDA...
Hybrid scaffolds made of xanthan and magnetite nanoparticles (XCA/mag) were prepared by dipping membranes (XCA) into dispersions magnetic for different periods time. The resulting hybrid presented magnetization values ranging from 0.25 emu g−1 to 1.80 at 70 kOe corresponding iron contents 0.25% 2.3%, respectively. They applied as matrices in vitro embryoid body adhesion neuronal differentiation embryonic stem cells; comparison, neat XCA commercial plastic plates also used. Adhesion rates...