Julio Colivet Gamboa - Academia.edu (original) (raw)
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Papers by Julio Colivet Gamboa
Industrial Crops and Products, 2017
The surface properties and microstructure of films composed of chemically modified cassava starch... more The surface properties and microstructure of films composed of chemically modified cassava starches (cross-linked, acetylated and doubly modified) were evaluated in this study. The films were produced using a casting technique with fixed concentrations of starch and sorbitol (4.0 and 1.2 g/100 g in the filmogenic solution, respectively). The hydrophilicity and surface characteristics of the films were analyzed by determining the optical contact angle (). The films were also evaluated for surface properties (polarity and nonpolar and polar components), water solubility, and water vapor permeability. It was determined that films produced from cross-linked and acetylated cassava starch showed greater hydrophobicity and better mechanical properties than those prepared with native cassava starch. The films prepared with doubly modified and acetylated cassava starch had a lower surface energy than the film prepared with untreated and cross-linked starch. The results from scanning electron microscopy, infrared spectroscopy and X-ray diffraction demonstrated marked differences between the films, which were dependent on the type of starch. According to the results obtained in this study, the physicochemical properties of films are related to the chemical structure, microstructure and surface properties.
Industrial Crops and Products, 2017
The surface properties and microstructure of films composed of chemically modified cassava starch... more The surface properties and microstructure of films composed of chemically modified cassava starches (cross-linked, acetylated and doubly modified) were evaluated in this study. The films were produced using a casting technique with fixed concentrations of starch and sorbitol (4.0 and 1.2 g/100 g in the filmogenic solution, respectively). The hydrophilicity and surface characteristics of the films were analyzed by determining the optical contact angle (). The films were also evaluated for surface properties (polarity and nonpolar and polar components), water solubility, and water vapor permeability. It was determined that films produced from cross-linked and acetylated cassava starch showed greater hydrophobicity and better mechanical properties than those prepared with native cassava starch. The films prepared with doubly modified and acetylated cassava starch had a lower surface energy than the film prepared with untreated and cross-linked starch. The results from scanning electron microscopy, infrared spectroscopy and X-ray diffraction demonstrated marked differences between the films, which were dependent on the type of starch. According to the results obtained in this study, the physicochemical properties of films are related to the chemical structure, microstructure and surface properties.