The use of nanoparticles as charge of biopolymer-based films has been recently studied, as an alternative to improve the physical properties of the films. However, the amelioration obtained is still limited probably because of problems concerning the dispersion of the nanoparticles in water, particularly when the casting technique is used. Thus, the aims of this project are the following: A) the study of the dispersion of nanoparticles in water, using three different parameters, B) the study of the effect of the dispersion on some physical and functional properties of gelatin films made of those dispersions. The films will be produced by the casting technique, with 5 g gelatin/100 g filmogenic solution and 30 g glycerol/100g gelatin. The nanoparticle concentration in relation to gelatin will be 0, 1, 3, 5, 8%. For the filmogenic solution preparation, the nanoparticles will be dispersed in water by the following techniques: - by agitation using a ultraturrax, at 25000 rpm/30 min., minimum; - with a high energy mill, type SPEX (speed <1200 rpm); - by sonication using an ultrasound machine working at 50 hertz. Besides de montmorillonite concentration, the duration of these treatments will be studied deeply. To study the quality of the nanoparticle dispersion, they will be analyzed by scanning electron and atomic force microscopy, by a quasi elastic light scattering particle size analyzer and by a Zeta potential analyzer. Besides, the nanocomposites films produced with the montmorillonite dispersions will be characterized for thickness, water content, microstructure, by scanning electron and atomic force microscopy, water vapor permeability, mechanical properties by tensile and puncture tests, solubility in water, color and opacity, gloss, glass transition, crystallinity, fourier transform infrared spectroscopy and contact angle.
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