S356 : Study of some physical and antimicrobial properties of pectin-carnoba wax bilxayer film containing nano TiO2
Thesis > Central Library of Shahrood University > Agricultural Engineering > MSc > 2016
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Abstarct: Today, because of environmental pollution, the use of biodegradable polymers in pruducing packaging materials, is highly considered by researchers. One of the potential applications of this type of biopolymers, is the production of active packaging with antimicrobial substances. In this study, emulsion film baxsed on pectin in method of casting were prepared, and the effects of nanoparticles of TiO2 (at concentrations of 0.5, 1, 2 and %3) and carnauba wax simultaneously were studied, on the mechanical properties and anti antimicrobial properties of films. The results showed that permeability of the moisture films was affected by the nanoparticles TiO2 and water vapor permeability decreased with increasing amounts of nanoparticles. property of water solubility and moisture absorption rate of films affected by increasing concentrations of nanoparticles and coated with carnauba wax also decreased. Mechanical test on the films showed that added wax carnauba to the film of pectin, tensile strength (the amount of force exerted on the surface) was lower than the control sample. But added nanoparticles of TiO2 at a rate of %1 makes improvement in films tensile strength.Carnauba wax was also increases the elasticity (The elongation at break) films, but conversely TiO2 nanoparticles, reduced the elasticity of the films. The results showed that the Young's modulus (Ratio of stress to strain) of carnauba wax and TiO2 nanoparticles were both significant decrease in the index. About feature films appearance, results showed that nanoparticles of TiO2 and carnauba wax in biopolymer structure decreased the clarity and brightness of films while increased their darkness. In the case of yellow index, carnauba wax caused increasing yellowing and nanoparticles of TiO2 was reduced yellowing. Also in case of whiteness index, carnauba wax caused redusing whiteness but nanoparticles of TiO2 was increased whitenessing. Anti-microbial test results showed that by increasing the amount of TiO2 nanoparticles films inhibitory effect against Escherichia coli increased at %3 concentration, showed a maximum inhibitory effect. Also edible films in terms of morphology, the distribution of nanoparticles and nanoparticle crystallization of TiO2 using scanning electron microscopy (SEM) and X-ray diffraction (XRD), has been studied. The results showed that by increasing the nanoparticles, concentration and agglomeration of nanoparticles increased.
Keywords:
#Nanocomposite film #Tio2 #Pectin #carnauba wax #Physical properties #Active packaging #Escherichia coli Link
Keeping place: Central Library of Shahrood University
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Keeping place: Central Library of Shahrood University
Visitor: