Preparation And Stabilized Pickering Emulsions Of Chitosan Nanoparticles

Preparation and application of nanoparticles prepared by natural biological materials and Pickering emulsions have important implications for food and cosmetics fields. Chitosan(CS) is a alkaline polysaccharide that existed in the nature. the resources of chitosan is abundant, The primary amine groups render special properties, like biodegradable, biocompatible, The current study focused on emulsification performance, stability mechanism and cosmetics application of Pickering emulsions stabilized by CS/TPP nanoparticles and CS/ALG nanoparticles.Chitosan/TPP nanoparticles are prepared by ioncrosslinking in this paper using sodium tripolyphosphate(TPP) as the crosslinking agent. The preparation method is mild without organic solvent. Nanoparticles with different size are prepared by modifying the parameter. For the purpose of preparing the small and stable nanoparticles, The optimum reaction conditions are as follows: the chitosan concentration is 1.5mg/m L, TPP concentration is 0.65mg/m L, the mass ratio of chitosan and TPP is 5:1, the p H of chitosan solution is 4.2. The nanoparticles have good stability by the study of stability of nanoparticles. It shows that the diameter of nanoparticles with good spherical shape is uniform by SEM.The O/W emulsions were prepared by homogenizing appropriate quantities of chitosan/TPP nanoparticles aqueous dispersion with liquid paraffin. These emulsions could stable to against coalescence over months. The factor effect on the emulsion had been investigated. The creaming and the size of emulsions decreased with the increasing of chitosan nanoparticles concentration. The stable emulsion without creaming was prepared by changing nanoparticle aqueous dispersion p H and Na Cl concentration finally. The rheological analysis indicated that emulsions have higher viscosity and more pronounced elastic responses with an increase in nanoparticles concentration. The Fluorescence microscope analysis indicated the enrichment of these particles at the oil–water interface of Pickering emulsions and the envelope of particles creates a barrier which impeded the droplets from coalescence. The emulsions prepared by CS/TPP nanoparticles in cosmetic cream formula have good heat resistance, cold resistance and centrifugal stability. Compared with the emulsions stabilized by surfactant, The skin feels better.Chitosan/ALG nanoparticles are prepared through electrostatic interaction between the carboxyl groups of alginate and the amine groups of chitosan. The factor effect on the size and zeta potential of nanoparticles is discussed, including chitosan molecular weight and degree of deacetylation, the ratio of the biopolymers, solution p H, addition of calcium chloride. Chitosan/ALG nanoparticles with the size about 120 nm were prepared under optimum conditions: the mass ratio of alginate, calcium chloride, and chitosan is 5:1:1.5, the chitosan solution p H is 5.4, the alginate solution p H is 5.2.The O/W emulsions were prepared by CS/ALG nanoparticles. The stable emulsion can be prepared by 1% nanoparticles. Phase inversion of emulsions prepared by 0.8% nanoparticles occurred when the value of Фo was 0.65, but 0.75 for 1.5% nanoparticles, higher than 1.5% CS/TPP nanoparticles. The emulsions stabilized by CS/ALG have broad p H range. The analysis of effect of Na Cl concentration suggest that electrolyte can change particles wettability. The emulsions prepared by CS/ALG nanoparticles in cosmetic cream formula have good heat resistance, cold resistance and centrifugal stability. Compared with the emulsions stabilized by chitosan/TPP nanoparticles, it has lower dosage, stronger emulsification, higher viscosity, and better feeling.