Properties Of Emulsions Stabilized By Regenerated Cellulose Suspensions From Different Sources

Nanocellulose can be used as emulsifier in the preparation of emulsion to avoid the addition of chemical emulsifiers.In this paper,the regenerated cellulose suspensions with good stability and high yield were prepared by dissolving the representative cellulose with phosphoric acid.The emulsion was obtained by Pickering emulsion method.The results of the study are as follows:Using microcrystalline cellulose,high-purity wood pulp board and absorbent cotton as raw materials,different sources of regenerated cellulose suspensions were prepared by phosphoric acid method.The microcosmic change before and after cellulose regeneration,and effect of the source and concentration of cellulose for suspension stability and rheological properties were studied.The TEM was used to characterize the regenerated cellulose from different sources.It was found that the diameters of the regenerated cellulose from different sources were similar and the difference in length.The degree of polymerization and the degree of crystallinity before and after the cellulose regeneration were analyzed and the cellulose after regeneration was found crystallinity and degree of polymerization both decreased;FT-IR and XRD indicated that regenerated cellulose was a typical cellulose II structure;regenerated cellulose suspensions from different sources all exhibited good suspension stability,at 0.6% w/v none of the above will be stratified.Rheological studies have found that under certain conditions,the order of storage modulus and loss modulus are as follows: regenerated cotton cellulose suspension > regenerated wood pulp cellulose suspension > regenerated microcrystalline cellulose suspension;regenerated cellulose from different sources liquid viscosity: regenerated cotton cellulose suspension > regenerated wood pulp cellulose suspension > regenerated microcrystalline cellulose suspension;prepared regenerated cellulose suspension with high static viscosity,shear thinning effect;temperature sweep curve showed that the regenerated cellulose suspension has a certain degree of heat resistance.With the oil of caprylic / capric triglycerides(GTCC)commonly used in cosmetics as oil phase and the regenerated cellulose suspension as emulsifier in different sources,the O / W Pickering emulsion was prepared and the effect of the source of the regenerated cellulose suspension and the O / W ratio on the particle size and rheological property of the emulsion and the mechanism of the emulsion stability were studied.The results showed that the average particle size of the stable emulsion of regenerated cellulose suspension from different sources was: regenerated microcrystalline cellulose suspension > regenerated wood pulp cellulose suspension > regenerated cotton cellulose suspension;with the increased of oil-water ratio,the particle size of the emulsion also increased.Rheological studies have shown that as the shear rate increased,the viscosity gradually decreased and the typical shear thinning phenomenon which was similar to that of the regenerated cellulose suspension;however,at the same shear rate,the source of the regenerated cellulose suspension for the effect of the viscosity of the emulsion was not significant;the loss modulus of the emulsion was higher than the storage modulus,indicating that the emulsion had gel properties;the viscosity of the emulsion increased with increasing temperature and decreased with decreasing temperature.The results of fluorescence microscopy,confocal microscopy and FE-SEM showed that the regenerated cellulose adsorbs on the oil-water interface and forms a threedimensional network structure between the microsphere surface and the microspheres.Therefore,the mechanism of the regenerated cellulose-stabilized emulsion was Pickering mechanism and three-dimensional network structure mechanism.