Preparation Of High-loading Nano-fragrance By Pickering Emulsion And Its Application On Catton

Lavender essential oil has been widely used in daily production because of its unique aromatic characteristics and biological activity,and has attracted the attention of consumers.However,lavender essential oils are mainly terpenes,which are extremely unstable,volatile and oxidatively degraded.This brings difficulties to the storage and transportation of essential oils,and also limits the application of essential oils in industrial production.First,this topic takes lavender essential oil as the oil phase,?-cyclodextrin / Tween-20 nanocrystals and sodium caseinate particles as the compound solid particle stabilizer,and ?-cyclodextrin / polyethylene glycol super Molecular hydrogel is used as auxiliary stabilizer to prepare oil-in-water Pickering nanoemulsion.Using droplet size as the main index,combined with secondary indexes such as loading capacity and emulsification efficiency,an oil-in-water Pickering nanoemulsion system was prepared.The effects of the concentration of nanocrystals,sodium caseinate particles and hydrogel essential oil on the three indicators of aromatic Pickering emulsion were investigated through a single factor parallel experiment to determine the best formula of Pickering emulsion,in which ?-cyclodextrin was 2.7 %;Tween-20: 0.8%;sodium caseinate: 4.1%;?-cyclodextrin and polyethylene glycol: 1.2%,lavender essential oil: 8.2%;deionized water: 81.8%,Pickering droplet size It is 205.63 nm and the essential oil loading is 44.7%.On this basis,the morphology of the Pickering emulsion droplets was characterized.The results of transmission electron microscopy showed that ?-cyclodextrin and Tween-20 formed nanocrystals with a size of 6.21 nm and had a certain emulsifying activity.The nanocrystals and casein acid The compound particles of sodium are adsorbed at the oilwater interface to form irregular spherical droplets.The periphery of the droplets has an interface film,which shows a gray color slightly different from the internal phase.The infrared spectrum analysis shows that the peak of C = O at 1747 cm-1 and the peak of C–O at 1248 cm-1 exist in the essential oil and almost disappear in Pickering emulsion,indicating that the lavender essential oil is completely covered by the interface film.Secondly,in order to explore the interaction between nanocrystals and protein particles(the concentration of nanocrystals is expressed in terms of ?-cyclodextrin concentration),this subject studied the interface adsorption behavior of the two.The contact angle test results show that the lower or higher nanocrystal concentration will reduce the contact angle value(less than 40 °).When the concentration is 35 m M,the highest contact angle is 50.72 °.The presence of sodium caseinate generally increases the size of the contact angle(greater than 50 °),and the highest contact angle of 60.48 ° is obtained at 4%,indicating that the composite particles have good emulsifying properties.The interfacial tension test results show that sodium caseinate mainly affects the process of reducing interfacial tension,while nanocrystals mainly affect the size of interfacial tension at equilibrium;there is a synergy between the two,which are adsorbed together at the oil-water interface and form a rigid Interface film.However,too high protein concentration will make the protein particles in a dominant position,replacing the adsorption sites of nanocrystals on the interface,so that the quality of the nanocrystals free in the dispersed phase increases,and the interface film formed by protein soft particles is not as good as nanocrystalline solid particles The strong rigidity is not conducive to the long-term stability of the emulsion.In addition,in order to study the effect of different particles on the stability of Pickeirng nanoemulsion,this subject has studied its rheological properties.Static rheological tests show that the Pickering nanoemulsion of lavender essential oil exhibits pseudoplastic fluid characteristics,and thins rapidly with shear.Dynamic rheological tests show that the linear viscoelastic zone of the emulsion increases with the increase of gel mass,but lower or higher hydrogel mass will make the low strain zone unstable.When the ?-cyclodextrin / Tween-20 nanocrystal is 35 m M,the difference between the elastic modulus and the viscous modulus increases from 0 to 0.85 Pa.The elasticity of Pickering nanoemulsion gradually reveals and strengthens.It resists external changes in a wide frequency range,and the viscoelastic transition point of the emulsion gradually moves to the high frequency direction.It is more conducive to the stability of the emulsion to increase the concentration of nanocrystals appropriately.The droplet size of the emulsion stored at 4,25,and 37 ? increased by 7,10.5,and 35 nm respectively after 5 days,indicating that the emulsion has good particle size stability at low temperature and room temperature,and the higher temperature makes the liquid The droplets coalesce or austenite ripens,and the droplet size increases.The aromatic lavender Pickering emulsion essence obtained under the best preparation conditions was impregnated on the cotton fabric.The aromatic cotton fabric had the best comfort at 60% dilution.The sample had a slow-release effect and remained scented after being left for 4 months.