| Self-assembly of amphiphilic macromolecules is an effective way to prepare functional nanoparticles.In 2005,the Armes team used self-assembly to prepare polymer colloidal particles as particulate emulsifier to stabilize oil/water emulsion for the first time,and then it become a research hotspot.Different from the polymer particulate emulsifiers,bio-particulate emulsifiers based on environmental friendly and biocompatible nature occurring macromolecules have attacted more and more attentions.Hyaluronic acid(HA),one of the natural macromolecules,with good biocompatibility,low cytotoxicity,and excellent moisture retention has been intensively exploited for potential applications in the fields of tissue engineering and drug delivery.But,HA have some shortcomings would limited its scope of application.Therefore,it is usually modified HA by physical or chemical methods to change the physical and chemical properties of HA to give it more functions.In this paper,by using photosensitive monomers hydrophobic modified HA and investigate it self-assembly behavior in selective solvent.The secondary assembly behavior of the HA-based colloidal particles on the oil-water interface was investigated.Finally,the appropriate colloidal particles will selected to prepare cosmetic creams to achieve the application of particulate emulsifier.The paper is mainly composed of the following parts:1.Preparation and emulsifying performance of cinnamic acid modified hyaluronic acid self-assembled colloidal particlesIn this chapter,by using photosensitive monomer cinnamic acid(CA)hydrophobic modified HA obtained HA-derivatives(HA-CA).HA-CA have amphiphilic nature can prepared colloidal particles by hydrophobic induced self-assembly in selective solvent(DMSO/H2O).The chemical structure and properties of HA-CA were determined by infrared(IR)spectroscopy,proton nuclear magnetic resonance(1H-NMR)and ultraviolet(UV)spectra.The assembly process of HA-CA was tracked by UV spectrophotometer and the structure,morphology and properties of HA-CA colloidal particles were characterized by nanoparticle size and Zeta potential analyzer,transmission electron microscopy(TEM),video optical contact angle measuring instrument.The HA-CA colloidal particles was used as particulate emulsifier to stabilize oil-water interface and the emulsification performance of HA-CA colloidal particles in different condition were investigated,such as pH value,salt concentration in aqueous phase,oil type and so on.The morphology of colloidal particles in oil-water interface was observed by styrene oil phase solidification method.The cell compatibility of colloidal particles and emulsions were studied by cell experiments.The results showed that HA-CA have absorbance in the range of UVB.HA-CA colloidal particles could be used as particulate emulsifier to prepare oil-in-water Pickering emulsion,and colloidal particles have certain moisture retention and good cell compatibility.2.Preparation and emulsifying performance of coumarin-derivative modified hyaluronic acid self-assembled colloidal particlesThis chapter by using photosensitive monomer 7-(2-hydroxyethoxy)-4-methylcoumarin(HEMC)hydrophobic modified HA obtained HA-derivative(HA-HEMC).HA-HEMC have amphiphilic nature can prepared colloidal particles by hydrophobic induced self-assembly in selective solvent(DMSO/H2O).The chemical structure and properties of HA-HEMC was characterized by IR spectroscopy,1H-NMR and UV spectra.The assembly behavior of HA-HEMC was studied by UV spectrophotometer.The structure,morphology and properties of HA-HEMC colloidal particles were characterized by dynamic light scattering(DLS),nanoparticle size and Zeta potential analyzer,TEM and so on.The HA-HEMC colloidal particles was applied as particulate emulsifier to stabilize oil-water interface and study the emulsification performance of HA-HEMC colloidal particles in different condition,such as degree of substitution(DS)of colloidal particles,mass concentration,oil type,pH value and salt concentration in aqueous phase were investigated.The morphology of colloidal particles in oil-water interface was observed by gelation trapping technology(GTT).The results showed that HA-HEMC have absorbance in the range of UVA and UVB.HA-HEMC colloidal particles can stable oil-in-water Pickering emulsions in the broader range of pH(3~11)and various concentration of NaCl.In addition,the colloidal particles were able to stabilize variety of oil-water system.3.Applications of HA-HEMC colloidal particles as particular emulsifies in the peraperation of sunscreenIn this chapter,HA-HEMC colloidal particles was selected as the object of study.The photosensitivity of colloidal particles was studied by UV spectrophotometer.The moisture retention of colloidal particles was studied by weighing method.The biocompatibility of colloidal particles was investigatived by cell experiments.The HA-HEMC colloidal particles was added to the cosmetic cream,which the quality of the cosmetic cream was examined by sensory evaluation,pH measurement and stability test,and the sunscreen performance of the cosmetic cream was evaluated by the UV transmittance test.Results showed that HA-HEMC colloidal particles have photosensitivity,moisture retention and cell compatibility.HA-HEMC colloidal particles as a new type of cosmetic raw material added to the cream will prepared the sunscreen cosmetic,and with the increase of the weight of colloidal particles,the quality and sunscreen performance of the cream have been improved. |
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