Investigation On Morphological Diversity Of Sodium Conjugated Linoleate Self-assemblies And The Relevant Application

Fatty acid with advantages of biocompatibility,self-assembly activity and responsiveness is a good molecular building block,which has been paid more and more attention.Fatty acid self-assemblies is a thermodynamic stability system,therefore,it is easy to be destroyed or transformed as changing of environment.However,the instability of fatty acid self-assemblies make it to be adjustable,it can be changed by counter-ion,temperature,pH,concentration and so on.Sodium conjugated linoleate?SCL?is a kind of semi-synthetic fatty acid which can be obtained in large quantities.Except the fundamental properties of fatty acids,the most important property of SCL is the self-crosslinking activity endued by conjugated double bond.Surfactant self-assemblies are morphological-diversity which had already been proved theoretically and got a little bit of electronic imaging.There was few complete report for morphological-diversity and concentration-dependence,and research for fine structure,because surfactant self-assemblies are instability and elements composed of conventional surfactant have weak scattering ability of electron.Self-assemblies that hardly characterize due to instability can be solved partly after crosslinking.Therefore,the first concern in this dissertation is that whether it could be solved by SCL with self-assembled ability,self-crosslinked ability and weak reducibility,prove the concentration-dependence of SCL and research fine structure of SCL self-assemblies?Pickering emulsion with advantages of low biotoxicity and long-term stability is attractive.Recently,emulsion stabilized by micelle is particularly novel.However,there are almost copolymer micelles in reports which are complex structure and low safety.Fatty acid self-assemblies are surface-active and pH-responsive,but not rigid which make it not to be solid particle emulsifier.Therefore,the second concern in this dissertation is that whether Pickering emulsion stabilized by self-crosslinked SCL micelle?SSCL-micelle?have an outstanding advantage?Fatty acid vesicles?FAV?have similar structure as liposome,and fatty acid is cheap and available easily,therefore,FAV may become substitutes for liposome.However,the instability of FAV becomes an obstacle for its development.Recently,researchers try to improve the stability of FAV in the form of composite vesicles or polymeric vesicles which loss biocompatibility and natural characteristics.Therefore,the third concern in this dissertation is that could it be solved by SCL when combine with the advantage of composite vesicles or polymeric vesicles?Based on the above questions,the main research work of this paper is as follows:?1?Research on morphological-diversity and concentration-dependence of SCLself-assembliesThe concentration-dependence of SCL had be proved with crosslinked activity,the self-assemblies changed step to step as concentration of SCL increased:spherical micelle?rodlike micelle?disclike micelle?threadlike micelle?wormlike micelle.Rodlike micelle was characterized clearly by in situ reduction and gold doping-TEM coupling technology?AuD-TEM?.Disclike micelle was characterized by TEM,SEM,AFM,positive staining technology by RuO₄ and so on.Threadlike micelle is a low viscosity of wormlike micelle.They have catenulaform structure with about 3 nm of width and micron-sized range of length.?2?Research on particle emulsifier of SSCL-micelleThe oil phase proportion of emulsion stabilized by 0.09 wt%SSCL-micelle could be as high as 95 vol%at pH 13.Therefore,SSCL-micelles have strong emulsification ability.Besides,the emulsion could be emulsified and demulsified by CO₂-responsibility or pH-responsibility.During the process of emulsification,SSCL-micelles spontaneously transform into“Janus”particles which result in high emulsifying ability.Morphology of emulsifiers has an effect on stability of emulsion,the emulsifying ability:threadlike micelle>disclike micelle>rodlike micelle>spherical micelle.This difference may be caused by the asymmetry and deformability of emulsifier.?3?Vesiculation of sodium conjugated linoleate in alkaline conditions induced by oligomerizationThe vesiculation of sodium conjugated linoleate?SCL?performed in alkaline pH range was induced by pre-oligomerization,and the average crosslinking degree of double bond within SCL molecules was controlled by UV irradiation.Oligo-SCL assembling fatty acid vesicles?FAV?were observed by transmission electron microscope?TEM?in diameter of10-20 nm.The performance results indicated that the oligo-SCL assembling FAV had better low temperature solubility and stronger resistance to acidic and calcium conditions in comparison with SCL micelles.Moreover,sizes of the oligo-SCL assembling FAV were calcium ion responsive.Therefore,it is great theoretical significant in self-assembly of FAV and shows a good application prospect in domestic detergents and personal care products.