Preparation,Microstructure Control And Performance Study Of Sodium Alginate And Its Composite Microspheres

Sodium alginate(ALG or SA)is an natural anionic polymer extracted from brown algae,which has been widely used in medicine,sewage treatment,food,textile industry and other fields due to the good characteristics of biodegradability,biocompatibility,ph-sensitive and a large number of active groups.The structural characteristics of sodium alginate determines that it is easy to be cured with valence cations or small molecules,resulting the design and regulation of the structure to be realized.The design and preparation of microspheres by the structural characteristics of sodium alginate have always been one of the hotspots in this field.In this paper,sodium alginate is taken as the research object,and the influence of different preparation processes and conditions on the formation of alginate microspheres was studied by means of microanalysis.On this basis,the adsorption and drug release properties of sodium alginate microspheres were investigated.Meanwhile,the hydroxyapatite and graphene hybrid microspheres of sodium alginate microspheres were synthesized by alginate structure,and the adsorption properties of the composite microspheres were also studied.The full text is divided into four chapters:In chapter one: Introduction.Sodium alginate as the main line introduced the properties and structure of sodium alginate,focusing on the preparation method of sodium alginate microspheres,the research status and application of sodium alginate composite microspheres.In chapter two: Preparation and microstructure control of sodium alginate microspheres.The sodium alginate microspheres were prepared by the emulsification cross-linking method and the effects of preparation conditions on microspheres morphology and microstructure were investigated.The results show that the particle size and dispersion of microspheres are mainly affected by stirring speed and stirring mode and the sphericity is mainly affected by the phase volume ratio of oil and water in the system of liquid paraffin as oil phase and as calcium chloride as crosslinking agent.In chapter three: The drug release properties of sodium alginate microspheres.In this chapter,the effect of preparation conditions on the drug loading properties of microsphereswere studied with curcumin as drug loading model.At the same time,it was studied that the release properties of microspheres under different pH environments and the microstructure changes of microspheres before and after drug loading and release.The experimental results show that the prepared microspheres have obvious pH sensitivity,and the acid environment is not conducive to the release of drugs.In chapter four: Preparation and adsorption properties of sodium alginate hybrid microspheres.The hydroxyapatite and graphene hybrid microspheres of sodium alginate microspheres were prepared respectively by inverse crosslinking-emulsion.The effects of mass ratio on the formation and microstructure of the composite microspheres were studied.The adsorption properties of microspheres were compared with methylene blue dye simulated wastewater as adsorbate.The relationship between the composition and structure of microspheres and their adsorption properties was discussed,and the adsorption mechanism of microspheres was discussed based on adsorption kinetics and thermodynamics theory.