Preparation Of Geopolymer Microspheres And Application In Drug Delivery

As a new type of inorganic material,geopolymers not only have low prices and abundant reserves in nature,but also have high strength,aging resistance,and no toxicity and harmlessness.Therefore,they have become a research hotspot at home and abroad.The synthesis of geopolymer materials usually uses fly ash,slag,metakaolin,etc.As raw materials,but due to the differences in the origin,the composition of the raw materials varies,and the application of geopolymer materials is limited.As an anti-inflammatory and pain-relief drug,ibuprofen has a short half-life and can easily cause sudden release of the drug after administration,thereby causing side effects on the human body.In order to control the composition of geopolymer materials and to make ibuprofen exert a sustained and long-lasting effect in the human body,this experiment used an artificial synthetic method to prepare geopolymer materials,which was modified to serve as a sustained release carrier for ibuprofen.,Not only the preparation process is simple,the raw materials are readily available but also has a good sustained release effect.Firstly,the amorphous A12O3-2SiO2 powder was prepared by sol-gel method,and Al2O3-2SiO2 powder was used as the precursor to prepare smooth geopolymer microspheres by suspension polymerization.Then,the geopolymer microspheres are activated and reacted with a silane coupling agent to undergo amination modification.Finally,the geopolymer microspheres and the aminated modified microspheres were used as sustained-release carriers for ibuprofen,and the loading and release of aminated microspheres and geopolymer microspheres were determined.The adsorption kinetic model of microspheres was explored.The result is as follows:(1)Preparation of geopolymer microspheres by suspension polymerization with a sample injection rate of 1 mL/min,a reaction temperature of 40℃,a stirring rate of 1200 r·min-1,and a reaction time of 3 h,on the condition that the volume fraction of Tween 80 is 7%,geopolymer microspheres with an average particle size of 41.17 μm were prepared.Scanning electron microscopy(SEM)observations showed that the microspheres had a good roundness.(2)Activate the hydroxyl groups on the surface of the microspheres with deionized water.After heating and activation of the microspheres in a boiling water bath for 3 h,the activated microspheres have an ethanol concentration of 99%and a rotation speed of 600 r·min-1.When the volume of silane coupling agent KH550 was 1.0 mL,reaction temperature was 85℃ and reaction time was 10 h,the grafting amount of amino group on the surface of microspheres was the highest,which was 3.02 mmol/g.(3)At a temperature of 30℃,shaking speed of 250 r·min-1,reaction time of 8 h,the microspheres have the highest loading on ibuprofen,and the highest loading of the aminated microspheres is 248.11 mg/g,the highest loading of the geopolymer microspheres was 127.97 mg/g.The loading experiments of aminated microspheres on ibuprofen accorded with the Freundlich equation,and the adsorption behavior conformed to the pseudo-second-order kinetics model.After sustained release experiments,it was found that the cumulative sustained release of aminated microspheres for 24 h was 91%,with good sustained-release behavior.