Preparation Of Bio-glass Ceramics By High-gravity Liquid Precipitation And Reaseach For Its Properties

Nano bio-glass ceramics have good mechanical and biological properties,and are considered to be promising human hard tissue repair or replacement materials.Bio-glass ceramic composite fillers are widely used in dental restorations.The inorganic components in the composite resin determine the properties of the composite resin,and the inorganic components should have characteristics such as small size and uniform morphology.At present,the preparation technology of bio-glass ceramics has been relatively mature,but the bio-glass ceramics prepared by the existing preparation methods have the problems of easy agglomeration,irregular shape,etc.,resulting in that the mechanical properties and biological activities of the materials after compounding with the resin are not good.To meet medical needs,the preparation process needs to be improved.Therefore,this paper proposes the preparation of nano bio-glass ceramics with uniform morphology,controllable size,and good dispersibility by using a high-gravity liquid phase precipitation method.Its preparation process and performance after being compounded with inorganic fillers and resins are studied.The main content of the full text is as follows:(1)In a traditional beaker,nano bio-glass ceramics precursor is prepared by reaction precipitation method.The effects of reactant concentration,reaction time,reaction temperature,addition of dispersant or not on the precursor of bio-glass ceramics were investigated in detail,and the optimum conditions for preparation were determined:the concentration of the reactants is as follows:AIC13·6H2O,0.8 mol/L,Na2Si03·9H2O,0.7 mol/L,CaC12,1.0 mol/L,NaF,0.3 mol/L,Na5P3O10,0.1 mol/L,reaction temperature,room temperature,reaction time,1.0 h,dispersant were added.In addition,the precursor of the bio-glass ceramic precursor can be crystallized after calcining,and the crystallization phenomenon of the glass ceramic obtained after the heat treatment is strengthened,and the types of precipitated crystal phases are increased.The method of calcining the precursor is a two-step heating method.The first step is to raise the temperature to 500 ?,hold it for 2 hours,nucleate the crystal,and heat up to 800 ?,in the second step to grow the crystal.(2)Nano bio-glass ceramics were prepared by a combination of high gravity technique and reaction precipitation method.The effects of feed flow rate,reaction time,and rotation speed on bio-glass ceramic precursors were investigated in detail.The optimum process conditions were obtained:the peristaltic pump feed flow rate was 150 ml/L,the reaction time was 0.5 h,and the rotation speed of the high-gravity rotating bed 1500 r/min.The prepared nano bio-glass ceramic particles have a nearly spherical shape,an average particle size of 30-40 nm,an average hydrated particle size of 60-70 nm,a good regularity and good dispersibility.(3)Bio-glass ceramics were modified and used as inorganic fillers to prepare composite resin.The mechanical properties and biological activity of the composite resin were tested.The bio-glass ceramics prepared by the two preparation methods can be well combined with the modifiers.Compared to the two composite resins,the composite resin with the bio-glass ceramics prepared by the high-gravity method as the inorganic filler has excellent mechanical properties as a whole,when the inorganic fillers and organic proportion of monomer is 1:1,the mechanical properties of the composite resin are the best.In addition,the biological activities of the two materials were tested by immersing the material in simulated body fluids for several days.Compared to the materials prepared by the beaker method,the materials prepared by the high-gravity method have better biological activity and deposit more hydroxyapatite with a more regular appearance.In this thesis,nano bio-glass ceramics were prepared by traditional beaker agitation and high-gravity technology combined with liquid-phase precipitation method.By comparing the performances of different products,the materials prepared by the high-gravity liquid-phase precipitation method are superior in micro-morphology and performance.In the traditional mixing method.It is expected to provide certain basic research results for the future industrial production of nano bio-glass ceramics...