Preparation Of Ultra-fine Nano Barium Sulfate And Its Application In Amylase Medical Slides

Ultra-fine barium sulfate(BaSO4)nanoparticles can be applied in the multi-functional layers of amylase medical slides with the white substance of high reflectance.Especially,BaS04 nanoparticles with regular morphology and uniform size are conducive to the formation of multi-functional layers with uniform pores and good property for the subsequent detection.Therefore,it is particularly important to prepare nano BaS04 particles with uniform size.In this paper,BaS04 nanoparticles were prepared by reverse microemulsion and microchannel reactor with BaCl2 and Na2SO4 as raw materials.The effects of three reaction modes,[H20]/[TritonX-100]molar ratio(R),reactant concentration,[co-surfactants]/[surfactants]molar ratio(P),co-surfactants types and aging time on the size and morphology of BaSO4 nanopariticles were investigated using reverse microemulsion.The best reaction condition for the synthesis of BaS04 particles was obtained with R =17.97,concentration was 0.10 mol/L,P between 2.11?4.22,the co-surfactants were n-pentanol?n-hexanol,the aging time was 24 h using double microemulsion method.Under the reaction conditions,the synthesized BaS04 nanoparticles had regular morphology with size of 18 to 22 nm.The effect of volume flows?reactant concentration?temperature?volume flow ratios on the size and morphology of BaS04 nanopariticles were investigated using a microchannel reactor.The suitable reaction condition was obtained with volume flow was 2.5 mL/min,reactant concentration was 0.10 mol/L,the temperature was 25 ?,pipe length was 10 cm and volume flow ratio was 5.0.Under the reaction conditions,cubic BaS04 nanoparticles with size of 25 to 55 nm can be obtanied.Utilizing BaSO4 nanoparticles prepared at optimized reaction conditions in microchannel reactor as raw materials,multi-functional layers were prepared.BaS04 nanopariticles with different regularity,surfactants and stirring time on BaS04 multi-functional layers were investigated.The experimental results show that micro surfactant Tween 80 can improve the permeability of multi-functional layers,and stirring time should not be less 120 min.The prepared BaS04 multi-functional layers were applied to the amylase medical slides,which reflected by the densitometer,the repeatability and stability of signal vaule curve were good.