Preparation Of Antimony Trioxide Microcrystals With Controllable Morphology And Diameter By Liquid Phase Method And Research On Aggregation

Antimony trioxide（Sb₂O₃）has unique physical and chemical properties.It’s widely used in chemical synthesis of pigment,catalyst,flame retardant,and passivator for petroleum cracking.It is also desirable in applications of battery manufacturing and film processing.The properties of antimony trioxide are closely related to the morphology and particle size of its particles.Therefore,it is of great significance to study the preparation of antimony trioxide with different morphologies and particle sizes.The current methods for preparing antimony trioxide with different characteristics are mainly carried out in an alkaline environment,which has problems such as complex process flow,serious particle agglomeration,and poor powder uniformity.In order to solve this problem,this thesis proposes to prepare antimony trioxide in an acidic environment.This method does not require additional surfactants,which greatly simplifies the process.By changing the reaction time of the system,the formation mechanism of the octahedral antimony trioxide crystallites was preliminarily discussed,and the agglomeration of antimony trioxide was also studied.This thesis also provides guidance for the preparation of metal oxides with controllable morphology and particle size.Details of the study are as follows:（1）Preparation of antimony trioxide microcrystals with controllable morphologyUsing the liquid phase method with glycol antimony（Sb₂（OCH₂CH₂O）₃）as the antimony source and water as the solvent,various antimony trioxides of different shapes such as lamellar,microneedle,spherical,and regular octahedral shapes were prepared and synthesized.Our study investigated the effects of changing the p H value of the solution in an acidic environment.When the p H value of the solvent is 1,a stacked layered antimony trioxide can be obtained;when the p H value of the solution is 2,a clear radial microneedle can be obtained;when the p H of the solution is 3,part of the octahedral antimony trioxide can be obtained;when the p H value is 4-6,the octahedral antimony trioxide can be obtained;when the p H value is 6,the uniform octahedral antimony trioxide can be obtained.By adjusting the reaction time,uniformly and regularly shaped spherical antimony trioxide can be obtained in a weak acidic environment.The crystallization of the octahedral antimony trioxide was observed through a designed experiment.It was found that the antimony trioxide was initially spherical,then the surface was etched and collapsed,and finally the octahedral antimony trioxide was formed.The research also incorporated the high-energy ball milling method to study the formation process of antimony trioxide.This served as a preliminary discussion of the formation mechanism of antimony trioxide microcrystals.（2）Preparation of antimony trioxide microcrystals with controllable particle sizeBy controlling the p H value of the reaction process,the average particle size(D₅₀)of the product antimony trioxide can be effectively adjusted.When the solvent increases from p H=1 to p H=6,the average particle size of antimony trioxide decreases first and then rises.At p H=2,nano-scale antimony trioxide with an average particle size of 48nm can be obtained.When comparing the nano antimony trioxide prepared by the liquid phase method with that prepared by ball milling,it is found that the particle size distribution of the powder prepared by the ball milling is tighter but the dispersibility is poor,while the particle size distribution of the powder prepared by the liquid method is larger but with better dispersion.（3）Study on the agglomeration of antimony trioxideBy observing the antimony trioxide in a static state over time,the uniformly dispersed antimony trioxide presents apparent agglomeration.This agglomeration gradually increases the particle size of the antimony trioxide.Using mechanical ball milling with stearic acid(C₁₈H₃₆O₂)and sodium polyacrylate（（C₃H₃Na O₂）n）as surfactants,ball milling for 6 hours can effectively reduce the soft agglomeration caused by standing.The dispersion and particle size of antimony trioxide can be reverted to that prior to standing.