Preparation,Modification And Application Of Porous Ceramics In Separation

Over the years,since the wettability of materials has demonstrated its unique application characteristics in many fields,the research and preparation of special wettability materials have gradually attracted widespread attention.In practical applications,the wettability requirements for materials under different conditions are significantly different.In most cases,it is required that the liquid can easily penetrate from the solid surface,but sometimes it is required that the liquid cannot pass through the solid surface.According to the different wettability of the liquid on the material surface,the materials can be divided into different categories,such as water can divide the material into hydrophilic and hydrophobic materials;and the oil is divided into lipophilic and oleophobic materials.By adjusting the wettability of the material,the liquid can be selectively through the material surface,thus achieving the separation of the mixture.This paper mainly includes the following aspects:(1)Porous ceramics were prepared by using combustion synthesis-molding method,with Al(NO3)3,Zr(NO3)4,CO(NH2)2 and starch as raw materials.The effects of the molar ratio of A12O3:ZrO2,starch content and firing temperature on the properties of porous ceramics were studied.The prepared porous ceramic materials were characterized by SEM,XRD,and BJH,et al,and then we analyzed the effect of these conditions on the shape,crystal size,pore size distribution,porosity,and sintering shrinkage of the porous ceramic material.The results show that when the molar ratio of Al2O3:ZrO2 is 1:0.15 and the amount of starch is 35 wt%,sintering at 1450 ? for 2 h can obtain a porous ceramic with the average pore size is about 42 nm and the porosity is about 46%.(2)The porous ceramics prepared in(1)was used as substrate,and 3-aminopropyltriethoxysilane was selected as a modifier to modify the porous ceramics.The modified porous ceramic materials were characterized by SEM,FT-IR,WCA,and EDS,et al,then we analyzed from these datas that the silane coupling agent is stably coupled to the porous ceramic.And we studied the effect of modification time,temperature and modifier concentration on the wettability of porous ceramic materials,the optimum modification conditions of the obtained porous ceramic materials were:modification time was 4 h,modification temperature was 70 ?,and the modifier concentration is 2%.Then four different silane coupling agents(C9H23NO3Si,CH3C13Si,C8H17Cl3Si,C18H37Cl3Si)were used to modify the porous ceramic materials under the above conditions.And they were applied to the separation experiments of oil-water mixtures to explore their separation efficiency,recycling performance and stability.The results show that the special wetting materials modified by different silanes all show good separation efficiency,and the separation effect of the mixture with different oil contents is maintained at more than 82%.Taking APTES as an example,the separation of the mixed oil with 10%oil volume can achieve a separation efficiency of 93%and the separation efficiency is basically unchanged after 10 cycles.After it is worn with a file,the same oil-water mixture was continuously separated,and the separation efficiency of the mixture could still reach 90%.This indicates that the material has potential use value in practical applications.