发泡-注凝成型/表面改性制备超亲水-疏油硅藻土多孔陶瓷

Foam-gelcasting/Surface Modification Synthesis of Superhydrophilicoleophobic Diatomite Porous Ceramics

先采用发泡-注凝成型法制备了硅藻土多孔陶瓷,并以此为基体,以CapstoneFS-50(CS-50)为改性剂,通过真空浸渍法制备了超亲水-疏油硅藻土多孔陶瓷,研究了烧结温度对硅藻土多孔陶瓷物相组成、显微形貌及常温物理性能及CS-50用量(质量分数)对改性硅藻土多孔陶瓷表面的油接触角及化学稳定性的影响。结果表明:随着烧结温度的升高(1 100~1 200℃),硅藻土多孔陶瓷中圆盘状硅藻土自身的多孔结构被堵塞的越来越严重,孔隙率由84.3%降至81.6%,而抗压强度从0.93 MPa增至2.01 MPa;随着CS-50用量的增大,所制备改性硅藻土多孔陶瓷的油接触角呈先增加后趋于稳定的变化趋势;当CS-50的用量为5%(质量分数)时,改性多孔陶瓷的油接触角高达138°,且其水接触角约为0°。此外,改性硅藻土多孔陶瓷在强酸、强碱以及盐腐蚀条件下,仍能保持稳定的亲水疏油性能。

An efficient and eco-friendly oil-water separation strategy is urgently needed to solve the problem of oily sewage due to the frequent occurrence of oil leakage accidents.Diatomite porous ceramics were firstly prepared by a foaming-gelcasting method,and then superhydrophilic-oleophobic diatomite porous ceramics were prepared by a simple vacuum impregnation method with the diatomite porous ceramics as a matrix and fluorine-containing polymer(Capstone FS-50) as a modifier.The effect of sintering temperature on the phase composition,microscopic morphology and physical properties of porous diatomite ceramics was investigated and the influence of CS-50 concentration on the oil contact angle and chemical stability of the surface of modified diatomite porous ceramics was also analyzed.The mesopore structure of disk-like diatomite becomes more and more blocked,the porosity of the porous samples decreases from 84.3% to 81.6% and the compressive strength increases from 0.93 MPa to 2.01 MPa as the sintering temperature increases from 1 100 to 1 200 ℃.The oil contact angle of the prepared modified diatomite porous ceramics firstly increases and then becomes stable with increasing Capstone FS-50 concentration.At the concentration of Capstone FS-50 of 5%,the oil contact angle of the porous ceramic is high up to 138°,and whose water contact angle is about 0°.In addition,the modified diatomite porous ceramics still maintain hydrophilic and oleophobic after soaking in acid,alkali and salt solutions,thus exhibiting superior chemical corrosion resistance.