碳纳米管改性海泡石多孔陶瓷及其高效油水分离性能研究

为了有效地从油/水混合液体中回收油, 本工作以纤维状海泡石为原料, 硝酸镍为催化剂前驱体, 聚乙烯粉体为造孔剂和碳源, 采用冷冻干燥结合催化裂解法制备了超疏水/超亲油碳纳米管(CNTs)改性海泡石多孔陶瓷, 研究了固含量和催化热解温度对改性多孔陶瓷形貌的影响, 并表征了其在pH=1的强酸、pH=14的强碱、373 K高温和77 K低温等极端环境中的表面润湿性能及水油分离性能。结果表明: 催化剂前驱体溶液浓度为0.5 mol/L、海泡石的固含量为15wt%、催化热解温度为973 K且保温时间为2 h时所制备的CNTs改性多孔陶瓷具有最好的超疏水/超亲油性能, 其对柴油、白油、植物油和真空泵油的最高吸附量分别是其自身质量的15.7、20.8、23和25倍; 其连续油水分离时油通量高达250 kg·s ^-1·m ^-2, 且在5 h内分离效率及选择性不发生明显降低。

Carbon Nanotube Modified Sepiolite Porous Ceramics for High-efficient Oil/Water Separation

To efficiently recovery oil from oil/water mixed liquid, fibrous sepiolite, polyethylene powder and nickel nitrate was respectively used as raw mateials, carbon source and pore-forming agents, and catalyst precursor to prepare carbon nanotubes (CNTs) modified sepiolite porous ceramics by freeze-drying/catalytic pyrolysis method, and the effects of solid content and pyrolysing temperature on the morphology of the modified porous ceramics were studied. The water contact angle and oil-water separation performance in severly environment such as acid (pH=1), alkali (pH=14), and high (373 K) and low temperature (77 K) were also characterized. The results showed that when the concentration of catalyst precursor solution was 0.5 mol/L, the solid content of sepiolite was 15wt%, the catalytic pyrolysis temperature was 973 K, and the soaking time was 2 h, the as-prepared CNTs modified porous ceramics possessed superhydrophobic/superlipophilic nature, and their maximum adsorption capacity for diesel, paraffin oil, vegetable oil, and vacuum pump oil is respectively 15.7, 20.8, 23 and 25 times of their own weight. The oil flux during the continuous separation process is up to 250 kg·s ^-1·m ^-2, and the separation efficiency and selectivity can be maintained without significant decreasing within 5 h.