纳米二氧化硅改性不锈钢网用于油水分离  

Nano-silica modified stainless steel mesh for oil-water separation

作　　者：展悦 崔永岩 王嘉宁 余正发 ZHAN Yue;CUI Yongyan;WANG Jianing;YU Zhengfa(College of Chemical Engineering and Materials Science,Tianjin University of Science&Technology,Tianjin 300457,China)

机构地区：[1]天津科技大学化工与材料学院,天津300457

出　　处：《精细化工》2024年第9期1933-1940,1957,共9页Fine Chemicals

摘　　要：以正硅酸乙酯为原料,采用溶胶-凝胶法制备了硅溶胶,将硅溶胶与预沉积聚多巴胺(PDA)的不锈钢网(SSM)反应,采用分步沉积和原位生长法制备了超亲水-水下超疏油不锈钢网(SSM-PDA-SiO_(2))。采用FTIR、XRD、TG、SEM和接触角测量仪对其进行了测试。探究了硅溶胶反应时间对SSM-PDA-SiO_(2)亲水-疏油性能的影响,通过自重力驱动测试了其油水分离性能,考察了其循环分离性和力学稳定性。结果表明,PDA作为“桥梁”将纳米SiO_(2)沉积到SSM表面上,硅溶胶与SSM反应8 h制备的SSM-PDA-SiO_(2)-8具有最佳的亲水-疏油性能,水滴能在其表面60 ms内完全铺展,其对二氯甲烷等5种有机溶剂的水下油接触角在156.4°~160.9°之间,对二氯甲烷的滚动角为4.0°,表现出超亲水-水下超疏油特性。首次分离正庚烷/水的油水混合物水通量为40165 L/(m^(2)·h),分离效率99.3%,在50次分离循环时水通量为17728 L/(m^(2)·h),分离效率仍>98%。经过35次砂纸摩擦循环后,SSM-PDA-SiO_(2)-8保持了98%以上的分离效率。PDA的羟基、氨基等亲水基团提高了SSM-PDA-SiO_(2)的超亲水-水下超疏油特性,纳米SiO_(2)增加了其表面粗糙度。Silica sol,prepared by sol-gel method using ethyl orthosilicate as raw material,reacted with stainless steel mesh(SSM)pre-deposited with polydopamine(PDA)through stepwise deposition and in-situ growth to obtain superhydrophilic-underwater superoleophobic stainless steel mesh(SSM-PDA-SiO_(2)),which was further characterized by FTIR,XRD,TG,SEM,and contact angle tester.The effect of reaction time on the hydrophilic-oleophobic properties of SSM-PDA-SiO_(2)was investigated.The oil-water separation performance was evaluated by self-gravity driving,while its cyclic separation and mechanical stability were further explored.The results showed that PDA acted as a"bridge"to deposit nano-SiO_(2)onto the surface of SSM.SSM-PDA-SiO_(2)-8 prepared with reaction time of 8 h exhibited the best hydrophilic and lipophobic properties,with water droplets spreading completely on its surface within 60 ms,the underwater oil contact angle to dichloromethane and other 5 organic solvents between 156.4°~160.9°,and the rolling angle to dichloromethane 4.0°,demonstrating its super-hydrophilic-underwater super-oleophobic properties.The modified stainless-steel mesh achieved an initial separation flux of 40165 L/(m^(2)·h)with a separation efficiency of 99.3%,and still maintained a flux of 17728 L/(m^(2)·h)and a separation efficiency of>98%even after 50 separation cycles,indicating its good recyclability.Moreover,the modified stainless steel mesh with 35 cycles of sandpaper abrasion retained a separation efficiency of over 98%,showing its good mechanical stability.Hydrophilic groups such as hydroxyl and amino groups of PDA improved the superhydrophilic and underwater superlipophobic properties of SSM-PDA-SiO_(2),while nano-SiO_(2)increased its surface roughness.

关 键 词：聚多巴胺 纳米SiO_(2) 油水分离 超亲水-水下超疏油性 不锈钢网 功能材料 

分 类 号：TG142.71[一般工业技术—材料科学与工程] TQ028[金属学及工艺—金属材料]