Pressure Response through Valve for Continuous Oil-Water Separation Based on a Flexible Superhydrophobic/Superoleophilic Thermoplastic Vulcanizate Film

Highly efficient oil-water separation shows urgent demand in industrial applications, especially in oil-spill accidents and organic solvent separation. Herein, a novel method is proposed for continuous oil-water separation by a pressure response through valve, which is loaded in a flexible convolute superhydrophobic/superoleophilic film based on low-density polyethylene (LDPE)/ethylene-propylene-diene terpolymer (EPDM) thermoplastic vulcanizate (TPV). The superhydrophobic/superoleophilic LDPE/EPDM TPV film (with contact angles of oil and water are 0° and 161.9°± 2.2°) is prepared only via a molding process where sandpaper is used as the template. The superhydrophobic/superoleophilic property of the TPV film shows robust performance in the activity endurance test. More importantly, the flexible LDPE/EPDM TPV film can be easily rolled up and loaded in through valve, which is the pressure response channel in oil-water separation. The typical separation pressure of oil and water is 3.01 and 6.17 kPa, which means the oil can be completely separated from the oil-water mixture under proper pressure in the pressure response through valve.     

镍基分支化ZnOHF表面的制备及油水分离性能

目的 解决目前油水分离材料大多存在的制备工艺复杂、设备昂贵、分离效率低、重复使用性差等问题。方法 采用水热法在镍网表面生长分支化羟基氟化锌(ZnOHF)粗糙结构,随后在表面沉积十八烷基三甲氧基硅烷(ODS)分子,得到超疏水/超亲油镍网。利用扫描电子显微镜(SEM)、X射线衍射仪(XRD)和傅里叶变换红外光谱仪(FT–IR)对其表面的微观形貌、组织和表面成分进行表征,利用接触角测量仪表征其静态和动态润湿性能。结果 镍网表面生长的分支化ZnOHF粗糙结构,与低表面能的ODS单分子层协同作用,使该表面对水的接触角高达158°,对油的接触角则为0°,且连续滴加油品时,油会在表面迅速铺展、渗透,并向下滴落。将不同品类的油与水混合,模拟不同情况下的油水分离效果,其分离效率均在95%以上;经过50次重复的油水分离测试后,其油水分离效率仍能保持91%,表现出良好的重复使用性能。结论 实验制备的超疏水/超亲油镍网具有制备方法简单、成本低廉、高效耐用等优点,为含油废水的处理提供了新方法。     

超疏水超亲油Cu-Ni复合镀层的制备及油水分离应用

针对目前超疏水超亲油表面制备工艺复杂、成本高等问题,采用工艺简单、可控性强的电化学沉积法制备出不锈钢网基底超疏水超亲油表面。通过在不锈钢网表面进行铜镍共沉积,得到一种叶片状的微纳米级粗糙结构,再利用正十二硫醇乙醇溶液对镀层进行表面修饰,最终获得超疏水超亲油Cu-Ni复合镀层。利用扫描电子显微镜(SEM)、接触角测试仪、X射线能谱仪(EDS)、傅里叶变换红外光谱仪(FT-IR)等对镀层表面微观形貌、浸润性以及化学元素组成进行表征分析。结果显示,制备的Cu-Ni复合镀层水接触角为155°±2°,油接触角为0°。对润滑油油水分离效率高达98%,且连续分离2 h后,分离效率仍高于95%,表现出稳定高效的油水分离性能。该制备方法耗时短、成本低,有潜力应用于规模化工业生产。     

Table Salt as a Template to Prepare Reusable Porous PVDF–MWCNT Foam for Separation of Immiscible Oils/Organic Solvents and Corrosive Aqueous Solutions

Many advanced materials are designed for separation of immiscible oils/organic solvents and aqueous solutions, including poly(vinylidene fluoride) (PVDF)‐based materials with superwettability. However, due to the limited solubility of PVDF, techniques (e.g., phase inversion and electrospinning) often involve the use of toxic organic solvents. Here a facile organic solvent‐free method is described to prepare a porous PVDF–MWCNT (multiwalled carbon nanotube) foam using table salt as a sacrificial template. The porous PVDF–MWCNT foam is characterized as superhydrophobic–superoleophilic with good elasticity due to its 3D porosity and low surface energy. The foam exhibits high adsorption capacity to a variety of oils/organic solvents and can be easily reused by squeezing, heating, or releasing in other solvents. Moreover, the foam is highly resistant toward UV exposure, corrosive aqueous solutions such as acidic, alkaline, salty solutions, and turbulent environments, and shows effective oils/organic solvents removal in these complex environments. The continuous separation of immiscible oils/organic solvents and corrosive aqueous solutions with vacuum assistance is also presented. The organic solvent‐free and reusable PVDF–MWCNT foam is a promising candidate for large‐scale industrial separation of oils/organic solvents and water in corrosive and turbulent conditions.     

铜表面超疏水和超亲油银膜的制备和性能

将铜片置于硝酸银溶液中,通过电交换反应制备了银膜,然后用12-羟基硬脂酸(HSA)进行修饰,在铜表面成功制备了HSA修饰的银膜,并对其形貌、亲水性、亲油性及水接触角的稳定性进行了研究。结果表明:制备的银膜具有微纳米二元结构的树枝晶;经HSA修饰后的银膜具备超疏水性和超亲油性,在水、无水乙醇、丙酮和正己烷中具有良好的稳定性,在空气中放置较长时间后接触角基本保持不变。     

One‐Step Fabrication of Superhydrophobic/Superoleophilic Electrodeposited Polythiophene for Oil and Water Separation

A facile, one‐step, and single‐component fabrication of superhydrophobic and superoleophilic coating by electropolymerization of polythiophene on a stainless steel mesh is presented. The resulting coating has low surface energy and shows surface morphology bearing both micro‐ and nano‐features without the need to add nanofillers, or pretreatment of the substrate to make it rough. The polythiophene coating also shows reversible wetting property (superhydrophobic to superhydrophilic, and vice versa) by electrochemical doping and dedoping. The coated mesh is shown to repel water of different pH (1, 7, and 14) and salt content. On the other hand, oil such as dichloromethane, gasoline, kerosene, dodecane, and crude oil can easily pass through the mesh. Therefore, the coated mesh is an excellent material for the separation of oil and water.     

激光-热处理复合工艺制备油水分离表面及性能研究

目的 研发一种高效、低成本的激光-热处理复合工艺,制备具有油水分离性能的泡沫铜表面,为石油污染的净化提供一种有效的参考方法。方法 首先利用纳秒激光在泡沫铜表面上诱导出多级微纳米结构,然后将泡沫铜放入低温烘箱中加热处理,通过调控激光参数和热处理相互作用制备出了超疏水超亲油泡沫铜表面,并使用扫描电子显微镜、光电子能谱仪和接触角测量仪,对激光加工前后泡沫铜表面的微纳结构、表面化学元素组成和油水在表面的润湿性进行了表征。结果 泡沫铜表面经纳秒激光加工后诱导生成的多级微纳结构受到包括激光扫描速率、激光加工功率和扫描间距等激光加工参数的显著影响。同时,配合低温热处理工艺,激光制备泡沫铜表面的化学成分快速转变,表面能显著降低,使得泡沫铜表面获得了超疏水超亲油的润湿特性。本工作制备的泡沫铜表面在空气中的最大水接触角为158.5°,油接触角为0°。并利用油水分离试验装置验证了激光-热处理复合工艺制备的超疏水超亲油泡沫铜表面可以使油和水选择性通过,分离效率超过90%。结论 激光-热处理复合工艺制备的具有多级微纳结构的泡沫铜表面具备优异的超疏水超亲油特性,展现出了良好的油水分离性能,有望实现海洋生态中石油污染的净化。