亚表面引发原子转移自由基聚合构筑温度响应型纳米纤维油水分离膜

亚表面引发聚合是一种用于制备共价嵌入型聚合物刷的新型改性策略.该方法在发展高稳定性聚合物刷功能化表界面材料方面具有显著的优势.本工作利用亚表面引发原子转移自由基聚合(sSI-ATRP)对静电纺丝聚丙烯腈(PAN)基纳米纤维膜进行亚表面改性,通过接枝聚N-异丙基丙烯酰胺(PNIPAM)制备了温度响应型纳米纤维油水分离膜(...     

Janus Copper Mesh Film with Unidirectional Water Transportation Ability toward High Efficiency Oil/Water Separation

Inspired by the special asymmetric wettability and controllable permeation function of cell membranes, we report a Janus nanostructured copper mesh film with unidirectional water transportation ability. Water can permeate from the hydrophobic side to the hydrophilic side, but is retained in the opposite direction. Notably, based on this special unidirectional water permeation property, both heavy oil/water mixtures (ρ _oil>ρ _water) and light oil/water mixtures (ρ _oil<ρ _water) can be separated. Additionally, the film demonstrates high separation efficiency and good recyclability. This paper reports a new Janus film that achieved highly efficient oil/water separation based on smart control of the wettability of the film. It is believed to have the potential to be used in many practical applications, such as wastewater treatment and oil‐spill cleanup.     

CO2‐Responsive Nanofibrous Membranes with Switchable Oil/Water Wettability

Responsive polymer interfacial materials are ideal candidates for controlling surface wetting behavior. Here we developed smart nanostructured electrospun polymer membranes which are capable of switching oil/water wettability using CO₂ as the trigger. In particular, the combination of CO₂‐responsiveness and porous nanostructure enables the as‐prepared membranes to be used as a novel oil/water on–off switch. We anticipate that the promising versatility and simplicity of this system would not only open up a new way of surface wettability change regulation by gas, but also have obvious advantages in terms of highly controlled oil/water separation and CO₂ applications.     

用于分离油水乳液的先进材料

海洋原油泄漏事故的频发以及工业污水排放量的日益增加,给生态环境和人类健康造成了巨大的威胁,因此,开发应用于油水分离的先进材料是重要的研究任务。相较于不混溶的油水混合物,油水乳液(也称为乳化油水)的分离是一个更加艰巨的挑战。本文以分离油水乳液的材料作为研究体系,首先从本质上分析了油水乳液的形成机理以及分离原理,强调了“尺寸筛分”效应和膜破乳技术的重要性;然后从基材的角度全面介绍并讨论了常用于分离乳化油水的先进材料的最新进展,详细阐述了各种不同改性方法在油水分离领域中的应用。对材料进行改性的出发点是“合适的孔径”以及“特殊润湿性能”,并能满足优异的分离能力、渗透能力、抗污染能力、机械能力和稳定性,而这些性能在实际的分离操作中是非常关键的。环境系统在未来会变得越来越复杂,真实环境下的油水乳液大多含有较多的污染物,而且分离条件大多较苛刻,因此油水分离材料需要不断地改进,以满足这样的条件。我们相信,未来能在苛刻条件下高效分离多种油水乳液和其他杂质的多功能性先进材料会有巨大的应用前景。     

选择性油水分离材料

水是人类赖以生存的基础,其重要性不言而喻。但是,当前水环境日益恶化,水污染日益加重,尤其是石油泄漏和有机污染物肆意排放给环境和生态系统造成了不可挽回的损害。因此,高效油水分离已成为亟待解决的问题。当前主要通过物理吸附、化学分散以及生物降解等方法进行油污清理;化学分散和生物降解法易对海洋环境造成二次污染,而物理吸附具有易于回收及无污染等优点。本文综述了近年来物理过滤和物理吸附油水分离材料的研究现状及尚待解决的难点,同时也展望了该领域未来研究的热点及发展方向。     

纤维素基超润湿材料在油/水分离应用中的研究进展

本文总结了纤维素基材料在油/水分离方面应用的研究进展。 以不同润湿性表面在油/水分离中的应用为切入点,介绍了3种不同的纤维素基油/水分离材料, 并结合作者所在课题组的研究工作,重点介绍了智能响应型油/水分离材料。 同时也总结了纤维素基超润湿材料在油/水分离之外的应用。 文章最后展望了纤维素基超润湿材料未来的研究方向并提出了亟待解决的问题。     

Rapid and Efficient Separation of Oil from Oil‐in‐Water Emulsions Using a Janus Cotton Fabric

A novel bi‐functional Janus cotton fabric is used to separate oil from oil‐in‐water emulsions. This fabric is superhydrophobic on one surface and polyamine‐bearing on the other. When used as a filter, the polyamine‐bearing side causes the micrometer‐sized oil droplets to coalesce. The coalesced oil then fills fabric pores on the superhydrophobic side and selectively permeates it. Oil separation using this method is rapid and the separated oil is pure. Furthermore, the content of the model oil hexadecane (HD) in water after a separation can be reduced to less than 0.03±0.03 vol %. These features demonstrate the practical potential of this technology.     

Oil/Water Separation with Selective Superantiwetting/Superwetting Surface Materials

The separation of oil from oily water is an important pursuit because of increasing worldwide oil pollution. Separation by the use of materials with selective oil/water absorption is a relatively recent area of development, yet highly promising. Owing to their selective superantiwetting/superwetting properties towards water and oil, superhydrophobic/superoleophilic surfaces and underwater superoleophobic surfaces have been developed for the separation of oil/water‐free mixtures and emulsions. In this Review, after a short introduction to oil/water separation, we describe the principles of materials with selective oil/water absorption and outline recent advances in oil/water separation with superwetting/superantiwetting materials, including their design, their fabrication, and models of experimental setups. Finally, we discuss the current state of this new field and point out the remaining problems and future challenges.     

Salt‐Induced Fabrication of Superhydrophilic and Underwater Superoleophobic PAA‐g‐PVDF Membranes for Effective Separation of Oil‐in‐Water Emulsions

Conventional polymer membranes suffer from low flux and serious fouling when used for treating emulsified oil/water mixtures. Reported herein is the fabrication of a novel superhydrophilic and underwater superoleophobic poly(acrylic acid)‐grafted PVDF filtration membrane using a salt‐induced phase‐inversion approach. A hierarchical micro/nanoscale structure is constructed on the membrane surface and endows it with a superhydrophilic/underwater superoleophobic property. The membrane separates both surfactant‐free and surfactant‐stabilized oil‐in‐water emulsions under either a small applied pressure (<0.3 bar) or gravity, with high separation efficiency and high flux, which is one to two orders of magnitude higher than those of commercial filtration membranes having a similar permeation property. The membrane exhibits an excellent antifouling property and is easily recycled for long‐term use. The outstanding performance of the membrane and the efficient, energy and cost‐effective preparation process highlight its potential for practical applications.     

超亲水超疏油油水分离膜的制备及其性能

超亲水-超疏油油水分离膜是一种过水隔油的特殊分离膜,在处理海洋溢油污染、环境含油废水时具有保持分离膜不被油污染的优势,有十分重要的实际意义。为了掌握近年来超亲水超疏油分离膜的发展动态,本文首先以液体静压力与毛细作用力为基础阐述亲水疏油膜的油水分离机理;然后分类概括超亲水-超疏油金属基底网膜、刺激响应油水分离膜、无基底聚合物膜材料的制备及各项性能的研究新进展;最后总结目前在该领域仍存在的问题并进行展望。     

渗透汽化芳烃/烷烃分离膜材料

芳烃/烷烃混合物的分离在石油化工及环保领域都具有重大意义.与传统的萃取精馏等技术相比,渗透汽化膜技术以其清洁、节能和高效的优点,应用于芳烃/烷烃混合物的分离并受到重视.本文综述了渗透汽化芳烃/烷烃分离膜的研究进展,概述了渗透汽化技术的基本原理和应用,重点介绍了用于渗透汽化芳烃/烷烃分离的聚酰亚胺、聚氨酯等高分子膜材料的结构特点和分离性能.总结了膜材料的接枝、共聚和共混,添加传质促进剂的改性方法.分析了渗透汽化芳烃,烷烃分离膜材料的研究思路,在此基础上对渗透汽化芳烃/烷烃分离膜材料的研究方向和发展前景进行了展望.     

Electrospun Polyacrylonitrile Nanofibrous Membranes for Point-of-Use Water and Air Cleaning

Novel electrospun polyacrylonitrile (PAN) nanofibrous membranes were prepared by using heat-press lamination under various conditions. The air permeability and the burst-pressure tests were run to select the membranes for point-of-use air and water cleaning. Membrane characterization was performed by using scanning electron microscopy, contact angle, and average pore size measurements. Selected membranes were used for both air dust filtration and cross-flow water filtration tests. Air dust filter results indicated that electrospun PAN nanofibrous membranes showed very high air-dust filtration efficiency of more than 99.99 % in between PM_0.3 and PM_2.5, whereas cross-flow filtration test showed very high water permeability over 600 L/(m²hbar) after 6 h of operation. Combining their excellent efficiency and water permeability, these membranes offer an ideal solution to filter both air and water pollutants.     

特殊润湿性油水分离材料的开发与研究

随着工业的发展,油水污染日渐严重,特别是石油的泄露、有机化学品的排放对生态环境造成了难以挽救的损害。因此,开发新型高效的油水分离材料与技术是一个极为重要的任务。特殊润湿性油水分离材料的出现,为科研人员指明了道路。本文以用于油水分离的特殊润湿性材料为研究体系;首先,对具有特殊润湿性油水分离材料的基本理论和设计理念进行分析;然后介绍了通过调控材料表面的微观结构和表面化学组成制备特殊润湿性材料实现不同的油水分离效果的研究进展,并且尝试从微纳米尺度上揭示特殊润湿性材料的特征,形成从微纳米尺度上揭示油水分离用材料化学品结构特征的技术基础。最后指出了目前在油水分离用功能材料化学品这一领域存在的一些问题,并对这一领域的发展趋势进行展望。     

Hypercrosslinked Additives for Ageless Gas‐Separation Membranes

The loss of internal pores, a process known as physical aging, inhibits the long‐term use of the most promising gas‐separation polymers. Previously we reported that a porous aromatic framework (PAF‐1) could form a remarkable nanocomposite with gas‐separation polymers to stop aging. However, PAF‐1 synthesis is very onerous both from a reagent and reaction‐condition perspective, making it difficult to scale‐up. We now reveal a highly dispersible and scalable additive based on α,α′‐dichloro‐p‐xylene (p‐DCX), that inhibits aging more effectively, and crucially almost doubles gas‐transport selectivity. These synergistic effects are related to the intimately mixed nanocomposite that is formed though the high dispersibility of p‐DCX in the gas‐separation polymer. This reduces particle‐size effects and the internal free volume is almost unchanged over time. This study shows this inexpensive and scalable polymer additive delivers exceptional gas‐transport performance and selectivity.     

Green Approach to the Fabrication of Superhydrophobic Mesh Surface for Oil/Water Separation

We report a simple and environment friendly method to fabricate superhydrophobic metallic mesh surfaces for oil/water separation. The obtained mesh surface exhibits superhydrophobicity and superoleophilicity after it was dried in an oven at 200 °C for 10 min. A rough silver layer is formed on the mesh surface after immersion, and the spontaneous adsorption of airborne carbon contaminants on the silver surface lower the surface free energy of the mesh. No low‐surface‐energy reagents and/or volatile organic solvents are used. In addition, we demonstrate that by using the mesh box, oils can be separated and collected from the surface of water repeatedly, and that high separation efficiencies of larger than 92 % are retained for various oils. Moreover, the superhydrophobic mesh also possesses excellent corrosion resistance and thermal stability. Hence, these superhydrophobic meshes might be good candidates for the practical separation of oil from the surface of water.     

一种可用于光降解的纳米氧化锌油水分离网

通过低温水热法在钢丝网上生长六棱柱形的氧化锌纳米柱.包覆了氧化锌纳米柱的钢丝网具有水下超疏油的特殊浸润性,并可用于油水分离.滤网在室温常压下可对含有汽油、柴油和原油等油水混合物进行高效快速分离,分离效率可达98%以上.材料可以承受1.4 kPa的油层压力且可反复使用.由于氧化锌的光响应性强,滤网可快速降解水中的亚甲基蓝,2 h的降解率可达80%.包覆了氧化锌纳米柱的钢丝网具备同时进行油水分离和降解环境中污染物的能力,是一种新型多功能水处理材料.     

Straightforward Oxidation of a Copper Substrate Produces an Underwater Superoleophobic Mesh for Oil/Water Separation

A superhydrophilic and underwater superoleophobic Cu(OH)₂‐covered mesh with micro‐ and nanoscale hierarchical composite structures is successfully fabricated through a one‐step chemical oxidation of a smooth‐copper mesh. Such mesh, without any further modification, can selectively separate water from oil/water mixtures with high separation efficiency, and possess excellent stability even after 60 uses. This method provides a simple, low‐cost, and scalable strategy for the purification of oily wastewater.