Ruixiang Qu

Nanocomposite Deposited Membrane for Oil-in-Water Emulsion Separation with in Situ Removal of Anionic Dyes and Surfactants

The decontamination of various pollutants including oils, organic dyes, and surfactants from water is an unprecedented issue throughout the world. A facile filtration process for in situ multifunctional water purification by employing a low-cost and easy-made catechol-polyethylenimine (PEI) nanocomposite deposited membrane has been designed. In combination with the intrinsic hydrophilicity of amino-rich groups, the resultant membrane possesses superhydrophilicity and underwater superoleophobicity, which is simultaneously advantageous for capturing anionic pollutants due to the electrostatic interaction. Such membrane can be successfully used for sundry surfactant-stabilized oil-in-water emulsions separation and pH-controllable removal of water-soluble dyes and the remaining surfactants at the same time. The excellent characteristics, i.e., fabrication protocol that is easy to scale up, better alkaline resistance, selectively controllable removal ability of anionic dyes, and surfactants with unaltered adsorption performance over 30 consecutive adsorption-desorption-washing cycles, will facilitate its versatility and practicability in environmental remediation and wastewater purification.

Polyacrylamide-Polydivinylbenzene Decorated Membrane for Sundry Ionic Stabilized Emulsions Separation via a Facile Solvothermal Method.

Aiming to solve the worldwide challenge of stabilized oil-in-water emulsion separation, a PAM-PDVB decorated nylon membrane is fabricated via a facile solvothermal route in our group. The main composition is PAM, while the PDVB plays a role as cross-linker in order to improve the interaction between the polymer and the substrate. By the combination of the superhydrophilic and underwater superoleophobic wettability of the PAM polymer with the micropore size of the substrate, the as-prepared material is able to achieve the separation of various stabilized oil-in-water emulsions including cationic type, nonionic type, and anionic type. Compared with previous works, the emulsions used in this case are more stable and can stay for several days. Besides, the solvothermal method is facile, cost saving, and relatively environmentally friendly in this experiment. Moreover, the PAM-PDVB modified membrane exhibits excellent pH stability, recyclability, and high separation efficiency (above 99%), which can be scaled up and used in the practical industrial field.

In situ dual-functional water purification with simultaneous oil removal and visible light catalysis.

Dual purification of both oily wastewater and dye-polluted water for enhancing the use of freshwater is an urgent task. We report herein, the facile synthesis of inorganic semiconductor nanomaterials anchored mesh for in situ dual-functional water purification. This resultant mesh combines the excellent capacity of oil removal and the advantage of photocatalytic performance for dye degradation under visible light irradiation at the same time. In addition, the mesh was easily regenerated and remained unaltered in photocatalytic performance over five successive dye degradation cycles. Given the innovative integration of special wettability and photocatalytic activity of such a semiconductor material under visible light for dual elimination of various pollutants from water, we anticipate that this approach will provide a promising pathway for versatile applications in oily wastewater treatment, water purification and so on.

Fabrication of robust mesh with anchored Ag nanoparticles for oil removal and in situ catalytic reduction of aromatic dyes

Effective removal of oils and aromatic dyes from water is of critical, global importance for environmental and water remediation. A green and facile electro-deposition approach to anchor Ag nanoparticles (NPs) onto the surface of a mesh support coated with polydopamine is proposed. The Ag NPs with high surface energy and specific surface area endow the resultant mesh with superhydrophilicity/underwater superoleophobicity as well as superior catalytic reduction ability of aromatic dyes. The mesh with anchored Ag NPs exhibits excellent oil removal capacity and in situ catalytic performance in the reduction of sundry aromatic dyes. Furthermore, the as-prepared mesh can be readily reused or stored in air even under harsh conditions because of its robust immobilization capability and strong resistance to oxidation. These versatile abilities integrated with a facile fabrication process provide promising potential for cost-effective water purification.

Thermo‐Driven Controllable Emulsion Separation by a Polymer‐Decorated Membrane with Switchable Wettability

A thermoresponsive Poly(N-isopropylacrylamide) (PNIPAAm)-modified nylon membrane was fabricated via hydrothermal route. Combining rough structure, proper pore size, and thermoresponsive wettability, the membrane can separate at least 16 types of stabilized oil-in-water and water-in-oil emulsions at different temperatures. Below the LCST (ca. 25 °C), the material exhibits hydrophilicity and underwater superoleophobicity, which can be used for the separation of various kinds of oil-in-water emulsions. Above the LCST (ca. 45 °C), the membrane shows the opposite property with high hydrophobicity and superoleophilicity, and it can then separate stabilized water-in-oil emulsions. The material exhibits excellent recyclability and high separation efficiency for various kinds of emulsions and the hydrothermal method is facile and low-cost. The membrane shows good potential in real situations such as on-demand oil-spill cleanup, industrial wastewater treatment, remote operation of oil/water emulsion separation units, and fuel purification.

One-step reduction and simultaneous decoration on various porous substrates: toward oil filtration from water

Effective purification of waste water tainted with either immiscible oil/water mixtures or surfactant-stabilized emulsions is always attractive for long-term water remediation. We report here on a versatile development of polydopamine coated copper surfaces on various porous substrates via a simple one-step immersing method. The incorporation of dopamine into this design not only optimizes the operation of preparing simple substances on copper surfaces on a wide range of substrates, but also endows the as-obtained membranes with superhydrophilicity and underwater superoleophobicity. Such membranes are capable of efficiently separating both immiscible oil/water mixtures and surfactant-stabilized emulsions based on the desired substrates, and they display superior chemical resistance to aggressive reagents, excellent recyclability and robust structural stability, making them promising candidates for a variety of oil filtration applications ranging from the treatment of oil/water mixtures to emulsified oily waste water.

A versatile CeO2/Co3O4 coated mesh for food wastewater treatment: Simultaneous oil removal and UV catalysis of food additives

Food waste water is one of the most urgent environmental problems for the close connection between food and our daily life. Herein, we use a simple hydrothermal method to prepare a highly efficient catalyst-CeO2/Co3O4 compound on the stainless steel mesh, aiming for food waste water treatment. Possessing the superhydrophilic property and catalytic ability under ultraviolet light, CeO2/Co3O4 coated mesh has successfully processed three representative contaminants in food wastewater, which are soybean oil (food oil), AR (food dye) and VA (food flavor) simultaneously with an one-step filtration. Besides, the mesh is stable in a wide pH range and performs well in reusability. Therefore, such a multifunctional material with simple preparation method, high processing efficiency and facile operation shows a promising prospect for practical production and application for food wastewater treatment.

Polymer Decorated Filter Material for Wastewater Treatment: In-situ Ultrafast Oil/water Emulsion Separation and Azo Dye Adsorption

Aiming to realize the wastewater treatment of various pollutants simultaneously, a dual-functional poly(ether amine)-polydopamine (PEA-PDA)-modified filter material was fabricated in this work for in situ separation of stable oil-in-water emulsion and adsorption of anionic azo dyes. PEA and PDA could be copolymerized via the Michael addition reaction on a polyurethane sponge substrate firmly. The as-prepared filter shows superhydrophilic and underwater superoleophobic wettability. After being squeezed in a glass tube, the material could separate different kinds of stabilized oil-in-water emulsions with high flux and efficiency. Besides, the PEA-PDA copolymer endows the material with the ability to adsorb large amounts of anionic azo dyes during the separation of emulsions with good adsorption capacity. Moreover, adsorbed dyes in the filter material could be easily desorbed in base aqueous solution and the whole process is conducted under gravity without external aid. This dual-functional material shows great potential for the application in industrial field because of its ability for the complex wastewater treatment.

A smart nano-V2O5/ODA-coated mesh for a co-responsive photo-induced wettability transition and ROS generation for in situ water purification

A co-responsive material is successfully fabricated by coating nano-vanadium pentoxide/octadecylamine (nano-V2O5/ODA) onto a copper mesh via a hydrothermal reaction. “Co-response” means that a material can realize a multi-performance transition under one environmental stimulus. Nano-V2O5 provides the material with a photo-induced wettability transition and reactive oxygen species (ROS) generation properties, while ODA produces a superhydrophobic material in its initial state. As a result, this material can achieve a reversible superhydrophobic/superhydrophilic transition under 254 nm ultraviolet (UV) light. By combining the wettability transition with ROS generation properties, a smart mesh can realize in situ photo-controlled water purification, i.e., the controllable and simultaneous removal of the oil and soluble contaminants. An extra V2O5-coated mesh is used as an auxiliary mesh to improve the oil removal and ROS generation efficiencies. Moreover, the mesh exhibits satisfactory reusability and physical/chemical stability, which is more promising for practical applications such as remote controlled water purification, timed discharge of sewage and microfluidic valves.