Physically Cross-Linked Double-Network Hydrogel for High-Performance Oil–Water Separation Mesh

Porous materials have become a burgeoning research interest in materials science because of their intrinsic porous characteristics, versatile chemical compositions, and abundant functionalities. Re...

Double – network hydrogel based on exopolysaccharides as a biomimetic extracellular matrix to augment articular cartilage regeneration

As an effective EOR method, polymer flooding has been recognized all over the world for its excellent flooding effect under certain conditions, large scope of recovery percentage improvement and good economic benefit. However, because of the large quantity of polymer contained In the produced fluid from the polymer flooding areas, oil-water separation Is becoming more and more difficult. This article, based on the actural conditions of the polymer flooding pilots, and the data from the pilots, discuss the gravity settling separation characteristics and the characteristics of electro-chemical dehydration under the condition of produced fluid with various concentration of polymer, analyzing the effect of water phase viscosity increase of polymer onto the oil-water separation rate, oil-water emulslflcation intensity, water-cut varatlon of the produced fluid and the electrochemical dehydration. Some research directions and the problems which should be paid attention to are also put forward.

Green and environmentally friendly oil–water separation is an important technique for reducing environmental pollution. In this study, the oil–water separation effect of the super-hydrophilic copper net was optimized through numerical simulation and orthogonal experiments. To be specific, a super-hydrophilic copper net was prepared using the solution etching method to perform oil–water separation experiments, and a favorable oil–water separation effect was achieved. First, the influences of oil–water flow velocity, copper net mesh size, and surface wettability on the oil–water separation effect of the super-hydrophilic copper net were explored via single-factor experiments. The results showed that the oil resistance of the super-hydrophilic copper net degraded, and its oil–water separation effect became poor due to the increasing oil–water flow velocity, enlarged copper net mesh size, and reduced oil contact angle on the surface of the super-hydrophilic copper net. On this basis, the optimized oil–water separation parameters were obtained through orthogonal experiments. The optimized process parameters were as follows: velocity = 0.1 m/s, copper net mesh size = 30 μm, oil contact angle = 150°, and oil removal rate = 95.7%. Furthermore, the copper net was etched using sodium hydroxide and sodium persulfate mixed solution to prepare a 500-mesh super-hydrophilic copper net for the oil–water separation experiment and then the oil removal rate reached 96.4%. The study results provide a theoretical basis, method, and means for the practical application of super-hydrophilic copper nets.

A stable underwater superoleophobic membrane constructed by CuO oriented rods and PAA water-adsorbent resin for fast and high efficient oil–water separation

In the field of contemporary epidermal bioelectronics, there is a demand for energy supplies that are safe, lightweight, flexible and robust. In this work, double-network polymer hydrogels were synthesized by polymerization of 3,4-ethylenedioxythiophene (EDOT) into a poly(vinyl alcohol)/poly(ethylene glycol diacrylate) (PVA/PEGDA) double-network hydrogel matrix. The PEDOT-PVA/PEGDA double-network hydrogel shows both excellent mechanical and electrochemical performance, having a strain up to 498%, electrical conductivity as high as 5 S m-1 and specific capacitance of 84.1 ± 3.6 mF cm⁻2. After assembling two PEDOT-PVA/PEGDA double-network hydrogel electrodes with the free-standing boron cross-linked PVA/KCl hydrogel electrolyte, the formed supercapacitor device exhibits a specific capacitance of 54.5 mF cm⁻2 at 10 mV s-1, with an energy density of 4.7 μWh cm-2. The device exhibits excellent electrochemical stability with 97.6% capacitance retention after 3000 charging-discharging cycles. In addition, the hydrogel also exhibits great sensitivity to strains and excellent antifouling properties. It was also found that the abovementioned hydrogel can achieve stable signals under both small and large deformations as a flexible sensor. The flexible and antifouling PEDOT-PVA/PEGDA double-network hydrogel-based supercapacitor is a promising power storage device with potential applications in wearable electronics.

Direct coating of a DKGM hydrogel on glass fabric for multifunctional oil-water separation in harsh environments

Sultan Hasanuddin 02 Training Ship which is a place for learning theory and practice of students at the Makassar Maritime Polytechnic. So that in supporting its operations requires periodic maintenance management that will ensure smooth and optimal performance in all supporting aspects. Likewise in the implementation of regulations that have required all ships to operate to install an Oil Water Separator that can separate oil and water before being dumped / falling into the sea. The use of Oil Water Separator must be maximized so that it can work properly, so it is necessary to carry out periodic and regular maintenance, the importance of maintenance management aims to evaluate the performance and effectiveness of the Oil Water Separator (OWS) in managing oil waste on ships by improving and increasing effectiveness and productivity in the utilization process to support smooth ship operations. Before making preparations in the maintenance stage, it is better to first make a proper plan and in accordance with the guidelines and also pay attention to field conditions both in terms of human resources and supporting spare parts and appropriate equipment. This study aims to evaluate the performance and effectiveness of the Oil Water Separator (OWS) in managing oil waste on the Sultan Hasanuddin training ship. By looking at the ship's ability to manage oil waste properly which will provide a positive image for the ship's Officers and Crew who are responsible for the environment, support sustainable practices and can increase trust from regulators and customers. Based on the results of field observations, there is still effectiveness in OWS performance with routine maintenance showing better separation efficiency than those that are rarely checked. However, the level of cleanliness of the effluent of the maintained OWS ranges from 5-10 ppm, while the unmaintained OWS reaches 20-50 ppm. The availability of spare parts and the level of personnel training are significant challenges.

ABSTRACTDue to the discharge of oily wastewater and oil extraction activities, the oil content and soluble pollutants in water bodies are increasing, causing serious damage to the environment. Therefore, materials with superhydrophilicity and underwater superhydrophobicity have attracted much attention in the field of oil–water separation. In this study, a graphene oxide (GO) brush (polyacrylic acid [PAA], grafted on GO) high‐efficiency hydrogel oil–water separation membrane with superhydrophilicity in air and superhydrophobicity under water was prepared by regulating the hydrophilicity through nano‐microstructures. Vacuum‐assisted filtration was utilized to prepare GO brushes into membranes. Due to the good hydrophilicity of PAA chains, grafting them onto GO sheets enhanced the hydrophilicity of the membranes and increased the surface roughness. This modification significantly increased the pure water flux of the membrane (maximum value of 428.56 L m−2 h−1 bar−1). With the synergistic effect of hydration capacity and layered nanostructures, the GO‐PAA membrane possesses superhydrophobic and underwater superoleophobic properties. As a result, the oil–water separation rate of GO‐PAA2 membrane was greater than 99.12%, which could realize the separation of various oil–water emulsions. Compared with the pristine GO membranes, the graphene brush membranes formed after PAA chain‐branch polymerization have higher stability and durability, stronger hydrophilicity, higher oil–water separation efficiency, and better application prospects.

Blend PES/CA hydrophilic membranes were prepared via a phase-inversion process for oil–water separation. PEG-400 was introduced into the polymer solution in order to enhance phase-inversion and produce high permeability membranes. A gas permeation test was conducted to estimate mean pore size and surface porosity of the membranes. The membranes were characterized in terms of morphology, overall porosity, water contact angle, water flux and hydraulic resistance. A cross-flow separation system was used to evaluate oil–water separation performance of the membranes. From FESEM examination, the prepared PES/CA membrane presented thinner outer skin layer, higher surface porosity with larger pore sizes. The outer surface water contact angle of the prepared membrane significantly decreased when CA was added into the polymer solution. The higher water flux of the PES/CA membrane was related to the higher hydrophilicity and larger pore sizes of the membrane. From oil–water separation test, the PES/CA membrane showed stable oil rejection of 88 % and water flux of 27 l/m2 s after 150 min of the operation. In conclusion, by controlling fabrication parameters a developed membrane structure with high hydrophilicity, high surface porosity and low resistance can be achieved to improve oil rejection and water productivity.

Superhydrophilic and underwater superoleophobic surfaces were fabricated by facile spray coating of nanostructured WO3 on stainless steel meshes and compared its performance in oil–water separation with ZnO coated meshes. The gravity driven oil-water separation system was designed using these surfaces as the separation media and it was noticed that WO3 coated stainless steel mesh showed high separation efficiency (99%), with pore size as high as 150 µm, whereas ZnO coated surfaces failed in the process of oil-water separation when the pore exceeded 50 µm size. Since, nanostructured WO3 is a well known catalyst, the simultaneous photocatalytic degradation of organic pollutants present in the separated water from the oil water separation process were tested using WO3 coated surfaces under UV radiation and the efficiency of this degradation was found to be quite significant. These results assure that with little improvisation on the oil water separation system, these surfaces can be made multifunctional to work simultaneously for oil-water separation and demineralization of organic pollutants from the separated water. Fabrication of the separating surface, their morphological characteristics, wettability, oil water separation efficiency and photo-catalytic degradation efficiency are enunciated.

Eco-friendly superwettable functionalized-fabric with pH-bidirectional responsiveness for controllable oil-water and multi-organic components separation

Fabrication of superhydrophobic nano-aluminum films on stainless steel meshes by electrophoretic deposition for oil-water separation

Edible oil is essential for people’s daily lifebut alsoresults in a large amount of oily wastewater simultaneously. Oil–waterseparation is a practical route that can not only purify wastewaterbut also recycle valuable edible oil. In this study, the superhydrophobiccopper mesh (SCM) was prepared by chemical etching, and a novel oil–watercentrifugal device was designed for high-efficiency separation ofedible oil wastewater. The kernel is a self-prepared SCM, which hasa water contact angle (WCA) of 155.1 ± 1.8° and an oil contactangle (OCA) of 0°. Besides, the separation performance of theSCM for edible oil–water mixtures was studied in this study.The results showed that the SCM exhibited excellent oil/water separationperformance, with a separation efficiency of up to 96.7% for sunflowerseed oil–water wastewater, 93.3% for corn oil–waterwastewater, and 98.3% for peanut oil–water wastewater, respectively.Moreover, the separation efficiency was still over 90% after 18 cycles.A model was established to analyze the oil–water separationmechanism via centrifugation. The oil–water centrifugal separationdevice has great potential for scale-up applications.

Oil–water separation using porous superhydrophilic materials is a promising method to circumvent the issue of oil-polluted water by separating water from oil–water mixtures. However, fabricating metal-based porous superhydrophilic materials with stable superhydrophilicity that can recover their strong hydrophilicity and have acceptable oil–water separation efficiency without complex external stimuli is still a challenge. Inspired by the anti-wetting behavior of broccoli buds, this study successfully fabricated metal-based superhydrophilic and underwater superoleophobic porous materials by hydrothermal treatment of stainless steel meshes (SSMs) combined with magnetron sputtering of metallic Ti and W. The process was then followed with annealing at 300 °C for 4 hours. The effects of coating materials, annealing temperature, and surface structure on the wetting behavior of the prepared meshes were studied and analyzed. The modified meshes exhibited unique broccoli-like microstructures coated with thin TiO2−xNx/WO3 films and showed superhydrophilicity with a 0° water contact angle (WCA) and underwater superoleophobicity with underwater oil contact angles (UOCAs) higher than 155°. They also maintained strong hydrophilicity for more than three weeks with WCAs of less than 13°. Besides, they could recover their initial superhydrophilicity with a 0° WCA after post-annealing at 80 °C for 30 minutes. Notably, the broccoli-like structures and the strong hydrophilic coatings contributed to a significant water flow rate (Q) of 3650 L m−2 h−1 and satisfactory oil–water separation efficiency of 98% for more than 15 separation cycles toward various oil–water mixtures. We believe that the presented method and fabricated material are promising and can be applied to induce hydrophilicity of various metallic materials for practical applications of oil–water separation, anti-fouling, microfluidic transport, and water harvesting.