Tungsten (W) incorporated mobil-type eleven (MEL) zeolite membrane (referred to as W-MEL membrane) with high separation performance was firstly explored for the separation of oil/water mixtures under the influence of ...Tungsten (W) incorporated mobil-type eleven (MEL) zeolite membrane (referred to as W-MEL membrane) with high separation performance was firstly explored for the separation of oil/water mixtures under the influence of gravity.W-MEL membranes were grown on stainless steel (SS) meshes through in-situ hydrothermal growth method facilitated with (3-aminopropyl)triethoxysilane (APTES) modification of stainless steel meshes,which promote the heterogeneous nucleation and crystal growth of W-MEL zeolites onto the mesh surface.W-MEL membranes were grown on different mesh size supports to investigate the effect of mesh size on the separation performance of the membrane.The assynthesized W-MEL membrane supported on 500 mesh (25μm)(W-MEL-500) exhibit the hydrophilic nature with a water contact angle of 11.8°and delivers the best hexane/water mixture separation with a water flux and separation efficiency of 46247 L·m^(-2)·h^(-1)and 99.5%,respectively.The wettability of W-MEL membranes was manipulated from hydrophilic to hydrophobic nature by chemically modifying with the fluorine-free compounds (hexadecyltrimethoxysilane (HDTMS) and dodecyltrimethoxysilane(DDTMS)) to achieve efficient oil-permselective separation of heavy oils from water.Among the hydrophobically modified W-MEL membranes,W-MEL-500-HDTMS having a water contact angle of146.4°delivers the best separation performance for dichloromethane/water mixtures with a constant oil flux and separation efficiency of 61490 L·m^(-2)·h^(-1)and 99.2%,respectively along with the stability tested up to 20 cycles.Both W-MEL-500-HDTMS and W-MEL-500-DDTMS membranes also exhibit similar separation performances for the separation of heavy oil from sea water along with a 20-fold lower corrosion rate in comparison with the bare stainless-steel mesh,indicating their excellent stability in seawater.Compared to the reported zeolite membranes for oil/water separation,the as-synthesized and hydrophobically modified W-MEL membranes shows competitive separation performances in terms of flux and separation efficiency,demonstrating the good potentiality for oil/water separation.展开更多
The membrane method based on adaptive wettability shows great advantages in oil-water separation.At present,researches focus on the excellent application performance of the membrane material,while the quantitative ana...The membrane method based on adaptive wettability shows great advantages in oil-water separation.At present,researches focus on the excellent application performance of the membrane material,while the quantitative analysis of interactions in oil-water separation is rarely recognized.Herein,we constructed an adaptable wettability membrane with multiple polymer networks by polydopamine(PDA)and mussel-inspired amphiphilic polymer.Based on the Owens three-probe liquid method,the surface energy of the modified membrane was verified to meet the adaptive wettability conditions,with surface energies(γ-8)of 147.6 mJ m^(−2)(superhydrophilic/underwater superoleophobic)and 49.87 mJ m^(−2)(superhydrophobic/superoleophobic),respectively.The adhesion or repulsion of the membrane to the oil phase under different conditions during the separation process was quantified by the chemical probe AFM technique.In addition,the oil-water selective separation mechanism was further analyzed in a simplified membrane microchannel model.The results show that the different wetting produces capillary additional pressure in opposite directions,resulting in different energies to be overcome when the oil or water passes through the microchannels,thus achieving selective separation.展开更多
In this paper, the superhydrophobic polyurethane sponge(SS-PU) was facilely fabricated by etching with Jones reagent to bind the nanoparticles of Ni-Co double layered oxides(LDOs) on the surface, and following modific...In this paper, the superhydrophobic polyurethane sponge(SS-PU) was facilely fabricated by etching with Jones reagent to bind the nanoparticles of Ni-Co double layered oxides(LDOs) on the surface, and following modification with n-dodecyl mercaptan(DDT). This method provides a new strategy to fabricate superhydrophobic PU sponge with a water contact angle of 157° for absorbing oil with low cost and in large scale. It exhibits the strong absorption capacity and highly selective characteristic for various kinds of oils which can be recycled by simple squeezing. Besides, the as-prepared sponge can deal with the floating and underwater oils, indicating its application value in handling oil spills and domestic oily wastewater. The good self-cleaning ability shows the potential to clear the pollutants due to the ultralow adhesion to water. Especially, the most important point is that the superhydrophobic sponge can continuously and effectively separate the oil/water mixture against the condition of turbulent disturbance by using our designed device system, which exhibit its good superhydrophobicity, strong stability.Furthermore, the SS-PU still maintained stable absorption performance after 150 cycle tests without losing capacity obviously, showing excellent durability in long-term operation and significant potential as an efficient absorbent in large-scale dispose of oily water.展开更多
Industrial production and domestic discharge produce a large amount of oily wastewater, which seriously affects the stability of the ecological environment. Membrane separation technology provides another path to trea...Industrial production and domestic discharge produce a large amount of oily wastewater, which seriously affects the stability of the ecological environment. Membrane separation technology provides another path to treating oily wastewater. And appropriate surface modification of the membrane helps to achieve high efficiency of treating oily wastewater. With green, economy and stability been more concerned.The focal research reports a completely biodegradable all cellulose composite filter paper(ACCFP) composed of Ⅰ-cellulose macrofibers and Ⅱ-cellulose matrix. It is a simple one-step impregnation method to adjust the surface microstructure of the pristine filter paper(PFP), and it does not involve with chemical reaction. The pre-wetted ACCFP consist of Ⅱ-cellulose hydrogel and Ⅰ-cellulose reinforcement in the process of oil-water separation. This layer of hydrogel is the fundamental to underwater superoleophobicity, which determines their eligibility for applications of efficient oil-water mixture or oil-in-water(oil/water) emulsion separation. The separation efficiency of oil-water mixture and oil/water emulsion exceed 95% and 99.9%, respectively. In addition, excellent mechanical properties of ACCFP in dry and wet conditions ensure its stability in service and prolong service life in applications. The focal study provides a new method for high-performance oil-water separation and it is more in line with sustainable chemistry.展开更多
Developing an effective and mechanically durable biomimetic membrane for the separation of highly emulsified aqueous oil is significant but challenging owing to its low water flux and serious membrane fouling.In this ...Developing an effective and mechanically durable biomimetic membrane for the separation of highly emulsified aqueous oil is significant but challenging owing to its low water flux and serious membrane fouling.In this work,a biomimetic membrane with superhydrophobicity and superoleophilicity was rationally developed via co-electrospinning of polysulfonamide/polyacrylonitrile(PSA/PAN)emulsion solution,followed by decorating of a-Fe2 O_(3) nanowire onto the membrane surface to create membrane roughness,and grafting of 1 H,1 H,2 H,2 H-perfluorododecyltrichlorosilane(FTCS)to lower membrane surface free energy.Benefiting from the nanowire-wrapped rough membrane structure and the low surface free energy FTCS,the resultant membrane showed superhydrophobicity with a high water contact angle(WCA)of 156°,superoleophilicity with a low oil contact angle(OCA)of 0°,which can separate the highly emulsified aqueous oil with an ultrahigh permeation flux over 7000 L m2 h-1 and high separation efficiency of about 99%.Significantly,the biomimetic membrane also displayed robust stability for long-te rm separation owing to its adva ntage of antifouling property,showing great potential applications in large-scale aqueous oil treatment.展开更多
Discharging untreated oily wastewater into the environment disrupts the ecological balance,which is a global problem that requires urgent solutions.Superhydrophilic and superoleophilic fibrous medium(FM)effectively se...Discharging untreated oily wastewater into the environment disrupts the ecological balance,which is a global problem that requires urgent solutions.Superhydrophilic and superoleophilic fibrous medium(FM)effectively separated oil–water emulsion as it was hydrophobic underwater.But its separation efficiencies(SEs)first increased to 98.9%,then dropped to 97.6%in 10 min because of oil-fouling.To tackle this problem,FM deposited with 0%–10%silica nanoparticle(NPsFMs),then coated by fluorocarbon polymer(X-[CH_(2)CH_(2)O]nCH_(2)CH_(2)O-Y-NH-COOCH_(2)C4F9)(FCNPs FMs),was used to enhance its roughness and regulate its initial wettability to improve the anti-fouling property.FCFM and FCNPs FMs were hydrophobic and oleophobic in air and oleophobic underwater.Their water contact angles,oil contact angles and oil contact angles were 115.3°–121.1°,128.8°–136.5°,and 131.6°–136.7°,respectively,meeting the requirement of 90°–140°for coalescence separation.FCNPs FM-5 had the best separation performance with a constant value of 99.8%in 10 min,while that of FCNPs FM-10 slightly decreased to 99.5%.Theoretical released droplet(TRD)diameter,calculated by the square root of the product of pore radius and fiber diameter,was used for the evaluation of coalescence performance.Analyzed by two ideal models,TRD diameter and fiber diameter showed a parabola type relationship,proving that the separation efficiency was a collaborative work of wettability,pore size and fiber diameter.Also,it explained the SEs reduction from FCNPs FM-5 to FCNPs FM-10 was revelent to the three parameters.Moreover,FCNPsFMs effectively separated emulsions stabilized by cationic surfactant CTAB(SEs:97.3%–98.4%)and anionic surfactant SDBS(SEs:91.3%–93.4%).But they had an adverse effect on nonionic surfactant Tween-80 emulsion separation(SEs:94.0%–71.76%).Emulsions made by diverse oils can be effectively separated:octane(SEs:99.4%–100%),rapeseed oil(SEs:97.3%–98.8%),and diesel(SEs:95.2%–97.0%).These findings provide new insights for designing novel materials for oil–water separation by coalescence mechanism.展开更多
The cyclonic-static microbubble flotation column has dual effects including the cyclonic separation and floatation separation with the characteristics of the small lower limit of the effective separation size, short s...The cyclonic-static microbubble flotation column has dual effects including the cyclonic separation and floatation separation with the characteristics of the small lower limit of the effective separation size, short separation time, large handling capacity, and low operation cost. It shows significant advantages in the oily wastewater treatment field, especially the polymer flooding oily wastewater treatment aspect. In this paper, the cyclonic separation function mechanism of the cyclonic-static microbubble flotation column was studied, the impact of the parameters including the feeding rate, aeration rate, circulating pressure, and underflow split ratio on the cyclonic separation efficiency was investigated, and the cyclonic separation efficiency model was established as well. In addition, by applying the Doppler Laser Velocimeter (LDV) and Fluent simulation software, the test and simulation to the single-phase flow velocity field of the cyclonic separation section of the cyclonic-static microbubble flotation column were carried out, and the velocity distribution rule of the cyclonic separation section was analyzed under the singlephase flow conditions.展开更多
Considering the serious environmental pollution and economic losses caused by increasing oil spills and chemical leaks,effective and eco-friendly methods of oil/water separation should be urgently developed.Herein,a f...Considering the serious environmental pollution and economic losses caused by increasing oil spills and chemical leaks,effective and eco-friendly methods of oil/water separation should be urgently developed.Herein,a facile strategy(about 20 min)was developed for integrating covalent organic framework(COF)particles with melamine sponges(MS)by covalent bonding,and then a superhydrophobic COF/MS composite(denoted OA-CP@MS)could be further obtained by following modification with a 1-octadecylamine/water dispersion.Specifically,the synthesis process was developed under a mild condition that avoids the need for sealing and high-temperature treatments.It was proven that the fabricated OA-CP@MS presented a prominent absorption capacity for various organic reagents,in which adsorption capacity of chloroform could be up to 173 g/g.Owing to its excellent chemical robustness in strong alkaline and saline environments and in various organic solvents,the prepared OACP@MS showed a great potential to perform oil/water separation in complex practical conditions.Its rapid preparation process,fluorine-free treatment,and water-based modification would extend the application of COF materials in oil/water separation.展开更多
It is of great necessity yet still a challenge to develop superwetting functional interfacial materials for simultaneously separating insoluble oil and degrading soluble dye pollutants in practical wastewater.In this ...It is of great necessity yet still a challenge to develop superwetting functional interfacial materials for simultaneously separating insoluble oil and degrading soluble dye pollutants in practical wastewater.In this work,a Ag-CuO heterostructure-decorated mesh was fabricated via facile alkali etchingcalcination and photoreduction approaches.The as-synthesized mesh with superhydrophilicity and underwater superoleophobicity displayed high separation efficiency(>99.998%)for diverse oil/water mixtures.Besides,it demonstrated more superior photocatalytic performance in dye degradation than those of bare CuO nanostructure-coated materials,which is primarily attributed to the intensive visible light harvesting and efficient electron-holes separation occurred on noble metal-semiconductor heterostructures.Furthermore,on account of the tenacity of Cu substrate as well as enhanced structural stability,this binary composite-decorated mesh exhibited highly reliable durability and robustness after 10 cycles of photocatalytic degradation tests,and even being ultrasonic worn for 30 min.More importantly,our developed mesh was capable of in situ catalytic degrading water-soluble organic dyes during oil/water separation under visible light irradiation.Therefore,such a dexterous and feasible strategy may afford a new route to construct bifunctional and predurable materials for actual sewage purification.展开更多
The influence of the structure and running parameters of a novel spiral oil wedge hybrid journal bearing on the fluid flow trace is investigated. The governing equation of the flow trace of lubricant is set up, and th...The influence of the structure and running parameters of a novel spiral oil wedge hybrid journal bearing on the fluid flow trace is investigated. The governing equation of the flow trace of lubricant is set up, and the simulation is carried out by using finite difference method. The results show that the lubricant flow status and end leakage quantity are greatly influenced by spiral angle,and that the rotating speed has little influence on the flow status. With advisable geometry design, the separation of lubricant between different oil wedges can be obtained, which can decrease the temperature rise effectively.展开更多
This paper presents a superhydrophobic melamine(ME)sponge(ME-g-PLMA)prepared via high-energy radiation-induced in situ covalent grafting of long-alkyl-chain dodecyl methacrylate(LMA)onto an ME sponge for efficient oil...This paper presents a superhydrophobic melamine(ME)sponge(ME-g-PLMA)prepared via high-energy radiation-induced in situ covalent grafting of long-alkyl-chain dodecyl methacrylate(LMA)onto an ME sponge for efficient oil–water separation.The obtained ME-g-PLMA sponge had an excellent pore structure with superhydrophobic(water contact angle of 154°)and superoleophilic properties.It can absorb various types of oils up to 66–168 times its mass.The ME-g-PLMA sponge can continuously separate oil slicks in water by connecting a pump or separating oil underwater with a gravity-driven device.In addition,it maintained its highly hydrophobic properties even after long-term immersion in different corrosive solutions and repeated oil adsorption.The modified ME-g-PLMA sponge exhibited excellent separation properties and potential for oil spill cleanup.展开更多
This article outlines the development of separated zone oil production in foreign countries,and details its development in China.According to the development process,production needs,technical characteristics and adap...This article outlines the development of separated zone oil production in foreign countries,and details its development in China.According to the development process,production needs,technical characteristics and adaptability of oilfields in China,the development of separate zone oil production technology is divided into four stages:flowing well zonal oil production,mechanical recovery and water blocking,hydraulically adjustable zonal oil production,and intelligent zonal production.The principles,construction processes,adaptability,advantages and disadvantages of the technology are introduced in detail.Based on the actual production situation of the oilfields in China at present,three development directions of the technology are proposed.First,the real-time monitoring and adjustment level of separated zone oil production needs to be improved by developing downhole sensor technology and two-way communication technology between ground and downhole and enhancing full life cycle service capability and adaptability to horizontal wells.Second,an integrated platform of zonal oil production and management should be built using a digital artificial lifting system.Third,integration of injection and production should be implemented through large-scale application of zonal oil production and zonal water injection to improve matching and adjustment level between the injection and production parameters,thus making the development adjustment from"lag control"to"real-time optimization"and improving the development effect.展开更多
This paper presents experimental results of cocracking of straight-run gasoline (SRG) and light gaS oil (LGO) in an improved pulsed-micro-pyrolyzer. It is shown that there are negative opergistic effect on the yields ...This paper presents experimental results of cocracking of straight-run gasoline (SRG) and light gaS oil (LGO) in an improved pulsed-micro-pyrolyzer. It is shown that there are negative opergistic effect on the yields and selectivities of ethylene and propylene in cocracking. The difference in coking tendencies betWeen the cocracking and the separate cracking is compared as well.展开更多
In recent years,numerous studies have been reported for oil/water separation,such as superoleophilic materials for oil absorption and underwater superoleophobic membranes for continuous separation.However,for the reco...In recent years,numerous studies have been reported for oil/water separation,such as superoleophilic materials for oil absorption and underwater superoleophobic membranes for continuous separation.However,for the recovery of oil slick pollution on near-shore ocean surface caused by various reasons,large area and fast availability of used materials are needed to be considered.Herein,we report an efficient and environmentally friendly method to fast process nylon mesh by surface diffuse atmospheric plasma(SDAP)for large-area oil/water separation.Nylon mesh is funcionalized by atmospheric plasma to generate micro/nano composite structures on the surface,resulting in superhydrophilicity and underwater superoleophobicity within only seconds.The pre-wetted modified nylon mesh can achieve high efficiency(>99.9%)and circulating water flux(~30,000 L·m^(-2)·h^(-1)),with high intrusion pressure(~3 kPa)and universality in oil/water separation.Regular plasma unconditionally generated in the atmosphere with the merit of efficiently functionalizing surface has the potential of large-area materials treatment.This study might take one step further for large-area industrial oily wastewater recovery and even oil slicks collection in near-shore water bodies.展开更多
A high performance preoxidized poly(acrylonitrile)(O-PAN)nanofiber membrane with excellent solvent resistance,thermal stability and flexibility was fabricated by the preoxidation of electrospun PAN nanofiber membrane....A high performance preoxidized poly(acrylonitrile)(O-PAN)nanofiber membrane with excellent solvent resistance,thermal stability and flexibility was fabricated by the preoxidation of electrospun PAN nanofiber membrane.The performance of resultant O-PAN nanofiber membrane was optimized by altering the PAN concentration and preoxidation temperature.The results showed that the O-PAN nanofiber membrane which made from PAN concentration of 14%(mass)and preoxidation temperature of 250.0℃ have a more optimal comprehensive performance.In the long-term separation test of SiO2 particle(1 μm)in DMAc suspension,the permeate flux of O-PAN nanofiber membrane stabilized at 227.91 L·m^(-2)·h^(-1)(25℃,0.05 MPa)while the SiO2 rejection above 99.6%,which showed excellent solvent resistance and separation performance.In order to further explore the application of the O-PAN nanofiber membrane,the OPAN nanofiber membrane was treated with fluoride and used in oil/water separation process.The O-PAN nanofiber membrane after hydrophobic treatment showed excellent hydrophobicity and good oil/water separation performance with the permeate flux about 969.59 L·m^(-2)·h^(-1)while the separation efficiency above 96.1%.The O-PAN nanofiber membrane exhibited a potential application prospect in harsh environment separation.展开更多
Because of the increasing amount of oily wastewater produced each day,it is important to develop superhydrophilic/underwater superoleophobic oil/water separation membranes with ultrahigh flux and high separation effic...Because of the increasing amount of oily wastewater produced each day,it is important to develop superhydrophilic/underwater superoleophobic oil/water separation membranes with ultrahigh flux and high separation efficiency.In this paper,a superhydrophilic/underwater superoleophobic N-isopropylacrylamide-coated stainless steel mesh was prepared through a simple and convenient graft polymerization approach.The obtained mesh was able to separate oil/water mixtures only by gravity.In addition,the mesh showed high-efficiency separation ability(99.2%)and ultrahigh flux(235239 L·m^(−2)·h^(−1)).Importantly,due to the complex cross-linked bilayer structure,the prepared mesh exhibited good recycling performance and chemical stability in highly saline,alkaline and acidic environments.展开更多
Currently,most of the materials for oil-water separation membranes are limited to fluorine-based polymers with low surface energy.However,it is not biodegradable and requires large amounts of organic and toxic solvent...Currently,most of the materials for oil-water separation membranes are limited to fluorine-based polymers with low surface energy.However,it is not biodegradable and requires large amounts of organic and toxic solvents in the membrane manufacturing process.Therefore,interest in the development of a new eco-friendly oil-water separation membrane that does not cause secondary pollution and exhibits selective wettability characteristics in water or oil is increasing.The biopolymeric nanofibrous membranes inspired by fish skin can provide specific underwater oleophobicity,which is effective for excellent oil-water separation efficiency and prevention of secondary contamination.Fish gelatin,which is highly soluble in water and has a low gelation temperature,can be electrospun in an aqueous solution and has the same polar functional groups as the hydrophilic mucilage of fish skin.In addition,the micro/nanostructure of fish skin,which induces superoleophobicity in water,introduces a bead-on-string structure using the Rayleigh instability of electrospinning.The solubility of fish gelatin in water was removed using an eco-friendly crosslinking method using reducing sugars.Fish skin-mimicking materials successfully separated suspended oil and emulsified oil,with a maximum flux of 2086 Lm^(−2) h^(−1) and a separation efficiency of more than 99%.The proposed biopolymeric nanofibrous membranes use fish gelatin,which can be extracted from fish waste and has excellent biodegradability with excellent oil-water separation performance.In addition,polymer material processing,including membrane manufacturing and crosslinking,can be realized through eco-friendly processes.Therefore,fish skin-inspired biopolymeric membrane is expected to be a promising candidate for a sustainable and effective oil-water separation membrane in the future.展开更多
The clearwater obtained from stabilized oily wastewater has become a worldwide challenge.Nowdays,the area of oil/water emulsion separation materials have accomplished great progress,but still faces the enormous proble...The clearwater obtained from stabilized oily wastewater has become a worldwide challenge.Nowdays,the area of oil/water emulsion separation materials have accomplished great progress,but still faces the enormous problems of low flux,poor stability,and pollution resistance.Nanocelluloses(cellulose nanocrystals(CNC))with the advantages of hydrophilicity,ecofriendliness,and regeneration are ideal materials for the construction of separation membranes.In this paper,a flexible,antifouling,and durable nanocellulose-based membrane functionalized by block copolymer(poly(N-isopropylacrylamide)-b-poly(N,Ndimethylaminoethyl methacrylate))is prepared via chemical modification and self-assembly,showing high separation efficiency(above 99.6%)for stabilized oil-in-water emulsions,excellent anti-fouling and cycling stability,high-temperature resistance,and acid and alkali resistance.More importantly,the composite membrane has ultra-high flux in separating oil-in-water emulsions(29,003 L·m^(−2)·h^(−1)·bar^(−1))and oil/water mixture(51,444 L·m^(−2)·h^(−1)·bar^(−1)),which ensures high separation efficiency.With its durability,easy scale-up,and green regeneration,we envision this biomass-derived membrane will be an alternative to the existing commercial filter membrane in environmental remediation.展开更多
Oil pollution is a serious environmental and natural resource problem.Traditional adsorption materials for oil–water separation have limitations in terms of their preparation cost,reusability,and mechanical propertie...Oil pollution is a serious environmental and natural resource problem.Traditional adsorption materials for oil–water separation have limitations in terms of their preparation cost,reusability,and mechanical properties.Among the conventional adsorption materials,super-hydrophobic/super-lipophilic materials are easily contaminated by oil.In this study,polypropylene(PP)is used as a foam substrate to prepare an open-cell PP foam via hot pressing,supercritical CO_(2) foaming,and electron beam(EB)irradiation.The impact of EB irradiation dose on the open-cell content of PP foam can lead to cell wall rupture,resulting in an open-cell structure that enhances oil-water separation performance.At an absorbed radiation dose of 200 kGy,the PP foams exhibit optimal oil–water separation performance,cyclic compression stability,heat insulation,and preparation cost.The open-cell content of PP foam is increased to 86.5%,the adsorption capacity for diesel oil is 42.8 g/g,and the adsorption efficiency remains at 99.6%after 100 cycles of oil desorption in a complex pH environment.Meanwhile,cracks and nano-voids simultaneously promote the capillary action of oil,and the oil transport rate is 0.0713 g/(g·s).This study provides a new concept for the preparation of open-cell polymer foams that can meet the demand for high oil-absorption capacity under complex acid-base pH conditions.展开更多
基金Financial support from the Science Fund for Creative Research Groups of the National Science Foundation of China (22021005)the National Natural Science Foundation of China (21776032)the Innovation Team of Dalian University of Technology (DUT2017TB01)。
文摘Tungsten (W) incorporated mobil-type eleven (MEL) zeolite membrane (referred to as W-MEL membrane) with high separation performance was firstly explored for the separation of oil/water mixtures under the influence of gravity.W-MEL membranes were grown on stainless steel (SS) meshes through in-situ hydrothermal growth method facilitated with (3-aminopropyl)triethoxysilane (APTES) modification of stainless steel meshes,which promote the heterogeneous nucleation and crystal growth of W-MEL zeolites onto the mesh surface.W-MEL membranes were grown on different mesh size supports to investigate the effect of mesh size on the separation performance of the membrane.The assynthesized W-MEL membrane supported on 500 mesh (25μm)(W-MEL-500) exhibit the hydrophilic nature with a water contact angle of 11.8°and delivers the best hexane/water mixture separation with a water flux and separation efficiency of 46247 L·m^(-2)·h^(-1)and 99.5%,respectively.The wettability of W-MEL membranes was manipulated from hydrophilic to hydrophobic nature by chemically modifying with the fluorine-free compounds (hexadecyltrimethoxysilane (HDTMS) and dodecyltrimethoxysilane(DDTMS)) to achieve efficient oil-permselective separation of heavy oils from water.Among the hydrophobically modified W-MEL membranes,W-MEL-500-HDTMS having a water contact angle of146.4°delivers the best separation performance for dichloromethane/water mixtures with a constant oil flux and separation efficiency of 61490 L·m^(-2)·h^(-1)and 99.2%,respectively along with the stability tested up to 20 cycles.Both W-MEL-500-HDTMS and W-MEL-500-DDTMS membranes also exhibit similar separation performances for the separation of heavy oil from sea water along with a 20-fold lower corrosion rate in comparison with the bare stainless-steel mesh,indicating their excellent stability in seawater.Compared to the reported zeolite membranes for oil/water separation,the as-synthesized and hydrophobically modified W-MEL membranes shows competitive separation performances in terms of flux and separation efficiency,demonstrating the good potentiality for oil/water separation.
基金We gratefully acknowledge the financial support from National Key Research and Development Project,China(2019YFA0708700)the National Natural Science Foundation of China(52222403,52074333)the Innovation Fund Project for graduate students of China University of Petroleum(East China)(22CX04049A).
文摘The membrane method based on adaptive wettability shows great advantages in oil-water separation.At present,researches focus on the excellent application performance of the membrane material,while the quantitative analysis of interactions in oil-water separation is rarely recognized.Herein,we constructed an adaptable wettability membrane with multiple polymer networks by polydopamine(PDA)and mussel-inspired amphiphilic polymer.Based on the Owens three-probe liquid method,the surface energy of the modified membrane was verified to meet the adaptive wettability conditions,with surface energies(γ-8)of 147.6 mJ m^(−2)(superhydrophilic/underwater superoleophobic)and 49.87 mJ m^(−2)(superhydrophobic/superoleophobic),respectively.The adhesion or repulsion of the membrane to the oil phase under different conditions during the separation process was quantified by the chemical probe AFM technique.In addition,the oil-water selective separation mechanism was further analyzed in a simplified membrane microchannel model.The results show that the different wetting produces capillary additional pressure in opposite directions,resulting in different energies to be overcome when the oil or water passes through the microchannels,thus achieving selective separation.
基金the financial support from National Key Research & Development Program of China (2017B0602702)。
文摘In this paper, the superhydrophobic polyurethane sponge(SS-PU) was facilely fabricated by etching with Jones reagent to bind the nanoparticles of Ni-Co double layered oxides(LDOs) on the surface, and following modification with n-dodecyl mercaptan(DDT). This method provides a new strategy to fabricate superhydrophobic PU sponge with a water contact angle of 157° for absorbing oil with low cost and in large scale. It exhibits the strong absorption capacity and highly selective characteristic for various kinds of oils which can be recycled by simple squeezing. Besides, the as-prepared sponge can deal with the floating and underwater oils, indicating its application value in handling oil spills and domestic oily wastewater. The good self-cleaning ability shows the potential to clear the pollutants due to the ultralow adhesion to water. Especially, the most important point is that the superhydrophobic sponge can continuously and effectively separate the oil/water mixture against the condition of turbulent disturbance by using our designed device system, which exhibit its good superhydrophobicity, strong stability.Furthermore, the SS-PU still maintained stable absorption performance after 150 cycle tests without losing capacity obviously, showing excellent durability in long-term operation and significant potential as an efficient absorbent in large-scale dispose of oily water.
基金the financial support from the National Key R&D Program of China (no. 2018YFB1501602)Science Foundation of Shanxi Province, China (Grant no. 201901D111006ZD)+1 种基金Fund for Shanxi “1331 project”Shanxi Province Platform Base and Talent Special Fund (no. 201705D211023)。
文摘Industrial production and domestic discharge produce a large amount of oily wastewater, which seriously affects the stability of the ecological environment. Membrane separation technology provides another path to treating oily wastewater. And appropriate surface modification of the membrane helps to achieve high efficiency of treating oily wastewater. With green, economy and stability been more concerned.The focal research reports a completely biodegradable all cellulose composite filter paper(ACCFP) composed of Ⅰ-cellulose macrofibers and Ⅱ-cellulose matrix. It is a simple one-step impregnation method to adjust the surface microstructure of the pristine filter paper(PFP), and it does not involve with chemical reaction. The pre-wetted ACCFP consist of Ⅱ-cellulose hydrogel and Ⅰ-cellulose reinforcement in the process of oil-water separation. This layer of hydrogel is the fundamental to underwater superoleophobicity, which determines their eligibility for applications of efficient oil-water mixture or oil-in-water(oil/water) emulsion separation. The separation efficiency of oil-water mixture and oil/water emulsion exceed 95% and 99.9%, respectively. In addition, excellent mechanical properties of ACCFP in dry and wet conditions ensure its stability in service and prolong service life in applications. The focal study provides a new method for high-performance oil-water separation and it is more in line with sustainable chemistry.
基金the National Natural Science Foundation of China(No.51873047)the Fundamental Research Funds for the Central Unive rsities(No.30919011266)+1 种基金the Key Laboratory of Low-Carbon Conversion Science&Engineering,Shanghai Advanced Research Institute,Chinese Academy of Sciences(No.KLLCCSE-201906)the Open Founds for LargeScale Instruments and Equipment of Nanjing University of Science and Technology。
文摘Developing an effective and mechanically durable biomimetic membrane for the separation of highly emulsified aqueous oil is significant but challenging owing to its low water flux and serious membrane fouling.In this work,a biomimetic membrane with superhydrophobicity and superoleophilicity was rationally developed via co-electrospinning of polysulfonamide/polyacrylonitrile(PSA/PAN)emulsion solution,followed by decorating of a-Fe2 O_(3) nanowire onto the membrane surface to create membrane roughness,and grafting of 1 H,1 H,2 H,2 H-perfluorododecyltrichlorosilane(FTCS)to lower membrane surface free energy.Benefiting from the nanowire-wrapped rough membrane structure and the low surface free energy FTCS,the resultant membrane showed superhydrophobicity with a high water contact angle(WCA)of 156°,superoleophilicity with a low oil contact angle(OCA)of 0°,which can separate the highly emulsified aqueous oil with an ultrahigh permeation flux over 7000 L m2 h-1 and high separation efficiency of about 99%.Significantly,the biomimetic membrane also displayed robust stability for long-te rm separation owing to its adva ntage of antifouling property,showing great potential applications in large-scale aqueous oil treatment.
基金supported by the National Key Research and Development Program of China under the contract number of 2017YFB0308000Program of Innovation Academy for Green Manufacture,CAS(IAGM2020C04)+1 种基金the State Key Laboratory of Heavy Oil Processing(SKLOP201903001)Key Research and Development Program of Hebei Province,China(20374001D)。
文摘Discharging untreated oily wastewater into the environment disrupts the ecological balance,which is a global problem that requires urgent solutions.Superhydrophilic and superoleophilic fibrous medium(FM)effectively separated oil–water emulsion as it was hydrophobic underwater.But its separation efficiencies(SEs)first increased to 98.9%,then dropped to 97.6%in 10 min because of oil-fouling.To tackle this problem,FM deposited with 0%–10%silica nanoparticle(NPsFMs),then coated by fluorocarbon polymer(X-[CH_(2)CH_(2)O]nCH_(2)CH_(2)O-Y-NH-COOCH_(2)C4F9)(FCNPs FMs),was used to enhance its roughness and regulate its initial wettability to improve the anti-fouling property.FCFM and FCNPs FMs were hydrophobic and oleophobic in air and oleophobic underwater.Their water contact angles,oil contact angles and oil contact angles were 115.3°–121.1°,128.8°–136.5°,and 131.6°–136.7°,respectively,meeting the requirement of 90°–140°for coalescence separation.FCNPs FM-5 had the best separation performance with a constant value of 99.8%in 10 min,while that of FCNPs FM-10 slightly decreased to 99.5%.Theoretical released droplet(TRD)diameter,calculated by the square root of the product of pore radius and fiber diameter,was used for the evaluation of coalescence performance.Analyzed by two ideal models,TRD diameter and fiber diameter showed a parabola type relationship,proving that the separation efficiency was a collaborative work of wettability,pore size and fiber diameter.Also,it explained the SEs reduction from FCNPs FM-5 to FCNPs FM-10 was revelent to the three parameters.Moreover,FCNPsFMs effectively separated emulsions stabilized by cationic surfactant CTAB(SEs:97.3%–98.4%)and anionic surfactant SDBS(SEs:91.3%–93.4%).But they had an adverse effect on nonionic surfactant Tween-80 emulsion separation(SEs:94.0%–71.76%).Emulsions made by diverse oils can be effectively separated:octane(SEs:99.4%–100%),rapeseed oil(SEs:97.3%–98.8%),and diesel(SEs:95.2%–97.0%).These findings provide new insights for designing novel materials for oil–water separation by coalescence mechanism.
基金the National Natural Science Foundation of China (No. 50974119) for the financial support for this project
文摘The cyclonic-static microbubble flotation column has dual effects including the cyclonic separation and floatation separation with the characteristics of the small lower limit of the effective separation size, short separation time, large handling capacity, and low operation cost. It shows significant advantages in the oily wastewater treatment field, especially the polymer flooding oily wastewater treatment aspect. In this paper, the cyclonic separation function mechanism of the cyclonic-static microbubble flotation column was studied, the impact of the parameters including the feeding rate, aeration rate, circulating pressure, and underflow split ratio on the cyclonic separation efficiency was investigated, and the cyclonic separation efficiency model was established as well. In addition, by applying the Doppler Laser Velocimeter (LDV) and Fluent simulation software, the test and simulation to the single-phase flow velocity field of the cyclonic separation section of the cyclonic-static microbubble flotation column were carried out, and the velocity distribution rule of the cyclonic separation section was analyzed under the singlephase flow conditions.
基金supported by the National Natural Science Foundation of China(Grant No.21876073)the Natural Science Foundation of Gansu Province,China(Grant No.20JR5RA235)。
文摘Considering the serious environmental pollution and economic losses caused by increasing oil spills and chemical leaks,effective and eco-friendly methods of oil/water separation should be urgently developed.Herein,a facile strategy(about 20 min)was developed for integrating covalent organic framework(COF)particles with melamine sponges(MS)by covalent bonding,and then a superhydrophobic COF/MS composite(denoted OA-CP@MS)could be further obtained by following modification with a 1-octadecylamine/water dispersion.Specifically,the synthesis process was developed under a mild condition that avoids the need for sealing and high-temperature treatments.It was proven that the fabricated OA-CP@MS presented a prominent absorption capacity for various organic reagents,in which adsorption capacity of chloroform could be up to 173 g/g.Owing to its excellent chemical robustness in strong alkaline and saline environments and in various organic solvents,the prepared OACP@MS showed a great potential to perform oil/water separation in complex practical conditions.Its rapid preparation process,fluorine-free treatment,and water-based modification would extend the application of COF materials in oil/water separation.
基金supported by the National Natural Science Foundation of China(21303232)the China Postdoctoral Science Foundation(2018M632610)
文摘It is of great necessity yet still a challenge to develop superwetting functional interfacial materials for simultaneously separating insoluble oil and degrading soluble dye pollutants in practical wastewater.In this work,a Ag-CuO heterostructure-decorated mesh was fabricated via facile alkali etchingcalcination and photoreduction approaches.The as-synthesized mesh with superhydrophilicity and underwater superoleophobicity displayed high separation efficiency(>99.998%)for diverse oil/water mixtures.Besides,it demonstrated more superior photocatalytic performance in dye degradation than those of bare CuO nanostructure-coated materials,which is primarily attributed to the intensive visible light harvesting and efficient electron-holes separation occurred on noble metal-semiconductor heterostructures.Furthermore,on account of the tenacity of Cu substrate as well as enhanced structural stability,this binary composite-decorated mesh exhibited highly reliable durability and robustness after 10 cycles of photocatalytic degradation tests,and even being ultrasonic worn for 30 min.More importantly,our developed mesh was capable of in situ catalytic degrading water-soluble organic dyes during oil/water separation under visible light irradiation.Therefore,such a dexterous and feasible strategy may afford a new route to construct bifunctional and predurable materials for actual sewage purification.
基金This project is supported by National Natural Science Foundation of China (No.50275089)
文摘The influence of the structure and running parameters of a novel spiral oil wedge hybrid journal bearing on the fluid flow trace is investigated. The governing equation of the flow trace of lubricant is set up, and the simulation is carried out by using finite difference method. The results show that the lubricant flow status and end leakage quantity are greatly influenced by spiral angle,and that the rotating speed has little influence on the flow status. With advisable geometry design, the separation of lubricant between different oil wedges can be obtained, which can decrease the temperature rise effectively.
文摘This paper presents a superhydrophobic melamine(ME)sponge(ME-g-PLMA)prepared via high-energy radiation-induced in situ covalent grafting of long-alkyl-chain dodecyl methacrylate(LMA)onto an ME sponge for efficient oil–water separation.The obtained ME-g-PLMA sponge had an excellent pore structure with superhydrophobic(water contact angle of 154°)and superoleophilic properties.It can absorb various types of oils up to 66–168 times its mass.The ME-g-PLMA sponge can continuously separate oil slicks in water by connecting a pump or separating oil underwater with a gravity-driven device.In addition,it maintained its highly hydrophobic properties even after long-term immersion in different corrosive solutions and repeated oil adsorption.The modified ME-g-PLMA sponge exhibited excellent separation properties and potential for oil spill cleanup.
基金Supported by the National Key Research and Development Program of China(2018YFE0196000)National Science and Technology Major Project of China(2016ZX05010-006)CNPC Scientific Research and Technical Development Project(2019B-4113)
文摘This article outlines the development of separated zone oil production in foreign countries,and details its development in China.According to the development process,production needs,technical characteristics and adaptability of oilfields in China,the development of separate zone oil production technology is divided into four stages:flowing well zonal oil production,mechanical recovery and water blocking,hydraulically adjustable zonal oil production,and intelligent zonal production.The principles,construction processes,adaptability,advantages and disadvantages of the technology are introduced in detail.Based on the actual production situation of the oilfields in China at present,three development directions of the technology are proposed.First,the real-time monitoring and adjustment level of separated zone oil production needs to be improved by developing downhole sensor technology and two-way communication technology between ground and downhole and enhancing full life cycle service capability and adaptability to horizontal wells.Second,an integrated platform of zonal oil production and management should be built using a digital artificial lifting system.Third,integration of injection and production should be implemented through large-scale application of zonal oil production and zonal water injection to improve matching and adjustment level between the injection and production parameters,thus making the development adjustment from"lag control"to"real-time optimization"and improving the development effect.
文摘This paper presents experimental results of cocracking of straight-run gasoline (SRG) and light gaS oil (LGO) in an improved pulsed-micro-pyrolyzer. It is shown that there are negative opergistic effect on the yields and selectivities of ethylene and propylene in cocracking. The difference in coking tendencies betWeen the cocracking and the separate cracking is compared as well.
基金This work was financially funded by the National Natural Science Foundation of China(Nos.22205247 and 21988102).
文摘In recent years,numerous studies have been reported for oil/water separation,such as superoleophilic materials for oil absorption and underwater superoleophobic membranes for continuous separation.However,for the recovery of oil slick pollution on near-shore ocean surface caused by various reasons,large area and fast availability of used materials are needed to be considered.Herein,we report an efficient and environmentally friendly method to fast process nylon mesh by surface diffuse atmospheric plasma(SDAP)for large-area oil/water separation.Nylon mesh is funcionalized by atmospheric plasma to generate micro/nano composite structures on the surface,resulting in superhydrophilicity and underwater superoleophobicity within only seconds.The pre-wetted modified nylon mesh can achieve high efficiency(>99.9%)and circulating water flux(~30,000 L·m^(-2)·h^(-1)),with high intrusion pressure(~3 kPa)and universality in oil/water separation.Regular plasma unconditionally generated in the atmosphere with the merit of efficiently functionalizing surface has the potential of large-area materials treatment.This study might take one step further for large-area industrial oily wastewater recovery and even oil slicks collection in near-shore water bodies.
基金supported by the Science and Technology Plans of Tianjin(18PTSYJC00170)the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(YESS20160168)The Analytical&Testing Center of Tiangong University was appreciated.
文摘A high performance preoxidized poly(acrylonitrile)(O-PAN)nanofiber membrane with excellent solvent resistance,thermal stability and flexibility was fabricated by the preoxidation of electrospun PAN nanofiber membrane.The performance of resultant O-PAN nanofiber membrane was optimized by altering the PAN concentration and preoxidation temperature.The results showed that the O-PAN nanofiber membrane which made from PAN concentration of 14%(mass)and preoxidation temperature of 250.0℃ have a more optimal comprehensive performance.In the long-term separation test of SiO2 particle(1 μm)in DMAc suspension,the permeate flux of O-PAN nanofiber membrane stabilized at 227.91 L·m^(-2)·h^(-1)(25℃,0.05 MPa)while the SiO2 rejection above 99.6%,which showed excellent solvent resistance and separation performance.In order to further explore the application of the O-PAN nanofiber membrane,the OPAN nanofiber membrane was treated with fluoride and used in oil/water separation process.The O-PAN nanofiber membrane after hydrophobic treatment showed excellent hydrophobicity and good oil/water separation performance with the permeate flux about 969.59 L·m^(-2)·h^(-1)while the separation efficiency above 96.1%.The O-PAN nanofiber membrane exhibited a potential application prospect in harsh environment separation.
基金supported by the National Natural Science Foundation of China(Grant No.51473070).
文摘Because of the increasing amount of oily wastewater produced each day,it is important to develop superhydrophilic/underwater superoleophobic oil/water separation membranes with ultrahigh flux and high separation efficiency.In this paper,a superhydrophilic/underwater superoleophobic N-isopropylacrylamide-coated stainless steel mesh was prepared through a simple and convenient graft polymerization approach.The obtained mesh was able to separate oil/water mixtures only by gravity.In addition,the mesh showed high-efficiency separation ability(99.2%)and ultrahigh flux(235239 L·m^(−2)·h^(−1)).Importantly,due to the complex cross-linked bilayer structure,the prepared mesh exhibited good recycling performance and chemical stability in highly saline,alkaline and acidic environments.
基金supported by the Technology Innovation Program(20018540)funded by the Ministry of Trade,Industry and Energy(MOTIE,Korea)+1 种基金supported by the Basic Science Research Program of the National Research Foundation of Korea(NRF)funded by the Ministry of Education(NRF-2021R1A4A2001403).
文摘Currently,most of the materials for oil-water separation membranes are limited to fluorine-based polymers with low surface energy.However,it is not biodegradable and requires large amounts of organic and toxic solvents in the membrane manufacturing process.Therefore,interest in the development of a new eco-friendly oil-water separation membrane that does not cause secondary pollution and exhibits selective wettability characteristics in water or oil is increasing.The biopolymeric nanofibrous membranes inspired by fish skin can provide specific underwater oleophobicity,which is effective for excellent oil-water separation efficiency and prevention of secondary contamination.Fish gelatin,which is highly soluble in water and has a low gelation temperature,can be electrospun in an aqueous solution and has the same polar functional groups as the hydrophilic mucilage of fish skin.In addition,the micro/nanostructure of fish skin,which induces superoleophobicity in water,introduces a bead-on-string structure using the Rayleigh instability of electrospinning.The solubility of fish gelatin in water was removed using an eco-friendly crosslinking method using reducing sugars.Fish skin-mimicking materials successfully separated suspended oil and emulsified oil,with a maximum flux of 2086 Lm^(−2) h^(−1) and a separation efficiency of more than 99%.The proposed biopolymeric nanofibrous membranes use fish gelatin,which can be extracted from fish waste and has excellent biodegradability with excellent oil-water separation performance.In addition,polymer material processing,including membrane manufacturing and crosslinking,can be realized through eco-friendly processes.Therefore,fish skin-inspired biopolymeric membrane is expected to be a promising candidate for a sustainable and effective oil-water separation membrane in the future.
基金the financial support provided by the National Natural Science Foundation of China(Nos.22108125,21971113,and 22175094)Independent Innovation of Agricultural Science and Technology in Jiangsu Province(Nos.CX(21)3166,and CX(21)3163)+3 种基金the Natural Science Foundation of Jiangsu Province(No.BK20210627)Doctor Project of Mass Entrepreneurship and Innovation in Jiangsu Province(No.JSSCBS20210549)Nanjing Science&Technology Innovation Project for Personnel Studying Abroad and Research Start-up Funding of Nanjing Forestry University(No.163020259)Q.C.Z.appreciates the funding support from City University of Hong Kong and Hong Kong Institute for Advanced Study,City University of Hong Kong.
文摘The clearwater obtained from stabilized oily wastewater has become a worldwide challenge.Nowdays,the area of oil/water emulsion separation materials have accomplished great progress,but still faces the enormous problems of low flux,poor stability,and pollution resistance.Nanocelluloses(cellulose nanocrystals(CNC))with the advantages of hydrophilicity,ecofriendliness,and regeneration are ideal materials for the construction of separation membranes.In this paper,a flexible,antifouling,and durable nanocellulose-based membrane functionalized by block copolymer(poly(N-isopropylacrylamide)-b-poly(N,Ndimethylaminoethyl methacrylate))is prepared via chemical modification and self-assembly,showing high separation efficiency(above 99.6%)for stabilized oil-in-water emulsions,excellent anti-fouling and cycling stability,high-temperature resistance,and acid and alkali resistance.More importantly,the composite membrane has ultra-high flux in separating oil-in-water emulsions(29,003 L·m^(−2)·h^(−1)·bar^(−1))and oil/water mixture(51,444 L·m^(−2)·h^(−1)·bar^(−1)),which ensures high separation efficiency.With its durability,easy scale-up,and green regeneration,we envision this biomass-derived membrane will be an alternative to the existing commercial filter membrane in environmental remediation.
基金financially supported by the National Natural Science Foundation of China(51773012)Fundamental Research Funds for the Central Universities(buctrc202135)China Scholarship Council Program(201906880031).
基金supported by the National Natural Science Foundation of China(Nos.12205225,U20A20257,and 51873166).
文摘Oil pollution is a serious environmental and natural resource problem.Traditional adsorption materials for oil–water separation have limitations in terms of their preparation cost,reusability,and mechanical properties.Among the conventional adsorption materials,super-hydrophobic/super-lipophilic materials are easily contaminated by oil.In this study,polypropylene(PP)is used as a foam substrate to prepare an open-cell PP foam via hot pressing,supercritical CO_(2) foaming,and electron beam(EB)irradiation.The impact of EB irradiation dose on the open-cell content of PP foam can lead to cell wall rupture,resulting in an open-cell structure that enhances oil-water separation performance.At an absorbed radiation dose of 200 kGy,the PP foams exhibit optimal oil–water separation performance,cyclic compression stability,heat insulation,and preparation cost.The open-cell content of PP foam is increased to 86.5%,the adsorption capacity for diesel oil is 42.8 g/g,and the adsorption efficiency remains at 99.6%after 100 cycles of oil desorption in a complex pH environment.Meanwhile,cracks and nano-voids simultaneously promote the capillary action of oil,and the oil transport rate is 0.0713 g/(g·s).This study provides a new concept for the preparation of open-cell polymer foams that can meet the demand for high oil-absorption capacity under complex acid-base pH conditions.