A CM-MnO2-STA sample for oil/water separation, photocatalytic degradation and anti-biofouling property was obtained via MnO2 micro/nano structure and subsequent modification of STA. This ...multifunction CM-MnO2-STA sample demonstrates great potentials in the field of wastewater treatment, oil spill cleanup, and anti-biofouling ability.
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•A CM-MnO2-STA sample was obtained by MnO2 micro/nano structure and STA.•This sample showed physical/chemical/mechanical stability in harsh environment.•This sample showed superior oil–water separation efficiency.•This sample showed great photocatalytic degradation activity.•This sample exhabited strong anti-biofouling adhesion potential.
Flexible multiple functional cellulose-based membrane (CM) for oil/water separation, anti-microbial and photodegradation are in great demand in marine wastewater treatment due to its’ effective and ecologically benign. Based on this requirement, MnO2 micro/nanoparticles were in situ deposited on CM sample surface followed by decoration of stearic acid (STA) for very effective oil/water separation, anti-fouling, and dye photodegradation triggered by visible light. The results demonstrated that this as-prepared CM sample showed superhydrophobicity with a water contact angle of 162 ± 2° and superoleophilicity with an oil contact angle of 0°. It also demonstrated exceptional high stability in hostile environments (acid and alkali solution, high temperature, wear resistance, underwater writing, self-cleaning) and a 2.6% increase in tensile strength. In addition, it can successfully separate emulsified oils from typical oil-in-water emulsions with good separation efficiency all over 98% and comparatively high flux (145.8 L·m−2·h−1). After 8 cycles, the separation efficiency of the n-hexane/water emulsion is still over 98%. Moreover, over 98% of MB was degraded by using superhydrophobic CM sample, indicating strong photocatalytic activity. Meanwhile, in the maritime environment, this biomimetic sample decreased the adherence of green algae by more than 95%, demonstrating strong anti-biofouling adhesion potential. It indicates that this cost-effective, scalable, environmental friendly, and efficient methodology presented superhydrophobic CM sample has the potential to promote the widespread development of multipurpose superwetting materials, with enticing potential for the treatment of complex oily wastewater.
Complicated contaminants in wastewater, such as intractable oils, organic colors, and adhering organisms, have generated major environmental problems that are hazardous to ecosystems and human ...health, and wastewater purification is complex and difficult to achieve with a single substance or single process. A facile yet environmentally friendly technique for fabricating a superhydrophobic, oil-water separation, anti-bioadhesion, and photocatalytic Pulp/cellulose nanofibers (CNFs) membrane for all-in-one wastewater treatment is presented here. In this strategy, the hierarchical micro/nanostructured CeO2 nanoparticles and stearic acid (STA)-coated Pulp/CNF (Pulp/CNF-CeO2-STA) membrane is fabricated via a straightforward and easy-to-operate coating method, which simultaneously endows the membrane with superwetting ability, good oil-water separation capacity, notable photocatalytic degradation capacity, and outstanding anti-bioadhesion action. According to the experimental results, the suitably prepared Pulp/CNF-CeO2-STA membrane displayed superior superhydrophobicity (water contact angle: 166 ± 2°), high separation efficiency (88%), and high throughput (73 L·m−2·h−1). This Pulp/CNF-CeO2-STA membrane also showed significant photocatalytic degradation (>94%) of organic dye pollutants in water, as well as good anti-bioadhesive performance against Chlorella. As such, it serves several functions in wastewater treatment, considerably simplifying installation and saving money in application. In conclusion, this unique coating process is environmentally benign and very practicable, paving the door for the development of multi-functional materials in environmental treatments.
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•A facile coating process for the production of Pulp/CNF-CeO2-STA membrane.•This membrane exhibits good oil/water separation for different oil density.•This membrane was found to be anti-bioadhesive to Chlorella.•The degradation test of methylene blue proved its photocatalytic performance.
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The oily wastewater has been widely concerned owing to growing industrial wastewater and marine pollution. Herein, a cellulose-based oil/water separation membrane was fabricated using ...a very simple alternating soaking process (ASP). First, the sodium alginate was coated on the cellulose membrane surface (filter paper), and then CaCO3 particles were assembled onto the membrane surface through ASP, finally we can get the superhydrophilic/underwater superoleophobic cellulose membrane (FP@SA/CaCO3) for oil/water separation. The underwater oil contact angle (OCA) of FP@SA/CaCO3 is 151.1°, which indicated that FP@SA/CaCO3 has good underwater superoleophobicity. Moreover, for different oil/water mixtures, the FP@SA/CaCO3 membrane has outstanding separation efficiency of over 99.2 % and the flux of over 400 L m−2 h−1. Besides, even after 20 reuse, FP@SA/CaCO3 still showed a high flux and separation efficiency, indicating FP@SA/CaCO3 has good reusability. The FP@SA/CaCO3 membrane with low cost and high performance shows a good application market for oily wastewater remediation in the future.
•Hydrophilic and hydrophobic nanoparticles concentrated in different polar solvents.•Hydrophobized silica nanoparticles form tighter and less reversible cakes.•Effect of solvent on cake resistance ...changes with particle surface and solvent type.•Continuous solvent exchange is achieved with no cake buildup.
Downstream processing of nanoparticles after synthesis frequently involves purification, concentration and solvent exchange steps. While these are typically done via centrifugation in lab scale, ultrafiltration is a practical and economical alternative in large scale continuous production. Treating suspensions in organic solvents via ultrafiltration requires solvent-stable membranes and in this study we present the performance of cellulose ultrafiltration membranes in the concentration and solvent exchange of hydrophilic and hydrophobized silica nanoparticles using isopropanol, water, dimethyl formamide and ethanol as solvents. Hydrophobized particles formed less permeable cake layers than hydrophilic particles during concentration. All fouling was reversible upon ultrasonication while physical cleaning via stirring could only recover the complete membrane permeance fouled with hydrophilic particles in dimethyl formamide and hydrophobic particles in isopropanol and water. Quality of nanoparticle recovery was assessed by the amount recovered in retentate and cleaning suspensions as well as the particle size after these steps. Highest recovery of hydrophilic particles was obtained in dimethyl formamide and that of hydrophobic particles in isopropanol. No agglomeration of recovered hydrophilic particles was observed, while hydrophobic particles recovered via physical cleaning partly agglomerated in isopropanol and dimethyl formamide. Finally, continuous solvent exchange from isopropanol to ethanol, water and dimethyl formamide was achieved with no performance loss throughout the process.
Fabrication of simple and efficient adsorbents is greatly vital to satisfy the requirements of removal of tellurium in wastewater treatment, yet remains challenging. Here, a facile and cost-effective ...strategy to develop ZIF-L coated self-crosslinking cellulose membrane (ZIF-L/SC membrane) for tellurium adsorption was presented. In-situ vertical growth of ZIF-L nanoplates with functional properties on membrane substrate is an available strategy, effectively remedying deficiency of pure nanosized sorbent in agglomeration problem and unhandy recovery. The SC membrane formed by strong hydrogen bonding among cellulose fibers is an excellent substrate, due to the favorable mechanical strength and abundant hydroxyl groups. The as-prepared ZIF-L/SC membrane shows advantageous morphology of large contact surface, fine thermal stability and eligible mechanical strength. The adsorption performance and possible mechanism of ZIF-L/SC membrane for Te (IV) were investigated by diverse characterization methods, showing admirable adsorption effect. Furthermore, the ZIF-L/SC membrane has excellent antibacterial properties, thus it is expected to deal with membrane fouling caused by microorganism breeding. Therefore, the bifunctional ZIF-L/SC membrane with excellent antibacterial activity is anticipated to be a promising candidate for efficient tellurium adsorbents, and simultaneously have potential in various fields in the future.
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•A facile and cost-effective strategy to develop ZIF-L/SC membrane for tellurium adsorption was presented.•SC membrane without any crosslinkers is an excellent substrate, showing favorable mechanical strength.•In-situ vertical growth of ZIF-L nanoplates shows advantageous morphology of large contact surface.•ZIF-L/SC membrane shows admirable tellurium adsorption performance and antibacterial effects.•Ecofriendly bifunctional ZIF-L/SC membrane is anticipated to have potential in various fields.
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Polyvinylidene difluoride (PVDF) is one of the most attractive electrolyte materials for solid-state batteries due to its high ionic conductivity, however, the battery performance is ...limited by the high electrolyte–electrode interfacial resistance. Herein, PVDF polymer mixed with ceramic Li7La3Zr2O12 is coated on cellulose support membrane (PLCSM) through a simple slurry-casting method. The ionic transport of PLCSM is originated from dimethyl formamide (DMF)-Li+ solvation structure, which plays a critical role in conducting lithium ions. β-PVDF after dehydrofluorination offers a high dielectric constant and enhances the dissociation of lithium salt. As a result, PLCSM with a total thickness of 85 µm presents an oxidation voltage of 4.9 V. Li-Li symmetric cells by employing PLCSM reveal that the critical current density (CCD) is increased to 1 mA cm−2. A full cell of LiFePO4 |PLCSM |Li with high mass loading (1.2 mA h cm−2) shows a first-cycle discharge capacity of 160 mA h g−1. With LiNi0.6Mn0.2Co0.2O2 as the cathode, the initial discharge capacity is 153 mA h g−1, and the capacity retention after 80 cycles is 80 %. The sandwiched PLCSM provides an effective strategy to achieve high-performance dendrite-free Li metal batteries.
Research and development towards sustainable chemistry includes also the development of new materials and the exploration of new ways to fabricate them. In this work, composite membranes were ...fabricated from fully biodegradable materials (cellulose) through a simple and scalable process, i.e., a combination of film casting, nonsolvent-induced phase separation and lamination, in which only environmentally friendly solvents are used. Filter paper was utilized as support material. Cellulose was dissolved in a mixture of an ionic liquid (1-ethyl or 1-butyl-3-methylimidazolium acetate) with a co-solvent (dimethylsulfoxide, DMSO) and used for casting the barrier layer. The influence of pre-wetting the filter paper with different liquids (water, glycerine, DMSO) was investigated. It was found that using DMSO as impregnation liquid improved both, the membrane separation performance and the strength of the lamination between the cellulose barrier layer and the filter paper as demonstrated by adhesion tests. Barrier layer thickness could be reduced to a few μm by appropriate cast film thickness. Membrane separation performance in terms of permeance and solute rejection could also be adjusted by the choice of cellulose concentration and co-solvent fraction in the casting solution. The applicability of the cellulose-cellulose composite membranes in ultrafiltration (UF) of aqueous or organic solvent-based mixtures was evaluated with dextran or polyethylene glycol and polyethylene oxide, respectively, as test solutes. Molecular weight cut-off data for one specific UF membrane type were ∼100 kDa, ∼170 kDa, or ∼390 kDa in water, dimethylformamide or DMSO. All results obtained in this study indicate that the novel membranes have potential as a more sustainable alternative material for various relevant separations.
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•Stable composite membranes fabricated by casting cellulose solution on filter paper.•Ultrafiltration properties tunable by cellulose solution in ionic liquid/DMSO mixture and coagulation in water.•Impregnation of filter paper support prevents pore blocking to yield high permeance.•Effective lamination between filter paper support and cellulose barrier layer.•Fully bio-based membranes with potential for aqueous and organic solvent ultrafiltration.
Solvent recycling and reuse are indispensable for ensuring a sustainable chemical industry and circular economy. In this study we report the fabrication of cellulose ultrafiltration membranes and ...their application in recovery of propylene glycol methyl ether acetate (PGMEA) used as developer solvent in SU-8 photolithography. Cellulose membranes were fabricated via alkaline hydrolysis of cellulose acetate membranes in aqueous NaOH. Membrane permeance and molecular weight cut-off (MWCO) were tuned via changing cellulose acetate concentration in precursor solution and evaporation of volatile co-solvent, acetone. MWCO of the membranes was found to be smallest in DMSO, followed by water and largest in methanol. The difference was attributed to the different hydrodynamic diameters of the probe molecules in these solvents. SU-8 rejection from its representative developer solutions in PGMEA was assessed in dead-end filtration at up to 80% permeate recovery. After the first filtration, the collected permeate was fed to the same membrane to simulate a two-stage filtration scenario. Rejection was in the range of 87%–89% in a first stage filtration and 79%–80% in a second stage, both operated at 80% permeate recovery. Recycled solvent could be used in photolithography although with some loss of pattern fidelity, possibly owing to remaining SU-8 and photoacid generator in PGMEA.
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•Cellulose membrane permeance and MWCO tuned between 0.40–23.3 LHM/bar and 4–15 kDa.•Permeance is via pore flow mechanism but is also affected by swelling and steric hindrance.•SU-8 can be recovered from its PGMEA solution and reused in photolithography.
Nanocellulose membranes have attracted widespread attention because of its nano pore size, environmental friendliness, hydrophilicity and biocompatibility. However, the low water permeation, weak wet ...strength and high bacterial adhesion limit their pratical application. Herein, an ultrafiltration membrane based on bacterial cellulose (BC) with high flux, high wet strength and antibacterial property was prepared by using nano silica as porogen and polyhexamethylene guanidine hydrochloride (PHGHE) as both crosslinker and fungicide. Without affecting the uniformity of the membrane, a high dosage of nano silica was conducted to construct straight-through channels in the membrane Z direction, which greatly reduces the actual capillary tube length and increases the flux. The effective pore size was successfully controlled below 90 nm and the flux reached a high level of 7147 L·m−2·h−1·bar−1. After PHGHE modification, the wet strength of the BC membrane increased by 4.5 times (up to 4.47 MPa) as well as significantly improved the antibacterial performance (zone of inhibition=15.0–15.2 mm). The underwater superoleophobicity and nanoscale pore size make it excellent at separating nanoparticles and nanoemulsions with sizes even lower than 100 nm in aqueous solutions. The developed high flux BC membrane would have wide applications in wastewater separation and purification.
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•Nanocellulose-based ultrafiltration membrane was prepared via a simple and controllable process.•High flux, high wet strength, antibacterial, and antifouling property were achieved.•Z-directional straight-through channels was constructed to increase the flux using nano silica as porogen.
