Nanofluidics derived from low‐dimensional nanosheets and protein nanochannels are crucial for advanced catalysis, sensing, and separation. However, polymer nanofluidics is halted by complicated ...preparation and miniaturized sizes. This work reports the bottom‐up synthesis of modular nanofluidics by confined growth of ultrathin metal–organic frameworks (MOFs) in a polymer membrane consisting of zwitterionic dopamine nanoparticles (ZNPs). The confined growth of the MOFs on the ZNPs reduces the chain entanglement between the ZNPs, leading to stiff interfacial channels enhancing the nanofluidic transport of water molecules through the membrane. As such, the water permeability and solute selectivity of MOF@ZNPM are one magnitude improved, leading to a record‐high performance among all polymer nanofiltration membranes. Both the experimental work and the molecular dynamics simulations confirm that the water transport is shifted from high‐friction‐resistance conventional viscous flow to ultrafast nanofluidic flow as a result of rigid and continuous nanochannels in MOF@ZNPM.
A rigid‐scaffold‐reinforced polymeric nanoparticles’ interfacial channel strategy is proposed for fabricating nanofluidic membranes that exhibit water permeance and dye/salt selectivity that are 1–2 orders of magnitude higher than conventional polymeric membranes. The unprecedented separation performance is due to the paradigm shift of water transport from conventional viscous flow to ultrafast nanofluidic flow in the membrane nanofluidics.
Separation of monovalent salt and antibiotics is of vital importance in membrane field. In this work, zwitterionic polyamide membrane was prepared by incorporating N, N-diethylethylenediamine (DEEDA) ...into interfacial polymerization firstly. Then, zwitterions were introduced into membrane matrix via grafting reaction with 1, 3-propanesultone (1, 3-PS). The resulting zwitterionic membrane exhibited optimal permeability of 14.6 L m−2 h−1.bar−1 and high rejection of organics. Meanwhile, owing to the incorporation of zwitterions, the zwitterionic membrane showed lower rejection of monovalent salt compared with that of the pristine polyamide membrane. Thus, the zwitterionic membrane behaved efficient separation ability of monovalent salt/antibiotics when NaCl/erythromycin mixture solution was chosen as the experimental solution. When bovine serum albumin was used as a foulant, the zwitterionic membrane also exhibited anti-fouling property. This work provided a facile way to prepare zwitterionic membrane with efficient separation ability of monovalent salt/antibiotics, which promoted the development of zwitterions in applications of nanofiltration membrane field.
•DEEDA and 1, 3-PS were utilized to prepare zwitterionic membrane.•Zwitterionic membrane exhibited high permeability and anti-fouling property.•Zwitterionic membrane could realize fast separation of ERY/NaCl.
Carbon nanotube enhanced thin-film nanocomposite membranes were prepared by incorporating carbon nanotubes (CNTs) into the active layers of membranes used for water treatment. For inclusion into ...these active layers, a grafting procedure for carbon nanotubes was set up to increase their hydrophobicity. Multiwalled carbon nanotubes (MWNTs) grafted by poly(methyl methacrylate) (PMMA) were synthesized via a microemulsion polymerization of methyl methacrylate (MMA) in the presence of acid-modified multiwalled carbon nanotubes (c-MWNTs). Subsequently, polyamide thin-film nanocomposite (TFN) membranes containing PMMA–MWNTs were prepared via interfacial polymerization. Morphology studies demonstrate that MWNTs have been successfully embedded into the active polyamide layer. The rejection of Na2SO4 was high (99%), and the water flux was about 62% increased compared to the thin-film composite membrane when using 2g/L piperazine (PIP) in the aqueous phase, 4g/L trimesoyl chloride (TMC) and 0.67g/L PMMA–MWNTs in the organic phase, which demonstrates that PMMA–MWNTs significantly improve selectivity and permeability.
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•Incorporating hydrophobic enhanced PMMA–MWNTs into polyamide membrane.•Enhanced performance were exhibited compared to the membranes without PMMA–MWNTs.•A novel surface morphologies of TFN membranes were observed.
Ultrafiltration (UF) has become an accepted process for drinking water treatment, but membrane fouling remains a significant problem. Polyethersulfone (PES)/SiO₂ composite membranes were prepared by ...phase inversion method with nano-SiO₂ as additive. Water contact angle measurement was conducted to investigate the hydrophilicity and surface wettability of the membranes. The effect of SiO₂ nanoparticles on the membrane permeation properties, anti-fouling performances, and membrane morphologies and structures was examined and discussed. The influence of SiO₂ on the water permeability, anti-fouling of the PES membranes were evaluated by raw water UF experiments. The results showed that the membrane structure was not obviously affected by addition of SiO₂, and the membrane performances such as hydrophilicity and anti-fouling ability were enhanced by adding SiO₂ nanoparticles.
Summary
In this paper, the overcharge tests of 25 Ah LiFePO4/graphite batteries are conducted in an open environment and the overcharge‐to‐thermal‐runaway characteristics are studied. The effects of ...current rates (C‐rates: 2C, 1C, 0.5C, and 0.3C) and states of health (SOHs: 100%, 80%, 70%, and 60%) on thermal runaway features are discussed in detail. The overcharge process can be summarized into five stages based on the experimental phenomena (C‐rate ≥ 1 and SOH ≥ 80%): expansion, fast venting after safety valve rupture, slow venting, intense jet smoke, and explosion, while the battery cannot explode at lower C‐rates and SOHs. The maximum pressure increases with the increase in C‐rate or SOH. There are five obvious inflection points in the voltage curve during overcharge process. The V1 (point B) of aged battery, corresponding to lithium plating on the anode, changes little with C‐rates. It is slightly lower than that of the new battery. A sharp drop in voltage (point E) is probably due to the internal short circuit (ISC), caused by the local melting and rupture of the separator. It takes more than 2 minutes from the moment of ISC to thermal runaway regardless of the SOH, indicating that there are a few minutes to take safety measures if the voltage is an indication parameter. The onset temperature of thermal runaway decreases first and then increases as the SOH decreases from 100% to 60% during 1C constant overcharge tests. These results can provide guidance for the thermal management of the whole battery life cycle and the reuse of retired batteries.
The overcharge tests of 25 Ah power LiFePO4/graphite batteries with different states of health (SOHs) are conducted under various current rates (C‐rates). The overcharge test is more dangerous as SOH or C‐rate increases. The onset temperature of thermal runaway decreases first and then increases with the SOH decreasing from 100% to 60%.
Superhydrophilic and antibacterial zwitterionic polyamide thin film composite nanofiltration membranes (ZTFCMs) with excellent water permeability and antibiotics selectivity were prepared through the ...interfacial polymerization of N-aminoethyl piperazine propane sulfonate (AEPPS) monomer with trimesoyl chloride (TMC) monomer on top of polysulfone ultrafiltration supporting membranes (PSF-UF). Chemical structures of the ZTFCMs were evaluated by attenuated total reflectance fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and element analysis (EA), with membrane microstructures and hydrophilicity being examined by microscopies and water contact angle, respectively. Superhydrophilic ZTFCMs were obtained with more AEPPS content on membrane surface, and they show excellent water permeability coupled with high erythromycin (ERY) retention. For example, the water permeability and retention to ERY of the ZTFCM (AEPPS aqueous concentration is 3.0wt%) are 8.4Lm−2h−1bar−1 and 96.5% (applied pressure is 6bar), respectively. In addition, the ERY concentration of the mixed feed increases exponentially from 100.0 to 350.7mgL−1 with a treatment capacity of 61.6Lm−2h−1 during 7.25h continuous concentration operation. Furthermore, ZTFCMs show a stable and good separation performance during a long-time filtration process of 168h and exhibit an exceptional antibacterial property assessed by Escherichia coli adhesion.
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•ZTFCMs are prepared with zwitterionic monomer by interfacial polymerization.•ZTFCMs are superhydrophilic and antibacterial.•ZTFCMs exhibit excellent water permeability and antibiotics/salt selectivity.
Zwitterionic polymers are attracting significant interest for nanofiltration (NF) membranes featuring exceptional permeability and antifouling performance. Here we introduce a facile strategy ...incorporating a controlled amount of zwitterionic component (N-aminoethyl piperazine propane sulfonate, AEPPS) onto polyamide thin film composite NF membranes that are prepared via interfacial polymerization between trimesoyl chloride (TMC) and piperazine (PIP). By immersing pristine polyamide NF membranes in AEPPS aqueous solution, reactive AEPPS molecules were effectively anchored to the membrane surfaces via chemical reactions between amine groups on AEPPS and acyl chloride groups on the membrane surfaces. The chemical reactions were characterized, and the incorporated AEPPS is shown to improve the membrane permeability without compromising salt rejection. When the concentration of AEPPS is 1wt%, the water flux increases from 28.0Lm−2h−1 to 57.6Lm−2h−1 while Na2SO4 rejection is maintained above 99.5%. Last but not the least, the membrane׳s antifouling property is simultaneously improved, with the flux recovery ratio being as high as 91.6% (pH 3.7) and 95.5% (pH 6.0).
•Zwitterionic monomers were incorporated on the surface of nanofiltration membrane.•Water flux of the membrane was 1 time improved with salt rejection maintained.•The membrane exhibited better antifouling property in nanofiltration process.
Organic solvent nanofiltration (OSN) as a high-efficient membrane separation technology has play an important role in chemical industrial separation, clean energy production, and high-value resources ...recycling, etc. Inspired by the asymmetric biological structure of Desert beetle, herein a novel kind of polymeric OSN membranes with asymmetric structure have been fabricated via fluorinated polymeric networks (FPNs) regulated interfacial polymerization. The FPNs were formed with m-phenylenediamine (MPD), dopamine (DA) and 1H,1H,2H,2H-Perfluorodecane-thiol (PFDT) via the Michael addition and Schiff-base reaction. The FPNs tailored thin-film composite membrane (FPN-TFC) with biomimetic asymmetric structure, e.g., much hydrophilic looser front surface and much hydrophobic denser rear surface, exhibits an optimum ethanol permeance ~15.7 L m−2 h−1.MPa−1 and high rejection ~99.5% for Rose Bengal (RB) dye molecules (test with 0.05 g L−1 RB ethanol solution at 25 °C under 1.5 MPa), which is almost 6 times higher than that of the conventional TFC membranes. Moreover, there is a good stability for the FPN-TFC membrane tested with different polar solvents in long-term operation process. Therefore, this work provides a guidance for the development of advanced polymeric OSN membranes with both high solvent permeability and solute selectivity, as well as good stability in OSN process, which would have broad application prospects in chemical and other industrial fields.
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•Polyamide OSN membrane was fabricated via fluorinated polymeric networks regulated interfacial polymerization.•There is biomimetic asymmetric structure for the polyamide OSN membrane.•The polyamide OSN membrane exhibits both high solvent permeance and solute rejection.•The polyamide OSN membrane has good stability and anti-fouling properties in long-term OSN process.
Nanocomposite membranes have gained growing attention in various application fields, especially in the separation and purification of resource substances. However, the nanomaterials and their ...membranes fabrication strategies usually suffer from complex procedures, high-energy consumption and lack of universality. Inspired by the unique self-polymerization and adhesion characteristic of marine mussels, we proposed a facile and versatile approach to synthesize zwitterionic dopamine nanoparticles via dopamine induced oxidative polymerization method, followed by the interfacial cross-linking on porous supporting layer to fabricate thin-film nanocomposite (TFN) membranes. The influences of nanoparticle composition, particle size and loading content on the membrane structure and performance were studied to optimize the fabrication conditions. The resultant TFN membrane exhibited high water permeance (98.0 L m−2 h−1 MPa−1) and good selectivity for di-/mono-valent salts (SNa2SO4/NaCl = ~4.50, SMgSO4/NaCl = ~4.49). Furthermore, by utilizing the protein, polysaccharide, and humic acid as model foulants, the zwitterionic dopamine nanoparticles based TFN membranes have been demonstrated with excellent fouling resistance and cleaning recovery property in separation applications.
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•Zwitterionic dopamine nanoparticles (ADNPs) were synthesized via dopamine induced oxidative polymerization method.•Thin-film nanocomposite membranes based on ADNPs were prepared by interfacial polymerization.•The membrane had high water permeability and good salt selectivity.•The membrane exhibited good stability and enhanced anti-fouling property.
Bio-ethanol as a clean and renewable fuel has gained more attention; however greater energy inputs make a slow progress in industry. Membrane technology has potential in the bioethanol production ...process as a highly selective and energy-saving separation process. This review presented membrane technologies applied in three aspects: (i) microalgae harvesting, (ii) sugar concentration and detoxification, (iii) bioethanol recovery. The performance of different membrane processes was summarized and compared. The advantages and limitations of membrane technologies for these applications are discussed, and it was thought that the hybrid process has great potential in improving membrane efficiency.
