| 1. |
- Orooji, Yasin, et al.
(författare)
-
Luminescent film : Biofouling investigation of tetraphenylethylene blended polyethersulfone ultrafiltration membrane
- 2021
-
Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 267
-
Tidskriftsartikel (refereegranskat)abstract
- Despite the huge contribution of membrane-based brine and wastewater purification systems in today’s life, biofouling still affects sustainability of membrane engineering. Aimed at reducing membrane modules wastage, the need to study biofouling monitoring as one of contributory factors stemmed from the short time between initial attachment and irreversible biofoulant adhesion. Hence, a membrane for monitoring is introduced to determine the right cleaning time by using fluorescent sensing as a non-destructive and scalable approach. The classical solid-state emissive fluorophore, tetraphenylethylene (TPE), was introduced as a sustainable, safe and sensitive fluorescent indicator in order to show the potential of the method, and polyethersulfone (PES) and nonsolvent-induced phase separation method, the most popular material and method, are used to fabricate membrane in industry and academia. Since the employed filler has an aggregation-induced emission (AIE) characteristic, it can track the biofouling throughout the operation. The fabricated membranes have certain characterizations (i.e. morphology assessment, flux, antibiogram, flow cytometry, surface free energy, and protein adsorption) which indicate that hybrid membrane with 5 wt % of TPE has identical biofouling activity compared to neat PES membrane and its optimal luminescence properties make it an appropriate candidate for non-destructive and online biofouling monitoring.
|
|
| 2. |
- Chen, Yuqing, et al.
(författare)
-
A review of lithium-ion battery safety concerns : the issues, strategies, and testing standards
- 2021
-
Ingår i: Journal of Energy Chemistry. - : Elsevier. - 2095-4956 .- 2096-885X. ; 59, s. 83-99
-
Tidskriftsartikel (refereegranskat)abstract
- Efficient and reliable energy storage systems are crucial for our modern society. Lithium-ion batteries (LIBs) with excellent performance are widely used in portable electronics and electric vehicles (EVs), but frequent fires and explosions limit their further and more widespread applications. This review summarizes aspects of LIB safety and discusses the related issues, strategies, and testing standards. Specifically, it begins with a brief introduction to LIB working principles and cell structures, and then provides an overview of the notorious thermal runaway, with an emphasis on the effects of mechanical, electrical, and thermal abuse. The following sections examine strategies for improving cell safety, including approaches through cell chemistry, cooling, and balancing, afterwards describing current safety standards and corresponding tests. The review concludes with insights into potential future developments and the prospects for safer LIBs.
|
|
| 3. |
- Essalhi, Mohamed, et al.
(författare)
-
10 - Thermo-osmosis
- 2021. - 1
-
Ingår i: Osmosis Engineering. - : Elsevier. - 9780128210161 ; , s. 279-312
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The existence of nonisothermal transport of liquids through a gelatin membrane was first described by Lippmann in 1907, and 5 years later, it was investigated by Aubert in more detail using membranes of gelatin pig’s bladder, parchment paper and viscose. In this phenomenon, there is no liquid/vapor phase transition and it is known as thermo-osmosis (TO) or thermal osmosis (TO). Lippmann also observed TO in air, obviously without prior knowledge of the work of Feddersen and Reynolds. However, at that time the lack of theory on irreversible processes prevented the progress towards understanding this phenomenon.
|
|
| 4. |
- Essalhi, Mohamed, et al.
(författare)
-
Desalination by direct contact membrane distillation using mixed matrix electrospun nanofibrous membranes with carbon-based nanofillers : a strategic improvement
- 2021
-
Ingår i: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 426
-
Tidskriftsartikel (refereegranskat)abstract
- Robust hydrophobic and superhydrophobic mixed matrix electrospun nanofibrous membranes (MM-ENMs) have been prepared from low- and high- molecular weight polyvinylidene fluoride with either multi-walled carbon nanotubes or graphene oxide nanofillers (0.05–0.5 wt%). The polymer solutions' properties, including their electrical conductivity, viscosity, and surface tension, were determined and used to guide the design of single-, dual-, and triple-layered MM-ENMs combining layers with different hydrophobic character. All MM-ENMs were subsequently prepared and characterized in terms of their morphology, hydrophobicity, mechanical properties, and direct contact membrane distillation (DCMD) performance. A thinner hydrophobic layer with a thicker hydrophilic support layer in dual-layered MM-ENMs reduced water vapor transport resistance and improved DCMD performance relative to single-layer MM-ENMs. Conversely, placing an intermediate hydrophilic layer between two hydrophobic layers in triple-layered MM-ENMs promoted water condensation (water pocket formation) and thus reduced DCMD performance. Over 10 h DCMD, the best-performing dual-layered MM-ENM allowed ultra-high permeate fluxes of up to 74.7 kg/m2 h while maintaining a stable permeate electrical conductivity of around 7.63 μS/cm and a salt (NaCl) rejection factor of up to 99.995% when operated with a feed temperature of 80°C, a permeate temperature of 20°C, and a feed solution containing NaCl at a concentration of 30 g/L.
|
|
| 5. |
- Essalhi, Mohamed, et al.
(författare)
-
Improvement of nanostructured electrospun membranes for desalination by membrane distillation technology
- 2021
-
Ingår i: Desalination. - : Elsevier. - 0011-9164 .- 1873-4464. ; 510
-
Tidskriftsartikel (refereegranskat)abstract
- A systematic study is carried out to determine the optimum electrospinning preparation condition to prepare an adequate electrospun nanofibrous membrane (ENM) for direct contact membrane distillation (DCMD). A structural properties investigation of ENM was carried out because of the significant impact of its architectural structure, nanofiber diameter, inter-fiber space and ENM thickness, on DCMD performance. The morphology, hydrophobicity, mechanical properties, crystallinity and DCMD desalination were investigated. A long-term DCMD experiment (100h) was carried out using 30 g/L NaCl aqueous solution, both in the feed and permeate side of the optimum ENM membrane to evaluate its potential to produce drinkable water in case of lack of distilled water, for instance in a remote area, emergency situation, and/or portable system. In this case, drinkable water could be produced after 28 h with a permeate flux of 57.5 kg/m2.h and a salt rejection factor greater than 99.9%. Another long-term DCMD experiment (65 h) was conducted using 30 g/L NaCl aquesous solution as feed but at a higher temperature and distilled water as permeate to evaluate the desalination stability, wettability and scaling of the optimum ENM. A permeate flux of 58.5 kg/m2.h was obtained with a salt rejection factor greater than 99.9%.
|
|
| 6. |
- Ismail, Norafiqah, et al.
(författare)
-
Experimental and theoretical studies on the formation of pure β-phase polymorphs during fabrication of polyvinylidene fluoride membranes by cyclic carbonate solvents
- 2021
-
Ingår i: Green Chemistry. - : Royal Society of Chemistry. - 1463-9262 .- 1463-9270. ; 23:5, s. 2130-2147
-
Tidskriftsartikel (refereegranskat)abstract
- The use of highly toxic solvents presents significant risks to both the environment and human health. Therefore, the adoption of green solvents will be crucial for achieving sustainable membrane production. This work reports the use of inexpensive environmentally friendly biobased and biodegradable cyclic carbonate solvents, namely ethylene carbonate (EC), propylene carbonate (PC), and butylene carbonate (BC), to fabricate polyvinylidene fluoride (PVDF) membranes. The solvent dependence of the phase inversion mechanisms, morphology, crystalline structures, and polymorphism of the prepared PVDF membranes were investigated. Polymorph analysis revealed that membrane fabrication in EC or PC yielded exclusively the β-phase product, whereas PVDF membrane fabrication in BC yielded a mixture of α and β phase material. The mechanism of β-phase formation was investigated using molecular dynamics simulation and shown to depend on the extent of hydrogen bonding at the polymer–solvent interface. The PVDF membrane formed in EC exhibited the highest porosity and pure water permeability, and was therefore tested in direct contact membrane distillation (DCMD), exhibiting promising results in terms of permeate flux and salt rejection. These results suggest that large-scale production of piezoelectric PVDF membranes using green solvents should be practically feasible.
|
|
| 7. |
- Kang, Yuqiong, et al.
(författare)
-
Phosphorus-doped lithium- and manganese-rich layered oxide cathode material for fast charging lithium-ion batteries
- 2021
-
Ingår i: Journal of Energy Chemistry. - : Elsevier. - 2095-4956 .- 2096-885X. ; 62, s. 538-545
-
Tidskriftsartikel (refereegranskat)abstract
- Owing to their high theoretical specific capacity and low cost, lithium- and manganese-rich layered oxide (LMR) cathode materials are receiving increasing attention for application in lithium-ion batteries. However, poor lithium ion and electron transport kinetics plus side effects of anion and cation redox reactions hamper power performance and stability of the LMRs. In this study, LMR Li1.2Mn0.6Ni0.2O2 was modified by phosphorus (P)-doping to increase Li+ conductivity in the bulk material. This was achieved by increasing the interlayer spacing of the lithium layer, electron transport and structural stability, resulting in improvement of the rate and safety performance. P5+ doping increased the distance between the (003) crystal planes from ∼0.474 nm to 0.488 nm and enhanced the structural stability by forming strong covalent bonds with oxygen atoms, resulting in an improved rate performance (capacity retention from 38% to 50% at 0.05 C to 5 C) and thermal stability (50% heat release compared with pristine material). First-principles calculations showed the P-doping makes the transfer of excited electrons from the valence band to conduction band easier and P can form a strong covalent bond helping to stabilize material structure. Furthermore, the solid-state electrolyte modified P5+ doped LMR showed an improved cycle performance for up to 200 cycles with capacity retention of 90.5% and enhanced initial coulombic efficiency from 68.5% (pristine) or 81.7% (P-doped LMR) to 88.7%.
|
|
| 8. |
- Yadav, Pooja, et al.
(författare)
-
Assessment of the environmental impact of polymeric membrane production
- 2021
-
Ingår i: Journal of Membrane Science. - : Elsevier. - 0376-7388 .- 1873-3123. ; 622
-
Tidskriftsartikel (refereegranskat)abstract
- Polymeric membranes are important in advanced separation technologies because of their high efficiency and low environmental impact. However, procedures for membrane production are far from sustainable and environmentally friendly. This work presents a life cycle assessment of the environmental impact of fabricating 1000 m2 of hollow fiber polymeric membranes. Membrane materials considered include the most popular fossil- and bio-based polymers in current use, i.e., polysulfones, polyvinylidene fluoride, and cellulose acetate. Solvents considered for use in polymer dope solution included polar aprotic solvents (N-Methyl-2-pyrrolidone, N, N-dimethylacetamide, and dimethylformamide) that are widely used in industry and an alternative green solvent (ethylene carbonate). The impacts of membrane production on global warming, marine ecotoxicity, human carcinogenic and non-carcinogenic toxicity, land use potential, and fossil resource scarcity were analyzed. Additionally, the impact on the sustainability and environmental cost of membrane production resulting from replacing fossil-based polymers with bio-based polymers or substituting toxic solvents with a green alternative was investigated. Hot spots in the membrane production process were identified, and measures to reduce the environmental impact of membrane production were proposed.
|
|
| 9. |
- Yahia, Mohamed, et al.
(författare)
-
Effect of incorporating different ZIF-8 crystal sizes in the polymer of intrinsic microporosity, PIM-1, for CO2/CH4 separation
- 2021
-
Ingår i: Microporous and Mesoporous Materials. - : Elsevier. - 1387-1811 .- 1873-3093. ; 312
-
Tidskriftsartikel (refereegranskat)abstract
- Effective and economical carbon dioxide-methane separation (CO2/CH4) is highly desirable in several industries such as sweetening natural gases and renewable natural gas (RNG) from biogas and landfills. Among the different separation technologies, membrane separation has been shown to have lower cost of production and lower CH4 losses. In this study, Zeolitic Imidazole Frameworks (ZIF-8) crystals with sizes varying from 45 nm to 450 nm were synthesized and incorporated in the polymer of intrinsic microporosity, PIM-1, to form mixed matrix membranes (MMMs). The structure, morphology, and physicochemical properties of the MMMs were characterized by 1H NMR, FTIR, XRD, TGA, and SEM. ZIF-8 crystal size was controlled using the concentration of sodium formate. The influence of the ZIF-8 crystal size on MMMs was studied by sorption, gas permeability, and aging of the membranes. The MMMs with ZIF-8 crystals of 120 nm particle diameter yielded the greatest improvement in gas transport properties; the CO2/CH4 selectivity-CO2 permeability was 11.4 and 9700 Barrer compared to PIM-1 with 6.4 and 9300 Barrer respectively. The former is near the Robeson 2008 upper bound, while PIM-1 is on the 1991 upper bound. After 40 days of aging, selectivity increased and permeability decreased; the changes were parallel to the Robeson upper bounds indicating increased polymer packing and diffusivity selectivity.
|
|
| 10. |
- Zhao, Yun, et al.
(författare)
-
Rational design of functional binder systems for high-energy lithium-based rechargeable batteries
- 2021
-
Ingår i: Energy Storage Materials. - : Elsevier. - 2405-8289 .- 2405-8297. ; 35, s. 353-377
-
Tidskriftsartikel (refereegranskat)abstract
- Binders, which maintain the structural integrity of electrodes, are critical components of lithium-based rechargeable batteries (LBRBs) that significantly affect battery performances, despite accounting for 2 to 5 wt% (up to 5 wt% but usually 2 wt%) of the entire electrode. Traditional polyvinylidene fluoride (PVDF) binders that interact with electrode components via weak van der Waals forces are effective in conventional LBRB systems (graphite/LiCoO2, etc.). However, its stable fluorinated structures limit the potential for further functionalization and inhibit strong interactions towards external substances. Consequently, they are unsuitable for next-generation battery systems with high energy density. There is thus a need for new functional binders with facile features compatible with novel electrode materials and chemistries. Here in this review we consider the strategies for rationally designing these functional binders. On the basis of fundamental understandings of the issues for high-energy electrode materials, we have summarized seven desired functions that binders should possess depending on the target electrodes where the binders will be applied. Then a variety of leading-edge functional binders are reviewed to show how their chemical structures realize these above functions and how the employment of these binders affects the cell's electrochemical performances. Finally the corresponding design strategies are therefore proposed, and future research opportunities as well as challenges relating to LBRB binders are outlined.
|
|
