High Flux Research Articles

Fabrication of eco-friendly nanocellulose-chitosan-calcium phosphate ternary nanocomposite for wastewater remediation

Nanocomposites have emerged as promising materials for pollutant removal due to their unique properties. However, conventional synthesis methods often involve toxic solvents or expensive materials. In this study, we present a novel ternary nanocomposite synthesized via a simple, cost-effective vacuum filtration method. The composite consists of calcium phosphate (CaP), biowaste-derived nanocellulose (diameter <50 nm) (NC), and chitosan (CH). The nanocomposite exhibited exceptional pollutant removal capabilities due to the hybrid approach of combining adsorption and size exclusion that widens and accelerates pollutant removal. When tested with synthetic wastewater containing 10 ppm of Ni ions and 10 ppm of Congo red (CR) dye, it achieved impressive removal rates of 98.7% for Ni ions and 100% for CR dye. Moreover, the nanocomposite effectively removed heavy metals such as Cd, Ag, Al, Fe, Hg, Mo, Li, and Se at 100%, and Ba, Be, P, and Zn at 80%, 92%, 87%, and 97%, respectively, from real-world municipal wastewater. Importantly, this green nanocomposite membrane was synthesized without the use of harmful chemicals or complex modifications and operated at a high flux rate of 146 L/m2.h.MPa. Its outstanding performance highlights its potential for sustainable pollutant removal applications.

Highly Anion-Conductive Viologen-based Two-Dimensional Polymer Membranes as Nanopower Generators.

Two-dimensional polymers (2DPs) and their layer-stacked 2D covalent organic frameworks (2D COFs) membranes hold great potential for harvesting sustainable osmotic energy. The nascent research has yet to simultaneously achieve high ionic flux and selectivity, primarily due to inefficient ion transport dynamics. This is directly related to ultrasmall pore size (<3 nm), much smaller than the duple Debye length in the diluted electrolyte (6~20 nm), as well as low charge density (<4.5 mC m-2). Here, we introduce a π-conjugated viologen-based 2DP (V2DP) membrane possessing a large pore size of 4.5 nm, strategically enhancing the overlapping of the electric double layer, coupled with an exceptional positive surface charge density (~6 mC m-2). These characteristics enable the membrane to facilitate high anion flux while maintaining ideal selectivity. Notably, V2DP membranes realize an impressive current density of 5.5×103 A m-2, surpassing previouslynanofluidic membranes. Inpractical application scenario involving the mixing of artificial seawater and river water, the V2DP membranes exhibit a considerable ion transference number of 0.70 towards Cl-, contributing to an outstanding power density of ~55 W m-2. Theoretical calculations reveal that thelarge quantity of anion transport sites act as binding sites evenly located in the positively charged N-containing pyridine rings.

Nanosheet BiOBr Modified Rock Wool Composites for High Efficient Oil/Water Separation and Simultaneous Dye Degradation by Activating Peroxymonosulfate.

The development of superlyophobic materials in liquid systems, enabling synchronous oil/water separation and dye removal from water, is highly desirable. In this study, we employed a novel superwetting array-like BiOBr nanosheets anchored on waste rock wool (RW) fibers through a simple neutralization alcoholysis method. The resulting BiOBr/RW fibers exhibited superoleophilic and superhydrophilic properties in air but demonstrated underwater superoleophobic and underoil superhydrophobic characteristics. Utilizing its dual superlyophobicity, the fiber layer demonstrated high separation efficiencies and flux velocity for oil/water mixtures by prewetting under a gravity-driven mechanism. Additionally, the novel BiOBr/RW fibers also exhibited excellent dual superlyophobicity and effective separation for immiscible oil/oil systems. Furthermore, the BiOBr/RW fibers could serve as a filter to continuously separate oil/water mixtures with high flux velocity and removal rates (>93.9%) for water-soluble dye rhodamine B (RhB) simultaneously by directly activating peroxymonosulfate (PMS) in cyclic experiments. More importantly, the mechanism of simultaneous oil/water separation and RhB degradation was proposed based on the reactive oxygen species (ROS) quenching experiments and electron paramagnetic resonance (EPR) analysis. Considering the simple modified process and the waste RW as raw material, this work may open up innovative, economical, and environmentally friendly avenues for the effective treatment of wastewater contaminated with oil and water-soluble pollutants.

Ultrahigh Energy Storage Performance of BiFeO3-BaTiO3 Flexible Film Capacitor with High-Temperature Stability via Defect Design.

Nanoengineering polar oxide films have attracted great attention in energy storage due to their high energy density. However, most of them are deposited on thick and rigid substrates, which is not conducive to the integration of capacitors and applications in flexible electronics. Here, an alternative strategy using van der Waals epitaxial oxide dielectrics on ultra-thin flexible mica substrates is developed and increased the disorder within the system through high laser flux. The introduction of defects can efficiently weaken or destroy the long-range ferroelectric ordering, ultimately leading to the emergence of a large numbers of weak-coupling regions. Such polarization configuration ensures fast polarization response and significantly improves energy storage characteristics. A flexible BiFeO3-BaTiO3 (BF-BT) capacitor exhibits a total energy density of 43.5 J cm-3 and an efficiency of 66.7% and maintains good energy storage performance over a wide temperature range (20-200 °C) and under large bending deformation (bending radii ≈ 2mm). This study provides a feasible approach to improve the energy storage characteristics of dielectric oxide films and paves the way for their practical application in high-energy density capacitors.

Effect of Central Dialysis Fluid Delivery System (CDDS) using high flux dialyzer versus Regular Water Treatment Stations on Endotoxemia and Inflammatory Markers among Prevalent Patients on Regular Hemodialysis

Abstract Background and Objectives Translocated endotoxins derived either from intestinal bacteria or backfiltration, have a wide range of adverse effects on patients. Most end stage renal disease (ESRD) patients have systemic inflammation which increases the risk of morbidity and mortality. The central dialysis fluid delivery system (CDDS) has been used exclusively in Japan since 1960s, and now is being used in Ain Shams University. Our aim of the study is to evaluate the effect of (CDDS) versus single patient dialysis fluid delivery system (SPDDS) on endotoxemia and inflammatory markers among prevalent patients on regular hemodialysis (HD). Methods Eighty Patients were randomly selected from HD units, then divided into two groups, (group I) doing HD using CDDS water purification system at El Demerdash Hospital, (group II) using regular water purification system at Ain Shams University Specialized Hospital. Pre- dialysis and post-dialysis serum samples were obtained to measure endotoxin levels of both groups, as well as postdialysis serum samples were obtained to measure interleukin 6 (IL6) level and highly sensitive Creactive protein (Hs CRP). Results Circulating endotoxemia was most notable in group II, The mean predialysis endotoxin level in group I was 0.07 ± 0.05 Eu/mL, while in group II was 0.20 ± 0.07 Eu/mL and mean of post-dialysis endotoxin level in group I was 0.04 ± 0.02 Eu/mL, while in group II was 0.15 ± 0.03 Eu/mL. IL6 as well as Hs CRP levels were higher in group II in comparison to group I. Conclusion Our data showed significant reduction in circulating endotoxins in CDDS group.

Effect of Dialysis Modality and Membrane Permeability on FGF 23 Level and Cardiovascular Calcification in ESRD Patients

Abstract Introduction Cardiovascular disease is the most common cause of death in patients with chronic kidney disease (CKD) and vascular calcification is one of the strongest predictors of cardiovascular risk. The prevalence of vascular calcification increases as glomerular filtration rate (GFR) declines and calcification occurs years earlier in CKD patients than in the general population. (26). Aim of the Study To study the effect of hemodialysis modality in controlling FGF-23and to determine the impact of FGF23 on cardiovascular calcification Patients and Methods We selected 50 patients ESRD maintained on hemodialysis divided into 2 groups, Group 1: comprised of 25 patients maintained on hemodialysis with high flux dialyzer and Group 2: comprised of 25 maintained on weekly session of hemodiafiltration and comparison between both groups regarding FGF23 serum level in addition to cardiovascular screening for calcifications using ECHO, Carotid intima-media thickness, and carotid duplex. Results we found that Post dialysis FGF23 was significantly lower in “hemodiafiltration patients” than ‘hemodialysis patients” and Reduction ratio was significantly higher in “hemodiafiltration patients”(P &amp;lt; 0.001).ECHO score and carotid duplex score were insignificantly different between both groups, but carotid intima-media thickness was significantly higher in haemodialysis patients (P value 0.035). Post HDF FGF 23 had a significant positive correlation with IMT (r = 0.579, P = 0.008). Serum FGF23 post-HD and HDF had significant positive correlation with serum Calcium (r = 0.659, P = 0.002), (r = 0.474, P = 0.035), PTH (r = 0.485, P = 0.03), (r = 547, P = 0.013) and CRP (r = 0.646, P = 0.002), (r = 707, P &amp;lt; 0.001) and serum Phosphorus (r = 0.462, P = 0.04), (r = 478, P = 0.033) respectively. In HD group Carotid Duplex Score had significant positive correlation with serum Ca (r = 0.469, P = 0.037), while in HDF group Carotid Duplex Score had significant positive correlation with PTH (r = 0.59, P = 0.006). Conclusion Using online HDF technique showed a significant reduction of FGF23 and improvement of carotid intima-media thickness calcification score.

Optimization of lithium vapor box divertor evaporator location on NSTX-U using SOLPS-ITER

Commercial fusion reactors will be faced with extremely high divertor target heat fluxes that will require mitigation. Simulations of detachment in an NSTX-U scenario projected to have 92 MW m−2 unmitigated peak target heat flux are presented, which reaches sub-10 MW m−2 target heat flux using a highly dissipating lithium vapor box divertor design. The lithium vapor box is a detached divertor design which employs lithium vapor evaporation and condensation to contain lithium below the X-point. Previous SOLPS modeling has indicated a lithium vapor box can reduce the heat flux down to 10 MW m−2 via simultaneous evaporation from the Private Flux Region (PFR) and the Common Flux Region (CFR) sides of the vapor box. It is found here that PFR evaporation has improved access to the separatrix leading to significantly more efficient power dissipation than CFR evaporation. Simulations of target evaporation with an evaporation distribution that is self-consistent with the temperature of a Capillary Porous System with Fast flowing liquid lithium could reach nLi / ne∼ 0.025–0.030 at the Last Closed Flux Surface (LCFS) depending on the liquid metal flow speeds and lithium sputtering yield, while PFR-side evaporation can reach acceptable heat fluxes with nLi / ne∼ 0.038 at the LCFS. However, PFR evaporator performance can be improved if the target is allowed to be hot enough such that it reflects lithium, reaching nLi / ne∼ 0.028 and reducing required lithium evaporation. Ultimately PFR evaporation and target evaporation are found to have similar ability to produce acceptable heat flux solutions with minimal upstream concentration.

Preparation of high-flux membrane for dye desalination by the stacked swelling strategy of small-molecule side chains

In this study, a high-flux PVDF membrane for dye desalination was prepared using the small-molecule stacked swelling strategy. Firstly, 1,3-bis [tris(hydroxymethyl) methylamino] propane was grafted on the molecular chain of poly(vinylidenefluoride-co-chlorotrifluoroethylene)(PVDF-CTFE) to prepare the non-porous membrane with a thin skin layer by the NIPS method. Then, this non-porous membrane was placed in the glutamate reaction solution to make it undergo the nucleophilic substitution reaction with the C-Cl bond on the main chain of PVDF-CTFE, and then swelling treatment was performed with an alkaline aqueous solution. In this paper, the influence of the swelling effect of small-molecule glutamate with different degrees of reactivity on the membrane pore size and structure was investigated, and the dye/salt separation performance of glutamate-treated swelling membrane was compared with that of the membrane treaded with the larger-molecule tris-propanesulfonic acid. Based on the fact that glutamic acid has small molecular size and steric hindrance, the results show that glutamic acid with different reaction degrees induced single-molecule swelling and multi-molecule stacked swelling, which led to the stepwise increase of membrane pore size. Within a certain degree of reaction, the membrane pore size entered into the pore size platform of different gradients. Therefore, the controllable adjustment of the pore size of the swollen membrane was realized by controlling the degree of reaction of the grafted side chains. The pore size of the multi-molecule stacked swelling membrane of small molecules not only achieved the effect of the single-molecule swelling membrane of larger molecules but also had a greater number of through holes and higher water flux, and the mechanical properties of the small-molecule stacked swelling membrane did not deteriorate significantly. The optimal small-molecule stacked swelling membrane, G12, not only had a high water flux of 99.4 Lm-2h-1bar-1 but also rejected nearly 99% of the dye and allowed most of the salts (>98%) to permeate through the membrane when dealing with the mixed solution of direct red 80 and NaCl.

Enhancing the scaling resistance of corrugated polyvinylidene fluoride hydrophobic membrane in membrane distillation: Impact of CF4 plasma modification, pulse flow, and negative pressure

Membrane distillation (MD) is an emerging technology for brine concentration, but plagued by scaling/fouling/wetting in realistic applications. There has been tremendous progress in the mitigation of scaling via chemical modification to reduce the surface energy and hydraulic operation to change flow state in feed channel. But there still lacks an undisputed cognition yet which approach outperforms the others. To address this issue, this study comprehensively investigates the impact of state-of-the-art technologies on scaling mitigation based on a surface corrugated hydrophobic PVDF membrane with high flux and potential for mass production. The technology selected include CF4 plasma modification, pulse flow, and negative feed pressure from both thermodynamic and hydraulic perspectives. CF4 plasma modification resulted in a low surface energy superhydrophobic surface, but the scaling resistance of the membranes was not significantly improved. Pulse flow effectively mitigated scaling, yet the intrusion of calcium sulfate into the membrane matrix still occurred. Negative pressure at the feed channel created a stable air layer, leading to excellent stable vapor flux and distillation conductivity. The results indicated that the hydraulic operation using negative pressure at feed was an efficient approach for scaling mitigation. This study further elucidated the mechanism underlying the scaling resistance of superhydrophobic membranes and underscored the importance of hydraulic factors in enhancing the scaling resistance in MD.

Assessing the Helium Potential of Variscan Batholiths: Insight From Corsica Island

AbstractMost of the current helium (He) reserves originate from fortuitous discoveries, mainly made during oil and gas exploration in sedimentary basins. As helium generation depends on U and Th α‐decay, old geological provinces gather key ingredients for high He accumulation. However, numerous He‐rich springs have also been documented in much younger rocks, such as Variscan granites (320–250 Ma). These latter discoveries question the current exploration guidelines and require revisiting some of the longstanding paradigms. Here, is investigated He migration along a major fault rooted in the Corso‐Sardinian batholith (France). Two thermal springs, Caldanelle and Guagno‐Les‐Bains, show significant outgassing activities of crustal sourced He with concentrations up to 1.45 vol% and flow rates of 110 m3 STP 4He/year. Besides He, the gas phase is dominated by N2 (≈98 vol%) and minor CH4. Based on a survey employing multidisciplinary methodologies, it is revealed that (a) Variscan rocks represent efficient 4He source rocks, (b) the main source of He comes from the underlying Eo‐Variscan basement, (c) A deeply rooted fault and dense fractures networks drain the He, (d) the helium loss is limited, (e) faults and fractures may act as partial traps, and finally (f) the presence of an efficient trap could promote a He‐rich reservoir with high flux but low reserves. In that sense, young post‐orogenic granites represent promising helium plays. The geological context in which Caldanelle and Guagno‐Les‐Bains are embedded is ubiquitous in European Variscan batholiths. This case study is therefore intended to serve as a guide for helium exploration and to provide insights into helium behavior within a Variscan geological context.

Fabrication of poly(ethylene terephthalate)-based porous sponges for oil-water separation

The accumulation of plastic waste poses a long-term threat to the environment, while oil pollution causes immediate and serious damage. In this study, we proposed a method to repurpose poly(ethylene terephthalate) (PET), one of the most abundant plastics, into an oil sorbent. By mixing and crosslinking with polyethylene glycol (PEG) using hexamethylene diisocyanate trimer (HDIT), the PET can be reformed as a porous sponge with high porosity and moderate mechanical strength. The sponge can absorb floating oil from water with a capacity of up to 22 g/g, demulsify O/W emulsions of different oil contents (1–4 %) with efficiencies of over 97 %, and have a high flux (∼726.7 L·m−2·h−1) under gravity. The sponge prepared with recycled PET materials shows identical mechanical properties and oil-water separation efficiencies. This work demonstrates a sustainable and promising approach to simultaneously managing plastic waste and addressing various oil pollutions, aligning also with the principles of a circular economy.

Evaluation of microplastic particle transmission in a microfiltration process using fluorescence measurements: Effect of pore size and flux

Microplastic (MP) pollution in the aquatic environment is widespread, with a significant fraction of these particles originating from municipal wastewater treatment plant (WWTP) effluents. Whereas membrane filtration processes are touted as an effective MP removal strategy, the rejection of irregularly-shaped plastic particles, similar to those found in WWTPs, is poorly understood. Here, we characterize the filtration of irregularly-shaped MP particles (∼10 μm) through Durapore® microfiltration membranes (0.45 and 5 μm pore sizes). These particles were produced via ball-milling/sieving processes from a fluorescent polyethylene feedstock, enabling particle concentrations to be quantified using a standard fluorometric plate reader. Permeate samples from the 0.45 μm membrane exhibited low fluorescent intensities relative to feed samples, implying minimal MP transmission. Conversely, appreciable MP transmission through the 5 μm membrane was noted, with sizable MPs (∼2–7 μm) found in the permeate. This transmission was exacerbated at higher fluxes which emphasizes how operating conditions can govern MP retention. Post-filtration analyses demonstrated that particle capture occurred largely at the feed-membrane interface, where greater MP intrusion into the membrane was seen at the larger pore size. These results reaffirm the importance of choosing an appropriate membrane/membrane pore size and operating conditions to maximize MP retention in WWTPs.

Urban air PCDD/Fs: Dry deposition fluxes and mass transfer coefficients determined using a water surface sampler

Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) cause significant environmental concerns. Atmospheric PCDD/Fs permeate water bodies and other ecosystems through wet and dry deposition. In an urban site, dry deposition flux samples of gaseous phase PCDD/Fs were collected by a water surface sampler (WSS) operated between June 2022 and June 2023. There is a conspicuous absence of literature on the direct measurement of dry deposition flux levels in the gaseous phase of PCDD/Fs. In the study, PCDD/Fs in the gas phase reaching the WSS dissolved in the water according to Henry's Law. The PCDD/Fs in the water were transferred to an XAD-2 resin column, sorbing the dissolved PCDD/Fs. The average monthly gas phase dry deposition flux was 34.07 ± 9.35 pg/m2-day (7.35 ± 2.16 pg I-TEQ/m2-day). The highest flux was measured in March (49.53 pg/m2-day), and the lowest was in August (18.64 pg/m2-day). These values indicated the direct flux from air to water. The atmospheric concentration of the gas-phase ranged from 68.38 to 126.88 fg/m3 (13.22–25.01 fg I-TEQ/m3). Dry deposition fluxes and concentrations of atmospheric PCDD/Fs were bigger in the colder months than in the warmer months. This was probably due to a significant increase in residential heating during the colder months, decreased photochemical reactions, and lower mixing heights. Regarding congeners in the dry deposition flux and concentration values in I-TEQ units, 2,3,7,8-TCDD compound predominated with the proportions of 31.61 ± 7.76% and 29.09 ± 12.34%, respectively. Concurrently measured dry deposition flux (Fg) and ambient air concentration (Cg) of PCDD/Fs were considered in the determination of mass transfer coefficient (MTC = Fg/Cg) calculation for each PCDD/F congener. The average MTC for targeted 17 PCDD/Fs was 0.45 ± 0.15 cm/s, and it fluctuated between 0.89 ± 0.30 cm/s for 2,3,7,8-TCDF and 0.2 ± 0.16 cm/s for OCDD.

Bilayer cellulosic FO membrane developed by polydopamine and nanochitosan through layer by layer coating process

A highly efficient bilayer cellulose acetate forward osmosis (FO) membrane was developed using polydopamine (PDA) and chitosan nanoparticles (CsNP) through layer by layer coating process and characterized using DLS, FESEM, AFM, EDX, and static contact angle. The use of CsNP and PDA led to an improvement in chemical properties, surface hydrophilicity, and structural parameter. The experimental tests for both RO and FO experiments were carried out to calculate structural parameter (it decreased from 0.59 mm for neat CA to 0.37 mm for CA-PDA/CsNP2) of membranes. Also, the salt rejection and water permeability of membranes were tested in RO mode using 40 mM NaCl, while the water flux and reverse salt flux of membranes were analyzed in FO test. The CA-PDA/CsNP2 membrane with 0.6 wt.% of CsNP in the coating solution not only showed a high water permeation flux about 21.23 LMH for 2 mM NaCl but also decreased its reverse salt flux from 7.08 to 4.52 gMH. According to the fouling test results, the normalized water flux of the neat membrane declined from 1 to about 0.65 while it was higher than 0.85 for CA-PDA/CsNP2 which represents an improvement in the antifouling property. This improvement was mainly due to an increase in the hydrophilicity of the coated membrane and the electrostatic repulsion among the foulant and surface of CA-PDA/CsNP2. The results showed that the fabricated CA-PDA/CsNP2 membrane shows a high potential application in the FO process and is more competitive than other existing FO membranes.

Bio-inspired super-wetting coatings constructed from interfacial mineralization of rare earth phosphate for oil/water separation applications

The oil fouling problem of lipophilic polymer matrix causes severe decline of separation performance, becoming one of the most serious challenges for oil/water separation. A chemical-stable and mechanical-strong anti-fouling coating is highly emerged. Herein, to achieve anti-fouling performance on diverse polymer substrates, a biomimic super-wetting coating is fabricated by interfacial mineralization of lanthanum phosphate (LaPO4). The strong interaction between ions makes LaPO4 very stable against acid, base, oil and mechanical impact, while the dense charges on the surface of LaPO4 attract water molecules and create a hydration layer to repulse oil under water. The membranes and meshes modified by such mineralized coating exhibit good separation efficiency (>99 %) and high permeation flux for oil-in-water emulsions and oil/water mixtures, respectively. In addition, notable cyclic flux recovery ability was fulfilled by water rinsing. The fabrication of such mineralized coating is easily operated through solution process and no harmful byproducts will be generated. Basically, the low-cost and eco-friendly mineralized coating is promising for oily water treatment in the practical complicated environment.

Vibrio neptunius-ULV11 cell-free supernatant as a promising antifouling approach in reverse osmosis systems

One of the most common problems observed in continuous operation of desalination plants, is the presence of biofouling in ultrafiltration (UF) modules and reverse osmosis membranes (ROMs), decreasing permeated water obtention and increasing energy consumption among other adverse effects. To solve this problem, desalination industry applied UF modules and ROMs cleaning procedures that aims to increase half-life operation time, however, many of the actual cleaning procedures are focused on the addition of chemical compounds that provokes secondary effects such as UF modules and ROMs disintegration leading to structural changes and a decrease in plant performance. Thus, new approaches to replace current cleaning compounds with new ecofriendly and less secondary effects technologies are necessary.In this study, we present a Vibrio neptunius strain ULV11 isolate, with a high capacity to remove fouling in RO systems. In detail, ULV11 cell-free supernatant (CFS) was used in replace of chemical agents as a cleaning solution according to standard operational protocol on 3-year-old membranes of continuous operation. The results showed that CFS can be used under operational conditions (such high pressure and flux) allowed us to recover permeate volumes similar to those observed in traditional chemical treatment with better conductivity. This recovery was accompanied by a reestablishment of membrane topology observed by atomic force microscopy and EPS remotion since concanavalin A signal trough confocal microscopy was decrease as compared with biofouling control.

Double diffraction imaging of x-ray induced structural dynamics in single free nanoparticles

Because of their high photon flux, x-ray free-electron lasers (FEL) allow to resolve the structure of individual nanoparticles via coherent diffractive imaging (CDI) within a single x-ray pulse. Since the inevitable rapid destruction of the sample limits the achievable resolution, a thorough understanding of the spatiotemporal evolution of matter on the nanoscale following the irradiation is crucial. We present a technique to track x-ray induced structural changes in time and space by recording two consecutive diffraction patterns of the same single, free-flying nanoparticle, acquired separately on two large-area detectors opposite to each other, thus examining both the initial and evolved particle structure. We demonstrate the method at the extreme ultraviolet (XUV) and soft x-ray Free-electron LASer in Hamburg (FLASH), investigating xenon clusters as model systems. By splitting a single XUV pulse, two diffraction patterns from the same particle can be obtained. For focus intensities of about 2×1012 W cm−2 we observe still largely intact clusters even at the longest delays of up to 650 picoseconds of the second pulse, indicating that in the highly absorbing systems the damage remains confined to one side of the cluster. Instead, in case of five times higher flux, the diffraction patterns show clear signatures of disintegration, namely increased diameters and density fluctuations in the fragmenting clusters. Future improvements to the accessible range of dynamics and time resolution of the approach are discussed.

High-performance ionic liquid-based membranes employed for efficient recovery of lithium

The effective Li separation in high Na/Li (or K/Li) ratio solution is a challenging issue for Li recovery industry. Here we present a novel functionalized ionic liquid (IL) with high Li selectivity and electroconductivity. This IL is synthesized with the deprotonated thenoyltrifluoroacetone ([TTA]−) anion and methyltributylammonium ([N4441]+) cation. The Li extraction performance and selectivity of [N4441][TTA], as well as extraction mechanism were systematically investigated. Then the [N4441][TTA] is integrated into cellulose triacetate (CTA). An ionic-liquid-based membrane named NTC is produced consisting of 36.1 wt% [N4441][TTA]. The NTC membrane shows a high Li initial flux of 1.89 × 10-2 mol⋅m−2⋅h−1. At a mass ratio Li: Na: K of 1:1:1, the separation factor of Li over the Na and K are 28.86 and 38.26, respectively. Finally, electrodialysis is employed to further enhance the Li transport. The initial flux significantly increases to 2.34 × 10-2 mol⋅m−2⋅h−1 when the current density is 1.5 mA⋅cm−2. This membrane is expected to be used for Li extraction from Na- and K-rich brine solutions.

Efficient separation of oil-in-water emulsion using (MgCoNiCuZn)O high-entropy ceramic membrane

In this study, we have successfully prepared (MgCoNiCuZn)O high-entropy ceramic membrane by the combination of diffusion-induced phase transformation and high temperature sintering. The membrane was used to separate oil/water emulsions. The results showed that the phase transformation between solvent DMAc and non-solvent H2O resulted in the formation of asymmetric pore structure including finger-like pores and sponge-like pores. After calcination, the porous structure was remained, and the transformation of high-entropy phase was completed. As the calcination temperature increased, the porosity decreased, resulting in densification of the membrane. However, the nanopore with the pore size of 3.433 nm was obtained after calcination at 850 ℃. The membrane exhibited good hydrophilicity in air and underwater oleophobicity, yielding the high pure water flux and separation efficiency simultaneously. After the calcination was performed at 900 ℃, a pure water flux of 6333 L/(m2⋅h) was obtained, and the separation efficiency of oil-in-water emulsion reached 99.87 %. The long-term stability of high-entropy ceramic membrane was studied. A flux of 520 L/(m2⋅h) was achieved even though the separation operation was performed for 10 h. After 10 h, the rejection rate consistently remained above 99 %, which proved that the membrane has excellent long-term stability.

Numerical simulation of the effects of toothed structure on the flow boiling characteristics of micro-fin tubes

Abstract The numerical simulation of R141b flow boiling in micro-fin tubes (MFTs) with a 1 mm equivalent diameter is conducted using the VOF and the Lee models. An analysis of the boiling heat transfer (HT) characteristics has been performed, considering impacts of the four factors. The most suitable correlation of boiling HT has also been evaluated. The summarized findings are as follows: the BHT coefficient within the MFTs consistently rises with increased mass velocity, heat flux, and saturation temperature. However, there is a presence of a partially dry-out region inside the MFTs at high heat flux. Additionally, the enhancement of boiling HT by elevating saturation temperature is not prominent in the low vapor quality range. HT coefficients of the MFTs with various fin structures ranked in magnitude are as follows: tapered MFTs &gt; trapezoidal MFTs &gt; circular MFTs. The model proposed by Wu is identified as the best predictor for flow boiling HT performance in horizontal MFTs, although its prediction accuracy is limited in the low vapor quality range.