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Capturing carbon dioxide (CO2) from flue gases is a crucial step towards reducing CO2 emissions. Among the various carbon capture methods, facilitated transport membranes (FTMs) have emerged as a promising technology for CO2 capture owing to their high efficiency and low energy consumption in separating CO2. However, FTMs still face the challenge of losing mobile carriers due to weak interaction between the carriers and membrane matrix. Herein, we report a sulfonated chitosan (SCS) gel membrane with confined amine carriers for effective CO2 capture. In this structure, diethylenetriamine (DETA) as a CO2‐mobile carrier is confined within the SCS gel membrane via electrostatic forces, which can react reversibly with CO2 and thus greatly facilitate its transport. The SCS ion gel membrane allows for the fast diffusion of amine carriers within it while blocking the diffusion of nonreactive gases, like N2. Thus, the prepared membrane exhibits exceptional CO2 separation capabilities when tested under simulated flue gas conditions with CO2 permeance of 1155 GPU and an ultra‐high CO2/N2 selectivity of above 550. Moreover, the membrane retains a stable separation performance during the 170 h continuous test. The excellent CO2 separation performance demonstrates the high potential of gel membranes for CO2 capture from flue gas. [ABSTRACT FROM AUTHOR]

In today's digital age, most individuals own smartphones and routinely use telecom services. As a result, understanding users' intentions to continue using specific mobile carriers based on their experiences becomes paramount for corporate sustainability. This study delves into the intricate dynamics of user experiences, aiming to elucidate the primary factors influencing continuance intention. By incorporating a unique theoretical framework that emphasizes customer experiences, this research seeks to bridge a gap in the current literature. Drawing from a sample size of 299 smartphone users who have active subscriptions with telecom services, we employed partial least squares structural equation modeling (PLS-SEM) to rigorously analyze the data. Our findings indicate a significant relationship where the corporate image is influenced by factors such as contract terms, perceived fees, call quality, and call center experience. Moreover, user satisfaction, another pivotal variable, is shaped by the same factors. Both corporate image and user satisfaction were found to be determinants of a user's continuance intention. The distinguishing value of this research lies in its holistic approach to user experience, uniquely integrating various service touchpoints to provide comprehensive insights into user intentions in the telecom domain. [ABSTRACT FROM AUTHOR]

Membrane separation is a promising alternative for gas purification. Facilitated transport (FT) membranes, with reversible reactions to promote CO2 transport, can simultaneously obtain high CO2 permeability and selectivity of CO2 over other gases, such as CH4, making FT membranes particularly interesting for CO2/CH4 separation. An overview of the state-of-the-art FT membranes used for CO2/CH4 separation is desired for the R&D of industrial membrane applications. This paper has reviewed the development progress and advances in various FT membranes for CO2/CH4 separation, including mobile carrier FT membranes, fixed site carrier FT membranes, and mixed matrix FT membranes. Over 100 different kinds of membrane materials with over 500 gas separation data have been summarized with performance data collected and analyzed. Perspectives of FT membranes for CO2/CH4 separation are also proposed.

Membrane separation is a promising alternative for gas purification. Facilitated transport (FT) membranes, with reversible reactions to promote CO2 transport, can simultaneously obtain high CO2 permeability and selectivity of CO2 over other gases, such as CH4, making FT membranes particularly interesting for CO2/CH4 separation. An overview of the state-of-the-art FT membranes used for CO2/CH4 separation is desired for the R&D of industrial membrane applications. This paper has reviewed the development progress and advances in various FT membranes for CO2/CH4 separation, including mobile carrier FT membranes, fixed site carrier FT membranes, and mixed matrix FT membranes. Over 100 different kinds of membrane materials with over 500 gas separation data have been summarized with performance data collected and analyzed. Perspectives of FT membranes for CO2/CH4 separation are also proposed. [ABSTRACT FROM AUTHOR]

Transmembrane anion transport is an important biological process in maintaining cellular functions. Thus, synthetic anion transporters are widely developed for their biological applications. Imidazolinium was introduced as anion recognition site to a multiblock amphiphilic structure that consists of octa(ethylene glycol) and aromatic units. Ion transport assay using halide‐sensitive lucigenin and pH‐sensitive 8‐hydroxypyrene‐1,3,6‐trisulfonate (HPTS) revealed that imidazolinium‐based multiblock amphiphile (IMA) transports anions and showed high selectivity for nitrate, which plays crucial roles in many biological events. Temperature‐dependent ion transport assay using 1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphocholine (DPPC) indicated that IMA works as a mobile carrier. 1H NMR titration experiments indicated that the C2 proton of the imidazolinium ring recognizes anions via a (C−H)+⋅⋅⋅X− hydrogen bond. Furthermore, all‐atom molecular dynamics simulations revealed a dynamic feature of IMA within the membranes during ion transportation. [ABSTRACT FROM AUTHOR]

Zn2+, Cu2+ and Ni2+ permeabilities through supported liquid membranes (SLMs) were determined experimentally from single, binary, and ternary ionic mixtures. Microporous polypropylene membrane was used as the frame to retain isopar-L solvent and di (2-ethylhexyl) phosphoric acid (D2EHPA) carrier. Sulfuric acid solution was used as a strip (receiving) solution. The ion permeability values were in the 10−7-10−6 cm2 s−1 range and increased with the concentrations of D2EHPA in isopar-L and the stripping sulfuric acid. The ion ideal selectivity ranged from 1.05 (Zn/Cu) to 8.40 (Zn/Ni), depending on the feed concentration. The single ion permeability was significantly higher than the binary mixtures, probably due to ion competition with D2EHPA carrier molecules. High selectivity was achieved using ternary mixtures: Zn2+ was the fast-permeating species due to preferential sorption with D2EHPA. Separating Zn2+ from Cu2+ and/or Ni2+ mixtures was most efficient with high D2EHPA concentration, concentrated H2SO4 strip solution, concentrated feed solution, and from multiple ionic mixes. [ABSTRACT FROM AUTHOR]

Abstract In this work, defect-free thin-film-composite (TFC) hollow fiber membranes containing various amino acid salts as CO 2 facilitated transport carriers were fabricated via dip-coating. Four different amino acid salts, i.e., potassium prolinate (ProK), potassium argininate (ArgK), potassium glycinate (GlyK) and potassium cysteinate (CysK), were selected and embedded within polyvinyl alcohol (PVA) matrix. TGA, FTIR, SEM and humid mixed gas permeation test were used for the evaluation. Experiments show that adding amino acid salts into the PVA matrix significantly increases the CO 2 permeance with little influence on the CO 2 /N 2 selectivity. ProK was found the most effective within the four investigated mobile carriers; The addition of 40% ProK into the PVA matrix nearly doubled the CO 2 permeance (from 399 to 791 GPU). The PVA/amino acid salt membranes also exhibited good long-term stability, in which both CO 2 permeance and CO 2 /N 2 selectivity remained nearly unchanged in a 20-h test and after a two-week shutdown period. Graphical abstract Image 1 Highlights • Four amino acid salts were used as mobile carriers in PVA-based membranes to enhance CO 2 transport. • Defect-free TFC hollow fiber membranes with selective layer thicknesses of <500 nm were fabricated. • Lab-size hollow fiber membrane module was prepared and tested using humid mixed feed gas. • Adding amino acid salt improves the CO 2 permeance significantly without sacrificing the selectivity. • The membranes show good long-term stability in the test and after a shutdown operation. [ABSTRACT FROM AUTHOR]

Supported liquid membranes (SLM) suffer from very slow mass transfer of the solute from the donor phase (DP) to the receptor phase (RP) through the liquid membrane (LM). In the present work, an attempt was made to accelerate the mass transfer in SLM by creating a modified configuration in which the DP and RP are made to flow either co- or counter-currently to each other. Variables, which could affect the removal of NaCl, were the volume ratio of DP to RP, type and quantity of sequestering agent (SA), presence of mobile carrier (MC), type of LM, and flow rate of DP and RP. The results showed that the higher the flow rate of DP and RP, the higher the mass transfer of NaCl. Quantity and type of SA and type of LM were prime important factors. Remarkably, the time required for transfer of NaCl from DP to RP was reduced from several hours in the case of stagnant SLM to several minutes in the present work. The mass transfer of NaCl was analysed based on kinetic laws of two consecutive irreversible first-order reactions. The values achieved establish the process is diffusion controlled, and the membrane entrance rate constants increase directly with initial concentration (Ci) and inversely with quantity of SA. [ABSTRACT FROM AUTHOR]

In the present work, a prototype was devised and constructed as a preliminary step for the development of industrial scale process in which desalination by an emulsion liquid membrane (ELM) technique takes place. The process is intended to be a breakthrough in the field of desalination, which should compete with the currently used reverse osmosis (RO) technique. A drawback of RO is the high cost of membrane and intensive pretreatment of seawater. The prototype consists of three stages: emulsion formation, desalination operation, and separation of the product into two phases (desalinated water and spent emulsion). The latter could be then adjusted and recycled for reuse in a second cycle. Several investigated factors which could affect the desalination process were: initial concentration (Ci), volume ratio of liquid membrane (LM) to receptor phase (RP), quantity of emulsifier, type of liquid membrane, type and quantity of sequestering agent (SA), time and power of ultrasonication (US), presence of mobile carrier (MC) and finally treatment ratio (ratio of volumes of donor phase (DP) to emulsion) (TR). The best conditions arrived at were: volume ratio of LM:RP = 4:1, necessary in forming a stable emulsion. The optimum quantity of MC was found to be 6.86 g Span 80 for 80 ml chlorobenzene and 20 ml 20% soluble starch, so that best transfer of the NaCl could take place from DP to RP. Soluble starch (2% b.w.) is a suitable sequestrant for NaCl, chlorobenzene was better than chloroform, the latter is better than Soltrol 220 as LM. It was also found that 5 min at 180 Watts of US to provide a stable emulsion. The quantity of emulsifier and Ci are of crucial importance that affects directly the desalination process. [ABSTRACT FROM AUTHOR]

In the present work, the removal of NaCl using the present type of supported liquid membrane technique has been investigated. A simple apparatus devised and constructed was used to conduct the experiments. Various factors that would affect the progress of transport were studied and these were initial concentration (Ci) of simulated seawater in donor phase (DP), presence of mobile carrier (MC) in the liquid membrane (LM), concentration of MC in LM, presence of sequestering agent (SA) in the receptor phase (RP), and speed of stirring. The volume ratio of DP to RP was kept constant at 2:1. Type (1,2 dichloroethane (DCE)) and thickness (2 mm) of LM were kept constant. Cellophane constituted the support for the LM. The most important findings emphasized the importance of the presence of a MC in the LM to enhance mass transfer through the LM and that an optimum concentration of MC existed. Also the importance of stirring in promoting mass transfer by minimizing the boundary layer intact to the cellophane support was elucidated. The best conditions arrived at were MC = 0.0538 mol/l (mol of dibenzo-18-crown-6/l of LM), SA = 0.0617 mol/l (mol of soluble starch/l of RP), slow stirring (100 rpm) of DP, and using DCE as LM. The mass transfer of NaCl was analyzed based on kinetic laws of two consecutive irreversible first-order reactions, and kinetic parameters (k1d,k2m,k2r,,tmax,,) for the transport of NaCl were investigated. The values obtained demonstrate that the process is diffusion-controlled. Results indicate that the membrane entrance and exit rate constants (k1,k2) increase directly withCiand inversely with quantity of SA. [ABSTRACT FROM PUBLISHER]

In the present work, removal of NaCl using the bulk liquid membrane (BLM) technique has been investigated, using a simple apparatus for conducting the experiments. Variables investigated were volume ratio of donor phase (DP) to receptor phase (RP), presence of sequestering agent (SA) in RP, type of organic liquid membrane (LM), quantity of mobile carrier (MC) in the LM. Stirring speed and volume of LM were kept constant at 100 rpm and 130 ml, respectively. The mass transfer of NaCl was analysed based on kinetic laws of two consecutive irreversible first-order reactions, and kinetic parameters (k1d,k2m,k2r,,tmax,, and) for the transport of NaCl were investigated. The values obtained demonstrate that the process is diffusionally controlled. Results indicate that the membrane entrance and exit rate constants (k1,k2) increase with decreasing DP:RP ratio and with decrease in quantity of MC, and quantity of SA, and the presence of dichloroethane (DCE) is preferred to chloroform (CF) as LM. [ABSTRACT FROM AUTHOR]

New amine-containing polymer/zeolite Y composite membranes were successfully synthesized for CO 2 /N 2 separation from flue gas. The polyvinylamine (PVAm) with a high molecular weight ( M W ¯ =719,000) was synthesized and used as the fixed-site carrier for CO 2 facilitated transport. The PVAm was incorporated with different aminoacid salts (mobile carriers), including potassium glycinate (KG), lithium glycinate (LiG) and piperazine glycinate (PG). The amine-containing polymer blend solution was coated onto a zeolite Y seed layer on top of a polyethersulfone (PES) substrate. The composite membrane with a selective amine layer thickness of more than 200 nm showed a better CO 2 /N 2 separation performance compared to the membrane without the zeolite Y seed layer, which was due to the fact that the zeolite Y layer had a smaller interparticle pore size than the PES substrate, resulting in minimizing the penetration of amine-containing polymer solution into the pores underneath and thus reducing the mass transfer resistance of CO 2 molecules through the membrane. The effects of different kinds of mobile carriers and various compositions and thicknesses of the amine-containing polymer layer were investigated. The resultant amine-containing polymer/zeolite Y composite membrane exhibited a CO 2 permeance up to ~1100 GPU and a CO 2 /N 2 mixed gas selectivity of at least 200 at the typical flue gas temperature of 57 °C. This high separation performance showed a great potential for the application of carbon capture from flue gas. [ABSTRACT FROM AUTHOR]

Herein, we report a reversible modular chloride transport process based on host-guest competitive interactions between an imidazolium-based chloride carrier and beta-cyclodextrin. We report evidence for the formation of the supramolecular complex between 1,3-bis(2-(adamantan-1-yl)ethyl)imidazolium bis(trifluorometyl-sulfonyl)imide with two β-cyclodextrins. Through fluorescence assays in liposomes and black lipid membrane experiments, we demonstrate that the formation of the supramolecular complex results in the inhibition of the chloride transport. We show that the chloride transport process can be entirely restored in the presence of competitive adamantyl-functionalized guests. This is the first example of an entirely reversible modular chloride transport process in phospholipid bilayers involving a mobile carrier transporter and cyclodextrin supramolecular complex. [ABSTRACT FROM AUTHOR]

In this paper, polyvinyl alcohol (PVA) membranes impregnated with amines (monoethanolamine and diethanolamine) were prepared for CO2/N2 separation. The cross-linking of DEA impregnated PVA by glutaraldehyde (GA) with different mass ratios (GA/PVA: 0.5, 1, 3, 5, 7%) were investigated with no use of acid catalyst or organic solvents. The effects of the amine type-concentration, cross-linking agent content, and feed pressure as well as stability were examined in both pure and mixed gases. Generally, CO2/N2 performance through the DEA-PVA membranes was higher than that of MEA-PVA membranes. The fabricated membranes were characterized by differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). The cross-linked membranes showed reasonable CO2/N2 permselectivities in comparison with uncross-linked membranes and these are recommended for high performance membrane for CO2/N2 separation. The best-yielding membranes (DEA-PVA/GA(1 wt%)/PTFE) represented the greatest CO2/N2 selectivity of 122.04 and 907.06 for pure and mixed gas experiments, respectively. [ABSTRACT FROM AUTHOR]

It is 25 years since the first report of a synthetic ion channel transporter. Today, dozens of molecular and supramolecular designs have been developed to facilitate ion and small molecule transport across a bilayer membrane. Presented here is a concise summary of the advances made over the past four years. The transporters are grouped into three mechanistic classes: mobile carrier, monomeric channel, and self-assembled pore. Common building blocks are crown ethers, steroids, cyclodextrins, peptides, curcubiturils, and calixarenes. The eventual goal is to produce functional supramolecular devices such as sensors, enzyme assays, and lead candidates for pharmaceutical development. [ABSTRACT FROM AUTHOR]

Abstract: CO2-selective membranes have a variety of applications, such as synthesis gas purification, natural gas sweetening, and greenhouse gas sequestration. In this study, CO2-selective membranes containing both mobile and fixed carriers in crosslinked poly(vinyl alcohol) were synthesized. Transport properties of membranes, including CO2 flux and permeability, H2 flux and permeability, CO2/H2 selectivity, and CO2/N2 selectivity, were studied with a gas stream consisting of hydrogen, carbon dioxide, and nitrogen. The effects of feed pressure, water content, and temperature on transport properties were investigated. The membranes showed good CO2 permeabilities and CO2/H2 selectivities up to 170°C. At 120°C, the CO2 permeability and CO2/H2 selectivity reached 8200 Barrers (1 Barrer=10−10 cm3 (STP)cm/(cm2 scmHg)) and 450, respectively. The synthesized membranes also had high CO2/CO selectivities in the temperature range of 100–170°C. [Copyright &y& Elsevier]

The separation of cadmium and zinc from a dilute aqueous sulfate media using supported liquid membrane (SLM) technique has been studied. The microporous polypropylene film Celgard-2400 was used as the solid support for the liquid membrane and TOPS-99 was used as the mobile carrier. The effect of different parameters such as flow rate, pH of feed solution, extractant concentration in membrane phase, acid concentration in strip solution, and Cd(II) and Zn(II) concentration in feed solution on metal ion flux was studied. It was observed that a flow rate of 100 mL/min was sufficient to minimize the resistance due to an aqueous boundary layer at the feed solution membrane interface. The zinc flux increased with an increase of pH from 1.5 to 3.5 and then decreased with a further increase of pH. The cadmium permeation started at a higher pH, i.e., 3.0 and increased with increase of pH up to 3.5 followed by a plateau. Also, with an increase of TOPS-99 concentration in the membrane phase up to 200 mol/m3, JZn increased and then decreased. The separation factors for cadmium and zinc were calculated at different experimental conditions and are reported. [ABSTRACT FROM AUTHOR]

The facilitated transport of Cd(Il) ions through a hollow-fiber-supported liquid membrane with bis-2-ethylhexyl phosphoric acid as carrier was studied. The mass transfer rate, expressed as permeability P, was measured as a function of mean aqueous solution velocity and carrier concentration. Characteristic ion permeabilities of 10–26 × 10−7 m/s were measured at feed velocities between 1 × 10−2−19 × 10−2 m/s at stripping velocities between 0.22 × 10−2−7x 10−2 m/s with constant feed flow. The measured permeabilities were compared to generally accepted mass transfer correlations. The predicted permeabilities adequately fit the experimental data, indicating that the rate limiting step in the transport of the ion was the diffusion through both aqueous films, feed and stripping, whereas the organic resistance of the membrane was negligible. Furthermore, the proposed model allowed the prediction of the permeability of cadmium for different experimental conditions, which is useful to perform experiments to reduce metal levels in water or other effluents. [Copyright &y& Elsevier]

In the present work, the supported liquid membrane (SLM) technique has been applied to the desalination of saline water. A simple apparatus designed and constructed in our lab was used to conduct the experiments. Various factors that would affect the degree of desalination were studied and these were: type of organic membrane liquid (ML), quantity of ML (i.e. its thickness), presence of emulsifier or mobile carrier (MC) in the ML, concentration of MC in ML, presence of polyelectrolyte (sequestrant) in the receptor phase and presence or absence of magnetic stirring. The volume ratio of donor phase to receptor phase was kept constant at 4:1 and the concentration of sodium chloride solution in the donor phase (simulated seawater) ranged between 36 and 39 g/L. Cellophane constituted the support for the ML. A previous work on desalination by emulsion liquid membranes (ELMs) has proven to be a successful one stage operation with a percent water recovery of 98% and in which >99% of the salt (equivalent to seawater concentration) is removed in only a few minutes. Accordingly, a preliminary work on desalination using SLM technique was attempted and evaluated and compared to the aforementioned ELM technique. The most important findings emphasized the importance of MC in the ML due to the enhancement of mass transfer through the liquid membrane (LM) and the importance of stirring in promoting mass stransfer by minimizing the boundary layer adjacent to the cellophane support. In addition, an optimum concentration of MC existed in the LM. However, desalination using SLMs is much slower than ELMs due to a much lower surface mass transfer area of the former compared with the ELMs. On the other hand, SLMs enable various factors that would affect the process of desalination to be conducted by simple means with a target of optimizing the process. [Copyright &y& Elsevier]

The in vitro uptake of zinc by erythrocytes was measured under near-physiological conditions, usingZn as a radioactive tracer. Because of the presence of serum albumin-a strong zinc ligand-a low concentration of medium free zinc was maintained. Under these conditions a high-affinity carrier for zinc transport over the cell membrane was identified. With human erythrocytes, a Michaelis constant ( K ) of 0.2 n M with respect to free medium zinc was measured and a V of 4.5 nmoles Zn transported per h/g dry wt. The K for medium Zn increases when the size of the internal erythrocytic Zn pool is augmented, whereas V remains virtually unchanged. A model to explain this phenomenon is proposed. It is suggested that this phenomenon could underlie observations, confirmed here, that the in vitro uptake of Zn by animal erythrocytes depends on the Zn status of the animal. [ABSTRACT FROM AUTHOR]