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A polymer inclusion membrane (PIM) that contains a polyvinyl chloride (PVC) polymer matrix and 1-octanol (OCT) as specific carrier (PO-PIM) was prepared to investigate the mass transfer behaviour of phenol in aqueous solutions. Results showed that the mass transfer behaviour of the PO-PIM for phenol conformed to the first-order kinetics. In addition, the mass transfer efficiency for phenol reached the maximum when the OCT content was 82.8 wt%. The mass transfer activation energy (E a ) was 14.46 kJ mol -1 , which indicated that intramembranous diffusion was the main controlling factor in the mass transfer process. The introduction of hydrophobic additives, such as kerosene, liquid paraffin and vegetable oil, into the PO-PIM could remarkably improve its stability. In an aqueous solutions of phenol ranging from 0 mg L -1 to 9000 mg L -1 , the initial flux (J 0 ) of kerosene/PVC/OCT-PIM (KPO-PIM) was positively correlated with the initial concentration of phenol. For a stripping solution with a feed solution pH of 2.0 and a sodium hydroxide concentration of 0.1 mol L -1 , the maximum permeability coefficient during stable mass transfer reached 12.55 μm s -1 . At a mass transfer area of 3.14 cm 2 , an enrichment factor (EF) of 3.5 for 200 mg L -1 of phenolic aqueous solution was achieved within 48 h through KPO-PIM., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

[Display omitted] • ·Trioctyl polyvinyl chloride ammonium (PVCT QAS) was synthesized for the first time. • ·PVCT QAS D has high stability of electrodriven mass transfer. • ·The mass transfer threshold in PVCT QAS D is 22 % QAS. • ·QAS content is the key factor to determining the performance of electrodriven mass transfer of PVCT QAS D. Trioctyl polyvinyl chloride ammonium (PVCT QAS) with quaternary ammonium salt content (QAS) of 25 % was synthesized by a nucleophilic substitution reaction of between polyvinyl chloride (PVC) and trioctylamine (TOA) for the first time. The mass transfer behavior of HCrO 4 −, CdCl 3 −, CoCl 4 2−, FeCl 4 −, and CuCl 4 2− metal complex anions within the plasticized PVCT QAS membrane followed a first-order kinetic rate equation. Taking the Cr(Ⅵ)-PVCT QAS system as a representative, the influences of plasticizer content and membrane thickness on the mass transfer performance were investigated, and the electrodriven mass transfer behavior of Cr(VI) was studied. The results showed that the mass transfer of HCrO 4 − in PVCT QAS D followed a jumping mechanism, with a QAS content threshold of 22 %. In the Cr(VI)-PVCT QAS electrodriven mass transfer system, the PVCT QAS D exhibited uniform electrochemical properties, and the membrane thickness had little influence on the mass transfer rate. The response of HCrO 4 − mass transfer rate to voltage depended on the distribution density of QAS in the membrane. The mass transfer performance of PVCT QAS D with QAS between 15 % and 20 % had a high dependence on the voltage, while the permeability coefficient of Cr(VI)-PVCT QAS system became stable when the voltage exceeded 10 V after surpassing the QAS content threshold. 50 μm QAS 25 % Cr(VI)-PVCT QAS system had a treatment efficiency of 710 mg·m−2·h−1 for HCrO 4 − at 10 V, while maintaining exceptional selectivity and stability. [ABSTRACT FROM AUTHOR]

The transport behaviour of Cr(VI) from the aqueous phase through a polymer inclusion membrane (PO-PIM) containing 1-octanol (OCT) as carrier and polyvinyl chloride (PVC) as support at a low voltage drive (0–30 V) is investigated. The correlation between the OCT content and the surface or cross-sectional micromorphology of PO-PIM is also analysed. Under optimised mass transfer conditions, the transmission rules and mechanism of Cr(VI) under an electrodriven membrane extraction system are investigated. Results show that the surface and interior of PO-PIM exhibit micro/nanopores with an OCT content exceeding 50% (w/w). The mass transfer behaviour of OCT to Cr(VI) conforms to the proton coupling mechanism. The voltage drive effectively solves the residue problem of Cr(VI) in the membrane phase, and the permeability coefficient ( P ) of PO-PIM to Cr(VI) increases with the voltage. The P of PO-PIM to Cr(VI) reaches 43.38 μm·s −1 at 30 V when the OCT content is 82.8% and the feed and stripping phases are pH 2.0 HCl solution and 0.1 mol·L −1 NaOH solution environments, respectively. After the introduction of hydrophobic kerosene into the membrane phase, the stability of the membrane is significantly enhanced. When the composition ratio of kerosene/OCT/PVC is 0.8:2.2:0.5 and the voltage is 30 V, the initial current density rise is only 0.1 A and the pH increases slightly with the repeated use of PO-PIM to four cycles. [ABSTRACT FROM AUTHOR]

The polymer inclusion membranes (PIMs) containing polyvinyl chloride (PVC) as polymer matrix and N,N-di(1-methylheptyl) acetamide (N503) as a specific carrier were prepared by solvent evaporation. Microstructure and mechanical properties of PIMs were characterized by scanning electron microscope (SEM) and tension tester, respectively. The prepared PIMs were used to investigate the facilitated transport of phenol from model solution. The mass transfer dynamics and the transmission thermodynamics of transport process were investigated. Meanwhile, the effects of carrier content in membrane and solution environment on the transport performance of PIMs and its stability were also researched. The results showed that the content of carrier in membrane had a significant impact on the microstructure and mechanical property of PIMs. The transport of phenol was in line with the first order kinetics equation. The PIM presented an optimal transport performance and a certain degree of stability when the carrier content in membrane was 68.8%, feed solution pH was 2 and sodium hydroxide concentration of strip solution was 0.1 mol/L. The initial flux of the PIM reached maximum 25.0 mg m −2 s −1 when phenol initial concentration was 8000 mg/L in feed solution. The thermodynamic analysis indicated that the transport of phenol through PIMs in the range of 0–45 °C was the diffusion-controlled process. [ABSTRACT FROM AUTHOR]

The effective extraction of liquid rubidium resources such as salt lake brine and seawater and the recovery of rubidium(I) at the end of the extraction process of lithium resources have always been a challenge in the industry. Two series of polymer inclusion membranes(PDA-PIM and PDT-PIM) were prepared to study the separation and enrichment of Rb(I). PDA-PIM and PDT-PIM used polyvinyl chloride (PVC) and dicyclohexano 18 crown 6(DCH18C6) as carriers, and tricaprylmethylammonium chloride (Aliquat 336) and trioctylphosphine oxide (TOPO) as a plasticizer, respectively. The optimal mass ratio (W/W) of PDA-PIM and PDT-PIM were P25D3.5A25 and P25D3.5T1, respectively. The applied electric field is a core condition for the mass transfer and separation of Rb(I). With the increase of voltage, the permeability coefficient P of Rb(I) and the separation factor (S) relative to Na(I) and K(I) increases. At 180 V, the PRb of PDA-PIM and PDT-PIM were 12.08 and 2.39 µm/s, and the SRB/NA were 11.21 and 14.44. After four mass transfer cycles of PDT-PIM, PRb only decreased by 4.6%. In addition, after 81.5 h of mass transfer, the enrichment ratio of Rb(I) was 3.02 times. These results show the excellent stability and mass transfer performance of PDT-PIM. It's of great significance for low concentration Rb(I) extraction. [Display omitted] • Separation of Rb(I), K(I) and Na(I) was realised by PIMs coupled with electric field. • PD-PIMs are composed of DC18C6/PVC and two different plasticisers. • Plasticiser improves the structure of PD-PIM and provides a mass transfer channel. • Voltage is the key factor affecting the permeability and selectivity of Rb(I). • The difference of hydration energy is the internal reason for selective separation. [ABSTRACT FROM AUTHOR]

• A method of the rapid detection of trace Cd(II), Zn(II) and Cu(II)was developed. • The ion concentration was reflected by the absorbance of optical sensor membrance. • The optical chromogenic reagent PAN was adsorbed on PIM by a monolayer. • Metal ions on the PIM are complexed with PAN on membrane surface to develop color. • This method had wide detection range, good stability and operational simplicity. A colour changeable optical sensing membrane was prepared for quantitative detection of Cd(II), Zn(II) and Cu(II) by using polyvinyl chloride membrane containing bis(2-ethylhexyl) phosphate for chemical absorption of chromogenic reagent 1-(2-pyridylazo)-2-naphthol. Under the optimum conditions, the three ions were measured by UV–visible spectrophotometer at λmax = 547, 554 and 560 nm, respectively. The linear ranges of 8.90 × 10-9-8.90 × 10-4 mol·L-1 [Cd(II)], 1.78 × 10-9-1.78 × 10-4 mol·L-1 [Zn(II)] and 1.78 × 10-7-1.78 × 10-3 mol·L-1 [Cu(II)] and detection limits of 3.89 × 10-9, 3.42 × 10-10 and 1.20 × 10-7 mol·L-1 were obtained, respectively. The response time was between 7 and 15 min. For common anions and cations, the sensing membrane exhibited good selectivity. Selective determination of Cd(II), Zn(II) and Cu(II) was achieved by adding a suitable masking agent. The sensing membrane was regenerated by soaking in nitric acid for 1–3 min and maintained a stable response after three times of reuse. The sensing membrane was successfully used for the determination of Cd(II), Zn(II) and Cu(II) in real samples. [ABSTRACT FROM AUTHOR]

Highlights The development of the electroplating and battery industries has increased the environmental problems and the needs for resource recovery of Cd(II). In this study, the Electro-membrane extraction (EME) behaviour of Cd(II) was investigated by using polymer inclusion membrane with bis(2-ethylhexyl) phosphate as carrier and polyvinyl chloride as base polymer(PD-PIM) at 0−80 V. Results showed that the EME of Cd(II) by PD-PIM can be obtained in the feed phase with pH 3–8 and stripping phase of dilute acid. Voltage is the main factor to increase the mass transfer rate of Cd(II). The applied electric field reduced the mass transfer activation energy of Cd(II) by PD-PIM and weakened the mass transfer interference of Cd(II) on the background material of the feed phase. After using kerosene-stabilised PD-PIM for operation at pH5, 60 V for 120 h, Cd(II) in the 1 L solution reduced from 15 mg/L to 0.08 mg/L, and the enrichment factor was 9.79. [ABSTRACT FROM AUTHOR]