Microporous Polypropylene Film Research Articles

Efficient Separation of Nd(III) and La(III) Via Supported Liquid Membrane Using EHEHPA (P507) as a Carrier

This work tested an effective and efficient Nd/La extraction and separation via flat-sheet supported liquid membrane. A microporous polypropylene film was used as the solid support for the liquid membrane and P507 as the extractant. The effect of Nd(III) and La(III) concentration in the feed, the concentration of P507, and acid solution concentration in the stripping phase on Nd and La extraction and separation were studied. The results suggest the extraction of La and Nd increases with the initial pH of the feed solution and P507 concentration. Maximum separation factor of 44.25 was obtained at the low P507 concentration of 5% (v/v).Graphical

Development of New Multilayer Active Packaging Films with Controlled Release Property Based on Polypropylene/Poly(Vinyl Alcohol)/Polypropylene Incorporated with Tea Polyphenols.

The polypropylene/poly(vinyl alcohol)/polypropylene (PP/PVA/PP) multilayer active films with controlled release property were developed, of which the intermediate PVA layer was incorporated with 4% (w/w) tea polyphenols (TP) and the microporous PP films with different pore size were used as the internal controlled release layer. The SEM results showed that each layer of these films was agglutinated tightly. With increasing pore size from 171.05 to 684.03µm, there were little effect on the films' color and opacity, the tensile strength (TS) and elongation at break (EAB) decreased slightly, the gas barrier (O2 and water vapor) property of the film reduced faintly, the time of achieving the release equilibrium in 50% ethanol decreased from 75hours to 30hours. The diffusion coefficient for the films increased with the increase of pore size, from 2.06 × 10-11 cm2 /s to 8.06 × 10-11 cm2 /s, suggesting that the release rate of TP increased as the pore size increased. The results were indicated that its release rate could be controlled by adjusting the size of pore. The films also exhibited different antioxidant activities due to their different release profiles of TP. It showed promise for developing the controlled release active packaging film based on this concept. PRACTICAL APPLICATION: Controlled release packaging is propitious to extension of food shelf life. The microporous polypropylene films with different pore size used as the internal layer of polypropylene/poly(vinyl alcohol)/polypropylene (PP/PVA/PP) multilayer active films was proved that the release rate of tea polyphenols in the intermediate PVA layer released from the films into the food simulant can be controlled by adjusting the size of pore in this study. It showed a good prospect for using microporous or perforation-mediated film as the internal layer of multilayer film to develop the controlled release active packaging film for food packaging.

Facilitated Transport of Cd(II) Through Supported Liquid Membrane with Tridodecylamine as Carrier

This work investigates the extraction of cadmium (II) from aqueous solution through supported liquid membrane system (SLM). A microporous polypropylene (Celgard 2400) film with tridodecylamine (TDDA) in xylene was used as a membrane phase. Cadmium chloride and hydrochloric acid was used as a feed phase, while ammonia solution was used as stripping reagent. Effect of concentrations of feed, strip solution, and carrier was investigated for the extraction of cadmium. The optimized concentration of Cd(II) and hydrochloric acid, carrier, and striping reagent solution were 1.33 × 10−3 mol/L, 1 mol/L, 30%, and 6 mol/L, respectively. Ninety-two percent extraction of cadmium (II) was achieved under the optimized conditions. In this work, tridodecylamine has been used as a carrier for the first time for the extraction of cadmium ions from wastewater.

Structure formation, stability, and thermal strain behavior of oriented microporous polypropylene films

Oriented porous polypropylene fi lms subjected to thermal fi xation under isometric conditions were prepared and studied. The thermal fi xation parameters ensuring the stability of the pore structure of the specimens were determined. The fi lm permeability as a function of the thermal fi xation temperature passes through a maximum at ~130°С. The behavior of the free porous specimens on heating was studied, and the changes in the permeability and pore structure characteristics in the course of the fi lm shrinkage were determined.

Synthesis and Characterization of LiFeBO3/C Composite By Spray Pyrolysis with Heat Treatment

Synthesis and Characterization of LiFeBO3/C Composite By Spray Pyrolysis with Heat Treatment

Extraction of Lead through Supported Liquid Membrane Using Triethanolamine/Cyclohexanone Carrier and Na2SO4strippant

Supported liquid membranes (SLM) have proved to be effective not only for removing but also for recovery of heavy metals from waste water. This work includes the study of separation and transport of Pb +2 ions through liquid membrane based on triethanolamine (TEA) in cyclohexanone supported in microporous polypropylene films. Therefore, this study aims to optimize the conditions for moving the Pb +2 ions against the concentration gradient, characterize the membrane by flux measurements, for their use in various industrial plants design to recover these ions. The effect of lead ion concentration, HNO3 in feed and TEA concentration in membrane has been studied. Optimized condition of transport of this metal ion is 1.0 M acid concentration in the feed phase and 0.1M Na2SO4 as the strippant when TEA concentration is 5.25 mol/dm 3 in the membrane, as the rationale of this study is to optimize the condition for the movement of lead ions from feed phase to strip phase and to recover metal ions from any industrial effluent and finally to characterize the membrane by determining the mobility and permeability of the complexed heavy metal ion to extract their respective metal ions.

Separation of zinc from lean sphalerite leached liquor in nitrate medium with D2EHPA using supported liquid membrane

Separation of zinc and lead from an aqueous nitrate medium using supported liquid membrane with di(2-ethylhexyl)phosphoric acid (D2EHPA) as mobile carrier was studied. Celgard-2500, a microporous polypropylene film, was used as the solid support for the liquid membrane with a plate and frame type of cell used for the experiments. The effects of different parameters such as pH of feed solution (1–3·5), D2EHPA concentration in the membrane phase (10–100 mol m−3), acid concentration in strip solution and flowrate of the aqueous solution on separation of lead and zinc were studied. It was observed that zinc flux across the membrane increased with pH of the feed solution up to 3·0 and thereafter decreased while zinc flux increased with the D2EHPA concentration in the membrane phase up to 75 mol m−3 and thereafter decreased. The flowrate of 100 mL min−1 was sufficient to reduce the resistances due to the aqueous boundary layer while 950 mol m−3 H2SO4 was found sufficient to strip the metals from the membrane phase in the strip phase. Under the study conditions, the copermeation of lead with zinc was observed to be negligible.

Separation of copper from chalcopyrite leach liquor containing copper, iron, zinc and magnesium by supported liquid membrane

A low-grade chalcopyrite ore was leached with H 2O 2/H 2SO 4 solution and the leach liquor contained 50.83 copper, 15.59 zinc, 30.43 iron and 3.20 mol/m 3 magnesium. From the leach liquor, separation of copper was carried out with the supported liquid membrane (SLM) using LIX84I as the mobile carrier, and distilled kerosene as the diluent. Celgard 2400, a microporous polypropylene film was used as the solid support for the liquid membrane. The effect of various parameters such as flow rate, pH of feed solution, extractant concentration in the membrane phase and acid concentration in the strip solution was investigated to obtain the optimum conditions for separation. It was observed that the flux of copper increased from 1.79 to 4.72 × 10 −5 mol/m 2 s with increase in flow rate from 20 to 120 mL/min after which the flux was decreased. Further, the flux of copper increased from 0.782 to 2.939 × 10 −5 mol/m 2 s and from 1.751 to 4.727 × 10 −5 mol/m 2 s with increase in pH from 1.5 to 2.5 and LIX84I concentration from 10 to 40%, respectively, but with further increase in pH and extractant concentration the flux of copper was decreased. The co-permeation of Zn, Fe and Mg with Cu was within 0.12–0.15, 0.089–0.10 and 0.82–1.03 mol/m 3, respectively. The experimental data were explained by mathematical equations describing the rate of transport. The forward reaction rate constant k 1, the diffusivity of the complex through the membrane D ¯ , and the aqueous film diffusion constant k w, were calculated to be 1.34 × 10 −8/1.82 × 10 −8 m/s, 4.94 × 10 −10 m/s and 1 × 10 −6 m/s, respectively.

Coupled transport of chromium(III) ions across triethanolamine/cyclohexanone based supported liquid membranes for tannery waste treatment

Coupled transport of Cr(III) ions across TEA–cyclohexanone has been studied with respect to triethanolamine (TEA) concentration in the microporous polypropylene film, sulphate ions in the feed and H 2SO 4 concentrations in the stripping phase, respectively. Optimum conditions of transport are TEA concentration (5.26 mol/dm 3) in the liquid membrane, 1.5 mol/dm 3 concentrations of both sulphate ions in the feed and 1.5 mol/dm 3 H 2SO 4 concentrations in the stripping phase. Ten times decrease in concentration level of Cr(III) ions has been observed practically in the feed solution. The flux has been found to increase with Cr(III) concentration increase in the feed. With sulphate ions increase in the feed, the permeability and distribution coefficient of Cr(III) ions has been found to increase; while, diffusion coefficient and mobility of TEA–Cr(III) complex have been found to decrease. The study indicates the practical aspect of direct transport of Cr(III) ions, without its reduction to Cr(VI). Supported liquid membranes (SLM) technique has been applied to remove Cr(III) ions from tannery effluents, where chromium is present in effluents in the third oxidation state.

Effect of different anions on separation of cadmium and zinc by supported liquid membrane using TOPS-99 as mobile carrier

In this present work, the effect of different anions such as Cl −, NO 3 −, SO 4 2−, CH 3COO −, SCN − and ClO 3 − on separation of cadmium and zinc by supported liquid membrane using TOPS-99 as mobile carrier was studied. Celgard 2400, a micro-porous poly-propylene film was used as the solid support for the liquid membrane. It was observed that, in the presence of 10 mol/m 3 of NaCl, NaNO 3, Na 2SO 4, CH 3COONa, NaSCN and NaClO 3 of added salt solutions in feed, the zinc flux J Zn, decreased, but cadmium flux J Cd remained constant at 0.125 × 10 −6 mol/m 2 s. In the presence of NaCl and NaNO 3 anions the highest flux for zinc obtained were 8.40 × 10 −6 and 5.06 × 10 −6 mol/m 2 s, respectively, with 500 mol/m 3 of added salt solution. In the presence of NaSCN, CH 3COONa and NaClO 3 salts the highest flux obtained for zinc were 6.58 × 10 −6, 6.00 × 10 −6 and 3.00 × 10 −6 mol/m 2 s, respectively, with 100 mol/m 3 of added salt solution in feed. But in presence of Na 2SO 4 salt the highest flux for zinc was 4.30 × 10 −6 mol/m 2 s with 50 mol/m 3 of added salt solution in the feed. At pH 2.25 the co-permeation of cadmium with zinc was negligible, so the highest separation factor was obtained at this pH. The maximum separation factors obtained in the presence of NaCl, NaNO 3, Na 2SO 4, CH 3COONa, NaClO 3 and NaSCN salt solutions were 39.04, 23.55, 20.02, 27.89, 13.94 and 30.61, respectively.

Separation of Cadmium and Zinc by Supported Liquid Membrane Using TOPS‐99 as Mobile Carrier

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, J Zn increased and then decreased. The separation factors for cadmium and zinc were calculated at different experimental conditions and are reported.

Effect of different anions on separation of copper and zinc by supported liquid membrane using TOPS-99 as mobile carrier

In the present work, the effect of different anions such as Cl −, NO 3 −, SO 4 2−, CH 3COO − and ClO 3 − on the separation of copper and zinc by supported liquid membrane using TOPS-99 as mobile carrier was studied. Celgard 2400, a micro-porous poly-propylene film was used as the solid support for the liquid membrane. It was observed that, the presence of 10 mol/m 3 of NaCl, NaNO 3, Na 2SO 4, and NaClO 3 in the feed solution enhanced the zinc flux, J Zn from 2.5 × 10 −5 to 4.52 × 10 −5, 4.99 × 10 −5, 5.2 × 10 −5 and 3.333 × 10 −5 mol/m 2/s, respectively. Further increase of anion concentration up to 1000 mol/m 3 in the feed, decreased the zinc flux to 3.45 × 10 −5, 3.6 × 10 −5, 2.19 × 10 −5 and 2.00 × 10 −5 mol/m 2/s, respectively. In presence of CH 3COONa in the feed, the zinc flux remained constant up to 10 mol/m 3 but with further increase in salt concentration, the zinc flux decreased. At pH 2.5 the co-permeation of copper with zinc was negligible and the highest separation factor was obtained at this pH. The maximum values of separation factor obtained in presence of NaCl, NaNO 3, Na 2SO 4, CH 3COONa and NaClO 3 were 1127.18, 1244.38, 1296.75, 623.44 and 831.17, respectively.

Separation of copper and zinc by supported liquid membrane using TOPS-99 as mobile carrier

The separation of copper and zinc from an aqueous sulphate media by supported liquid membrane (SLM) using di-2-ethyl hexyl phosphoric acid (TOPS-99) as mobile carrier has been studied. Celgard-2500, a microporous polypropylene film, was used as the solid support for the liquid membrane. A plate and frame type of cell was used for the experiment. The effects of different parameters such as flow rate, pH of feed solution, TOPS-99 concentration in the membrane phase and acid concentration in strip solution on separation of copper and zinc were studied. It was observed that flow rate of 100 mL/min (velocity 85.7 m/h) was sufficient to reduce the resistances due to the aqueous boundary layer. Zinc was permeated in a pH region 1.5–5.0, while copper permeation started at pH 3.0. At pH 2.5, the co-permeation of copper with zinc was negligible, and a high separation factor was achieved at this pH.

EXTRACTION OF CADMIUM(II) BY SUPPORTED LIQUID MEMBRANE USING TOPS-99 AS MOBILE CARRIER

The permeation rate of Cd(II) from a dilute aqueous sulfate media using supported liquid membrane technique has been studied. The microporous polypropylene film celgard 2500 was used as solid support for the liquid membrane and TOPS-99 was used as mobile carrier. Effect of different parameters such as stirring rate, Cd(II) concentration in feed solution, pH of feed solution, extractant concentration in membrane phase, and acid concentration in strip solution on cadmium flux was studied. It was observed that stirring speed of 500 rpm was sufficient to minimize the resistance due to aqueous boundary layer. Cadmium flux, J Cd(II) increases with increase in pH of feed solution from 3.0 to 6.0 as well as with increase of cadmium concentration in feed solution. Also with increase in TOPS-99 concentration in membrane phase up to 100 mol/m3 J Cd(II) increases and then becomes constant.

High energy Li-ion rechargeable battery using thin lithium film composite separator

It has been demonstrated that small amounts of active lithium metal can be added to a lithium-ion (Li-ion) battery via the separator by using vacuum deposition techniques. Lithium films (4–8 μm) were deposited onto micro-porous polypropylene film that is used as the separator in Li-ion cells. We have demonstrated that the lithium electrochemically reacts with either electrode depending on the geometry of assembly. As a result, the intrinsic irreversible capacity of negative electrode can be compensated using volumetrically efficient lithium metal. Hence, Li-ion cells can be designed and constructed with significantly higher energy than those assembled with conventional techniques.

Microporous polypropylene films and fibers containing finely dispersed vinyl polymers with crosslinkage

© 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 1089–1092, 1999

Novel interpenetrating polymer networks of polypropylene/poly(n-butyl acrylate)

Novel interpenetrating polymer networks of polypropylene/poly(n-butyl acrylate) have been prepared via in-situ polymerization within a biaxially stretched microporous polypropylene film. The volume fraction of poly(n-butyl acrylate) in composite films was higher than 40%. The fine-dispersed anisotropic dual-phase continuous interpenetrating network structure was confirmed by surface analysis and transmission electron microscope observation. The interfacial action between polypropylene and poly(n-butyl acrylate) was relatively clear. The elastic moduli of the composite films were lower than that of the matrix film. The swelling of poly(n-butyl acrylate) in organic solvent was strikingly limited by the polypropylene network. All these properties were in agreement with the anisotropic interpenetrating network structure. © 1997 Elsevier Science Ltd.

Facilitated Transport of Gold through a Membrane via Complexation to Thiourea-Based Reagents

Abstract The facilitated transport of Au(III) from hydrochloric acid solutions through double solid supported liquid membranes (SSLMs) is reported. The organic phase consisted of a chloroform solution of thiourea-based extraction reagents, dodecyl-thiourea (DTH) or nonylthiourea (NTH), physically absorbed onto microporous polypropylene films, Celgard 2500 or Celgard 2400 (Celanese Plastic Inc.). A cell composed of three compartments, including a reservoir of organic solution, with double SSLM was used in this study. Aqueous solutions of thiourea, KSCN, or Na2S2O3 were used for removing Au(III) from the membrane phase. The permeability coefficient, P, of the SSLM was determined from the slope of Iog[Au]/[Au]o or log A/Ao vs time plot. The influences of the stirring rate in aqueous feed and organic solutions, of the stripping reagents and their concentration, of the carrier concentration, and of the concentration of HCl in the aqueous feed on the permeability coefficient were determined. A model describing ...

Hybrid liquid membrane (HLM) and supported liquid membrane (SLM) based transport of titanium (IV)

Titanium(IV) transport through a hybrid liquid membrane (HLM) and a suported liquid membrane (SLM) systems was studied. 1 mol/kg di-(2-ethylhexyl) phosphate (DEHPA) or a mixture with mono-(2-ethylhexyl) phosphate (MEHPA) in benzene was used as a carrier, impregnated into the membrane in the SLM, or as a bulk carrier solution (stirring or circulating) between membranes in the HLM. Celgard ® 2400 (25 μm thickness), 2402 (50 μm) hydrophobic microporous polypropylene films were used as the SLM support. The same hydrophobic membranes, hydrophilic Celgard ® 3400 (25 μm), cation-exchange Neosepta ® CM-1, anion exchange Neosepta ® ACH-45 membranes were used as barriers in the HLM system. 0.1 mol/kg Ti(IV) hydrochloric acid solutions, at pH=0.65 and at 7 mol/kg HCl, were studied as a feed phase. The receiver (strip) phase was a 2 mol/kg HCl solution. Titanium transport rate through the SLM from low and high acidity feed is found in the range of 3–4×10 −6 mol/m 2 s. Preloading of the carrier by 0.08 M Ti(IV) before impregnation shows two-fold increase of the transport rate from high acidity feed. The rate-controlling step of the transport is the kinetics of a back-extraction process. Presence of the MEHPA, a strong complexant of titanium, in the carrier leads to a drastic decrease in the transport rate. Elution of the carrier solution from the support and gel layer formation on the strip phase exit of the membrane is the main disadvantage of the SLM system for application in titanium separation. Titanium transport rate through the HLM with hydrophobic membranes is close to that in the SLM. Preloading by 0.08 M Ti of the initial carrier phase leads to a 6-fold increase of the titanium flux from the high acidity feed. MEHPA, as additive to the carrier, leads to fouling of the membrane. Preloading of the carrier phase by titanium may prevent the negative effect of gel formation. The rate-controlling step of the transport is the resistivity of the feed phase inside the pores (for ino-exchange membranes), competing with the back-extraction kinetics. Elimination of the carrier phase elution from the membrane pores and of the membrane fouling at the same or close mass transfer rates, are decisive advantages of the titanium separation processing by the HLM in comparison with the SLM.

Thorium Ions Transport across Tri-n-butyl Phosphate—Benzene Based Supported Liquid Membranes

Abstract Transport of Th(IV) ions across tri-n-butyl phosphate (TBP) benzene based liquid membranes supported in microporous hydrophobic polypropylene film (MHPF) has been studied. Various parameters such as variation of nitric acid concentration in the feed, TBP concentration in the membrane, and temperature on the given metal ions transport have been investigated. The effects of nitric acid and TBP concentrations on the distribution coefficient were also studied, and the data obtained were used to determine the Th ions—TBP complex diffusion coefficient in the membrane. Permeability coefficients of Th(IV) ions were also determined as a function of the TBP and nitric acid concentrations. The optimal conditions for the transport of Th(IV) ions across the membrane are 6 mol·dm−3 HNO3 concentration, 2.188 mol·dm−3 TBP concentration, and 25°C. The stoichiometry of the chemical species involved in chemical reaction during the transport of Th(IV) ions has also been studied.