Volume Ratio Of Internal Phase Research Articles

Permeable emulsion-templated porous polyepoxides

Porous polyepoxides are attractive materials for a range of applications. Liquid foam precursors can be net-shaped by moulding. We report preparation of permeable polyepoxide, Araldite®2020, foams with porosities in the range of 45–60% from surfactant-stabilised W/O medium internal phase emulsion templates. Alteration of internal phase volume ratio and surfactant concentration were used to tailor the properties of the resulting polyMIPEs. These polyepoxide foams had elastic moduli in the range of 60–200 MPa and compression strengths between 2 and 6.5 MPa with permeabilities up to 200 mD. The theoretical average molecular weight between crosslinks was 534 g mol−1, while the foams had 500 ± 50 g mol−1. Swelling tests confirmed the excellent chemical stability of the porous epoxy. However, the swelling ratio depended on the polarity of the solvents used. It decreased with decreasing solvent polarity.

Removal of Ibuprofen at Low Concentration Using a Newly Formulated Emulsion Liquid Membrane

Ibuprofen (IBP) is a pharmaceutical product that is widely prescribed as an over-the-counter painkiller. It has been classified as a contaminant of emerging concern (CEC) that has received global attention in the search for a better wastewater separation technology. The emulsion liquid membrane (ELM) is one of the potential solutions for IBP removal from wastewater owing to its advantages, such as the ability to remove a highly soluble solute, energy efficient and tuneable formulation. To develop this ELM, a series of parameters such as stirring speed, emulsification time, organic to internal phase volume ratio (O/I), internal phase concentration, carrier concentration and surfactant concentration were studied. The extraction was carried out for 15 min stirring time and the concentration of IBP in the feed phase was determined using a UV-Vis spectrophotometer. The optimum formulation for the ELM was found at 300 rpm stirring speed, 20 min emulsification time, 3:1 of O/I, 0.1 M ammonia, NH3 (stripping agent), 6 wt% trioctylamine, TOA (carrier) and 2 wt% sorbitan monooleate, Span 80 (non-ionic surfactant). IBP removal of 89% was achieved at the optimum parameters of ELM. The current research demonstrated that a newly formulated ELM has great potential in removing a low concentration IBP from wastewater.

Removal of safranin from aqueous solution through liquid emulsion membrane

One of the real issues of the recent years is water contamination because of harmful synthetic dyes. Liquid Membranes (LM) resemble a promising alternative to the current separation processes, demonstrating various points of interest as far as effectiveness, selectivity, and operational expenses. The improvement of various Liquid Membranes designs has been a matter of examination by few researchers, particularly for the expulsion of dyes from aqueous solutions. The choice of organic surfactants plays an essential role in the efficiency of the dye removal. In LM design, the most significant step towards productivity is the decision of the surfactant type and its concentration. Liquid emulsion membrane (LEM) was used to remove safranin from aqueous solutions in which the emulsion was made with the help of D2EHPA as carrier, kerosene was used as a diluent and Span 80 (Sorbiton monooleate) was used as an emulsifying agent or surfactant. Various sorts of internal stages were utilized, to be specific sulphuric acid and sodium hydroxide. The impact of parameters influencing extraction efficiency such as pH of feed solution, concentrations of surfactant and emulsifying agent in membrane phase, volume ratio of internal phase to membrane phase, internal phase concentration, agitation speed and time of extraction were analyzed.

Application of edible paraffin oil for cationic dye removal from water using emulsion liquid membrane

Using an emulsion liquid membrane based on edible oils is investigated for removing cationic dyes from aqueous solutions. There is a great potential for using edible oils in food industry extraction processes. The parameters affecting the stability of the emulsion and the extraction rate were studied. These parameters were the emulsification time, the stirring speed, the surfactant concentration, the internal phase concentration, the feed phase concentration, the volume ratio of internal phase to organic phase and the treat ratio. In order to stabilize the emulsion without using a carrier, edible paraffin oil and heptane are used at an 80:20 ratio. The optimum conditions for the extraction of methylene blue (MB), crystal violet and methyl violet (CV and MV) cationic dyes using edible paraffin oil as an environment friendly solvent are represented. A removal percentage of 95% was achieved for a mixture of dyes. The optimum concentration of sodium hydroxide in the internal phase, which results a stabile emulsion with a high stripping efficiency of 96%, was 0.04 M. An excellent membrane recovery was observed and the extraction of dyes did not decrease up to seven run cycles.

The use of a multilayer perceptron (MLP) for modelling the phenol removal by emulsion liquid membrane

Extraction of phenol from aqueous solution was studied using emulsion liquid membrane (ELM). In this study, due to the extreme complexity and non linearity of ELM process, a multilayer perceptron (MLP) was developed to predict the extraction efficiency of phenol. The effect of operational parameters such as: the ratios of volume ratio of internal phase to organic phase, volume ratio of emulsion to aqueous external phase, the emulsification speed and time, the surfactant concentration, the extractant and sodium hydroxide concentrations were studied to optimize the conditions for maximum removal of phenol. The results showed that a network with 3 hidden neurons was highly accurate in predicting the extraction efficiency (more than 98%). This accuracy was reflected by high correlation coefficient R=0.99 and a root mean square error below 0.5. The result indicated that the MLP model explained in this study is an applied tool to predict the extraction efficiency of phenol by ELM.

High internal phase emulsions stabilised by supramolecular cellulose nanocrystals and their application as cell-adhesive macroporous hydrogel monoliths.

Nanosized celluloses are attractive building blocks to generate hierarchically advanced materials and have been gradually explored in emulsion applications. Here we report a high internal phase emulsion (HIPE) prepared by using supramolecular cellulose nanocrystals (CNCs) as Pickering stabilisers via one-step emulsification, and interconnected macroporous hybrid hydrogels were produced by utilizing this HIPE as a template. A quadruple hydrogen bonding moiety 2-ureido-4[1H]-pyrimidone (UPy) was firstly grafted onto the surface of cellulose nanocrystals through simple free radical polymerization. The polymer grafting was confirmed by elemental analysis and thermogravimetry. The UPy modified CNCs (CNC-UPy) exhibited superior emulsion stabilising ability compared to the pristine CNCs, and the oil-in-water emulsions with an internal phase volume ratio of 80% showed good long-term stability. The properties of resulting macroporous polyHIPE hydrogels, such as swelling behaviours, porous structures and mechanical strength, were investigated on the dependence of CNC-UPy concentrations. In addition, the macroporous hybrid hydrogel exhibits excellent cytocompatibility and cell adhesion as demonstrated by mouse bone mesenchymal stem cell (mBMSC) culture. With these promising properties, the developed hydrogels demonstrate great potential as active biological scaffolds for tissue engineering.

Rare earth extraction from wet process phosphoric acid by emulsion liquid membrane

The recovery of rare earths (RE) during the wet processing of phosphoric acid is very important, the method of emulsion liquid membrane (ELM) with di(2-ethylhexly) phosphate (D2EHPA) as carrier has the high selectivity while cannot provide a satisfactory extraction rate. Here novel method of emulsion liquid membrane (ELM) using Aniline as carrier to extract RE from the feed solution was proposed. The method could increase the extraction rate of RE in the real sample to 93%. The effects of different parameters such as type and concentration of carrier and surfactant, hydrochloric acid concentration, organic to internal phase volume ratio, membrane to external phase volume ratio on extraction of RE3+ were investigated. Quantitative extraction (>93%) of RE3+ was observed with 6 vol.% Aniline and 4 vol.% T154 liquid membrane at external to internal phase volume ratio of 10 for the feed solution. The proposed method of ELM using Aniline as carrier can be expected to provide a practical, efficient, and economical method for extracting RE from phosphate leach solution with high acidity in the industry of wet process phosphoric acid.

Mass transfer and equilibrium characteristics of defluorination from groundwater by emulsion liquid membrane

AbstractBACKGROUNDThe defluorination of fluoride contaminated groundwater by emulsion liquid membrane using primary amine LK‐N21 as fluoride carrier and Span 80 as surfactant has been investigated.RESULTSThe purification process comprised preparation of W/O emulsion, extraction and demulsification operations. The transport mechanism of fluoride by emulsion liquid membrane using primary amine LK‐N21 as fluoride carrier was determined. The extraction conditions, i.e. surfactant and carrier concentration, type and concentration of precipitant, emulsification time and speed, volume ratio of internal phase to organic membrane phase, external phase pH and volume ratio of external phase to W/O emulsion for purification of the fluoride contaminated groundwater were studied.CONCLUSIONSThe treated natural groundwater samples finally were found to have been treated with high extraction efficiency, thus meeting the limiting values of the quality standard of class II for groundwater in China. Equilibrium extraction correlation was found to represent well the fluorine equilibrium relation in the emulsion membrane extraction system from the experimental data. Optimization of the purification conditions and system enabled realization of the practical defluorination needs for fluoride contaminated groundwater. © 2016 Society of Chemical Industry

Extraction of neodymium from nitric acid feed solutions using an emulsion liquid membrane containing TOPO and DNPPA as the carrier extractants

The transport of Nd(III) from nitric acid medium across emulsion liquid membrane (ELM) using di-nonyl phenyl phosphoric acid (DNPPA) as the carrier extractant and Span 80 (sorbitol monoleate) as the surfactant in Petrofin as the diluent and sulphuric acid as the internal phase has been systematically investigated. The effect of different physical and chemical parameters such as stirring speed, neodymium concentration, external phase nitric acid concentration, extractant concentration, external to internal phase volume ratio, stripping agent concentration has been investigated on the extraction of Nd(III). The synergistic extraction of the metal ion has also been studied using mixtures of DNPPA and tri-n-octylphenyl phosphine oxide (TOPO) as the carrier extractants in the ELM. Quantitative extraction (>97%) of Nd(III) was observed with 0.3M DNPPA+0.13M TOPO and 1% (v/v) Span 80 liquid membrane at external to internal phase volume ratio of 10 for a feed having 500mg/L Nd(III) at 0.5M nitric acid concentration. The mechanism of extraction of Nd(III) has also been discussed in the light of the results obtained.

Injectable, interconnected, high-porosity macroporous biocompatible gelatin scaffolds made by surfactant-free emulsion templating.

High-porosity interconnected, thermoresponsive macroporous hydrogels are prepared from oil-in-water high internal phase emulsions (HIPEs) stabilized by gelatin-graft-poly(N-isopropylacrylamide). PolyHIPEs are obtained by gelling HIPEs utilizing the thermoresponsiveness of the copolymer components. PolyHIPEs properties can be controlled by varying the aqueous phase composition, internal phase volume ratio, and gelation temperature. PolyHIPEs respond to temperature changes experienced during cell seeding, allowing fibroblasts to spread, proliferate, and penetrate into the scaffold. Encapsulated cells survive ejection of cell-laden hydrogels through a hypodermic needle. This system provides a new strategy for the fabrication of safe injectable biocompatible tissue engineering scaffolds.

Extraction of Priority Pollutant 4-Nitrophenol from Water by Emulsion Liquid Membrane: Emulsion Stability, Effect of Operational Conditions and Membrane Reuse

This work aims to the extraction of the priority pollutant 4-nitrophenol (4-NP) from water by emulsion liquid membrane (ELM). Liquid membrane consists of a diluent (hexane) and a surfactant (Span 80). Sodium carbonate solution was used as internal aqueous phase. Effects of important experimental conditions governing the stability of the W/O emulsion were investigated. Influence of operating parameters that affects the permeation of 4-NP such as surfactant concentration, emulsification time, sulfuric acid concentration in external phase, acid type in external phase, internal phase concentration, type of internal phase, stirring speed, volume ratio of internal phase to membrane phase, treatment ratio, 4-NP initial concentration, and diluent type was examined. This study also evaluated the effect of Na2CO3 concentration in the internal aqueous phase on the stripping of 4-NP. Additionally, the reuse of the recovered membrane was studied. Under most favorable conditions, practically all the 4-NP and aniline (AN) molecules present in the feed phase were extracted. The recovery of the membrane phase was total and the extraction of 4-NP was not decreased. The ELM treatment process represents a very interesting advanced separation process for the removal of 4-NP and AN from aqueous solutions.

High Internal Phase Emulsion Templating with Self-Emulsifying and Thermoresponsive Chitosan-graft-PNIPAM-graft-Oligoproline

High internal phase emulsion (HIPE)-templating is an attractive method of producing high porosity polymer foams with tailored pore structure, pore size and porosity. However, this method typically requires the use of large amounts of surfactants to stabilize the immiscible liquid phases, and polymerizable monomers/cross-linker in the continuous minority phase to solidify the HIPE, which may not be desirable in many applications. We show that polyHIPEs with a porosity of 73% can be formed solely using a copolymer of chitosan-graft-PNIPAM-graft-oligoproline (CSN-PRO), which acts simultaneously as emulsifier and thermoresponsive gelator, and forms upon removal of the liquid templating phases, the bulk structure of the resulting polyHIPE. With only a small amount of surfactant (1%v/v in the aqueous phase), and varying the polymer concentration and internal phase volume ratio, different polyHIPEs with porosities of up to 99%, surface areas in excess of 300 m(2)/g and controlled pore interconnectivity can be formed. The poly(CSN-PRO)HIPEs are also shown to be thermoresponsive and remained intact when immersed into water above 34 °C but dissolve below their LCST, which is useful for applications such as drug delivery and tissue engineering scaffolds.

Acetaminophen extraction by emulsion liquid membrane using Aliquat 336 as extractant

In this work, extraction of acetaminophen (ACTP), currently named as paracetamol, from aqueous solutions by emulsion liquid membrane (ELM) using Aliquat 336 as carrier was investigated. An ELM system is made up of hexane as diluent, Span 80 as the surfactant and potassium chloride as the inner aqueous solution. Influence of operating conditions that affects the permeation of ACTP such as surfactant concentration, extractant concentration, emulsification time, sulfuric acid concentration in external phase, acid type in external phase, internal phase concentration, type of internal phase, stirring speed, volume ratio of internal phase to membrane phase, treatment ratio, ACTP initial concentration and diluent type was examined. Additionally, the effect of KCl concentration in the internal aqueous phase on the stripping of ACTP and the reuse of the recovered membrane was studied. Under most favorable conditions, it was possible to extract practically all of ACTP molecules from the feed external solution. The recovery of the membrane phase was total and the extraction of ACTP was not decreased. The ELM treatment represents a very interesting advanced separation process for the removal of ACTP even from complex matrices such as natural water, sea water and sewage water effluent.

Removal of non-steroidal anti-inflammatory drugs ibuprofen and ketoprofen from water by emulsion liquid membrane

In this work, the removal of the worldwide non-steroidal anti-inflammatory drugs ibuprofen (IBP) and ketoprofen (KTP) by emulsion liquid membrane (ELM) was carried out. An ELM system is made up of hexane as diluent, Span 80 as the surfactant and sodium carbonate as the inner aqueous solution. Effect of experimental conditions that affect the extraction of IBP such as surfactant concentration, emulsification time, sulfuric acid concentration in external phase, acid type in external phase, internal phase concentration, type of internal phase, stirring speed, volume ratio of internal phase to membrane phase, treatment ratio, IBP initial concentration, diluent type and salt was investigated. The obtained results showed that by appropriate selection of the operational parameters, it was possible to extract nearly all of IBP molecules from the feed solution even in the presence of high concentration of salt. Under optimum operating conditions, the efficiencies of IBP removal from distilled water (99.3 %), natural mineral water (97.3 %) and sea water (94.0 %) were comparable, which shows that the ELM treatment process represents a very interesting advanced separation process for the removal of IBP from complex matrices such as natural and sea waters. Under the optimized experimental conditions, approximately 97.4 % KTP was removed in less than 20 min of contact time.

Macroporous materials from water-in-oil high internal phase emulsion stabilized solely by water-dispersible copolymer particles

Water-in-oil (W/O) high internal phase emulsions (HIPEs) were prepared by utilizing water-dispersible copolymer particle stabilizer, whose concentration in the internal phase could reach as high as 12.0 wt% (equivalent to 52 wt% relative to the continuous phase). Accordingly, the macroporous materials with high content of skeleton substance would be obtained by the dissolving of these copolymer particles into the continuous phase and without any chemical reaction. And the morphology, the density and the mechanical property of the macroporous materials could be easily tailored through varying the standing time after emulsification, particle concentration in the aqueous phase and the internal phase volume ratio.

Polymerised high internal phase ionic liquid-in-oil emulsions as potential separators for lithium ion batteries

In situ ionic liquid (IL) filled poly(merized) high internal phase emulsion monoliths and films were produced by polymerizing surfactant stabilized IL/monomer emulsion templates. The resulting in situ ionic liquid filled macroporous polymers have almost the ionic conductivity of the neat ionic liquid electrolyte. The effect of surfactant and lithium salt concentration, monomer to crosslinker ratio as well as internal phase volume ratio on the morphology and ionic conductivity were studied. It was found that the morphology of the resulting polyHIPEs affects significantly their ionic conductivity. PolyHIPEs with bigger pore throats have a higher ionic conductivity.

A one-step process to a Janus emulsion

Aqueous high internal phase volume ratio (O/W 90/10) Janus emulsions of a vegetable oil and a silicone fluid were prepared in a single step emulsification by the common vibrator equipment. The basis for the unique structure is discussed in relation to pair-wise interactions between the components with especial emphasis on the surfactant concentration in the aqueous phase.

High-Porosity Macroporous Polymers Sythesized from Titania-Particle-Stabilized Medium and High Internal Phase Emulsions

Particle-stabilized high internal phase emulsions have been used to synthesize tough and very high porosity macroporus polymers with a closed-cell pore structure. In this study, we show that Pickering water-in-oil emulsion templates with up to an 85 vol % internal phase can be stabilized by only 1 wt % of titania particles with their surfaces suitably modified by the adsorption of 3.5 +/- 0.5 wt % oleic acid. The pore structure and mechanical properties of the resulting macroporous polymers were tailored by altering the internal phase volume ratio of the emulsion template and the titania particle concentration used to stabilize the emulsion templates. The pore size and pore size distributions increase with increasing internal phase volume of the emulsion template as well as decreasing titania particle concentration used to stabilize the emulsion template. The mechanical properties, namely, Young's modulus and the crush strength of the macroporous polymers, increased with decreasing porosity and increasing foam density. The toughest macroporous polymer had the lowest porosity but also the smallest pore size and narrowest pore size distribution.

Extraction of bisphenol A from aqueous solutions by emulsion liquid membrane

In this work, the extraction of bisphenol A (BPA), an endocrine disrupting compound, from aqueous solutions by emulsion liquid membrane (ELM) was studied. Liquid membrane consists of a diluent (hexane) and a surfactant (Span 80). 0.05N sodium hydroxide solution was used as internal aqueous phase. Effects of experimental conditions that affect the stability such as surfactant concentration, emulsification time, internal phase concentration and volume ratio of internal phase to membrane phase was investigated. The important variables governing the permeation of BPA were examined. These variables are sulfuric acid concentration in external phase, acid type in external phase, internal phase concentration, type of internal phase, surfactant concentration, stirring speed, volume ratio of internal phase to membrane phase, treatment ratio, BPA concentration, diluent type and presence of salt. This study also investigated the effect of NaOH concentration in the internal phase on the stripping of BPA. The results showed that by appropriate selection of the extraction and stability conditions, it was possible to extract nearly all of BPA molecules from the feed solution even in the presence of high concentration of salt. Under optimum conditions, very good stripping efficiency (98%) can be achieved.

Study on removal of cadmium from wastewater by emulsion liquid membrane

Removal of cadmium from wastewater using emulsion liquid membrane (ELM) is studied in the present study. A polyamine-type surfactant was used for stabilizing the emulsion phase. Tri-iso-octyl amine (TIOA) has been used as a carrier for transferring of cadmium through the membrane. The results show good performance in the separation process. To determine the optimum operation conditions, the effect of several parameters such as surfactant concentration, carrier concentration, pH of external and internal phases, oil to internal phase volume ratio, emulsion to external phase volume ratio, solvent type, solute concentration, presence of iodide and chloride in external phase, and mixing conditions have been investigated.