Water Emulsion Research Articles

Designing integrated Janus membrane based on a double-cross-linked polyphenol hydrophilic layer for complex emulsion separation

Efficient separation materials with multifunctional and switchable properties are urgently needed to treat submicron-scale oily droplets. Herein, tannic acid (TA) and polyethylenimine (PEI) were blended with poly(vinylidene fluoride) (PVDF) and used to coat a polydimethylsiloxane (PDMS)-modified non-woven fabric immersed in a CuSO4/H2O2 coagulation bath. TA and PEI form a phenolamine hydrophilic network that migrates to the surface and firmly binds to the PVDF substrate. CuSO4 catalyses the H2O2 oxidation, promoting the self-polymerisation of phenol hydroxyl group for forming a carboxyl group. Furthermore, the remaining Cu2+ ions complex with TA to form a metal–phenol cross-linked network. A double-cross-linked hydrophilic layer with polyphenols as connection points was formed on the PVDF surface. The hydrophilic contact angle of the membrane reached 0°. A rough structure with PDMS micro-/nanoparticles was constructed on the PVDF underside via surface nanocasting and the hydrophobic contact angle of the membranes reached 165°. In experiments, each side of the obtained Janus membranes demonstrated surface superhydrophilic and superlipophilic properties and a high flux and excellent separation efficiency for various oil–water emulsions. The integrated Janus membranes are suitable for unidirectional liquid collection, oil–water emulsion separation, cationic pigment adsorption and dealing with complex dye–emulsion pollutants. The integrated structure formed by the hydrophilic layer and the membrane enhances the fouling resistance of the membrane and the removal rate of pollutants reached >99 %. This research presents a simple approach to prepare Janus membranes with asymmetric wettability.

Recycling polycarbonate wastes to prepare hydrophobic and super mechanically robust aerogels with excellent oil–water and emulsion separation performance

With the development of our society, plastic pollution is becoming more and more prominent. It is attractive and challenging to recycle plastic wastes to prepare valuable products at low cost. In this study, we report a unique strategy to obtain hydrophobic and super robust aerogels from polycarbonate wastes: (1) 4,4-diaminodibenzomethane is used to decompose polycarbonate (PC) waste, (2) the degradation product is compounded with organically modified montmorillonite (OMMT) to gel up through sol–gel transition, (3) solvent exchange and ambient-drying are performed to obtain the final aerogel samples. The addition of OMMT not only promotes the ring opening of the oxazine rings in the polymer matrix and the gelation rate of the system, but also strengthen the prepared aerogels due to the formation of stronger honeycomb network structure as a result of hydrogen bonding between OMMT and polymer matrix. The resulting aerogels can withstand up to 46,000 times its own weight and exhibits superb hydrophobic properties with contact angle up to 146.2°, as well as being suitable for use in a wide range of pH values. Besides, the aerogels possess good capacity for continuous oil–water separation, whose oil absorption performance does not deteriorate perceptibly after 50 cycles of oil absorption and degreasing. The aerogel obtained by this simple method not only has superb mechanical properties, hydrophobic properties, and oil–water emulsion separation, but also has many potential industrial applications and, most importantly, solves the waste disposal dilemma.

Effect of adding gelatin on the stability of water in water emulsions formed by mixtures of amylopectin and guar gum

Stable water in water (W/W) emulsions of guar rich droplets dispersed in an amylopectin rich continuous phase (G/A) and the inverse (A/G) can be achieved by adding gelatin and inducing microphase separation of the latter by cooling. In this research, the effect of gelatin on the emulsion stability was further studied by storing the emulsions at 10, 20 and 25 °C. The visual aspect, the microstructure, and the viscosity of the emulsions were investigated at different times during storage at different temperatures and pH. It was found that depending on the conditions, the gelatin phase wetted the interface or formed small discrete microdomains that adsorbed at the interface and dispersed in the bulk phases. The observed differences in morphology and stability are related to the interplay of the rates of aggregation, phase separation of gelatin, which itself depend on the gelatin concentration, temperature and pH. Emulsions could be prepared in this manner that were stable for at least one week and remained visually homogeneous. We believe that this is a promising method to stabilize W/W emulsions as long as the components of the emulsion are incompatible with aggregated gelatin.

Effect of Added Acrylate Demulsifier for Increasing Antioxidants Functional in Diesel Fuel Oil

Biodiesel is produced by an esterification process with hygroscopic chemicals, otherwise the biodiesel is very easy to produce water, and the hydrocarbon compounds were easily oxidized, causing corrosion in the stockpiling process such as in storage tanks and distribution pipes. Antioxidants have been shown to reduce the formation of water in the biodiesel stockpiling process. While the demulsifier plays a role in helping to separate water and oil. In this study, the addition of an acrylate-based demulsifier in the accumulation of biodiesel-containing antioxidants was carried out. The antioxidant used in the form of tertiary butylhydroquinone with a concentration of 0.5 M has been able to play an active role in inhibiting the formation of water in the biodiesel stockpiling process. However, the stability of the water and oil emulsion has not been achieved properly, therefore the addition of an acrylate-based demulsifier with a volume of 2 mL, 5 mL, and 10 mL into 100 mL biodiesel can separate oil and water well. The biodiesel that has been added with a demulsifier is evaluated at storage times of 24 hours, 48 hours, and 72 hours. The result is that the storage for 72 hours is more effective in separating water and oil than storage for 24 hours and 48 hours. To evaluate the water content in the biodiesel stockpiling process out using 831 KF Coulometric and Fourier-Transform Infrared Spectroscopy analysis.

Easy preparation of wood-base membrane with fouling resistance in complex environments for efficient oil–water emulsion separation

Easy preparation of wood-base membrane with fouling resistance in complex environments for efficient oil–water emulsion separation

Study on atomization mechanisms and spray fragmentation characteristics of water and emulsion butachlor.

Agricultural chemicals are commonly used to control pests and weeds, but cause pesticide waste problems. Oil-based emulsions are often used as pesticide formulations to improve pesticide utilization. In this study, the spray visualization experiment of the water and oil-based emulsion butachlor is carried out using an ST flat fan nozzle at 0.1-0.5 MPa pressure. The dimensionless method is used to analyze the difference in liquid sheet fragmentation morphology and disintegration process and the influence of different fragmentation methods on droplet size. It is found that the hydrophobic components in pesticide have a significant effect on the morphology and process of atomization fragmentation. When spray liquid is water, the liquid sheet breaks up into liquid ligaments due to the Rayleigh instability, then the ligaments break up into droplets. The side view of a liquid sheet is a large-amplitude wave disturbance. When the spray liquid is the emulsion butachlor, holes are generated on the liquid sheet, then the holes break up into droplets. The fragmentation method of emulsion spray is the perforation mechanism. Compared with water spray, the presence of the pesticide butachlor increases the droplet size and spray angle and improves the uniformity of droplet size distribution but reduces the breakup length. The spray angle shows a power law dependence of the Weber number with a power of 0.17 for all conditions tested here. At 0.3 MPa, DV50 increases 25%, and span decreases from 1.187 to 1.172. This study could provide reference for the addition of agricultural additives, the improvement of spray operation efficiency, and the establishment of spray fragmentation mechanism.

Hydrophobization of petf-surfaces for water-in-oil emulsions separations

The technique of poly(ethylene terephthalate) track-etched membranes (PETF TMs) modification to increase of water-in-oil emulsions separations is developed. The water-in-oil emulsions separations by using PETF TMs with regular pore geometry and pore sizes 200 and 350 nm is described in the article. PETF TMs were modified with octadecyltrichlorosilane by spin-coating method to increase their hydrophobic properties. The results of changes in the pore diameters and the contact angle after PETF TMs modification are presented. The obtained samples were characterized by AFM, SEM and gas permeability test. Chloroform–water and n-hexadecane–water emulsions have been used as a test liquid for water-in-oil emulsions separations. At an operating vacuum of 700 mbar, the specific filtration performance of chloroform: water emulsions were 51.5 and 932.0 l/(m2 ⋅ h), hexadecane: water were 46.1 and 203.4 l/(m2 ⋅ h) for PETF-200 / OTS and PETF-350 / OTS, respectively. The degree of purification of emulsions by modified membranes according to the refractive index is of 100 %. Obtained membranes can be used to separate oil-water emulsions in order to prevent the corrosion of pipelines and changes of crude oil viscosity, as well as the treatment of water purification from oil industry waste.

Emulsion-assisted polyaniline grown on molybdenum diselenide nanoflowers for efficient counter electrode application in dye-sensitized solar cells

ABSTRACT Molybdenum diselenide (MoSe2) is often composed with conducting polymers like polyaniline (PANI) to lower the stacking and increase the active sites for catalysis. The method of polymerization and the concentration of monomer play a significant role in the growth of PANI nanostructures over the MoSe2 surface. Here, MoSe2-PANI nanocomposites have been synthesized with different molar concentrations of the monomer in the emulsion of chloroform and distilled water using ammonium persulfate (APS) as the initiator. The increased surface area of the composite MPAN (1:1) compared to pristine MoSe2, as observed from the FESEM and BET study, is fruitful for counter-electrode application in dye-sensitized solar cells (DSSC). The lower Rct values for the MPAN (1:1) and increased current in cyclic voltammetry further approved the suitability of the MoSe2-PANI as a counter electrocatalyst. The counter electrodes against N719 dye-sensitized TiO2 photoanode in DSSC yielded the best results for MPAN (1:1), generating an efficiency of 6.45%.

The effect of α-tocopherol incorporated into different carriers on the oxidative stability of oil in water (O/W) emulsions.

The effect of the antioxidant activity of α-tocopherol incorporated into different carriers on the oxidative stability of oil in water emulsion was investigated. The antioxidant activity of free and encapsulated α-tocopherol was measured in a 2,2-diphenyl-1-picrylhydrazyl reaction. Apart from α-tocopherol micelles, the samples showed similar antioxidant activity. The number of primary oxidation products in the emulsion with tocopherol liposomes and niosomes was lower than in the emulsion with micelles. During storage, the lipid peroxides gradually increased, whereas in emulsion with no α-tocopherol carriers added they remained constant. The content of the conjugated dienes first increased, and after 14 days at the end of testing time it remained stable in both types of emulsions. Our results might suggest that α-tocopherol when encapsulated into carriers exhibits lower antioxidant activity. The results obtained could be due to the better solubility of α-tocopherol in lipid droplets and thus the lower availability for the interfacial region, which is thought to be the place of the most pronounced lipid oxidation.

Laboratory Studies on the Separation of Various Oil–Water Emulsions in a High-Frequency Electromagnetic Field

Laboratory Studies on the Separation of Various Oil–Water Emulsions in a High-Frequency Electromagnetic Field

Innovating superparamagnetic chitosan hybrid nanoparticles for a high-efficiency separation of oil from oil–water emulsions

Abstract In an era marked by rapid industrialization and heightened automobile usage, the demand for crude oil has surged, inducing ecological degradation and resource depletion. Effective management of intricate oily wastewater presents a formidable challenge. While diverse methods like gravity separation, centrifugation, and membrane techniques are employed for oil-water separation, gravity separation is the prevailing choice, yet limited to unstable emulsions. These methods often involve toxic substances harmful to marine life. Our research focuses on separating oil microemulsions in aqueous solutions. This study explores the application of superparamagnetic chitosan coagulants, revealing an optimal 10 ml dosage for peak efficiency. Aiming for rapid oil separation, we achieved a breakthrough with just 30 minutes, establishing a new benchmark. Rigorous VSM testing solidified the particles' magnetic capabilities, augmented through size reduction. Notably, at a 15% oil concentration, a remarkable 99.26% efficiency in oil separation was achieved, offering potential in microbiology, medicine, and drug delivery systems.

Preparation of a composite of polyacrylate and nano‐SiO2 particles and evaluation of its performance of oil–water mixture treatment

AbstractTo acquire a material with simultaneous oil–water emulsion demulsification and oil‐absorbing performance, SiO2 nanoparticles were introduced into the acrylate polymerization system to prepare oil absorbent SiO2/P (SMA‐co‐MMA‐co‐BA) (PSA‐SiO2). PSA‐SiO2 was synthesized from monomers and functional materials, including methyl methacrylate (MMA), butyl acrylate (BA), octadecyl methacrylate (SMA) and SiO2 hydrophobically modified by vinyltrimethoxysilane. The molecular structure of PSA‐SiO2 was characterized by FT‐IR, and its morphology was observed using scanning electron microscopy. In addition, the optimal synthesis conditions for the polymerization system, such as the monomer ratio, the amount of crosslinker and stabilizer and then the particle size and dose of SiO2, were discussed in detail. PSA‐SiO2 had a decent oil absorbency for pure halogenated and aromatic hydrocarbons (49.10, 56.41, 47.32, 43.45, 36.22, and 30.14 g/g for CH2Cl2, CHCl3, CCl4, C2Cl4, toluene and styrene, respectively). Furthermore, SiO2, as a functional material, makes composites that possess excellent demulsification properties for oil‐in‐water emulsions. The oil removal efficiency of CHCl3 in Tween 80‐stabilized and CTAB‐stabilized emulsions were 94.88% and 98.11%, respectively. All results indicated that PSA‐SiO2 had valuable potential for oil removal and emulsion treatment.Highlights An organic–inorganic composite was synthesized by suspension polymerization. The composite was applied for absorbing pure oil or removing oil form water. By modification, the composite acquired the demulsification ability. The composite accomplished one‐step demulsification and emulsion treatment. The oil absorption and emulsion treatment could achieve at room temperature.

Tuning of Morphology and Surface Properties of Porous Silicones by Chemical Modification

The behavior of materials against water is a key element in many practical applications. Silicones are hydrophobic by nature and can be chemically modified to become hydrophilic or highly hydrophobic, while combining intrinsic surface properties with morphological details may lead to superhydrophobic materials. Chemically modified porous silicones and their surface properties have rarely been investigated. Our aim in this study was to tune the surface properties of porous silicone materials by a combination of chemical modification and emulsion templating The porous silicones were obtained by two cross-linking reactions in toluene–water emulsion, in mild conditions: dehydrocoupling of poly(methylhydrogen)siloxane (PMHS) and dimethyl-methylhydrogensiloxane copolymers and UV-initiated thiol-ene addition on a poly(dimethyl-methylvinyl)siloxane, respectively. Apart from the pores generated by water droplets, in the first process, additional large pores appeared due to hydrogen evolution. Their size and number diminished along with the cross-linking degree; thus, the porosity was tuned by adjusting the composition of the reaction mixture. Chemical modifications were performed in situ to introduce more hydrophobic groups (hexane and trimethylsilane) or hydrophilic groups (thioethanol), modifications that were followed by FT-IR spectroscopy. The inner morphology and powder wetting behavior of the crushed samples were investigated by SEM, tensiometry analyses, and contact angle measurements. The materials showed morphological particularities and surface properties that spanned from hydrophilic to superhydrophobic with lotus or petal effects.

Size distribution of migrating particles and droplets under gravity in concentrated dispersions measured with static multiple light scattering

HypothesisLight scattering techniques can provide a non-intrusive measurement of particle and droplet size distribution but are limited to relatively diluted liquid dispersions. Measurement of particle velocity distributions (PVD) and particle/droplet size distributions (PSD) in diluted to highly concentrated solid suspensions and emulsions can be performed by coupling the static multiple light scattering technique (SMLS) to mathematical models describing the vertical motion under gravity of polydisperse particles and droplets. ExperimentsMeasurement of the PSD using SMLS was performed on silica particles dispersed in water with monomodal, bimodal and trimodal PSDs ranging from 570 nm and 7.90 µm. Quasi-monodisperse certified latex particles with 815 nm mean diameter dispersed in water and non-controlled emulsions of hexadecane-water emulsions at volume fractions ranging from 0.005 % to 20 % were also characterized with SMLS. These measurements were compared to certified size distributions, and to laser diffraction and dynamic light scattering measurements. FindingsRobust, highly resolutive and concentration-dependent measurement of the PVD and PSD of solid particles and droplets was achieved for diluted to highly concentrated liquid dispersions. As interactions between particles or droplets are dependent on the dispersed phase concentration, accurate characterization of as-formulated industrial liquid dispersions can be performed with SMLS.

Curcumin clarithromycin nano-form a promising agent to fight Helicobacterpylori infections

Helicobacter pylori (H. pylori) is the main cause of gastric diseases. However, the traditional antibiotic treatment of H. pylori is limited due to increased antibiotic resistance, low efficacy, and low drug concentration in the stomach. This study developed a Nano-emulsion system with ability to carry Curcumin and Clarithromycin to protect them against stomach acidity and increase their efficacy against H. pylori. We used oil in water emulsion system to prepare a novel Curcumin Clarithromycin Nano-Emulsion (Cur-CLR-NE). The nano-emulsion was validated by dynamic light scattering (DLS) technique, zeta potential; transmission electron microscopy (mean particle size 48 nm), UV–visible scanning and Fourier transform infrared spectroscopy (FT-IR). The in vitro assay of Cur-CLR-NE against H. pylori was evaluated by minimum inhibitory concentration (12.5 to 6.26 µg/mL), minimum bactericidal concentration (MBC) and anti-biofilm that showed a higher inhibitory effect of Cur-CLR-NE in compere with, free curcumin and clarithromycin against H. pylori. The in vivo results indicated that Cur-CLR-NE showed higher H. pylori clearance effect than free clarithromycin or curcumin under the same administration frequency and the same dose regimen. Histological analysis clearly showed that curcumin is highly effective in repairing damaged tissue. In addition, a potent synergistic effect was obvious between clarithromycin and curcumin in nano-emulsion system. The inflammation, superficial damage, the symptoms of gastritis including erosion in the mouse gastric mucosa, necrosis of the gastric epithelium gastric glands and interstitial oedema of tunica muscularis were observed in the positive control infected mice and absent from treated mice with Cur-CLR-NE.

Efek Penambahan Antioksidan dan Demulsifier Secara Polimerisasi Pada Proses Penimbunan Diesel Fuel

B30 is an environmentally friendly fuel used for diesel engines. B30 is very easily contaminated with water sourced from the production process and raw materials from the B30. This water content causes corrosion and has an impact on landfilling. A demulsifier is a way to break down the B30 and water emulsion. In this study, the demulsifier used was acrylate-based and mixed with polar and non-polar solvents. The addition of a demulsifier with a volume of 2 mL, 5 mL, and 10 mL in the stockpiling process with variations of 2 hours, 4 hours, and 6 hours obtained an effect on the volume of water, where the volume of water increases with longer storage time. But the effectiveness of the demulsifier can be evaluated by potentiometrically measuring the water content and FTIR. The demulsifier that was made was also added with an antioxidant in the form of tertiary butylhydroquinone (TBHQ) with a concentration of 0.5 M and obtained more separate water layers than without the addition of TBHQ. To obtain the water content value after adding TBHQ, the coulometric and Fourier Transform Infra Red methods were used, which yielded higher results when compared to the absence of TBHQ. So that antioxidants and dimulsifiers have a positive effect on the process of storing diesel fuel.

Efficiency of oil separation and demulsification following sonication gel degradation: Influence of Cr(III) ions, NaCl concentrations, and sodium-based retarders

This study investigates the impact of chromium (III) ions, salinity, and retarders on demulsification efficiency and oil separation in oil–water emulsions stabilized by hydrolyzed polyacrylamide (HPAM) aqueous solutions. Two different concentrations of HPAM (1000 and 2000 ppm) and NaCl (0–200,000 ppm), along with two distinct retarders (sodium lactate and sodium malonate), were employed to prepare the emulsion samples. A comprehensive analysis of emulsion stability and demulsification duration was conducted under varying treatment conditions, such as the presence or absence of chromium (III) ions and resin application for chromium removal. Results demonstrate that the presence of chromium (III) ions significantly increases emulsion stability, while their removal leads to a marked reduction in demulsification duration. Notably, the impact of salinity was found to depend on the specific retarder used, with sodium lactate and sodium malonate exhibiting differing demulsification durations. As the HPAM concentration was raised from 1000 to 2000 ppm, the demulsification duration also, regardless of the presence or absence of chromium (III) ions. Additionally, the oil separation rates were higher in samples treated with a resin for chromium removal and are notably influenced by the choice of retarder. In particular, using sodium malonate as a retarder resulted in a significant improvement in the oil separation rate compared to sodium lactate under various salinity conditions. The findings of this study provide valuable insights into the optimization of oil–water separation processes, offering the potential for improved oil recovery and environmental sustainability. This study is particularly novel in its comprehensive investigation of the interplay between different factors (chromium, salinity, and retarders) in oil–water separation processes.

Oily wastewater treatment by a continuous flow electrocoagulation reactor with polarity switch: Assessment of the relation between process variables and the aluminum released to the environment

Electrocoagulation with electrical polarity inversion was used to treat oil in water emulsions (145 ± 5 mg dm−3) using a cylindrical 4.8 dm3 reactor in continuous mode. The effects of spatial time and time between polarity inversion were explored using a three-level full factorial design (32), followed by Spearman correlation (ps), which has shown that the aluminum concentration in the treated effluent is not directly dependent on the mass of aluminum released by the electrodes. Nonetheless, the loss of mass of the electrodes is correlated (ps = 0.6970) to oil removal and to less electric power consumption (ps = −0.6909). Surface response analysis revealed that increasing the number of inversion cycles reduces electrode degradation. The treatment reduced the effluent's chemical oxygen demand by over 92.8%. Regarding environmental impact, there is an inverse statistical correlation between aluminum in the treated effluent and oil removal (ps = −0.7426), indicating that removing more oil with less environmental impact is possible. The better condition, considering oil removal and lower electrode consumption, was obtained with a spatial time of 36 min and a polarity inversion time of 10 s; for this condition, oil removal reached 87.0% with an energy expenditure of about 7.21 kW h.m−3.

PERFORMANCE OF AMAZONIAN BIOSORBENTS IN THE SEPARATION PROCESS OF EMULSIFIED OIL WITH RIO NEGRO WATER

Currently, one of the most serious environmental problems society is facing is water contamination by oil spills. The use of sorbents from agricultural residues has been considered a very promising approach for the effective treatment of oil contaminated water. Therefore, this work investigates the use of biosorbents obtained from cupuaçu shell (Bio-CP) and sacha inchi shell (Bio-SI) in the oil removal process. The characterization of adsorbents was carried out by FTIR, XRF, and TGA. Adsorption tests were carried out in a finite bath using 0.1 g of biosorbent and diesel/Rio Negro water emulsions at 400 mg.L-1 in a contact time of 60 minutes. The results show that Bio-CP has a higher oil adsorption capacity (190.8 mg.g-1) compared to Bio-SI (174.93 mg.g-1), and better oil removal, 95.4%, if compared to 87.47% for Bio-SI. The results indicate that cupuaçu and sacha inchi shells can be effective in the production of biosorbents to remove diesel from contaminated water.

Polymer surfactants as viscosity reducers for ultra-heavy oil: Synthesis and viscosity reduction mechanism

Polymeric surfactants have poor viscosity-reducing effect and little adaptability on ultra-heavy oils. We synthesized a novel polymeric surfactant, named PAMOs, by introducing 2-acrylanmido-2-methylpropanesulfonic acid (AMPS) and sodium alpha-olefin sulfonate (AOS) into the acrylamide (AM) backbone for viscosity reduction in ultra-heavy oil. The PAMOs with high surface and interfacial activity, strong emulsification, good molecular efficiency and viscoelasticity, which emulsified ultra-heavy oil effectively. The formed oil in water (O/W) emulsions with small droplet size and high stability. PAMOs also reduced the oil-water mobility ratio. At a concentration of 3 mg/mL, PAMOs reduced viscosity by more than 90% for different ultra-heavy oils (>15000 mPa·s), showing a broad range of suitability. Combining experimental and molecular dynamics simulation results, polymeric surfactants penetrate into the asphaltene molecular layers to form a “sandwich” structure, weakening the interaction forces between asphaltenes. The structure obtained via the ion-pair dipolar coupling between the polar groups, such as amide and sulphonic acid, and the asphaltene molecules. By strong hydrogen bonding between PAMOs and asphaltene, the supramolecular structure of asphaltene is destroyed and transformed into a low molecular structure. At the meantime, re-agglomeration is prevented by the steric hinerance of hydrophobic long chains, thus achieving viscosity reduction of ultra-heavy oil. It shown that polymeric surfactants have unique advantages in the field of viscosity reduction for ultra-heavy oil.