Particle Size Distribution Of Emulsions Research Articles

Pickering Emulsions and Viscoelastic Solutions Constructed by a Rosin-Based CO2-Responsive Surfactant.

Designing stimulus-switch viscoelastic solutions and Pickering emulsions with reversible CO2-responsive behavior remains a challenge. A rosin-based CO2-responsive surfactant, N-cetyl-maleimidepimaric acid N,N-dimethylenediamide (C16MPAN), was synthesized and used to prepare CO2-triggered viscoelastic solutions and Pickering emulsions. This surfactant exhibited excellent CO2-responsive performance in water and formed a viscoelastic solution. This viscoelastic system was investigated by dynamic light scattering (DLS), rheology, and cryogenic transmission electron microscopy (Cory-TEM). The shear viscosity of the system increased by 3-4 orders of magnitude after bubbling with CO2 and a large number of elongated, flexible, tubular wormlike micelles were observed. Further, Pickering emulsions were prepared by C16MPAN+ synergistically with cellulose nanocrystals (CNCs), whose stability and switchability were investigated via adsorption isotherm, droplet size, contact angle, and macroscopic photographs. C16MPAN+ was adsorbed with CNCs to form mechanical barriers at the oil-water interface, making the emulsion stable for at least three months, and desorption from CNCs enabled emulsion breaking. The cycle could be switched reversibly multiple times and the particle size distribution of emulsion was basically the same. This work enriches the application of biomass resources in intelligent responsive materials.

The Stability, Rheological Properties and Interfacial Properties of Oil-in-Water (O/W) Emulsions Prepared from Dielectric Barrier Discharge (DBD) Cold Plasma-Treated Chickpea Protein Isolate and Myofibrillar Protein Complexes.

In order to increase the development and utilization of chickpea protein isolate (CPI) and improve the stability of myofibrillar protein (MP) emulsions, the effect of dielectric barrier discharge (DBD) plasma-modified CPI on the emulsifying properties of MP was investigated. Three different O/W emulsions were prepared using MP, MP + CPI complex, or MP + DBD-treated CPI complex as the emulsifier. Compared with the emulsion prepared from MP, the emulsifying activity index and stability of DBD-treated CPI and MP complex (MP + CPIDBD) were increased (p < 0.05) from 55.17 m2/g to 74.99 m2/g and 66.31% to 99.87%, respectively. MP + CPIDBD produced more stable emulsions with the lowest Turbiscan stability index (TSI) values for a given 3600 s. At shear rates from 0 to 1000-1, MP + CPIDBD-stabilized emulsions had higher viscosities, which helped to reduce the chance of aggregation between oil droplets. The optical microscope and particle size distribution of emulsions showed that MP + CPIDBD emulsions had the lowest droplet size (d4,3) and exhibited more uniform distribution. MP + CPIDBD emulsions had lower interfacial tension. DBD pretreatment increased the adsorbed protein content in the emulsion stabilized by MP + CPIDBD as compared to the MP + CPI complex and promoted the adsorption of CPI by higher ratios of adsorbed proteins as indicated by its intensity in SDS-PAGE. Scanning electron microscopy confirmed that the emulsion prepared from MP + CPIDBD had smaller particle size and more uniform dispersion. Therefore, using DBD-modified CPI could enhance the stability of MP emulsions.

Preparation and stabilization of Pickering emulsions by cationic cellulose nanocrystals synthesized from deep eutectic solvent

In this work, short rod-like cationic cellulose nanocrystals (AH-CNCs) were prepared by sodium periodate oxidation combined with deep eutectic solvent method. The effects of different content AH-CNCs on the properties of the emulsion were studied. With the increase of AH-CNCs content, the diameter of emulsion droplets decreased and the stabilization time prolonged. The electrostatic attraction between the negative charge accumulated at the oil-water interface and AH-CNCs with positive charge improved the stability of the emulsion. Then, the rheological properties showed the interaction of nanocellulose in the continuous phase increased the viscosity of the emulsion. In addition, the droplet diameter of emulsion of 120 s was smaller at different ultrasonic time, the particle size distribution of emulsion changed from monodisperse to polydisperse with the increase of oil volume, the salt concentration had little effect on the droplet size of emulsion, and the preparation of emulsion under acidic conditions was more stable.

A collaborative emulsification system capable of forming stable small droplets of oil-in-water emulsions for enhancing heavy oil recovery

Water flooding for heavy oil development has a relatively low recovery effect. Emulsification system flooding is a very effective method for enhanced heavy oil recovery after water flooding. However, the sizes of oil-in-water (O/W) emulsion droplets formed by conventional emulsification systems and heavy oil are relatively large. Large droplet emulsions result in higher additional resistance when flowing in the porous media of the reservoir, which restricts the development effect on heavy oil recovery. In this study, a primary alcohol ethoxylate (AEO12) + sodium dodecyl sulfate (SDS) + alkali (NaOH) mixed collaborative emulsification (CE) system was developed and its formula was optimized. The optimal collaborative emulsification system formula is primary alcohol ethoxylate (0.25%) + sodium dodecyl sulfate (0.25%) + NaOH (0.05%). Through interfacial tension measurements, microemulsion state observations, emulsion particle size distribution tests, multiple light scattering, and fluidity experiments in simulated reservoir porous media, the oil-in-water emulsion stability and the mechanism of collaborative emulsification for improving heavy oil recovery were studied. Compared with the surfactant, the collaborative emulsification system can be more closely arranged at the heavy oil–water interface, so that the system can significantly reduce interfacial tension (IFT) (0.008 mN/m), formed a more stable and smaller oil-in-water emulsion (0.2 μm). It can greatly reduce the influence of additional resistance on its fluidity in reservoir porous media, and still has an excellent viscosity reduction rate at high temperatures (99.50% at 20 °C; 88.55% at 100 °C). Finally, through microscopic visualization experiments, it was shown that the collaborative emulsification system has an excellent ability to improve the sweep coefficient, and the residual heavy oil can be emulsified into oil droplets that are much smaller than pore throats. The developed collaborative emulsification system has excellent potential for enhancing heavy oil recovery after water/hot water flooding.

Ultrasonic assisted oil-in-water emulsions stabilized by flaxseed protein isolate: influence of different oils

In this study, the physicochemical properties and stability of ultrasonic assisted flaxseed protein isolates (FPI) emulsions containing medium chain triglycerides (MCT), soybean oil, flaxseed oil, or docosahexaenoic acid (DHA) algae oil were investigated. The particle size distribution, zeta-potential, turbiscan stability index (TSI), and backscattering profiles were determined. The results showed that the emulsions containing flaxseed oil had the smallest droplet size and the lowest TSI value after 30 min ultrasonic treatment. Flaxseed oil emulsions showed the best storage stability with minimum clarified layer and cream layer after 10 days storage. MCT emulsions were more sensitive to salt, and less stable than other oil emulsions. Soybean oil, flaxseed oil, and DHA oil emulsions had good stability under low ionic strengths (0–50 mM NaCl), and became unstable under high ionic strengths (150 and 300 mM). Thermal treatment had great influence on the particle size distribution of emulsions. The particle size of the four oils emulsions increased after heating at 90 °C for 30 min. However, the particle size of DHA oil and flaxseed oil emulsions decreased after heating at 50 °C for 30 min. In conclusion, ultrasonic treatment is one of the effective ways to improve stability of FPI-stabilized emulsions, which are based on the oil type and ultrasound intensity. The effects of oil type and chain length on particle size and stability of FPI-stabilized emulsions could be further studied.

Synthesis of surface ion-imprinted polymer for specific detection of thorium under acidic conditions

A fibrous surface ion-imprinted polymer (IIP) was synthesized for thorium removal through direct electron beam radiation using thorium as a template. Polypropylene coated by polyethylene non-woven fabrics (PE/PP) was used as a substrate. The PE/PP non-woven fabrics were irradiated in the presence of the phosphoric monomer (2-HMPA) composed of 2-hydroxyethyl methacrylic phosphoric acid diester (50%) and monoester (50%) emulsified with the crosslinker. Hence, the formation of the three-dimensional IIP-Th crosslinked network and complexation between thorium (template) and 2-HMPA was investigated. The emulsion stability and particle size distribution of emulsion were determined using dynamic light scattering (DLS). Various factors influencing the synthesis of the thorium ion-imprinted (Th-IIP) non-woven PE/PP such as the absorbed radiation dose, monomer concentration, and type of crosslinker were investigated. The IIP-Th was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy–energy-dispersive X-ray (SEM–EDX), and X-ray photoelectron spectroscopy (XPS) and applied as an adsorbent for the removal of thorium using the batch adsorption method. The IIP-Th achieved a maximum distribution coefficient of 3.293 g/L and selectivity ratio (Th(IV)/U(VI)) of 9.5 after 90 min of contact time under acidic conditions. The adsorption kinetics of IIP-Th followed the pseudo-second-order kinetic model for both Th(IV) adsorption and U(VI) adsorption. The synthesized fibrous surface ion-imprinted polymer is a promising candidate for the selective removal of thorium ions from aqueous solution.

Studies and properties of styrene/butadiene/γ-(methacryloxypropyl) trimethoxy silane copolymer emulsion at room temperature

The copolymer of styrene/butadiene/γ-(methacryloxypropyl) trimethoxy silane (random -Bd-St-MPS- copolymer) was synthesized by the semi-batch emulsion terpolymerization. The copolymer of random -Bd-St- and -Bd-St-MPS- copolymer were characterized by fourier transform infrared (FTIR) and proton nuclear magnetic resonance (1H NMR) analysis, respectively. From FTIR and 1H NMR, the random -Bd-St- and -Bd-St-MPS- copolymers were synthesized successfully. The effect of the St:Bd:MPS ratio on the solids content, particle size, fraction of gel, thermal properties, and mechanical properties were studied. The particle size distribution of emulsion was uniform. The thermal stability of the random -Bd-St-MPS- copolymer was better than that of -Bd-St-, and increased with the increasing of MPS feed content. When the mass of MPS was 2 phr, the tensile strength of silica reinforced -Bd-St-MPS- copolymer was 10.35 MPa.

Optimization of low-energy Pickering nanoemulsion stabilized with montmorillonite and nonionic surfactants

Nanoemulsions have been widely studied and used in food, medicine, cosmetics and other industries. However, there are few studies on nanoemulsions stabilized with solid particles. In this work, water-in-oil nanoemulsions were prepared with stearyltrimethylammoniumchloride modified montmorillonite (STAC/MMT) and nonionic surfactants using low-energy method. STAC/MMT was characterized by FT-IR, XRD, SEM, TEM and a three-phase contact angle measuring instrument. In particular, the effect of additional order was investigated. The most stable emulsion was obtained by adding STAC/MMT and surfactant to the oil phase and the water phase, respectively, and then slowly dropping the water phase into the oil phase. The particle size distribution of emulsion was carried out using dynamic light scattering and the effects of STAC/MMT content, surfactant type and oil composition on emulsion stability were revealed. It proved that the surfactant and solid particles had synergistic interaction in the system. When the ratio of STAC/MMT to emulsifier (w/w) was 0.40, Tween® 85 was selected, and the ratio of Vitamin E to mix oil phase (w/w) was 0.20, the obtained emulsion was the most stable. The emulsion showed good thermal and static stability, and had potential applications in drug carriers, food and cosmetics.

Production and Optimization of the Extraction Conditions of a Biosurfactant of Candida Utilis Ufpeda1009 with Potential of Application in the Food Industry

Biosurfactants are amphipathic molecules with capacity to reduce the surface and interfacial tension of aqueous solutions, arousing great industrial interest due to the diversity of structures and production from renewable sources, allowing the obtention of products with unique characteristics. In the food industry, for example, the use of biosurfactants produced by some yeasts is very promising, since they do not present any risk of toxicity and pathogenicity, and can be applied in emulsification, for improvement of mass texture, as antimicrobial agents and in the replacement of fats. Thus, the aim of this work was to produce a biosurfactant by the yeast Candida utilis UFPEDA1009 with potential application as an emulsifier in foods. The yeast was grown in mineral medium containing 6% canola frying oil and 6% glucose, under 150 rpm agitation for 88 h at 28 °C. After the production process, the surface and interfacial tension, yield and Critical Micelle Concentration (CMC), as well as the particle size distribution of emulsions were determined. The surface and interfacial tensions obtained were, respectively, 35.33 ± 0.19 and 2.53 ± 0.02 mN/m, with biosurfactant yield varying from 13.10 ± 0.04 to 48. 05 ± 0.21 g/L. The biosurfactant CMC was 0.6 g/L. The emulsions showed small particle sizes, with uniform shape and more separated particles, appearing resistance to coalescence. In general, it was observed that the increase in the concentration of the biosurfactant resulted in the decrease of the particle size, that is, the higher the concentration of a given biosurfactant, the greater the stability of the emulsion. The microbial surfactant was incorporated in the mass of a biscuit formulation in substitution of the animal fat, which showed improvements in the texture profile of its mass. Therefore, the biosurfactant produced is promising for application in food formulations as an emulsifier.

Study on the Influencing Factors of the Particle Size Distribution of Emulsion for ASP Flooding

Study on the Influencing Factors of the Particle Size Distribution of Emulsion for ASP Flooding

Effect of high-pressure homogenization preparation on mean globule size and large-diameter tail of oil-in-water injectable emulsions

The effect of different high pressure homogenization energy input parameters on mean diameter droplet size (MDS) and droplets with > 5 μm of lipid injectable emulsions were evaluated. All emulsions were prepared at different water bath temperatures or at different rotation speeds and rotor-stator system times, and using different homogenization pressures and numbers of high-pressure system recirculations. The MDS and polydispersity index (PI) value of the emulsions were determined using the dynamic light scattering (DLS) method, and large-diameter tail assessments were performed using the light-obscuration/single particle optical sensing (LO/SPOS) method. Using 1000 bar homogenization pressure and seven recirculations, the energy input parameters related to the rotor-stator system will not have an effect on the final particle size results. When rotor-stator system energy input parameters are fixed, homogenization pressure and recirculation will affect mean particle size and large diameter droplet. Particle size will decrease with increasing homogenization pressure from 400 bar to 1300 bar when homogenization recirculation is fixed; when the homogenization pressure is fixed at 1000 bar, the particle size of both MDS and percent of fat droplets exceeding 5 μm (PFAT5) will decrease with increasing homogenization recirculations, MDS dropped to 173 nm after five cycles and maintained this level, volume-weighted PFAT5 will drop to 0.038% after three cycles, so the “plateau” of MDS will come up later than that of PFAT5, and the optimal particle size is produced when both of them remained at plateau. Excess homogenization recirculation such as nine times under the 1000 bar may lead to PFAT5 increase to 0.060% rather than a decrease; therefore, the high-pressure homogenization procedure is the key factor affecting the particle size distribution of emulsions. Varying storage conditions (4–25°C) also influenced particle size, especially the PFAT5.

Microencapsulation of wheat germ oil.

Wheat germ oil (WGO) is beneficial for health since it is a rich source of omega-3, omega-6 and tocopherol. However, as it contains polyunsaturated fatty acids, it is prone to oxidation. The aim of this study was to encapsulate wheat germ oil and determine the effects of core to coating ratio, coating materials ratio and ultrasonication time on particle size distribution of emulsions and encapsulation efficiency (EE) and surface morphology of capsules. Maltodextrin (MD) and whey protein concentrate (WPC) at different ratios (3:1, 2:2, 1:3) were used as coating materials. Total solid content of samples was 40% (w/w). Five core to coating ratios (1:8, 1:4, 1:2, 3:4, 1:1) were tried. Ultrasound was used at 320W and 20kHz for 2, 5, 10min to obtain emulsions. Then, emulsions were freeze dried to obtain microcapsules. It was observed that, increasing WPC ratio in the coating resulted in higher encapsulation efficiency and smaller particle size. Microcapsules prepared with MD:WPC ratio of 1:3 were found to have higher EE (74.35-89.62%). Increase in oil load led to decrease in EE. Thus 1:8 core to coating ratio gave better results. Increasing ultrasonication time also had a positive effect on encapsulation efficiency.

Hofmeister Salts Affect Buildup of Thin Multilayer Films Surrounding Oil Droplets

The layer-by-layer electrostatic deposition method is a novel technique to precisely control the interfacial properties of multilayered films such as charge, thickness, permeability, and composition. The formation and stability of multilayered emulsions is however often plagued by extensive droplet flocculation and aggregation even at ideal polyelectrolyte concentrations where saturation should occur. Addition of salts may reduce the degree of attractive interactions ions and thus improve deposition. To test this hypothesis, the influence of different Hofmeister salts (KCl, NaCl, LiCl, and NH4Cl) at various salt concentrations (0–2500 mM) on the aggregation behavior of multilayered emulsions was investigated. A simple coating process of fish gelatin interfacial membranes with sugar beet pectin was used. Our results show that mean particle diameter and particle size distribution of emulsions initially decreased from 600 nm to 328 nm with increasing salt concentrations up to 250 mM. Above a critical level (>500 mM), heavy aggregation of emulsions at the presence of chaotropic salts occurred whereas kosmotropes reduced flocculation and creaming. Microscopic images and isothermal titration calorimetry confirmed particle size measurements. Results thus suggest that addition of salts may be an extremely useful tool to modulate and improve depositioning of alternatingly charged polymers on surfaces.

Research on the Emulsifying Ability of Surfactants in Crude Oil

Abstract A novel colorimetric method to measure the emulsifying ability of surfactants for crude oil has been proposed. The emulsifying ability of five surfactants for two kinds of crude oil was determined at different temperatures and salinities. The oil-water interfacial tension, particle size distribution of emulsion, emulsion stability and ability of reducing viscosity by emulsifying were investigated at the corresponding condition. The results show that there is no correlation between emulsifying ability and HLB value of surfactants. The property of crude oil has a certain impact on the emulsifying ability, and the interfacial activity is the main influencing factor on it. The emulsifying ability is affected obviously by temperature. At first it increases and then it decreases with rising temperature. Inorganic salts of low concentration are beneficial to enhance the emulsifying ability. The emulsifying ability has negative correlation with the particle size of emulsion, and positive correlation with the ability of reducing viscosity by emulsifying. There is no inevitable relation between emulsifying ability and emulsion stability.

Factors Evalution of Particle Size Distribution of Heavy Oil Emulsion

Used the heavy oil of Du 84 well 53-55 in Liaohe oil field, the impact factors of the heavy oil emulsion size distribution were analyzed. The higher concentration of emulsifier, the smaller size of average particle emulsion and the particle size distribution tends to be more uniform. With the stirring rate increasing the size distribution tends to be uniform first then tend to be disperse, and the time used would be shorter to reach equilibrium with agitation rate being faster.With prolong of the stirring time the particle size distribution of the emulsion trends to be more uniform. After emulsifier 0.3%LZC-C-02 being added in heavy oil it will become O/W emulsion and the external phase is water and the viscosity of the emulsion is small with good flowability.

Influences of Ion Abundance of Cationic Hydrophilic Polyurethane Modified with Polysiloxane on its Emulsion Properties

Several cationic water-based polyurethanes end-capped with silicone coupling agent with different ion abundance are prepared. The effects of ion abundance of those polyurethanes on its emulsion particle size distribution, wet rubbing fastness improvement, hydrophility and soft handle are studied. The results show that the sample with moderate cationic ion abundance has optimal efficiency for color fixing of reactive dyes, and the quaterized cationic groups in polyurethane molecule should has positive contribution to hydrophility and soft handle of the treated fabric, especially for the color fabric treated with higher concentration polyurethane emulsion.

In situ emulsion polymerization and characterization of poly(butyl acrylate‐co‐methyl methacrylate)/silica nanosystems

In this study influence of monomer ratio, butyl acrylate (BA), and methyl methacrylate (MMA) as well as silica nanofiller morphology (pyrogenic and colloidal) and concentration on the emulsion particle size distribution and properties of polyacrylate film (PA) synthesized by in situ emulsion polymerization were investigated. The ratios of the monomers BA/MMA were 100/0, 70/30, 50/50, 30/70, 0/100 and the filler concentration 0–10.0 mass%. PA nanocomposite films were characterized by using thermogravimetric analysis, differential scanning calorimetry, and tensile test. Research has shown that monomer ratio has significant influence on glass transition temperature (Tg). The addition of both types of silica filler, pyrogenic and colloidal, has no effect on Tg. Thermogravimetric analysis showed that systems with higher BA fraction have better thermal stability than systems with higher MMA fraction. Addition of the both type of silica nanofiller enhanced thermal stability of PAs, however, systems with colloidal silica are more stable. Pyrogenic silica and higher amounts of colloidal silica nanofiller increased PA emulsion particle size up to several micrometers. Addition of higher amounts of colloidal silica improved mechanical properties compared to the neat PA matrix. POLYM. ENG. SCI., 53:2292–2298, 2013. © 2013 Society of Plastics Engineers

Emulsifying Properties of Squid Mantle Actomyosin (Illex argentinus)Stored at 2-4°C. Effect of some Inhibitors

The possible effect of the proteolytic activity on emulsifying properties of squid ( Illex argentinus ) mantle actomyosin stored at 2-4°C and the effects of cocktail of protease inhibitors [phenylmethylsulfonyl fluoride (PMSF), iodo acetic acid (IAA) and ethylene diamine-tetra acetic acid (EDTA)] were investigated. Oil/water emulsion and their stability were studied by optical characterization using a vertical scan analyzer. The particle size distribution of emulsions was obtained with a particle analyzer. O/W emulsions formulated with actomyosin of squid mantle with inhibitors showed certain stability during the first 15-20 min, and then destabilize during the analyzed remaining time, reaching BS (Backscattering) of approximately 20% with no significant changes thereafter. However, in emulsions formulated with actomyosin without inhibitors, the decrease in BS was recorded at 30-40 min, indicating a greater stability, as a function of the storage time, in comparison with those in presence of inhibitors actomyosin. The particle size distribution of both emulsions presented, for actomyosin with and without inhibitors, three droplet populations at zero time. Greater droplet size, De Brouker mean diameter D [4.3], was observed for either emulsions formulated with actomyosin without and with inhibitors, at 24 and 48h of storage. The addition of SDS solution led to a reduction of the population of large particles suggesting the presence of stable flocs under the analyzed conditions. In addition, the P (polidispersity) values corresponding to actomyosin without inhibitors were significantly (p < 0.05) higher than those of actomyosin with inhibitors. Both emulsions exhibited a significant destabilization by creaming and flocculation. The stability of emulsions was enhanced when aggregates appeared in emulsions, mainly for emulsions stored without inhibitors. These results suggest that the proteolytic activity can favour the emulsifying properties of actomyosin obtained from squid mantle stored at 2-4°C. The structure of flocs would affect positively the stability of O/W emulsions.

In-vitro evaluation of hydrocolloid–based encapsulated fish oil

The release behaviour of hydrocolloid-based encapsulated fish oil was carried out to understand its applicability as a controlled release delivery system. A casein-based Maillard reaction product (MRP), [caseinate–glucose-dried glucose syrup, MRP] and its corresponding non-MRP-based encapsulant materials were used to form stable emulsions with fish oil. The emulsion particle size distribution was found to be uniform with 90% of the particles below 1.3 μm. These oil/water emulsions were spray dried to obtain free-flowing fish oil microcapsules. All casein-based microcapsules had a free fat content of <1% and the encapsulation efficiencies were all >97%. A sequential in-vitro release protocol and a method for evaluation of the released oil in simulated gastric and intestinal fluids (SGF/SIF) were developed and tested in this study. A comparative analysis of release behaviour between caseinate and whey protein-based MRP and non-MRP-based encapsulant materials was also obtained. The amount of released oil after subjecting to the sequential in-vitro protocol was found to be <2% and 36% for caseinate and whey protein-based MRP microcapsules respectively.

Preparation, structure and properties of comb-branched waterborne polyurethane/OMMT nanocomposites

Comb-branched waterborne polyurethane/organo-montmorillonite (CWPU/OMMT) nanocomposites were prepared by in situ intercalating polymerization process based on the main materials including IPDI, DMPA, polycaprolactone diols, comb-branched polymeric diols and OMMT. The average particle size of emulsion increases and the particle size distribution of emulsion becomes broader with the increase of OMMT content. The results of X-ray diffraction (XRD) and transmission electron microscope (TEM) show that OMMT is homogeneously dispersed into the CWPU matrix with intercalated or exfoliated structure. The properties of CWPU/OMMT nanocomposites are dependent on OMMT content. When the OMMT content is 3 wt%, CWPU/OMMT nanocomposite exhibits excellent overall properties: the particle size of emulsion 63.6 nm, tensile strength 42.0 MPa, E′ 20.3 MPa at 80 °C, water absorption 13% at 24 h and surface contact angle for water over 100°.