Emulsion Particles Research Articles

Improving the Safety of Clinical Management of COVID-19 Patients Receiving Aminoglycosides and Parenteral Nutrition: Y-site Compatibility Studies

PurposeAminoglycosides (AMGs) are broad-spectrum bactericidal antibiotics that can resolve bacterial infections co-existing with COVID-19 or exploit their potential antiviral activities. Patients presenting the most severe forms of COVID-19 due to escalating catabolism and significant lean body mass loss often require the concomitant administration of parenteral nutrition (PN) and antibiotics. The Y-site administration is one of the approaches allowing the co-administration of two intravenous medications in patients with limited vascular access. Our study aimed to investigate the compatibility of AMGs and selected commercial PN admixtures enriched in omega-3 fatty acids. MethodsGentamycin (GM), amikacin (AM), and tobramycin (TM) solutions for infusion were combined with Nutriflex Omega Special (NOS) and Smofkabiven (SFK). Three different volume ratios were investigated: 1:2, 1:1, and 2:1, simulating Y-site administration. Samples underwent visual examination and determination of the lipid emulsion particle size, zeta potential, and pH immediately after preparation and after four hours of storage at room temperature (22 ± 2 °C) with sunlight exposure. ResultsGM and AM combined with NOS in all studied ratios met the set-up acceptance criteria. The addition of TM to NOS in a 2:1 volume ratio and all tested AMGs to SFK in all studied combinations significantly influenced the stability of the oil-water system leading to the appearance of globules larger than 5 µm exceeding the pharmacopeial limit of 0.05% immediately after preparation or after four hours of storage. ConclusionIn conclusion, our study showed that NOS was less prone to destabilization of oil-in-water systems by AMGs than SFK. In justified clinical cases, due to the lack of appearance of precipitate or enlarged lipid droplets, the combined administration of GM and AM with the NOS could be considered, provided tested volume ratios of the drug and MCB in the infusion line are maintained. However, it should be noted that such an infusion may be associated with the risk of changes in the pharmacokinetics of the drug.

Development and characterization of a continuous ultrasound emulsification and nano-emulsion polymerization process

Typically, nano-emulsions are prepared in batch high-speed homogenization or ultrasound processes and polymerized afterwards in batch reactors. However, fully continuous processes have the potential to decrease production costs and energy consumption compared to batch processes. This research thus focuses on implementing ultrasound into a fully continuous emulsification and nano-emulsion polymerization process to obtain latex nano-particles from butylmethacrylate and ethylene glycol dimethacrylate. The goal of this research is to produce nano-emulsions and nano-particles with the smallest obtainable size and polydispersity in a fully continuous two-stage process. In the first stage or emulsification stage, parameters like flowrate, residence time and acoustic power are varied to influence and determine the optimal energy density. In second stage or reaction stage, residence time and reaction temperature are studied to obtain particles of monodisperse sizes. Samples produced in both stages are analysed with Dynamic Light Scattering to measure the average size and polydispersity (PdI) of the emulsion droplets and particles. Emulsification results indicate that droplet size and PdI decreases at increasing energy densities (J/ml) until 60 J/ml after which a constant droplet size of 150 nm and PdI of 0.230 are reached. Furthermore, a particle size of 50 nm and PdI of 0.080 were achieved in both batch and continuous polymerization reactors after 5 min at 85 °C. By implementing the most optimal process parameters, small emulsion droplets and particles were obtained more energy efficient in a shorter emulsification and reaction time compared to literature ultrasound assisted nano-emulsion polymerization processes.

An amphiphilic nano titanium dioxide based nanofluid: Preparation, dispersion, emulsion, interface properties, wettability and application in enhanced oil recovery

The emulsification flooding is an effective method for enhance oil recovery. In this work, an amphiphilic nano titanium dioxide (ANTD) was prepared by the chemical reaction of nano titanium dioxide (NTD) with the titanate coupling agent. The contact angle experiments shown that the contact angle of NTD changed from 11.6° to 110.6°after modification, which became more lipophilic. The dispersion testing shown that Span85 was the best dispersant for ANTD. The nanofluid was configured by using 0.05 g of ANTD and 100 ml of 0.05 % Span85, which was tested by the emulsification experiment, the interface tension experiment and the dilatation rheological experiment. The result shown that the nanofluid can be emulsified to form the W/O emulsion with the crude oil, the average emulsion particle size was 1.96 µm, and the nanofluid could reduce the oil-water interface tension and improve the strength of the interface film. The wettability alteration experiment shown that the nanofluid can change the core from oil-wet to water-wet. The flow displacement experiment demonstrated that the oil recovery rate increased by 26.4 % after the nanofluid flooding. Finally, the Nuclear Magnetic Resonance experiment shown that the nanofluid could reduce the oil-water mobility rate, and expand the swept volume, thus enhancing oil recovery.

Fabrication of carboxymethyl starch/xanthan gum combinations Pickering emulsion for protection and sustained release of pterostilbene

Carboxymethyl starch (CMS)/xanthan gum (XG) combinations with different ratios (CMS/XG: 1/1, 3/1, 5/1, 7/1, 9/1, w/w) were used as Pickering emulsion delivery systems to encapsulate pterostilbene (PTS) to improve its stability. The results showed that the Pickering emulsion prepared using CMS/XG combinations could effectively encapsulate PTS. When the mass ratio of CMS to XG was 1:1, the encapsulation efficiency reached 91.20 %. The spherical particles in the PTS emulsion were dissociated and homogenous. The results of backscattered light experiments and storage stability studies showed that the PTS emulsion system prepared using CMS/XG was uniform and stable, with no obvious phase separation or emulsion droplet coalescence. With an increase in the mass ratio of XG, the water distribution in the emulsion became more evenly distributed, and the aggregation of droplets was reduced. The PTS emulsion prepared using CMS/XG improved the storage retention percentage of PTS. The cumulative release of PTS in the simulated gastric fluid was significantly lower than that in simulated intestinal fluid. The Pickering emulsion prepared using CMS/XG combinations can be used as a delivery system for functional foods and help to develop an efficient and reliable release system for hydrophobic bioactive substances.

Sludge interface measurement in the storage tank utilizing neutron backscattering technique: A field experiment

Modern industrial plant operations commonly necessitate a measurement system of the liquids level interface in the oil storage tank. Various advanced-level indicators almost meet the demand, but these may not be in online condition and are less accurate due to sedimentation in the bottom tank. Sedimentation or sludge known as a petroleum hydrocarbons complex emulsion, contained water and solid particles generated during distribution, storage, or even production. The neutron backscatter technique can help the maintenance system of the tank or vessel by measuring sludge levels from outside the wall. This paper presents a non-intrusive method for identifying the interface between two materials in the crude oil storage system. A fast neutron source (241Am–Be) with activity 1 Ci (Ci) and a portable backscattering neutron detector are used for storage tank measurement. The storage tank has an outer diameter (OD) of 34 m and a height of 11 m. Time measurement is 2 s for each position, starting from 0 m to 11 m. The slow neutron intensity can be correlated to the hydrogen concentration inside chemical compounds. The interface between sludge and oil is identified at 27 cm from the bottom plate. The method has the potential for non-destructive measurement of sludge in a refinery facility.

Enhancement of gum Arabic/casein microencapsulation on the survival of Lactiplantibacillus plantarum in the stimulated gastrointestinal conditions

Probiotic products that contain lactobacilli have long histories of safe use as Lactobacillus strains have many physiological functions in the gastrointestinal tract (GIT). However, the viability of probiotics can be affected by food processing and the adverse environment. This study investigated the O/W (Oil-in-water emulsions) emulsions formed by coagulation of casein/GA (Gum Arabic) complexes for Lactiplantibacillus plantarum microencapsulation, and the stability of the strains during gastrointestinal environment were also determined. The results showed that the particle size of the emulsion decreased from 9.72 μm to 5.48 μm when the GA concentration increased from 0 to 2 (w/v), and the emulsion particles were found to be more uniform as observed by CLSM (Confocal Laser Scanning Microscope). The surface of this microencapsulated casein/GA composite forms smooth, dense agglomerates and has high viscoelasticity, which effectively improved casein's emulsifying activity (8.66 ± 0.17 m2/g). After the casein/GA complexes microencapsulation, a higher viable count was detected after gastrointestinal digestion in vitro, and the activity of L. plantarum is more stable (about 7.51 log CFU/mL) during 35 days of storage at 4 °C. The results of study will help to design lactic acid bacteria encapsulation systems based on the GIT environment for the oral delivery strategy.

Effect of oil content and protein particles concentration on non-dairy whip topping based on Pickering emulsion system and their 3D printing properties

Non-dairy whip topping is a typical food emulsion system that is popular among consumers. In this study, a novel non-dairy whip topping without hydrogenated vegetable oil was fabricated based on Pickering emulsion system. The results of particle size and stability of the pre-whipping emulsion showed that the initial emulsion particle size increased to 472.00 ± 1.73 nm as the oil content increased to 30%, and the particle size of the aged emulsion increased to 974.00 ± 9.54 nm,and the stability decreased. The particle size tended to decrease and stability gradually increased with increasing protein particles concentration. Based on the observation of bubbles in the cream system after whipping, it was found that the increase of oil content and protein particles concentration was helpful to the cream structure. Furthermore, the results of rheological and textural properties showed that all the creams presented shear thinning characteristics, and with the increase of oil content and protein particles concentration, the viscosity and energy storage modulus (G′) increased, indicating good printability. Additionally, the 3D printing of the creams displayed that the viscosity was too large to reduce the accuracy of printing, while the accuracy and stability of the printed shapes reached 99.27% and 99.72% at 25% oil content and 1.6% protein particles concentration, respectively. This study will be important for Pickering emulsion system to solve health problems in food and expand food 3D printing applications.

Oil-in-Oil Pickering emulsions stabilized with kaolinite

Oil-oil Pickering emulsions are remarkable systems in pharmaceutical and cosmetic sciences, minimizing oxidation and hydrolysis reactions. Versatile and environmentally friendly clay minerals are poorly discussed in literature as stabilizing particles in these unconventional oil-oil emulsions. We investigated the effect of kaolinite applied in a castor oil/silicone oil emulsion at different oil fractions and kaolinite concentrations. Samples without kaolinite showed a limited and low stability self-emulsification. According to the particle concentration increase, emulsions presented higher emulsified volumes and lower droplet diameter, from 100 to 20 µm. Microscopic images revealed Pickering emulsions, where cage effect started to be observed at 2 wt% kaolinite. Castor oil and silicone oil behaves like liquids, however, in the presence of kaolinite the emulsions formed changed to a solid viscoelastic system, improving long-term stability.

A smart material: Multi-stimulus-responsive composite microspheres prepared via RAFT polymerization as recyclable pickering emulsifiers and their application in stabilizing real oil phases

The development of smart composites to sustainably separate and recover oil from oily water had attracted much attention. In this study, tri-block (P(LMA-b-NIPAM-b-AA)) polymer brushes were controllably “grown on” the Fe3O4 surface by three-step surface-initiated reversible addition fragmentation chain transfer (SI-RAFT) polymerization to prepare Fe3O4-P(LMA-b-NIPAM-b-AA) (MNPLNA) magnetic nanospheres with interfacial activity. The MNPLNA nanospheres were characterized to demonstrate the triple response of pH, temperature and magnetism. Meanwhile, the comparison experiments showed that the MNPLNA nanospheres with tri-block structure had excellent interfacial activity. Then, the O/W type of Pickering emulsion was prepared by using MNPLNA nanospheres as the particle emulsifier. The size variation pattern of Pickering emulsion was comprehensively investigated by adjusting the concentration of nanospheres, oil-water ratio, electrolyte concentration and polarity of oil phase. Pickering emulsions were controllably separated by the action of an external magnetic field, and could be reversibly switched at least 10 cycles between emulsified and broken states under the trigger of pH and temperature. In addition, MNPLNA nanospheres exhibited excellent emulsification properties for stabilizing variety of real oil phases (e.g., canola oil, kerosene, diesel and crude oil). Based on this, MNPLNA nanospheres were applied as smart multifunctional materials in simulated kerosene-containing wastewater separation. MNPLNA nanospheres could be used to recover kerosene with high recovery rate after 10 separation cycles under the stepwise action of pH, temperature and magnetic field.

Ultrasound-assisted multilayer Pickering emulsion fabricated by WPI-EGCG covalent conjugates for encapsulating probiotics in colon-targeted release

This study demonstrated the influences of ultrasound-assisted multilayer Pickering double emulsion capsules on the pasteurization and gastrointestinal digestive viability of probiotic (L. plantarum) strain liquid. Firstly, the role of ultrasonic homogenization on the morphology of W1/O/W2 double emulsions were studied. The double emulsion formed by ultrasonic intensity at 285 W had a single and narrow distribution with smallest droplet size. The double emulsion particles were then coated with chitosan(Chi), alginate (Alg), and CaCl2(Ca). The multilayer emulsion after pasteurization and gastrointestinal digestion both had the highest viability at 5 coating layers, but its particle size (108.65 μm) exceeded the limit of human oral sensory (80 μm). It could be noted that the deposition of 3–4 layers of coating had similar activity after pasteurization/GIT digestion. And droplets with 3 layers of coating were the minimum and most available formulation for encapsulated probiotics (L. plantarum). Hence, the results suggest that the use of ultrasound-assisted multilayer emulsions encapsulated with probiotics in granular food and pharmaceutical applications is a promising strategy.

Controlled ibuprofen release from Pickering emulsions stabilized by pH-responsive cellulose-based nanofibrils

Pickering emulsions represent a promising avenue in the field of controlled drug delivery systems. Recently, cellulose nanofibers (CNFs) and chitosan nanofibers (ChNFs) have gained interest as eco-friendly stabilizers for Pickering emulsions, yet their application in pH-responsive drug delivery systems remains unexplored. However, the potential of these biopolymer complexes in formulating stable, pH-responsive emulsions for controlled drug release is of significant interest. Here, we show the development of a highly stable, pH-responsive fish oil-in-water Pickering emulsion stabilized by ChNF/CNF complexes, with optimal stability achieved at a 0.2 wt% ChNF concentration and an average emulsion particle size of approximately 4 μm. Our results demonstrate long-term stability (16 days of storage) for ChNF/CNF-stabilized emulsions, with the interfacial membrane's pH modulation facilitating controlled, sustained ibuprofen (IBU) release. Furthermore, we observed a remarkable release of approximately 95 % of the embedded IBU within the pH range of 5–9, while the drug loading and encapsulation efficiency of the drug-loaded microspheres reached their peak at a 1 % IBU dosage, with values of 1 % and 87 %, respectively. This study highlights the potential of using ChNF/CNF complexes in designing versatile, stable, and entirely renewable Pickering systems for controlled drug delivery, with potential applications in food and eco-friendly products.

Synthesis and characterization of sago starch nanocrystal laurate as a food grade particle emulsifier

Starch nanocrystals (SNCs) are tiny particles that possess unique qualities due to their small size, such as increased crystallinity, thin sheet structure, low permeability, and strong resistance to digestion. Although sago starch nanocrystals (SNCs) are naturally hydrophilic, their properties can be modified through chemical modifications to make them more versatile for various applications. In this study, the esterification process was used to modify SNCs using lauroyl chloride (LC) to enhance their surface properties. Three different ratios of LC to SNC were tested to determine the impact on the modified SNC (mSNC). The chemical changes in the mSNC were analyzed using FTIR and 1H NMR spectroscopy. ##The results showed that as the amount of LC increased, the degree of substitution (DS) also increased, which reduced the crystallinity of the mSNC and its thermal stability. However, the esterification process also improved the hydrophobicity of the SNC, making it more amphiphilic. The emulsification capabilities of the mSNC were investigated using a Pickering emulsion, and the results showed that the emulsion made from mSNC-1.0 had better stability than the one made from pristine SNC. This study highlights the potential of SNC as a particle emulsifier and demonstrates how esterification can improve its emulsification capabilities.

Role of pH and cations on emulsion formation and stability of crude oils

Emulsification plays a crucial role in various areas. However, undesirable emulsions, especially water-in-oil (W/O) emulsions, formed during crude oil production, transportation, processing, and stockpiling, become significant issues in the petroleum industry. Various studies have focused on evaluating the factors affecting emulsion stability and their mechanisms, which hardly explain the relationship with emulsion formation. This study assessed the effects of pH and cations on the transformation of emulsion types and their stability based on the observed emulsion formation process and emulsion particle sizes. It was found that the final W/O emulsions were transformed from water-in-oil-in-water (W/O/W) emulsions for all brine conditions. At neutral pH, more W/O emulsions were formed through the transformation of W/O/W emulsion, but the high pH broke down most of the W/O/W emulsion into free water and oil. Emulsion particles’ zeta potential or electrokinetics plays a significant role in W/O/W emulsion stability at high pH. The transformation of emulsion types in cation solutions was similar to neutral pH; the amount of W/O emulsion depends on cation species. The W/O/W emulsion stability under different pH in the following order: neutral pH < low pH < high pH, whereas final W/O emulsion stability is as follows: high pH < low pH < neutral pH; MgCl2 < CaCl2 < NaCl. The stability of the emulsion is influenced by the properties of the crude oil, such as viscosity and TAN/TBN ratio, which affect the oil film thickness of the W/O/W. Based on these findings, a stability mechanism is proposed for the emulsion under different pH and cations.

Structure, interface properties and curcumin encapsulation of hogskin particles stabilized novel Pickering emulsions

Hogskin is a kind of natural and safe high-quality organic material, which can be used to prepare Pickering emulsion. However, its poor storage stability is a key technical problem that restricts its wide application. In this study, preparation and characterization of hogskin particles and stable hogskin Pickering emulsion were conducted, and the functional characteristics of curcumin embedding were also discussed. The results suggested that the Pickering emulsion had good storage stability within 2 months. Besides, diverse pH values and ionic strengths had little influence on the change in emulsion particle size, but zeta potential showed an opposite change trend. Observation under the microscopy showed that the hogskin particles were irreversibly adsorbed onto oil-water interface, and the emulsion exhibited shear thinning and elastic behaviors. After ultraviolet treatment for 7 h and storage for 8 days, curcumin exhibited a good retention rate in Pickering emulsion, and the final retention rate reached 87.54%.

Novel Insight into Pickering Emulsion and Colloidal Particle Network Construction of Basil Extract for Enhancing Antioxidant and UV-B-Induced Antiaging Activities.

We developed a facile preparation method of oil-in-water (O/W) Pickering emulsion in an emollient formulation using basil extract (Ocimum americanum L.) as a solid particle stabilizer by fine-tuning the concentration and mixing steps of common cosmetic formulas, such as humectants (hexylene glycol and glycerol), surfactant (Tween 20), and moisturizer (urea). The hydrophobicity of the main phenolic compounds of basil extract (BE), namely, salvigenin, eupatorin, rosmarinic acid, and lariciresinol, supported high interfacial coverage to prevent coalescence of globules. Meanwhile, the presence of carboxyl and hydroxyl groups of these compounds provides active sites for stabilizing the emulsion using urea through the formation of hydrogen bonds. Addition of humectants directed the in situ synthesis of colloidal particles during emulsification. In addition, the presence of Tween 20 can simultaneously reduce the surface tension of the oil but tends to inhibit the adsorption of solid particles at high concentrations, which otherwise formed colloidal particles in water. The level of urea and Tween 20 determined the stabilization system of the O/W emulsion, whether interfacial solid adsorption (Pickering emulsion, PE) or colloidal network (CN). Variation of the partition coefficient of the phenolic compounds present in basil extract facilitated the formation of a mixed PE and CN system with better stability. The addition of excess urea induced interfacial solid particle detachment, which caused the oil droplet enlargement. The choice of stabilization system determined the control of antioxidant activity, diffusion through lipid membranes, and cellular antiaging effects in UV-B-irradiated fibroblasts. Particle sizes of less than 200 nm were found in both stabilization systems, which is beneficial for maximizing their effects. In conclusion, this study provides a technological platform to realize the demand for natural dermal cosmetic and pharmaceutical products with strong antiaging effects.

Influence of structure of porous polyketone microfiltration membranes on separation of water‐in‐oil emulsions

AbstractPressure‐driven filtration is a suitable alternative to conventional methods for separation of surfactant‐stabilized water‐in‐oil (W/O) emulsions. In this work, porous polyketone (PK) membranes for W/O emulsion separation with outstanding organic solvent resistance were prepared by non‐solvent‐induced phase separation (NIPS). The porous PK membrane structures were controlled by changing the non‐solvent concentration in the coagulation bath. The water contact angle in oil increased as the methanol concentration in the coagulation bath increased because of the formation of a rougher membrane surface, implying higher under‐oil hydrophobicity. The PK membranes were able to separate several surfactant‐stabilized W/O emulsions consisting of various organic solvents, with high oil purity value (99.9%). Permeance increased with increasing methanol concentration in coagulation bath due to the increase in membrane pore size and porosity. The best performing membrane, prepared with 45 wt% methanol coagulation bath, showed over 4000 LMH/bar permeance using emulsions of different particle sizes. Furthermore, the relationship between permeance and the ratio of the PK membrane pore size to the W/O emulsion particle size suggested that the initial permeance was dependent on pore size. The PK membranes demonstrated huge potential for W/O emulsion separation because of their easily‐controlled structures, high under‐oil hydrophobicity, and high separation performance.

Polysaccharide Nanofiber-Stabilized Pickering Emulsion Microparticles Induce Pyroptotic Cell Death in Hepatocytes and Kupffer Cells.

The intracellular uptake and interaction behavior of emulsion microparticles in liver cells critical to host defense and inflammation is significant to understanding their potential cytotoxicity and biomedical applications. In this study, the cell death responses of fibroblastic, hepatocyte, and Kupffer cells (KCs) induced by four types of emulsion particles that are stabilized by polysaccharide nanofibers (cellulose or chitin), an inorganic nanoparticle (β-tricalcium phosphate), or surfactants are compared. Pickering emulsion (PE) microparticles stabilized by polysaccharide nanofibers or inorganic nanoparticles have a droplet size of 1-3µm, while the surfactant-stabilized emulsion has a diameter of ≈190nm. Polysaccharide nanofiber-stabilized PEs (PPEs) markedly induce lactate dehydrogenase release in all cell types. Additionally, characteristic pyroptotic cell death, which is accompanied by cell swelling, membrane blebbing, and caspase-1 activation, occurs in hepatocytes and KCs. These PE microparticles are co-cultured with lipopolysaccharide-primed KCs associated with cytokine interleukin-1β release, and the PPEs demonstrate biological activity as a mediator of the inflammation response. Well-designed PPE microparticles induce pyroptosis of liver cells, which may provide new insight into regulating inflammation-related diseases for designing potent anticancer drugs and vaccine adjuvants.

Preparation of phase change microcapsules with high thermal storage and temperature sensitive for thermal management

Preparing microcapsules with core-shell structure by encapsulating phase change materials (PCM) in the shell is considered as an effective method to solve the leakage problem of PCM during use. Herein, a phase change microcapsule (MPCM) based on n-eicosane core and polyurea shell was prepared. This MPCM was prepared by interfacial polymerization of isophorone diisocyanate (IPDI) and ethylenediamine (EDA) using Pickering emulsion as a template and sulfonated lignin (SL) derived from industrial by-products as an emulsifier. The morphology, chemical structure and optimal preparation conditions of the MPCM were investigated by polarized light microscopy, fourier infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The results showed that the SL emulsified n-eicosane oil-in-water emulsion particles had good dispersion and homogeneous particle size. MPCM-2 with combined optimal conditions in MPCM exhibited regular spherical shape, high enthalpy of phase change (209.8 J/g), high encapsulation ratio (82.9 %), good thermal cycling stability, and negligible leakage rate. When PDMS and MPCM-2 were compounded and applied to thermal management, the MPCM-2/PDMS composite exhibited a much slower temperature rise and fall. Moreover, a plateau period appears at the crystallization and melting temperatures. Moreover, the phase change energy storage of MPCM/PDMS could be easily observed by the change of color after the introduction of temperature-sensitive particles. In summary, the present MPCM has good thermal storage and thermal management capabilities and provides a good application prospect for thermal energy storage systems.

Study on Wastewater Demulsification Technology of Crude Oil in Xinjiang Oilfield

The Second Oil Production Plant of Xinjiang Oilfield produces a large amount of highly emulsified crude oil, which has a serious impact on the subsequent oil-water separation. At present, the concentration of demulsifier has increased to 2000 mg/L, but the demulsification effect is still poor. In this paper, the source and physical properties of highly emulsified crude oil are investigated firstly. The results show that highly emulsified crude oil is composed of three kinds of liquid: (1) conventional water flooding (WF); (2) chemical flooding (CF); (3) fracturing backflow fluid (FB). Among them, high zeta potential, low density difference, high viscosity, and small emulsion particles are responsible for the difficulty in the demulsification of the WF emulsion, while the high pH value is the reason why the CF emulsion is difficult to demulsify. Therefore, systematic experiments were implemented to investigate the optimal demulsification approach towards the three liquids above. As for the WF emulsion, it was necessary to raise the temperature to 70 °C and the concentration of the demulsifier to 200 mg/L. Moreover, it was only necessary to add 200 mg/L of demulsifier to break the CF emulsion after adjusting the pH value to 7, while no extra treatments were needed to break the FB emulsion. We hope this study can provide a new insight for the treatment of emulsions in the later stage of oilfield development.

Preparation of asymmetric Janus hollow silica microparticle and its application on oily wastewaters

Janus nanoparticles have aroused the interest of scholars because of their highly efficient emulsification of spilled oils in wastewater. In this work, interfacially active Janus hollow glass microparticles (J-HGMPs) of asymmetric wettability were designed and synthesized in order to achieve more efficient separation of emulsified oil droplets from oily wastewater. Surface characteristic techniques such as FTIR, SEM, zeta potential and contact angle measurements had been employed to assess the amphiphilic surface properties of J-HGMPs. The oil removal/recovery performance of J-HGMPs in different oil–water systems and their interfacial activities were studied. As a particulate emulsifier, J-HGMPs could remove/recover > 96% oil from oil–water mixed phase. The results showed that J-HGMPs had strong interfacial activities and anchored firmly at oil/water interfaces. This high adsorption energy was also evaluated and verified via the calculation of Gibbs free energy. Overall, this study provided a novel and low-cost oil recovery method via a convenient buoyancy force that could be effectively applied in the treatment of oil spills while achieving the goal of benign and green environmental protection.