High Hydrophilic-lipophilic Balance Research Articles

Mechanism for adjusting the strength of interphase adsorption layers of "Skimmed milk – surfactant substance" in dessert products

Today, the range of dessert products produced by the restaurant industry of Ukraine is wide and diverse and is determined by its nomenclature. Mousse is one of the most common dessert dishes ordered in restaurants of various levels. The traditional technological scheme of mousses production is to some extent labor-intensive, and this makes it difficult to satisfy consumer demand. Therefore, the use of a dry mixture in the recipe composition of mousses is justified. This article is devoted to the investigating the regulatory mechanisms of interphase adsorption layer strength at the interface of the water – oil and water – air phases by introducing surfactants into the dry mixture for the manufacture of dessert products. The choice of surfactants and their concentrations for the formation of interfacial adsorption layers in systems is based on the consideration of surface activity, hydrophilic-lipophilic balance (HLB) and protein concentration, which determines the behavior of the mixture of surfactants in the system. The issue of the influence of surfactants with high and low HLB and their mixtures and the use of a system with three surfactants E472e-E472b-E322, which allow to obtain whipped emulsions from a dry mixture, are considered.

MECHANISM FOR ADJUSTING THE STRENGTH OF INTERPHASE ADSORPTION LAYERS OF "SKIMMED MILK – SURFACTANT SUBSTANCE" IN DESSERT PRODUCTS

Today, the range of dessert products produced by the restaurant industry of Ukraine is wide and diverse and is determined by its nomenclature. Mousse is one of the most common dessert dishes ordered in restaurants of various levels. The traditional technological scheme of mousses production is to some extent labor-intensive, and this makes it difficult to satisfy consumer demand. Therefore, the use of a dry mixture in the recipe composition of mousses is justified. This article is devoted to the investigating the regulatory mechanisms of interphase adsorption layer strength at the interface of the water–oil and water–air phases by introducing surfactants into the dry mixture for the manufacture of dessert products. The choice of surfactants and their concentrations for the formation of interfacial adsorption layers in systems is based on the consideration of surface activity, hydrophilic-lipophilic balance (HLB) and protein concentration, which determines the behavior of the mixture of surfactants in the system. The issue of the influence of surfactants with high and low HLB and their mixtures and the use of a system with three surfactants E472e-E472b-E322, which allow to obtain whipped emulsions from a dry mixture, are considered.

Utilization of Emulsion Inversion to Fabricate Tea (Camellia sinensis L.) Flower Extract Obtained by Supercritical Fluid Extraction-Loaded Nanoemulsions.

This study aimed to obtain tea flower extract (TFE) using supercritical fluid extraction, to determine the compounds present in the TFE and to establish its antioxidant activity. The fabrication of TFE nanoemulsions was also investigated using response surface methodology (RSM). UHPLC-ESI-QTOF-MS/MS and UHPLC-ESI-QqQ-MS/MS analysis showed that the TFE was composed of catechin and its derivatives, flavonols and anthocyanins, suggesting its potential as a free radical scavenger with strong reducing powers. A central composite design was applied to optimize the independent factors of the nanoemulsions. The factors had a significant (p < 0.05) effect on all response variables. The optimum level of factors for the fabrication was a surfactant-to-oil ratio of 2:1, a high hydrophilic-lipophilic balance (HLB) surfactant to low HLB surfactant ratio (HLR) of 1.6:1, and a PEG-40/PEG-60 hydrogenated castor oil ratio of 2:1. The responses obtained from the optimum levels were a 34.01 nm droplet size, a polydispersity index of 0.15, and 75.85% entrapment efficiency. In conclusion, TFE could be an antioxidant active ingredient and has been successfully loaded into nanoemulsions using RSM.

Block Copolymers of Ethylene Oxide and Propylene Oxide: Prospects for Medical and Pharmaceutical Application in Russia

Block copolymers of ethylene oxide and propylene oxide (EO/PO block copolymers) are polymeric non-ionic surfactants with a high hydrophilic–lipophilic balance also referred to as pluronics, poloxamers, or proxanols. These compounds are among the most demanded modern excipients for the production of medicines. EO/PO block copolymers are used both in the production of traditional (liquid, semi-solid, and solid) dosage forms and as part of targeted delivery systems. The extensive application of EO/PO block copolymers is due to the diverse array of their properties, including not only solubilising, emulsifying, gelling, and other effects but also thermoreversibility, which is essential for developing in situ delivery systems and 3D printing technologies.The aim of the study was to evaluate the potential of EO/PO block copolymers for medicinal use and to assess the range of medicinal products approved in the Russian Federation that contain EO/PO block copolymers.This review presents an analysis of the register of poloxamer-containing medicines approved in the Russian Federation, a list of the largest manufacturers of EO/PO block copolymers in the world, and a study of the possibility to use copolymers for medical purposes. Currently, there are more than 10 chemical manufacturers producing EO/PO block copolymers for the pharmaceutical, biotechnology, and other industries around the world. EO/PO block copolymers are included in more than 60 medicinal products present in the Russian pharmaceutical market; this observation indicates the need to phase out the import of poloxamers.

Effect of alcohols on water solubilization in surfactant-free diesel microemulsions

Microemulsions are preferred over other methods of mixing two immiscible liquids as they are thermodynamically stable, but require a high percentage of surfactant. Surfactant-free microemulsions, on the other hand, use an amphisolvent instead of surfactants, making them an economical alternative. The current experimental investigation focuses on formulation of surfactant-free water-in-diesel microemulsions with the help of straight-chain aliphatic alcohols as diesel replacement for IC engines. Dynamic light scattering measurements revealed these microemulsions had average water droplets of less than 10 nm. The microemulsions were formulated using single-alcohol, two-alcohols, and three-alcohols. It becomes crucial to study the water solubilization of microemulsions as the addition of water in diesel improves combustion efficiency. The water solubilization in surfactant-free microemulsions was found to be dependent on the hydrophilic–lipophilic balance (HLB) of the alcohols, as it determined the solubilizing property of alcohol. The microemulsions could only be formulated in the HLB range of 6.27 to 7.76 and were found to have maximum water solubilization in the HLB range of 6.67 to 7.63. Butanol had the highest water solubilization in a single alcohol system, butanol–ethanol in the ratio of 3:1 for the two-alcohol system, and propanol–butanol–octanol in the ratio of 3:1:1 for three-alcohol systems. Alcohols with higher HLB were more hydrophilic, causing migration of alcohol from the interface to bulk water. In comparison, alcohol with a lower HLB caused the migration of alcohol from the interface to bulk diesel, which resulted in reduced water solubilizations. Hence, the microemulsions could not be formulated beyond specific HLB range. The formulated microemulsions could be a prospective substitute for diesel fuel as alcohols can be derived from renewable routes.

Effect of hydrophile–lipophile balance of the linker in Gal/GalNAc ligands on high-affinity binding of galactosylated liposomes by the asialoglycoprotein receptor

In this study, we explored the effect of the hydrophile–lipophile balance (HLB) in the linker unit of Galactose (Gal)/N-acetylgalactosamine (GalNAc) ligands on their affinity toward asialoglycoprotein receptors (ASGPRs). Two Gal/GalNAc ligands with lipophilic linkers—{(5-cholesten-3b-ol)[(2-acetamido-2-deoxy-d-galactopyranose-6-o)sebacate]} (CHS-6-GalNAc) and {(5-cholesten-3b-ol)[(d-galactopyranose-6-o)sebacate]} (CHS-6-Gal)—and two with hydrophilic linkers—{(5-cholesten-yl)[(4-O-b-D-galactopyranosyl)-D-glucitol-6-yl]sebacate} (CHS-1-Gal) and {(5-cholesten-3a-ol)[(2-acetamido-2-deoxy-d-galactopyranose-6-o)3,6-dioxa-octanedioate]} (CHS-PEG2-6-GalNAc)—were synthesized by enzymatic catalysis. Compared with unmodified liposomes, all Gal/GalNAc ligand–modified liposomes showed higher efficiency toward the hepatocyte target as evaluated by weighted-average overall drug-targeting efficiency (Te*) in vivo and HepG2 cell uptake efficiency in vitro. The ligands containing linkers with high HLB values (i.e., CHS-PEG2-6-GalNAc and CHS-1-Gal) exhibited higher ASGPR affinity than those containing linkers with low HLB values (i.e., CHS-6-GalNAc and CHS-6-Gal). We used molecular-dynamics (MD) simulations to investigate the structure–activity relationship between the HLB value of the linker in a ligand and ASGPR affinity. MD simulation results indicated that a Gal/GalNAc ligand with a more hydrophilic linker (i.e., higher HLB value) unit tended to have a higher solvent-accessible surface area (SASA), leading to lower steric hindrance for effective ASGPR recognition. The results of this study will provide an improved design for Gal/GalNAc ligand–based surface-modified liposomes with high ASGPR affinity.

Thermo-responsive nonionic amphiphilic copolymers as draw solutes in forward osmosis process for high-salinity water reclamation

Recently, thermo-responsive nonionic amphiphilic copolymers have shown a great potential as forward osmosis (FO) draw solutes for high-salinity water desalination and zero-liquid discharge (ZLD). However, the relationship between the copolymer structural properties and key characteristics as draw solutes, as well as copolymer's chemical stability after regeneration have not been much studied. In this work, we systematically investigated poly (ethylene oxide)-block-poly (propylene oxide)-block-poly (ethylene oxide) (PEO-PPO-PEO) copolymers as draw solute. The results showed that the PEO segments significantly influenced the viscosity, osmotic pressure and lowest phase separation temperature of the copolymer aqueous solutions. Among four commercial copolymers studied, Pluronic® L35 with moderate molecular weight (Mn 1,900 Da), 50% PEO, and relatively high hydrophilic-lipophilic balance (HLB) showed the best draw solution (DS) performance. It also showed great stability in physiochemical properties and draw capacity after more than ten cycles of regeneration. On the other hand, despite the fact that membrane fouling was observed due to the use of copolymer DS, the FO flux (∼1.2 L m‒2 h‒1, as similar with the virgin membrane) was not affected when high-salinity feedwater such as seawater RO brine was applied. Overall, our study has provided a more comprehensive understanding on the characteristics of nonionic amphiphilic copolymer DS and showcased the promise of copolymer-driven FO process in high-salinity water desalination and ZLD.

Evaluation of the Pharmaceutical Properties of Clobetasol Propionate Ointments and Base Stability of the Mixture with Heparinoid Oil Based Creams

Clobetasol propionate ointment (CLPO) formulations have been classified as members of the "strongest" steroidal efficacy group, with eight of these formulations currently marketed in Japan. Evaluations of pharmaceutical properties of each formulation revealed three classification types: droplet dispersion type containing propylene glycol (PG) and surfactant, type with surfactant but not PG, and other types. These rheological properties were diverse, with no correlation found between viscosity and ointment type. However, when CLPO and six types of heparinoid oil-based cream (HPOC) formulation mixtures were stored at 37℃, a liquid layer was observed starting at 24 h for one CLPO formulation in which polyoxyethylene hydrogenated castor oil 40 was used as a surfactant out of the four droplet-dispersion type ointments and two low-viscosity HPOC formulations. In contrast, one other type of CLPO formulation that contained a surfactant with polysorbate 80, but not PG, exhibited a liquid layer for all of HPOC formulations. This suggests that CLPO formulations that contain a surfactant with a high hydrophilic-lipophilic balance value are likely to generate a liquid layer for mixtures containing HPOC formulation. The present results demonstrate that not only the pharmaceutical properties of the eight CLPO formulations differ from one another, but also that the stabilities of HPOC formulation mixtures are significantly different. Therefore, pharmacists need to focus on inactive as well as active pharmaceutical ingredients to select formulations that patients will want to use, in addition to successfully treating their pathological conditions.

Effect of hydrophilic–lipophilic balance values of sucrose esters on cornstarch retrogradation

AbstractBackground and objectivesThe relationship between the different hydrophilic–lipophilic balance (HLB) values of sucrose esters and the retardant effect on the cornstarch retrogradation have not been investigated. The present research was aimed to evaluate the effects of the sucrose esters with different HLB values on the retrogradation properties by analyzing the changes in the crystalline structure and water mobility of cornstarch gels after storage.FindingsAll sucrose ester with HLB value (2–15), especially the HLB 15, could retard the long‐term retrogradation of cornstarch gels. After being stored for the same time, the retrograded cornstarch gels containing sucrose ester of HLB 15 had the lowest hardness, relative crystallinity, and R1047/1022. Compared with the additive‐free cornstarch, the hardness, relative crystallinity, and R1047/1022 of cornstarch with sucrose ester of HLB 15 were significantly decreased by 142 g, 8.66%, and 0.41, respectively, after being stored at 4°C for 7 days.ConclusionsSucrose ester with a high HLB value showed a strong retardant effect on the starch retrogradation.Significance and noveltyThese results suggested that sucrose ester with higher HLB value might be a more effective additive in retarding the retrogradation of cornstarch gels.

Application of a liquisolid technique to cannabis sativa extract compacts: Effect of liquid vehicles on the dissolution enhancement and stability of cannabinoids

This work describes the application of liquisolid technique to enhance cannabinoid dissolution from Cannabis sativa L. (CS) compacts. Effects of five vehicles, namely, volatile (ethanol) and nonvolatile (caprylocaproyl macrogolglycerides, polyethylene glycol 400, oleoyl macrogolglycerides and polysorbate 20) liquids, on tablet properties, dissolution and stability were investigated. The viscid oleoresin CS extract was mixed with vehicles before being transformed into free-flowing powder by the use of microcrystalline cellulose and colloidal silica as carrier and coating materials. Liquid vehicles had a nonsignificant effect on liquid load factor of CS extract. CS liquisolid compacts had acceptable tableting properties in terms of weight variation, friability, hardness, content uniformity and disintegration time. Different vehicles affected the hardness, disintegration, and wettability of CS compacts and thus the dissolution behaviors of cannabinoids to different extents. Dissolutions of cannabinoids from CS compacts were rate-limited by the disintegration process. Liquisolid formulations using nonvolatile liquids with low polarity or high hydrophilic-lipophilic balance yielded more than 90% cannabinoid dissolution. Stability studies revealed nonsignificant changes in tablet characteristics, cannabinoid content and dissolutions of CS compacts when stored at 5 ± 3 °C for 3 months. This work presents a general concept of how to successfully formulate CS extract with cannabinoid dissolution enhancement characteristics.

Quality by design enabled the development of stable and effective oil-in-water emulsions at compounding pharmacy: the case of a sunscreen formulation

It is widely accepted that the use of topical sunscreens has medical importance with potential to prevent skin damage by protecting from solar ultraviolet radiation (UVR) effects. Pharmaceutical emulsions require an optimal qualitative and quantitative combination of emollients, emulsifiers and others compounds such as softening agents and, for sunscreens, a combination of chemical and physical UV filters. Herein, we applied the quality by design (QbD) concept to achieve stable and effective compounded sunscreen emulsions. By using the statistical tool of design of experiments, it was possible to identify the influence of emulsifier type (with low and high Hydrophile-Lipophile Balance) and concentrations of emollient and softening agent on the achievement of formulations with suitable organoleptic and physicochemical features. Compounded emulsions with pleasant macroscopic aspects were obtained. Three formulations with physicochemical properties in targeted ranges were selected, namely pH ∼6.0, conductivity > 0.0 µS/cm2, spreadability factor ∼1–1.5 g/mm2, viscosity ∼12000 mPa.s and sunscreen protection factor ∼30. Freeze-thaw cycle and accelerated stability study under different storage conditions allowed selecting a stable emulsion that ensured photoprotection in biological assays. The QbD approach was essential to select the best, low-cost compounded sunscreen emulsion, with targeted physicochemical parameters.

Effect of HLB value on the properties of chitosan/zein/lemon essential oil film‐forming emulsion and composite film

SummaryThe properties of film‐forming emulsion with emulsifiers of different hydrophilic–lipophilic balance were evaluated, and the performance of chitosan/zein composite film containing lemon essential oil was examined. The retention ratio of lemon essential oil in the film and the release of lemon essential oil from film to food simulation system were also quantitatively analysed. Results showed that the emulsifier with higher hydrophilic–lipophilic balance would make lemon essential oil disperse evenly in the film‐forming emulsion, leading to smaller particle size and a lower viscosity of emulsion. Compared with C/Z/L, with the increasing hydrophilic–lipophilic balance value of emulsifier, the tensile strength and water contact angle of films decreased to 28.06 MPa and 23.39°, respectively. Emulsifier with high hydrophilic–lipophilic balance value could effectively increase the initial retention ratio of essential oils in the film, and the maximum initial retention rate of the C/Z/L‐15 film was 79.12%. The release of lemon essential oil in each treatment increased rapidly at first and then it slowed down. C/Z/L‐15 had the highest retention rate after 12 days, and C/Z/L‐11 had the best sustained release effect when lemon essential oil was released into the food simulant.

Poloxamer 188 (P188), A Potential Polymeric Protective Agent for Central Nervous System Disorders: A Systematic Review.

Poloxamer 188 (P188) is an FDA-approved biocompatible block copolymer composed of repeating units of Poly(Ethylene Oxide) (PEO) and poly(propylene oxide) (PPO). Due to its amphiphilic nature and high Hydrophile-Lipophile Balance (HLB) value of 29, P188 is used as a stabilizer/emulsifier in many cosmetics and pharmaceutical preparations. While the applications of P188 as an excipient are widely explored, the data on the pharmacological activity of P188 are scarce. Notably, the neuroprotective potential of P188 has gained a lot of interest. Therefore, this systematic review is aimed at summarizing evidence of neuroprotective potential of P188 in CNS disorders. The PRISMA model was used, and five databases (Google Scholar, Scopus, Wiley Online Library, ScienceDirect, and PubMed) were searched with relevant keywords. The search resulted in 11 articles, which met the inclusion criteria. These articles described the protective effects of P188 on traumatic brain injury or mechanical injury in cells, neurotoxicity, Parkinson's disease, Amyotrophic lateral sclerosis (ALS), and ischemia/ reperfusion injury from stroke. All the articles were original research in experimental or pre-clinical stages using animal models or in vitro systems. The reported activities demonstrated the potential of P188 as a neuroprotective agent in improving CNS conditions such as neurodegeneration.

Effects of different surfactant properties on anti-wetting behaviours of an omniphobic membrane in membrane distillation

Surfactant-induced membrane wetting remains a severe challenge for MD membranes, even for omniphobic membranes. The anti-wetting characteristic of the omniphobic membrane engendered by surfactant-contained feed solutions have not been systematically studied. In this work, a robust omniphobic membrane #PVDF-F with a super liquid-repellent property was developed. It involved constructing a fluorinated re-entrant structure on a dopamine-coated polyvinylidene fluoride (PVDF) nanofibrous membrane. Four different ionic surfactants, including sodium lauryl sulfonate (SLS), sodium dodecyl sulfonate (SDS), dodecyl trimethyl ammonium bromide (DTAB) and cetyl trimethyl ammonium bromide (CTAB) were added into the 3.5 wt% NaCl feed solutions to evaluate the anti-wetting performances of as-developed omniphobic, control nanofibrous and commercial PVDF membranes. Compared to SLS, the SDS with a higher hydrophilic-lipophilic balance (HLB) value tends to stay in the feed solution and reduces the surface tension of feed solution, thereby accelerating membrane wetting. Besides, when the experimental dosage (Ed) is above its theoretical critical micelle concentration (CMC) value, the excessive free surfactant molecules form micelles and instantly adsorb onto membrane pore walls, promoting both convection and diffusion toward the permeate side and accelerating membrane wetting. Nonetheless, the omniphobic membrane still exhibited the most stable MD performance when treating the surfactant-stabilized oil-in-water emulsion.

Influence of the Polymer Microstructure over the Phase Separation of Thermo-Responsive Nanoparticles.

Thermo-responsive nanoparticles (NPs), i.e., colloids with a sharp and often reversible phase separation in response to thermal stimuli, are coming to the forefront due to their dynamic behavior, useful in applications ranging from biomedicine to advanced separations and smart optics. What is guiding the macroscopic behavior of these systems above their critical temperature is mainly the microstructure of the polymer chains of which these NPs are comprised. Therefore, a comprehensive understanding of the influence of the polymer properties over the thermal response is highly required to reproducibly target a specific behavior. In this study, we synthesized thermo-responsive NPs with different size, polymeric microstructure and hydrophilic-lipophilic balance (HLB) and investigated the role of these properties over their phase separation. We first synthesized four different thermo-responsive oligomers via Reversible Addition-Fragmentation Chain Transfer (RAFT) Polymerization of poly(ethylene glycol)methyl ether methacrylate. Then, exploiting the RAFT living character, we chain-extended these oligomers with butyl methacrylate obtaining a library of NPs. Finally, we investigated the NP thermo-responsive behavior, their physical state above the cloud point (Tcp) as well as their reversibility once the stimulus is removed. We concluded that the solid content plays a minor role compared to the relative length of the two blocks forming the polymer chains. In particular, the longer the stabilizer, the more favored the formation of a gel. At the same time, the reversibility is mainly achieved at high HLB, independently from the absolute lengths of the block copolymers.

Curing Behavior of Waterborne Paint Containing Catalyst Encapsulated in Micelle

This research has studied the feasibility of fabricating a catalyst that activates at 80 °C to ensure the curing performance of two-pack isocyanate curable paints, while remaining inactive at 40 °C to ensure storage stability and pot life. The research examined whether the added dibutyl tin dilaurate (DBTL) provided a catalytic function for curing the waterborne paint, which remains almost inactive at 40 °C and activates at 80 °C or higher. It was confirmed that the use of a non-ionic surfactant with a hydrophilic-lipophilic-balance (HLB) of between 13 and 14 resulted in rapid curing at a temperature of 80 °C or higher, thereby demonstrating catalytic properties. The results also show that the viscosity of the paint remained virtually unchanged after exposure for 1 h at 40 °C. This wass presumed to be the result of the DBTL, which was constrained by the micelles up to a temperature of 70 °C, breaking down the micelles at a temperature of 80 °C or higher. It was also confirmed that the catalytic switching properties were not obtained at a lower or higher HLB. It was found that selecting the non-ionic surfactant by HLB can control the activating temperature of the catalytic properties.

Dopamine-functionalized poloxamers for antibacterial coating

Over the past decades, great progress has been made in antifouling materials such as zwitterionic polymers for many arenas, especially biomedical devices. However, many difficulties such as high cost and large-scale preparation of antifouling materials remain to be solved as of today. In this study, several dopamine-functionalized poloxamers (DPs) were synthesized. Staphylococcus aureus adhesion assay demonstrated that DPs possessed powerful antibacterial performance, due to long poly (ethylene oxide) (PEO) segments and high hydrophile-lipophile balance (HLB) values. Also, poloxamer 407 without incorporating dopamine possessed comparable antibacterial performance as compared with those dopamine-modified formulations. Poloxamers407 and poloxamer188 for pharmaceutical excipients approved by FDA, have a potential to serve as antifouling materials for biomedical devices.

Synthesis of highly stable κ/ι-hybrid carrageenan micro- and nanogels via a sonication-assisted microemulsion route

Novel carrageenan micro- and nanogels were developed via a sonication-assisted microemulsion processing route. The diameter of the dry samples ranged 197.3 −421.35 nm whereas the diameter of the samples suspended in water ranged 467.8–605.9 nm. Hybrid κ/ι-carrageenan, rather than κ- or ι-carrageenan was used for the first time for the preparation of micro- and nanogels. KCl was used as a cross-linking agent and Tween 80 was used as surfactant. The micro- and nanogels suspended in water were found to simultaneously exhibit a lower diameter, and a lower swelling ratio with higher Tween 80 content. The micro- and nanogel suspension yields a zeta potential value of −50.5 mV, superior to values reported elsewhere for pure κ- or ι-carrageenan micro- and nanogels. The high stability was attributed to the high hydrophile-lipophile balance (HLB = 15) value of Tween 80. These results suggest that hybrid κ/ι-carrageenan micro- and nanogels are promising candidates for smart therapeutics applications.

Heavy-oil recovery improvement by additives to steam injection: Identifying underlying mechanisms and chemical selection through visual experiments

To mimic the gravity assisted drainage and flooding type, steam displacement tests we performed previously (Bruns and Babadagli, 2017) on cores saturated with 27,000 cP heavy-crude-oil; a visual Hele-Shaw model was designed to simulate the same process and identify the physical characteristics of the steam-condensate-oil interface and the role played by added chemicals. The majority of the chemicals/chemical blends showed either improvement in the rate or ultimate recoveries in the coreflooding tests and, based on this data, the best performing and the most thermally stable chemicals were selected for the visual tests. These chemicals include ionic liquids, anionic surfactant (linear toluene sulfonate), non-ionic surfactants, biodiesel (thermally stable surface active agents), solvents (heptane), and nano-fluids (silicon oxide). The chemical solution was injected at a constant rate and pressure after being vaporized in an oven along with steam; the whole process was recorded with a camera.The contribution to recovery improvement through these phenomena in flooding and gravity controlled cases were identified. Foaming, emulsification, and IFT reduction yielding reduced drag forces between two phases at the interface and were observed to be the main reason for positive contribution of chemicals. Biodiesel exhibited a diffusion-like behavior near the injection port where no residual oil was noticed. The solvent (heptane), simulating ES-SAGD, stabilized the flow of steam in the late stage of the experiment due to the viscosity reduction. Improved oil + condensate drainage was assumed to be the contributing mechanism because of the change in surface properties during the injection of the ionic liquid. Nanoparticle, silicon oxide, and the linear toluene sulfonate (LTS) showed similar improvements in tip-splitting of the displacing fingers. It was concluded that the interfacial tension (IFT) reduction resulted in a wider occupation of the Hele-Shaw cell (better lateral sweep). Non-ionic surfactants showed different emulsion capabilities and high efficiency in steam/condensate displacement with a higher HLB (hydrophile - lipophile balance) value.

Modification of lecithin-based emulsions with phospholipases

ABSTRACT Phospholipases have been used in different food processes, but mainly on degumming vegetable oils. More recently, the use of these enzymes has been extended to the manufacture of bread and dairy products. However, little is known on phospholipases effect on lecithin-based emulsions and how the emulsion size contributes to such effect. This work aimed to explore the effect of phospholipase type A1 (PLA1) on lecithin-based emulsions with different droplet size distribution. The PLA1 was able to hydrolyze lecithin phospholipids aggregated in (oil-in-water) emulsions, generating different lysophospholipids. The larger the particle size in the emulsion, the higher the enzymatic activity of PLA1. According to theoretical calculations, the lysophospholipids had higher hydrophile-lipophile balance (HLB) and had a lower critical packing parameter (p) than phospholipids. In consequence, the emulsions having more lysophospholipids were more prone to flocculate and to coalescence.