Surfactant Type Research Articles

Surfactant Effects in Porous Electrodes for Microemulsion Redox Flow Batteries

The effect of surfactant additives on electrochemical behavior in porous electrodes was investigated using vanadium redox flow battery half-cells and the dependence of volumetric kinetics and mass transport on electrolyte, surfactant, and electrode type was explored. Without surfactant added, carbon paper electrodes demonstrated greater kinetics and transport compared to carbon felt, for a given electrolyte. Additionally, posolyte kinetics are greater than negolyte kinetics by one to three orders of magnitude, depending on the electrode type. Addition of surfactant increased electrode wettability and possibly electrochemical surface area. However, this was accompanied by a decrease in volumetric mass transport, due to stronger electrolyte-electrode interactions. The presence of sodium dodecyl sulfate (SDS) influenced posolyte and negolyte kinetics differently. Kinetics showed a dependence on electrode type and surfactant. On carbon felt, volumetric kinetics decreased for both posolyte and negolyte with SDS addition. On carbon paper, SDS decreased volumetric kinetics for the posolyte but increased (>2X) kinetics for the negolyte! This kinetic enhancement depends on surfactant chemistry: cetyltrimethylammonium bromide, a cationic surfactant, failed to increase kinetics. Furthermore, SDS did not increase areal specific resistance. These findings show the superior performance of carbon paper compared to carbon felt and suggest SDS as a possible VRFB negolyte additive.

Explore the Impact of Surfactant Type on the Stability and Separation Efficiency of Oil–Water Emulsions of Real Wastewater from Al-Basrah Crude Oil Using Microbubble Air Flotation

Explore the Impact of Surfactant Type on the Stability and Separation Efficiency of Oil–Water Emulsions of Real Wastewater from Al-Basrah Crude Oil Using Microbubble Air Flotation

나노 크기의 금속 유기 골격체, ZIF-8 합성을 위한 이온성 액체 마이크로에멀젼 합성법의 체계적 연구

Porous Metal-Organic Frameworks (MOFs) are composed of metal ions and organic ligands. Recently, nano-sized MOFs have been widely utilized in biomedical fields, including biosensing and drug delivery. Researchers are primarily focusing on reducing their particle sizes to the nanoscale with a uniform size distribution. An ionic liquid microemulsion, the one of the MOF synthesis mehtods is in the limelight as an effective way with the following advantages: grain size uniformity and eco-friendliness. In this work, systematic study to control grain size, morphology, and yield of ZIF-8 (Zeolitic Imidazolate Framework-8) through ionic liquid microemulsion method was conducted in the new systems ‘water / surfactant (TX-100 or AOT) / CnmimX (n, the number of carbon = 2, 3, 4, 6, 8, 10 / X = Cl, Br, I)’. Furthermore, not only how the type of anion of ionic liquids, the length of carbon chain in them, the type of surfactants and the mass ratio change of the components affect the ZIF-8 synthesis results, respectively, was analyzed quantitatively through several characterization methods such as PXRD, TEM, DLS and FT-IR. Through this study, we aim to shed light on the infinite possibility of ionic liquid microemulsion method to synthesize desired size of nano-size MOF with uniformity.

Formulation, development, and characterization of loratadine emulgel

Background: This study was to develop loratadine (LTD) emulgels to treat localized skin allergy. Method: Initially oil-in-water emulsion was prepared by 3 different types of surfactants & finally gelling agent carbopol 940 was incorporated into emulsion to produce emulgel (i.e., standard conventional method). Results: The developed formulations were characterized using various parameters including particle size (PS), zeta potential (ZP), polydispersity index (PDI), entrapment efficacy (EE), pH, extrusion efficacy, physical stability, in-vitro drug release studies, and scanning electron microscopy (SEM). PS, EE, PDI, ZP and In-vitro studies ranges between 186.25 ± 6.42 mm (LE-F4) to 395.24 ± 8.64 mm (LE-F1), 62.38 ± 0.36 % (LE-F2) to 76.48 ± 0.69 % (LE-F4), 0.276 ± 0.02 (LE-F4) to 0.652 ± 0.02 (LE-F1), 16.45 ± 2.13 mV (LE-F1) to 29.46 ± 2.78 mV (LE-F3) and 21.90 ± 0.3 % (LE-F1) to 68.30±0.9 % (LE-F4) respectively. Conclusion: Based on all physicochemical properties, LE-F4 formulation was considered to be optimized with minimum PS (186.25±6.42 nm), PDI (0.276±0.02), satisfactory positive surface charge (23.15 ± 1.89 mV) and maximum EE (76.48±0.69 %). FTIR studies were confirmed that there is no physical interaction between drug and excipients and SEM studies revealed that vesicle size was spherical with smooth texture. A significantly greater rate of drug release (i.e., 68.30 ± 0.90%) was seen in the LTD emulgels that were made with cationic surfactant (i.e., LE-F4) and found to be good spreadability and extrudability.

Exploring the impact of surfactant types and formulation variables on the EACN of crude and model oils

Characterizing the hydrophobicity of oils remains a significant challenge for the academic and industrial scientific communities, striving to optimize the formulation of Surfactant/Oil/Water (SOW) systems. Various descriptors, including the required Hydrophilic-Lipophilic Balance (required HLB) and the Equivalent Alkane Carbon Number (EACN), have been proposed to characterize oil hydrophobicity. Indeed, it is already known that the EACN of crude oils can be rapidly determined through dynamic Phase Inversion Temperature-induced (PIT) experiments. The study herein presents an alternative method to characterize the EACN of crude and model oils through dynamic Salinity-induced Phase Inversion (SPI) using two reference SOW systems, one with the ionic extended surfactant propyl heptyl propoxylated sodium sulfate (i-C3C7PO4SO4Na) and the other with the nonionic surfactant decyl tetraethylene glycol ether (C10EO4). Results reveal that the EACN of crude and model oils strongly depend not only on the chosen formulation variable but also on the nature of the surfactant. Discrepancies in EACN values for crude oils range between −0.2 and 3.3 units. These differences are justified by several factors: the segregation of the polar fraction for crude oils and its dependence with temperature, the high solubility of the nonionic surfactant in polar oils and the differing structures of both surfactants at the interface that changes the effective packing parameter of the system. When inversing a crude oil at high salinity conditions using temperature as formulation variable, a weighted average EACN value obtained with salinity from the two surfactants yields more realistic results than the EACN obtained from PIT. These findings found a direct application in the enhanced oil recovery field in which the attainment of ultra-low interfacial tension is essential to have an efficient crude oil desaturation.

Comparison of porcine versus bovine surfactant in preterm respiratory distress syndrome: Evidence from real-world data. A multicentre collaboration from Karnataka.

Porcine surfactant (200 mg/kg initial dose) seems to be superior to bovine surfactants (100 mg/kg) in respiratory distress syndrome (RDS). There is limited data on the choice of surfactant from the developing world. Logically, using higher doses of porcine surfactant comes with an additional cost burden. We decided to evaluate the clinical effects of different types of surfactants. A retrospective analysis was conducted from August 2019 to December 2022 in six tertiary centers. Neonates 24-34 weeks of gestation with RDS requiring either porcine (200 mg/kg) or bovine surfactant (100 mg/kg) were enrolled. The proportion of BPD, redosing, and other morbidities in either group were analyzed. The outcomes in preterm ≥28and <28 weeks subgroups were analyzed. Of 1149 eligible babies, 302 (26%) received surfactant after stabilization with CPAP. One hundred fifty-eight received porcine, and 144 received bovine surfactant. There was a higher BPD in porcine compared to the bovine group on univariate analysis [24 (15%) vs. 6 (4%); OR: 4; 95% CI: 1.6-10; p = 0.002]. On logistic regression, the gestational age and PDA requiring treatment were independent predictors of BPD, and the type of surfactant and centres did not influence BPD. Redosing [27 (17%) vs. 18 (12%), OR: 1.4; 95% CI: 0.7-2.7; p = 0.2] was not different between both surfactant types. Other morbidities like mortality, air leaks, invasive ventilation, and CPAP duration were also not different between the groups. We could not find a difference in the outcomes of BPD and redosing using porcine surfactant at 200 mg/kg compared to bovine surfactant. Considering the cost burden in the developing world, efficacy needs to be evaluated in randomized clinical trials.

Development and field application of strongly resilient temporary plugging diversion agent for fracturing

Temporary plugging diversion fracturing in multistage horizontal well is normally used to improve stimulation efficiency and increase production in unconventional reservoirs. Temporary plugging agent plays an important role in diversion fracturing. A strongly resilient temporary plugging diversion agent can improve the effectiveness of fracturing diversion. Therefore, a novel organosilicon temporary plugging diversion agent (QBZU) was developed through micellar copolymerization method. Self-synthesized strongly resilient temporary plugging diversion agent (QBZU gel) was prepared by using acrylamide, N, N′-methylene bisacrylamide, surfactants, organosilicon, ammonium persulfate and sodium bisulfite as chemical raw materials. The micellar copolymerization is investigated to overcome the incompatibility of hydrophobic organosilicon and water-soluble monomer by adding some appropriate surfactants. The experimental results indicated that the combination of sodium dodecyl sulphonate and Tween 80 provided excellent copolymerization results. The characteristics of compressive resistance, salt resistance, shearing resistance, resilience and degradation are superior compared with traditional rigid granular temporary plugging agent widely used in oilfields (QG hydrogel). According to the experimental evaluation results of QBZU, its pressure-bearing capacity can reach 56.3MPa, shearing strength can reach 410N, elastic modulus can reach 80MPa, and Poisson ratio can reach 0.48. Meanwhile, the main synthetic factors affecting the resilient performance of QBZU were investigated, including polymer concentration, organosilicon concentration and the types of surfactant. Based on the fracturing pressure curve and microseismic monitoring results, the plugging and fracture diversion effectiveness was further confirmed.

Prediction of Foam Rheology Models Parameters Utilizing Machine Learning Tools.

Rheological models are usually used to predict foamed fluid viscosity; however, obtaining the model constants under various conditions is challenging. Hence, this paper investigated the effect of different variables on foam rheology, such as shear rate, temperature, pressure, surfactant types, gas phase, and salinity, using a high-pressure high-temperature foam rheometer. Power-law, Bingham plastic, and Casson fluid models fit the experimental data well. Therefore, the data were fed to different machine learning techniques to evaluate the rheological model constants with different features. In this study, seven different machine learning techniques have been applied to predict the rheological models' constants, including decision tree, random forest, XGBoost (XGB), adaptive gradient boosting, gradient boosting, support vector regression, and voting regression. We evaluated the performance of our machine learning models using the coefficient of determination (R2), cross-plots, root-mean-square error, and average absolute percentage error. Based on the prediction outcomes, the XGB model outperformed the other ML models. The XGB model exhibited remarkably low error rates, achieving a prediction accuracy of 95% under ideal conditions. Furthermore, our prediction results demonstrated that the Casson model accurately captured the rheological behavior of the foam. Additionally, we used Pearson's correlation coefficients to assess the significance of various properties in relation to the constants within the rheological models. It is evident that the XGB model makes predictions with nearly all features contributing significantly, while other machine learning techniques rely more heavily on specific features over others. The proposed methodology can minimize the experimental cost of measuring rheological parameters and serves as a quick assessment tool.

Chemical vapor deposition of silicon carbide on alumina ultrafiltration membranes for filtration of microemulsions

Worldwide, a considerable amount of oily wastewater is generated, with oil droplets from 2 to 200 nm that are difficult to separate because of their size and colloidal stability. This study presents a novel approach for effectively separating microemulsions via cubic silicon carbide (3C-SiC)-coated alumina (Al2O3) membranes fabricated based on low pressure chemical vapor deposition (LPCVD). SiC was deposited at a relatively low temperature at 860 °C on 100 nm Al2O3 membranes using two precursors: SiH2Cl2 and C2H2. With the increase in deposition time, up to 25 min, the pore size decreased from 41 nm to 33 nm, which is a smaller pore size of a SiC membrane than previously used for oil/water separation. The polycrystalline 3C-SiC-coated membranes showed improved hydrophilicity (water contact angle of 15°) and highly negatively charged surfaces (−65 mV). Microemulsion filtration experiments were carried out at a constant permeate flux (80 Lm−2 h−1) for six cycles with varying deposition time, pH, surfactant types, and pore sizes. The fouling of the SiC-coated membrane was, compared to the Al2O3 membrane, effectively mitigated due to the enhanced electrostatic repulsion and hydrophilicity. Surfactant adsorption mainly occurred when the surface charge of the microemulsion and the membranes were opposite. Therefore, the surface charge of the alumina membrane changed from positive to negative when soaked in negatively charged microemulsions, whereas SiC-coated membranes remained negatively charged regardless of surfactant type. The membrane fouling was alleviated when the membrane and oil droplets had the same charge. Lastly, the 62 nm SiC-coated membrane with 20 min coating time was the best choice for the filtration of the microemulsion, because of the high rejection of the oil droplets and low fouling tendency.

Demulsification of surfactant-rich emulsion systems by using amphiphilic or positively charged magnetic nanoparticles

Emulsified oily wastewater comes from many fields, such as oil exploitation, processing, storage and transport, mechanical processing and food and catering industries, causing serious environmental pollution. Considerable part of emulsified oily wastewater was extremely stable and difficult to be treated due to the existence of high-concentration surfactants. Magnetic demulsification of oil-in-water (O/W) emulsion by using magnetic nanoparticles (MNPs) attracted more and more attentions because of its flexible and efficient process; however, the study regarding the treatment of emulsified oily wastewater containing high-concentration surfactant was still few. In this study, amphiphilic dimethyloctadecyl [3-(trimethoxysilyl) propyl] ammonium chloride (DOTAC)-coated MNPs (M-DOTAC) and hydrophilic but highly positively charged quaternized chitosan (QC)-coated MNPs (M-QC) were employed to treat the O/W emulsions containing various contents of anionic and nonionic surfactants. Influence of surfactant type and concentration on the demulsification performance of the two MNPs was investigated in detail. Results showed that M-DOTAC could more effectively demulsify the nonionic surfactant-stabilized emulsion mainly via hydrophobic interaction, while M-QC could more efficiently demulsify the anionic surfactant-stabilized emulsion mainly via electrostatic interaction. With increasing surfactant concentration, the MNPs were still able to completely demulsify the emulsion at a relatively higher dosage. Moreover, when the two classes of MNPs were used together, highly stable emulsion system with containing both anionic and nonionic surfactants could be completely demulsified. These results suggested the synthesized two MNPs could provide simple but powerful approach to treat different emulsified oily wastewaters with containing high-concentration surfactants.

Research Progress of eco-friendly Sugar-based Surfactants

Surfactant is a common industrial product widely used in chemical industry, food production, biomedicine and other fields. A variety of glucose-based bisubstituted surfactants have been developed, which not only contain the advantages of other classes of sugar-based surfactants, but also have the properties of mild conditions of use, good bactericidal ability, and non-irritation of the skin, etc. In addition, sugars are widely sourced and renewable, and the production of sugar-based surfactants with degradability has become a hot spot of the current research. This paper summarises the types of common sugar-based surfactants, the test methods of related properties and the application prospects.

Development, optimization, in-vitro, and in-vivo evaluation of chitosan-inlayed nano-spanlastics encompassing lercanidipine HCl for enhancement of bioavailability

Low bioavailability is a major challenge in the development of new pharmacological formulations for oral administration. The vasoselective calcium channel blocker lercanidipine HCl (LER) has a bioavailability of only 10 % owing to its first-pass metabolism and poor solubility. To address the bioavailability issue, the intranasal route was frequently adopted for medications. Therefore, this research's objective was to develop an intranasal chitosan coated nanospanlastics-loaded with LER to improve its bioavailability and diffusion. LER spanlastic nanovesicles (LER-SNVs) were developed and optimized using a factorial design employing the thin-film hydration technique. The researchers studied the influence of the type of Span surfactant, type of edge activator (EA), and ratio of Span to EA on encapsulation efficiency (EE%); the particle size of the spanlastic; the percentage of drug release; and the cumulative LER diffused per unit area after 24 h, or Q24 (g/cm2). Following optimal formulation development, chitosan was utilized to modify its surface. Subsequently, the pharmacokinetics and biocompatibility of optimal chitosan-coated preparation were ascertained in rats. The results of the SNV analysis showed that their mean size was below 400 nm and that the EE% reached 94 %. In contrast to the LER dispersion, the designed LER-SNVs boosted drug transmucosal permeation. The pharmacokinetic studies showed a fourfold (p < 0.05) increase in the relative bioavailability of LER after the nasal delivery of LER-loaded surface-modified SNVs compared with an oral LER dispersion. Optimal CS-coated formulation was found biocompatible with studied animals. In conclusion, the use of SNVs for the nasal delivery of LER has shown promise, and the results could lead to better management of hypertension.

Assessment of spilled oil dispersion affected by dispersant: Characteristic, stability, and related mechanism

Oil dispersion, a crucial process in oil transport, involves the detachment of oil droplets from slicks and their introduction into the water column, influencing subsequent oil migration and transformation. This study examines oil dispersion, considering characteristics, stability, and mechanisms, while evaluating the impact of dispersants and salinity. Results show the significant role of surfactant type in dispersants on oil dispersion characteristics, with anionic surfactants exhibiting higher sensitivity to salinity changes compared to nonionic surfactants. The dispersion efficiency varies with salinity, with anionic surfactants performing better in low salinity (<20‰) and nonionic surfactants showing superior performance at 30–35‰ salinities. Rheological analysis illustrates the breakup and coalescence of oil droplets within the shear rates of breaking waves. An increase in interfacial film rigidity impedes the coalescence of oil droplets, contributing to the dynamic stability of the oil-water hybrid system. The use of GM-2, a nonionic dispersant, results in the formation of a solid-like interface, characterized by increased elastic modulus, notably at 20‰ salinity. However, stable droplet size distribution (DSD) at 35‰ salinity for 60 h suggests droplets can remain dispersed in seawater. The enhancement of stability of oil dispersion is interpreted as the result of two mechanisms: stabilizing DSD and developing the strength of viscoelastic interfacial film. These findings offer insights into oil dispersion dynamics, highlighting the importance of surfactant selection and salinity in governing dispersion behavior, and elucidating mechanisms underlying dispersion stability.

Investigation on foam properties of Gemini quaternary ammonium salt containing hydroxyl hydrophilic headgroup

Four Gemini quaternary ammonium salts, tetramethylene-1,4- bis [N, N-bis(hydroxypropyl)-hexa/decyloxypropylammonium] bromide (GC6/10-P) and tetramethylene-1,4-bis [N, N-bis(hydroxyethyl)-hexa/decyloxypropylammonium] bromide (GC6/10-E) were synthesized by two-step reactions. This study analyzes the foam properties, including foamability, foam stability, and foam size distribution, of GC6/10-P and GC6/10-E using the Foamscan method. The influence of surfactant concentration and gas flow rate on the properties of Gemini quaternary ammonium salt foam was also studied. Additionally, the relationship between surfactant structure and foam morphology in aqueous solutions was discussed. The results show that all four types of Gemini quaternary ammonium salt surfactants are low-foaming surfactants. The foam capacity (FC) sequence is as follows: GC10-E > GC10-P > GC6-E > GC6-P. The foamability and foam stability are enhanced with increasing surfactant concentration, which increases the adsorbed quantity of surfactant molecules at the air-water interface. The foam produced by GC6-P/E systems is the most unstable; the foam behaviors show faster Ostwald ripening and drainage process in aqueous system. It seems that 150–200 mL/min is an ideal air intake speed. The presence of hydroxyl in the molecular structure enhances the formation of hydrogen bonding between surfactants and water molecules, leading to greater molecular compactness. The results indicate that the foaming behavior of hydroxyl Gemini quaternary ammonium salts can be correlated with concentration and alkyl chains. Foamscan are proposed to research the foaming and foam stability behavior and provide a useful guide for evaluating the foamability of cationic surfactants-based systems, especially in the development of environmentally friendly foam systems suitable for low-foaming products.

Surfactant-Enhanced Assisted Spontaneous Imbibition for Enhancing Oil Recovery in Tight Oil Reservoirs: Experimental Investigation of Surfactant Types, Concentrations, and Temperature Impact

Surfactant-assisted spontaneous imbibition is an important mechanism in enhanced oil recovery by capillary pressure in low permeability and tight oil reservoirs. Though many experiments have been conducted to study the mechanism of enhanced oil recovery by surfactant-assisted spontaneous imbibition, the effects of surfactant type, concentration, and temperature have not been well studied. Using tight sandstone outcrop core samples with similar permeability and porosity, this paper experimentally studies surfactant-assisted spontaneous imbibition using three different surfactant types, i.e., sodium dodecylbenzene sulfonate (SDBS), cocamidopropyl betaine (CAB), and C12–14 fatty alcohol glycoside (APG). In addition to the type of surfactant, the effect of the surfactant concentration and the temperature is also investigated. The study results show that the ultimate oil recovery of spontaneous imbibition with formation water and denoised water is about 10%. Surfactant can significantly improve the oil recovery of spontaneous imbibition by reducing the interfacial tension between oil and water, emulsifying crude oil and improving oil mobility. APG showed better performance compared to SDBS and CAB, with a maximum oil recovery factor of 36.19% achieved with formation water containing 0.05% APG surfactant. Lower concentrations (0.05% APG) in the formation water resulted in a higher oil recovery factor compared to 0.1% APG. Increasing temperature also improves oil recovery by reducing oil viscosity. This empirical study contributes to a better understanding of the mechanism of surfactant-assisted spontaneous imbibition and enhanced oil recovery in tight oil reservoirs.

Molecular Dynamics Simulations of the Short-Chain Fluorocarbon Surfactant PFHXA and the Anionic Surfactant SDS at the Air/Water Interface.

The research and development of alternatives to long-chain fluorocarbon surfactants are desperately needed because they are extremely toxic, difficult to break down, seriously harm the environment, and limit the use of conventional aqueous film-forming foam fire extinguishing agents. In this study, mixed surfactant systems containing the short-chain fluorocarbon surfactant perfluorohexanoic acid (PFHXA) and the hydrocarbon surfactant sodium dodecyl sulfate (SDS) were investigated by molecular dynamics simulation to investigate the microscopic properties at the air/water interface at different molar ratios. Some representative parameters, such as surface tension, degree of order, density distribution, radial distribution function, number of hydrogen bonds, and solvent-accessible surface area, were calculated. Molecular dynamics simulations show that compared with a single type of surfactant, mixtures of surfactants provide superior performance in improving the interfacial properties of the gas-liquid interface. A dense monolayer film is formed by the strong synergistic impact of the two surfactants. Compared to the pure SDS system, the addition of PFHXA caused SDS to be more vertically oriented at the air/water interface with a reduced tilt angle, and a more ordered structure of the mixed surfactants was observed. Hydrogen bonding between SDS headgroups and water molecules is enhanced with the increasing PFHXA. The surface activity is arranged in the following order: PFHXA/SDS = 1:1 > PFHXA/SDS = 3:1 > PFHXA/SDS = 1:3. These results indicate that a degree of synergistic relationship exists between PFHXA and SDS at the air/water interface.

Experimental study of adsorption/desorption and enhanced recovery of shale oil and gas by zwitterionic surfactants

Shale reservoirs have the characteristics of low permeability and low porosity. In order to enhance the recovery of shale oil and gas, surfactant flooding is a mature reservoir oil recovery method. However, the adsorption of different surfactants on the reservoir rock surface is restricted, depending on the type of surfactant. Therefore, a zwitterionic surfactant (OPHS) was synthesized from oleic acid, 3-dimethylaminopropylamine and sodium 3-chloro-2hydroxypropanesulfonate, and characterized by FTIR, 1H NMR, and TGA, and the mechanism of the OPHS for enhancing oil and gas recovery on shale surfaces was investigated. The results showed that the critical micelle concentration (CMC) of OPHS surfactant solution is 7.9 × 10-4 mol/L and the γCMC is 27.5 mN/m; the concentration of 0.1 % OPHS surfactant solution could reduce the contact angle of the cores from 127.2° to 38.8°, which resulted in spontaneous imbibition; The absolute Zeta potential of shale particles in the OPHS surfactant solution was measured at 39 mV, whereas in deionized water at 15.3 mV. This difference can be attributed to the formation of a stable hydration film on the surface of shale particles induced by the wetting reversal effect. Spontaneous imbibition experiments showed that a 0.1 % solution of OPHS surfactant was able to increase the recovery rate by more than four times compared to the imbibition solution without added surfactant; In high-pressure gas adsorption/desorption experiments, the OPHS surfactant solution demonstrated a higher affinity for adsorption onto the shale surface. It effectively occupied adsorption sites, ultimately facilitating methane gas desorption from the shale. In summary, OPHS zwitterionic surfactants exhibit the capability to desorb hydrocarbons from shale pores through mechanisms such as wetting reversal and competitive adsorption. This research holds significant potential for advancing the field of shale oil and gas recovery, providing valuable insights for enhancing recovery processes.

Novel resveratrol smart lipids; design, formulation, and biological evaluation of anticancer activity.

Although resveratrol (RES) is an efficacious molecule, its therapeutic activity is impeded by significant limitations, such as rapid oral absorption, poor oral bioavailability, and low water solubility. Therefore, the preparation of RES in different pharmaceutical carriers represents an important tool to enhance its therapeutic applications. This study aims to potentiate the anti-cancer activity of RES by formulating it into a novel nanocarrier called Smart Lipid. RES-loaded Smart Lipids were prepared by high-shear hot homogenization method utilizing a 21 × 32 factorial design with three factors at different levels: the total lipid concentration, the concentration of surfactant, and the type of surfactant. The responses were evaluated based on entrapment efficiency percentages and particle size. Our novel optimized RES-loaded Smart Lipid formula showed small particle size (288.63 ± 5.55 nm), good zeta potential (-16.44 ± 0.99 mV), and an entrapment efficiency of 86.346 ± 3.61% with spherical, clearly distinct, and no signs of fusion by transmission electron microscopy. Further characterization was done using differential scanning calorimetry, which showed no interaction between the drug and other components as the optimum lyophilized formula showed a peak at 54.75°C, which represents the lipid mixture, with an undetectable characteristic peak of the drug, which indicates entrapment of the drug, and the structure of the compounds was confirmed by Fourier transform-infrared spectroscopy, in which the majority of the drug's characteristic peaks disappeared when loaded into Smart Lipid, which may indicate Smart Lipid's ability to reduce the stretching and bending between bonds in RES. In addition, the optimized formula showed a sustained release pattern compared to RES suspension. Finally, the cytotoxic activity of the optimized RES-loaded Smart Lipid on different cell lines (human breast adenocarcinoma (MCF7), human hepatocellular carcinoma (HepG2), and human colon cancer cells (HT29)) was assessed through MTT assay (7-fold reduction in the IC50, from 3.7 ± 0.5 μM for free RES to 0.5 ± 0.033 μM for Smart Lipid loaded formula against MCF7, 3-fold reduction in the IC50 against HepG2 cells, from 10.01 ± 0.35 to 3.16 ± 0.21 μMm, and a more than 10-fold reduction in the IC50 from more than 100 to 10 ± 0.57 μM against HT-29 cells) and its effect on cell cycle progression and apoptosis induction were assessed using flow cytometry and annexin V kit, respectively. Our results showed that RES-loaded Smart Lipid significantly reduced cell viability, induced cell cycle arrest at G0/G1 phase, and apoptosis compared to free formula and free RES suspension. Loading RES into this novel kind of nanocarrier enhanced RES absorption, cellular accumulation, and improved its anticancer properties.

Structural Analysis of Aggregates Formed by Linear- and Star-type Quaternary Ammonium Salt-Based Trimeric Surfactants Using Rheology and Small-Angle X-ray Scattering.

We performed a structural analysis of aggregates formed by two types of trimeric surfactants based on quaternary ammonium salts─linear-type 3Cnlin-s-Q and star-type 3Cntris-s-Q─featuring varying alkyl chain lengths (n) and spacer chain lengths (s) in aqueous solutions. We performed rheology, dynamic light scattering, and small-angle X-ray scattering measurements on the trimeric surfactants and investigated the effects of the alkyl chain length, spacer chain length, spacer skeleton structure, and surfactant concentration on their aggregation behavior. Linear-type 3C12lin-3-Q transitioned from gel solutions to worm-like micelles at high concentrations, and 3C14lin-3-Q became gel solutions over a wide range of concentrations. In contrast, all other studied surfactants formed ellipsoidal micelles. The minor and major axes of the ellipsoidal micelles formed by liner-type 3Cnlin-3-Q increased with the increasing alkyl chain length. As the spacer chain length of 3Cnlin-s-Q increased from 3 to 6, and as the spacer skeleton expanded from linear-type 3Cnlin-s-Q to star-type 3Cntris-s-Q, the surfactants formed ellipsoidal micelles without the formation of aggregates with a high-order structure, demonstrating this behavior over a broad concentration range.

Experimental and theoretical investigation on the mechanism of cationic surfactants-assisted phosphogypsum crystal transformation

The massive discharge and stockpiling of phosphogypsum became an increasingly severe issue on environment. The transformation of phosphogypsum into fibrous alpha-type hemihydrate gypsum (α-HH) with high L/D(ratio of length-to-diameter) is one of the effective routes to achieve the high-valued utilization. In this work, six types of cationic surfactants, including CTAB, STAC, CHEC, CGG, CPAM and PDDA were selected to investigate their different effects on shape of α-HH crystals through hydrothermal method under the condition of 160 °C(0.6 MPa saturated vapour pressure) for 3 h. The results showed that the introduction of all selected surfactants can increase the length-to-diameter (L/D) ratio of α-HH crystals. As the concentration of surfactants increases, the L/D ratio first increases and then decreases, and the highest L/D ratio of 171.3 was obtained by using CTAB at 0.6 %. The mechanism of regulated growth of α-HH crystals into fibrous structure following c-axis in the presence of six cationic surfactants was also demonstrated. Moreover, the adsorption mechanism of cationic surfactants on the α-HH surface was investigated by molecular dynamics simulation and theoretical analysis. It is found that the order of binding energy (Eb) between the addition and α-HH crystal faces is Eb(11¯0) > Eb(110) > Eb(200) > Eb(002). This work provides insightful guidance from both experimental and theoretical perspectives for controlling the crystal form of α-HH and preparing high-strength gypsum.