Effect Of Surfactant Concentration Research Articles

Formulation and Optimization of Solid Lipid Nanoparticle-based Gel for Dermal Delivery of Linezolid Using Taguchi Design.

Linezolid (LNZ) is a synthetic oxazolidinone antibiotic approved for the treatment of uncomplicated and complicated skin and soft tissue infections caused by gram-positive bacteria. Typically, LNZ is administered orally or intravenously in most cases. However, prolonged therapy is associated with various side effects and life threatening complications. Cutaneous application of LNZ will assist in reducing the dose, hence minimizing the unwanted side/adverse effects associated with oral administration. Dermal delivery provides an alternative route of administration, facilitating a local and sustained concentration of the antimicrobial at the site of infection. The current research work aimed to formulate solid lipid nanoparticles (SLNs) based gel for dermal delivery of LNZ in the management of uncomplicated skin and soft tissue infections to maximise its benefits and minimise the side effects. SLNs were prepared by high-shear homogenisation and ultrasound method using Dynasan 114 as solid lipid and Pluronic F-68 as surfactant. The effect of surfactant concentration, drug-to-lipid ratio, and sonication time was investigated on particle size, zeta potential, and entrapment efficiency using the Taguchi design. The main effect plot of means and signal-to-noise ratio were generated to determine the optimized formulation. The optimized batch was formulated into a gel, and ex-vivo permeation study, in-vitro and in-vivo antibacterial activity were conducted. The optimised process parameters to achieve results were 2% surfactant concentration, a drug-to-lipid ratio of 1:2, and 360 s of sonication time. The optimized batch was 206.3± 0.17nm in size with a surface charge of -24.4± 4.67mV and entrapment efficiency of 80.90 ± 0.45%. SLN-based gel demonstrated anomalous transport with an 85.43% in vitro drug release. The gel showed a 5 cm zone of inhibition while evaluated for in vitro antibacterial activity against Staphylococcus aureus. Ex-vivo skin permeation studies demonstrated 20.308% drug permeation and 54.96% cutaneous deposition. In-vivo results showed a significant reduction in colony-forming units in the group treated with LNZ SLN-based gel. Ex-vivo studies ascertain the presence of the drug at the desired site and improve therapy. In-vivo results demonstrated the ability of SLN-based gel to significantly reduce the number of bacteria in the stripped infection model. The utilization of SLN as an LNZ carrier holds significant promise in dermal delivery.

Stability analysis of CO2 microbubble for CO2 sequestration and mobility control in enhanced oil recovery

This study addresses the challenge of CO2 microbubble stability in enhanced oil recovery (EOR), with a focus on the combined effects of surfactant concentration, brine concentration, brine-oil ratio, and gas flow rate. Microbubble destabilization, driven by phase separation and improper brine-oil ratios, is a critical issue in EOR. The novelty of this research lies in the use of Acacia concinna, a natural, non-ionic surfactant, to enhance microbubble stability sustainably. The study systematically investigates foamability, drainage kinetics, surface tension, rheology, and bubble size distribution to assess microbubble stability. The results showed that increasing surfactant concentration and brine-oil ratio significantly impacted foam stability and bubble size distribution, with optimal stability conditions observed at 2 wt% surfactant concentration (53.6 min), 5000 ppm brine concentration (47.6 min), a brine-oil ratio of 1:2 (52.4 min), and a CO2 gas flow rate of 1 lpm. Key findings also indicate that increasing NaCl concentration from 5000 to 20,000 ppm caused an increase in microbubble diameter, while higher gas flow rates reduced bubble size. The work introduces new empirical correlations for predicting bubble size distribution based on column diameter, surfactant and brine concentrations, viscosity, density, and gas superficial velocity. These correlations provide a more accurate means of optimizing EOR processes, improving oil recovery efficiency while enhancing CO2 sequestration, contributing to both energy production and environmental sustainability.

Experimental and molecular dynamics simulation of the effect of surfactant concentration on the wettability of bituminous coal

Currently, studies on the mechanism of coal dust wetting have largely ignored the key factor of surfactant concentration, so it is of significant scientific value to systematically investigate the effect of concentration change on the efficacy of surfactant wetting of coal dust. In this paper, with the help of macroscopic wettability experiments and molecular dynamics simulations, the wetting characteristics of SDBS surfactant on coal at different concentrations were analyzed in depth. An increase in the concentration of the SDBS surfactant solution causes the wettability of the coal to show a crest change that increases and then decreases. Coal wettability is optimized when the solution concentration reaches a specific threshold of 7 wt%. The simulation results show that SDBS surfactant mostly forms hydrogen bonds with water molecules in the form of strong hydrogen bonds, and the hydrogen bonding ability with water molecules is stronger than that of coal. There is a positive correlation between the onset distribution of water molecules within coal and the overlap region at the coal/water interface. The dynamic properties of water molecules show the order E<F<D<C<B<A. The number of highly active sites does not continuously increase with the amount of SDBS molecules adsorbed, but begins to decrease after a critical point is reached. The results of the study contribute to a theoretical framework to guide and use different types of surfactants to improve coal dust wettability at various concentration levels.

Surfactant-enhanced mobilization of polycyclic aromatic hydrocarbons from an historically contaminated marine sediment: Study of surfactants’ concentration effect and continuous test for sediment flushing simulation

Contamination of marine sediments by polycyclic aromatic hydrocarbons (PAHs) poses a significant environmental threat, necessitating effective remediation strategies. This paper investigates the application of surfactants, both synthetic and natural, for the remediation of PAH-contaminated sediments, providing a systematic guideline for the preliminary selection of surfactants for flushing/washing operations, the optimal operative conditions, and the technical approach for PAH mobilization, especially in the context of a real aged contamination scenario. The study included a batch configuration test to evaluate the effect of surfactant concentration on PAH mobilization. Subsequently, a continuous configuration column experiment was performed to simulate a flushing operation of contaminated sediment. The study of process conditions highlighted that the increase in surfactant concentration led to a significant increase in PAH removal from the sediment, reaching almost 30 % efficiency using a 5 % wt surfactant solution. The column test showed great efficiency of the investigated surfactants in PAH mobilization through the flushing process of the contaminated matrix, resulting in 30 times greater efficiency than water within a much smaller pore volume range.

Role of surfactants in the degradation and sustainable dyeing for reactive dyeing wastewater

To enhance the decolorization rate of thermally activated sodium persulfate in dye wastewater, C.I. Reactive Black 5 (RB5) was investigated in this study, which was evaluated by the decolorization of the dye solution. The effect of surfactant concentration (including anionic surfactant sodium dodecyl sulfate (SDS), nonionic surfactant Tween 80 (TW-80) and amphoteric surfactant (BS-12)), SPS concentration, and reaction temperature on the degradation of RB5 was studied. Furthermore, the relationship between free radicals and RB5 degradation was investigated. The results showed that the addition of SDS and TW-80 would inhibit the decolorization of RB5. Correspondingly, the effect would enlarge as the surfactant concentration increased. Nevertheless, the addition of BS-12 wouldn’t affect the final decolorization of RB5 dye solution, despite it could increase the decolorization rate in the initial stage. After 10 min of decolorization, compared to the dye liquor without BS-12, the decolorization could increase by 9.07 % and 0.69 %, respectively, after adding 0.5 and 1.0 CMC of BS-12. Besides, when reactive dyes were degraded by thermally activated sodium persulfate, the SO4-· and ·OH would work together, and SO4-· played a major role while ·OH played an auxiliary part. When the treated wastewater was used for dyeing, the addition of BS-12 could effectively regulate the dyeing rate. The fixation and K/S value were increased by 1.1 % and 0.20, respectively. Furthermore, the dyed fabrics also exhibited improved uniformity, with negligible differences in color fastness. The effects of adding SDS were similar to BS-12, while it decreased the exhaustion and fixation rate of RB5. In addition, non-ionic TW-80 was unfavorable to dyeing. This work provides a new way for efficient treatment of dyeing wastewater as well as reuse, opening an environmentally friendly treatment concept.

Study of Interfacial Properties of Anionic–Nonionic Surfactants Based on Succinic Acid Derivatives via Molecular Dynamics Simulations and the IGMH Method

Surfactants are widely used in fields such as oil recovery and flotation. The properties and mechanisms of surfactants can be effectively studied using molecular dynamics (MD) simulations. Herein, the aggregation behavior of surfactants was studied at the oil–water interface by MD simulation, and the micro-morphology of surfactants was analyzed under a low concentration and saturated state at the oil–water interface, respectively. The visualization results of the MD simulation showed that DTOA was saturated at the oil–water interface at 120 surfactant molecules, whereas 160 surfactant molecules were required for BEMA. In addition, the effect of surfactant concentration on the interfacial thickness and hydrogen bond distribution was studied, with the inflection point of hydrogen bond distribution identified as a characteristic parameter for surfactant saturation at the oil–water interface. The aggregation behavior of their hydrophobic and hydrophilic chains at the oil–water interface was qualitatively assessed using order parameters. Finally, the aggregation state of surfactants in salt-containing systems was studied, and it was found that the surfactants could effectively adsorb magnesium ions and calcium ions at the oil–water interface. However, the curve of the number of hydrogen bonds varies greatly, with a possible reason being that BEMA has a different coordination manner with diverse metal ions. This study provides some original insights into both the theoretical study and practical application of anionic and nonionic surfactants.

Solutal Marangoni augmented levitation time of an aqueous surfactant drop over an immiscible oil pool

Droplets are found to exhibit a finite residence time over the volatile liquid pool due to the confined evaporation mediated sustained thin film draining. The levitated drops are quite critical in biomedical applications such as for the biophysical micro reactors. It is hypothesized that the presence of surfactants can induce solutal Marangoni and can further enhance the levitation time. Moreover, the surfactant drops can closely mimic the bio drop assay. Droplets of surfactant solutions are allowed to impact over a series of volatile hydrocarbon oils to understand the effect of surfactant concentration, impact height and the properties of the oil pool using high speed imaging technique. Flow visualization is employed in the pendant droplet mode to understand the Marangoni induced internal circulation. The droplets of surfactant solutions are found to exhibit enhanced residence time compared to the case of non-surfactant drops. The levitation time is a function of the surfactant concentration and the volatility of the oil pool. A mathematical model is developed incorporating the effect of solutal Marangoni to test the hypothesis and is found to predict the levitation time with reasonable accuracy. A universal floating–sinking regime map was developed incorporating the influence of governing parameters.

Quercetin Solid Lipid Microparticle Stability and Deposition in Rat Lungs: A Study of Surfactant Effect

This study aims to determine the effect of surfactant concentration on Quercetin SLM as a potential carrier of respiratory diseases, especially ones resulting from oxidative stress injury. Quercetin is a natural antioxidant with high activity. SLM was formed with 5% compritol 888 ATO as a lipid and different concentrations of poloxamer 188 as a surfactant. SLM was produced by a combination of emulsification and sonication involving freeze drying. SLM is characterized by organolepsis, morphology, yield, particle size, drug loading, and entrapment efficiency. The antioxidant activity of quercetin SLMs was tested using the ABTS method. SLMs are characterized as having round and smooth morphology, high yield (F1 88.53%; F2 91.44%; F3 92.87%); particle size (F1 1.81 um; F2 1.90 um; F3 1.94 um); high drug loading (F1 15.96%; F2 13.74%; F3 13.19%); and high entrapment efficiency (F1 96.53%; F2 87.94%; F3 87.48%). Increasing surfactant concentration did not produce a significant difference between formulas. Quercetin SLM showed high antioxidant activity (Quercetin 94.43%; F1 94.35%; F2 94.36%; F3 94.37%). SLM was stable at storage temperatures between 25°C and 40°C. The effect of surfactant can be seen on particle size, drug loading, and entrapment efficiency at 40°C. Results of in vivo deposition study indicated that all SLM formulas were able to deliver quercetin to the lungs. Increasing the concentration of surfactant in Quercetin SLMs made no difference to the lung deposition as confirmed by observations conducted at 1 hour and 4 hours. Quercetin SLM has the potential for lung delivery by inhalation.

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.

Prediction of globule size and globule size distribution of emulsion liquid membrane in a pulsed packed column

In this work, the emulsion globule size of an ELM system in a pulsed packed column in different surfactant concentrations was studied for the first time. The emulsion liquid membrane consists of kerosene as a diluent and Span 80 as a surfactant. The effect of surfactant concentration and hydrodynamic parameters, including pulse intensity and flow rates of the dispersed phase and continuous phase, on globule size, was investigated. Based on the results, increasing the concentration of Span 80 up to 3.5 % v/v results in 58–64 % reduction in the Sauter mean diameter (D32) and narrowing the size distribution of the globules. Operating parameters such as pulse intensity and flow rates of continuous and dispersed phases have been investigated so that the influence of flow rates was considerably smaller than the effect of pulse intensity on the globule size distribution. Also, the results showed that with increasing pulse intensity, D32 decreased by 29 %. A new empirical correlation for D32 calculation was also suggested, Featuring 4.91 % average absolute relative error (AARE). Finally, the globule size distribution was predicted using the normal probability function and the dimensionless correlations accurately predicted their parameters and the measured %AARE of α and β were 8.3 and 3.4, respectively.

Further Exploration of Heat of Immersion as a Method to Quantify Wettability for Particulates: Effect of Temperature.

A previous paper [Weston et al. Ind. Eng. Chem. Res. 2015, 54, 4274-4284] by our group concluded that to distinguish between the wettability of different particles, heat of immersion is the best method, as opposed to the Washburn or sessile drop method. In this paper, heats of immersion of three different particles with three different wettabilities are measured at different temperatures to examine one critical assumption concerning the temperature dependence of the heat of immersion. In addition, surfactants are added to the water, and the effect of surfactant concentration on the heat of immersion is measured. One particularly noteworthy aspect of the current study is that some measurements were made at temperatures greater than 100 °C and hence pressures higher than atmospheric pressure with no more difficulty than measurements made at atmospheric pressure. The previous paper showed that, for certain particles, the relationship used by us and others between the heat of immersion and contact angle gave impossible values for certain surfaces. In this paper, the derivation of that expression is reexamined, and certain assumptions are highlighted. Because of issues with the assumptions, we agree with the conclusion from our previous paper that using the heat of immersion as a qualitative measure of wetting is appropriate. However, without measurement of the values of the liquid-solid interfacial energy with temperature as well as the gas-solid interfacial energy with temperature, conversion to the contact angle directly is not appropriate. However, for the same surface, using this approach to quantify the contact angle as a function of temperature is likely appropriate if the contact angle is measured using some other method at one temperature, at least over the limited temperature range (up to 150 °C) explored in this study.

Ultralow interfacial tension achieved by extended anionic surfactants with a short hydrophobic chain

Extended surfactant is a new type of oil displacement agent with excellent performance in enhanced oil recovery (EOR). In this paper, the novel extended surfactants with short hydrophobe (ethylhexyl) have been studied. The dynamic interfacial tensions (IFTs) between extended surfactant (C8PxEyC) solutions and n-alkanes were measured by the spinning drop method. The effect of surfactant concentration, polyoxypropylene (PO) numbers, polyoxyethylene (EO) numbers and electrolyte on the IFTs were investigated. The experimental results show that the interfacial activity of the extended surfactants mainly depends on the PO groups, and the short hydrophobe extended anionic surfactant shows the similar behavior of reducing IFT to that of long alkyl chain one. The IFTs decrease with an increase of the PO numbers against n-alkanes, and an increase of the EO numbers leads to the destruction of the tight arrangement of the adsorption film because the size of EO group is smaller than that of PO group, which results in an increase of IFT. The addition of electrolyte can reduce the IFTs by weakening the electrostatic repulsion between surfactant molecules at the interface, but it has little effect on its HLB. The long EO chain of extended surfactant prevents divalent cation from binding two surfactant counterions, which results in the little effect on reducing IFT. This study is of great significance for the insight of extended surfactants and their application in high-salt reservoirs.

Quantitative analysis on resistant forces at oil-surfactant-rock interfaces with dynamic wettability characterization

Adhesion of oil at rock surface plays an important role in the liberation of oil from micro-/nano-pores, especially for heavy oil that has extremely high viscosity. Although molecular dynamics simulation is widely used to study the interfacial interaction for some specific oil-water-rock systems, experimental measurements provide more realistic and reliable evidence. In this work, we propose a dynamic wettability characterization method to indirectly measure resistant forces at oil-surfactant-rock interfaces, including frictional force, wettability hysteresis force, and viscous force, which are parallel with the oil-solid interface. The adhesive force, which is normal to the oil-solid interface is calculated through measurement of work of adhesion. The results show that work of adhesion instead of contact angle can better describe the adhesion of oil at solid surface. The effect of surfactant concentration on work of adhesion is different for water-wet and oil-wet surfaces. Moreover, average viscous forces are calculated through force analysis on oil drops moving along solid surface in different surfactant environments. It is found that viscous force has a magnitude comparable to the frictional force during the movement, while the wettability hysteresis force is negligible. On the other hand, the adhesive force calculated from the work of adhesion is also comparable to the viscous force. Therefore, both the resistant forces parallel with and normal to the oil-solid interface should be minimized for the liberation of oil from rock surface. This work proposes a simple method to evaluate the wetting capability of different surfactants and measure the adhesive force between heavy oil and rock surfaces indirectly, which provides insight into the adhesion of heavy oil at rock surface and would be valuable for the development of surfactant-based oil recovery methods.

Unveiling Synergistic Bonds: Exploring Spectroscopic Interactions between Tween 20 and Bromocresol Green for Enhanced Applications

Background: Surfactants and dyes interact in ways that can significantly alter the optical properties of solutions, a phenomenon with broad implications across various scientific fields, including healthcare. Understanding these interactions, especially in aqueous environments, is crucial for developing advanced diagnostic tools and enhancing drug delivery systems. Objective: This study aimed to investigate the interactions between the non-ionic surfactant Tween 20 and the dye Bromocresol Green (BCG) in aqueous solutions. By elucidating these interactions, the research sought to explore the potential for improving the accuracy and efficiency of spectroscopic assays used in medical diagnostics and therapeutic applications. Methods: Aqueous solutions of BCG were prepared in varying concentrations of Tween 20 surfactant. Spectroscopic analyses were conducted at two wavelengths, 510 nm and 520 nm, to observe the effects of surfactant concentration on dye absorbance. The critical micelle concentration (CMC) was determined by analyzing changes in absorbance and reciprocal absorbance (1/A) patterns. Beer’s Law was applied to calculate the molar absorption coefficients, providing a quantitative measure of the interaction strength between the dye and surfactant molecules. Results: The study found that the absorbance of BCG increased linearly with the concentration of Tween 20 up to the CMC, after which the increase continued at a different rate. At 510 nm, absorbance values ranged from 0.277 to 1.627 au as Tween 20 concentration increased from 0.005 mM to 0.017 mM, with molar absorption coefficients (ε) escalating from 0.483 to 2.839 (10^3 cm^2 mmol^-1). Similar trends were observed at 520 nm, underscoring the impact of micelle formation on dye-surfactant interactions. Conclusion: The interaction between Tween 20 and BCG significantly affects the absorbance properties of BCG in aqueous solutions, with marked changes observed upon reaching the CMC. These findings highlight the potential of surfactant-dye interactions to enhance the performance of spectroscopic assays in healthcare settings, offering pathways to more sensitive diagnostic techniques and efficient drug delivery systems.

Effect of Surfactant Concentration on Physicochemical and Antibacterial Properties of Eugenol Nanoemulsions

Introduction:: Nanoencapsulation has gained popularity in recent decades due to its numerous benefits, such as improved stability, oxidation resistance, retention of volatile ingredients, controlled release, delivery of multiple active ingredients in a row, improvement in organoleptic properties, reduction of toxic side effects, and water solubility. Methods:: The present study was aimed to prepare eugenol nanoemulsions (EuNEs) using non-ionic surfactant (Tween 80) by ultrasound-assisted techniques and to evaluate the effects of surfactant concentration on their droplets size, polydispersity index (PDI), zeta potential, storage stability, antioxidant, and antibacterial activities. Antimicrobial activity of the prepared nanoemulsions was tested against Gram-positive; Staphylococcus aureus, Bacillus subtilis and Gram-negative; Escherichia coli, and Alcaligenes faecalis bacteria using well diffusion method. Results:: The results showed that the droplet size decreased after a threshold Tween 80 concentration (10%), while PDI value increased with the increase in surfactant concentration (Tween 80). method: The droplets size, poly dispersity index (PDI), zeta potential, storage stability, antioxidant, and antibacterial activities of the prepared nanoemusions were characterized. Conclusion:: The prepared EuNEs exhibited good antibacterial activity against all the four bacterial strains: E. coli, A. faecalis, S. aureus, and B. subtilis. conclusion: No phase separation, creaming, layering or deposition of large oil droplet were observed in the prepared nanoemulsions (EuNE-5, EuNE-7.5, and EuNE-10) except in case of 15%, v/v Tween 80 (EuNE-15) during 30 days of storage

Investigated the effects of surfactant concentration on cobalt ferrite nanoparticles synthesized in reverse micelles

The use of reverse micelles as nanoscale hydrophilic voids of microemulsions in the manufacture of ferrites has been recognized since the 1960s, but there has been very little attention on the structural and magnetic properties with respect to surfactant concentration. This paper investigates the influence of surfactant sodium dodecyl sulphate (SDS) concentrations on cobalt ferrite (CoFe2O4) nanoparticles prepared by reverse micelles at annealing temperatures 250°C and 500°C. Samples with varied cobalt to SDS ratios (Co: SDS = 1: 0.33, 1: 0.5, 1: 0.66) were subjected to XRD, TGA, TEM, FTIR and VSM Studies. All the samples exhibited single-phase spinel structures with crystalline diameters ranging from 10 to 18 nm. As the SDS concentration increased the crystallite size decreased. The TEM images showed the particle size in the range of 7.6 -17.7 nm. VSM investigations show the ferromagnetic behavior of the sample. The observed increase in coercivity with respect to annealing temperature for the same concentration reflects the single-domain nature of the nano particles. This underscores the crucial role of annealing conditions in customizing cobalt ferrite nanoparticles as a suitable application in longitudinal magnetic recording media.

CO2 soluble surfactants for carbon storage in carbonate saline aquifers with achievable injectivity: Implications from the continuous CO2 injection study

Continuous CO2 injection (CCI) into saline aquifers suffers from low sweep efficiency. While utilizing foam can effectively address this issue, a relatively potent foam design may undesirably reduce the injectivity of CO2. In this study, the potential of CO2-soluble surfactants assisted carbon storage in carbonate saline aquifers was evaluated by core flooding tests and numerical simulations. It is found that foam can be generated at the displacement front during continuous CO2 injection with 0.39 g/L surfactant (CCI + S, fg = 100 %). The CO2 saturation can reach 60 % after 1.0 pore volume of CCI + S, approximately 50 % higher than that of CCI. The maximum pressure gradient is around 1.5 psi/ft at an injection rate of 1.0 ft/d in 162 mD Indiana Limestone for CCI + S. The effects of surfactant concentration, foam quality, and rock permeability were also investigated by core flooding. Moreover, the influence of surfactant partitioning and adsorption on CO2 transport behavior was systematically evaluated by numerical simulation in synthetic and geological models, using modeling parameters that are realistic for field applications. The advantage of injecting surfactant with CO2 is more evident in heterogeneous saline aquifers. Such novel injection strategy provides a promising approach for carbon sequestration in saline aquifers by controlling the mobility of CO2 at the displacement front and simultaneously maintaining acceptable injectivity in the field. The CCI + S process may also impose less risk to the caprock. Expanding the potential CO2 storage sites to heterogeneous saline aquifers could be a game-changer. Our understanding of foam dynamics in porous media could also be advanced.

Study Evaluates CO2 Storage Potential During CO2 Mobility-Control Optimization

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 212969, “Evaluation of CO2 Storage Potential During CO2 Mobility-Control Optimization for Enhanced Oil Recovery,” by Alvinda Sri Hanamertani, SPE, Ying Yu, SPE, and Omar El-Khatib, SPE, University of Wyoming, et al. The paper has not been peer reviewed. _ CO2 mobility control through foam technology has enabled better sweep efficiency and, consequently, better oil productivity during enhanced oil recovery (EOR) processes. Along with enhancing oil production, a sound potential exists for in-situ generated foam to enhance CO2 storage. However, the effect of the different in-situ foam generation strategies on the combined goal of maximum oil production and carbon storage is not well elucidated in the literature. In the complete paper, the authors methodically evaluate the simultaneous optimization of CO2 storage and oil recovery using multiple injection strategies. Introduction The current investigation is a continuation of two previous studies that provided a methodology for screening and using foaming agents for optimized CO2 storage in sandstone and carbonate formations. A base case of tertiary CO2 flooding was established for comparison with in-situ foam generation by two approaches: single-cycle surfactant-alternating-gas (SAG) flooding and coinjection of CO2 and surfactant. Additionally, the effect of surfactant concentration on foam efficiency, CO2 storage capacity, and oil recovery were evaluated in both approaches at reservoir conditions. Materials and Methods Fluids and Porous Medium. In this study, a synthetic brine with total dissolved solids of 20 wt% was used as blank brine and laden with a commercial zwitterionic surfactant that was used to prepare surfactant solutions with concentrations of 0.5 and 1 wt% active matter in the synthetic brine. Three core plugs were drilled from an Indiana limestone outcrop block. The cores were then cleaned and oven-dried at 95°C. Experimental Procedure. Vacuum saturation with brine was commenced for the three cores. The porosity of the cores was calculated using their dry and brine-saturated weights. Then, the 100% brine-saturated core was placed in a core holder and loaded into an oven set to 90°C. The pore pressure was fixed at 2,000 psi, and the confining pressure was controlled at 3,000 psi throughout the flooding experiment. The brine permeability of the core samples was evaluated by measuring the pressure drop across the core at different brine-injection flow rates. In the first experiment (IL1), oil drainage with a flow rate of 0.2 cm3/min was performed to establish irreducible water saturation of 46.9%. This total flow rate was kept the same throughout the three experiments. Then, a waterflooding stage was begun and the oil recovery was recorded. After reaching a plateau in oil recovery, supercritical CO2 (scCO2) was injected during the EOR process until the oil production plateaued.

Formulasi Susu Pembersih Ekstrak Etanol Herba Pegagan (Centella Asiatica) Menggunakan Surfaktan Tween 80 Dan Span 80

Gotu Kola herb is a natural antibiotic that contains the compound asiaticoside which has anti-acne properties in cleansing cosmetics such as cleansing milk. The use of appropriate surfactants can help form cleansing milk preparations. The aim of this research was to see the effect of surfactant concentration on the physical properties of cleansing milk with ethanol extract of gotu kola herb using Tween 80 and Span 80 surfactants. Cleansing milk preparations were made with five formulas with different concentrations of Tween 80 and Span 80, namely 1%, 2%, 3 %, 4 %, and 5 %. The research results showed that the different surfactant concentrations for each formula did not affect the organoleptic, homogeneity, pH and specific gravity of the cleansing milk, but did affect the spreadability of the cleansing milk. The higher the surfactant concentration, the smaller the spreadability of the cleansing milk. All cleansing milk preparations meet SNI characteristics.&#x0D; &#x0D;

Emulsion Polymerisation of Poly(Methyl Methacrylate)-Grafted-Graphene Oxide (PMMA-GO): Effect of Surfactant Concentration on Colloidal Stabilization

Graphene oxide (GO) exhibits a wide range of outstanding mechanical, electrical, and physical characteristics, and it is of substantial interest to impart such qualities onto polymeric materials such as poly (methyl methacrylate) PMMA for wider specialized functionalization. The attention of this work is on the development of emulsion polymerization procedure to prepare PMMA-GO nanocomposite and the effect of sodium dodecyl sulphate (SDS) surfactant dosages incorporated during the polymerization, on the effect of PMMA surface interactions in oil. The grafting efficiency is quantified using the Fourier-transform infrared spectroscopy (FTIR), and the effect of surfactant concentration on PMMA-GO stability is examined using UV-Visible spectroscopy, zeta potential and particle size analyses using the Malvern Zetasizer. The surfactant free emulsion has a better stabilization in terms of zeta potential analysis compared to emulsion of PMMA-GO with 0.32, and 0.4 wt. % of SDS. The polymerized PMMA-GO can be used as a model system to alter wax crystallization at low temperatures in oil and gas industries.