Cocamidopropyl Research Articles

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.

Synergistic Effect and Phase Behavior of SCG-CAPB-H2O Ternary Compound System

The physical properties of sodium cocoyl glycinate (SCG) and the synergistic effects within the SCG/CAPB complex system were investigated using visible–ultraviolet spectrophotometry and a surface tension meter. Analysis of the synergistic parameters of the complex system revealed that the combination of SCG and cocamidopropyl betaine (CAPB) yielded superior results compared to the individual use of SCG. Building upon this, the ternary phase behavior of the SCG/CAPB/H2O system was further explored. Different lyotropic liquid crystal phases were identified using polarized optical microscopy (POM) and small-angle X-ray scattering (SAXS). Surfactant solutions with varying mass fractions exhibited diverse phase behaviors, including the micellar phase (L1), micelle–solid mixed phase (L1-S), hexagonal phase (H), and lamellar phase (Lα), with the insoluble solid phase predominating. The investigation of the ternary phase diagram of SCG/CAPB/H2O provided valuable guidance for detergent formulation screening, enriched the understanding of sodium cocoyl glycinate complex systems, and further promoted the utilization of amino acid-based surfactants in the field of personal care products.

Encapsulation of eucalyptus and lavender oils by spray drying improves their dispersibility

Active components of essential oils degrade easily in air. Moreover, their introduction into aqueous formulations is not straightforward due to hydrophobic nature. Spray drying encapsulation may solve both problems by entrapping the sensitive oil components inside a fine powder. In this contribution, using a Design Of Experiment (DOE) approach, we optimized the spray drying conditions, as well as a feed composition to obtain the encapsulated eucalyptus oil in a powder form at reasonable yield (29.0–32.1 %). The optimum feed contained maltodextrin and Gum Arabic mixture (3:1) as a carrier (6 %), EO at 5 % and emulsifier at variable concentrations (1–5 %). When re-dispersed in water, they produced dispersions stable for at least 30 days, much longer than the starting emulsions used for encapsulation. The best results were obtained for Cocamidopropyl Betaine (CAPB), Coco-Glucoside and Caprylyl/Capryl Glucoside. The best-performing emulsifier (CAPB) was also employed for encapsulation of lavender oil using the same DOE approach.

Biological and Synthetic Surfactants Increase Class I Integron Prevalence in Ex Situ Biofilms

The role of biocides in the spread of antimicrobial resistance (AMR) has been addressed but only a few studies focus on the impact of surfactants on microbial diversity and AMR, although they are common constituents of cleaners, disinfectants, and personal care products and are thus released into the environment in large quantities. In this study, we used a static ex situ biofilm model to examine the development of four biofilms exposed to surfactants and analyzed the biofilms for their prevalence of class I integrons as a proxy for the overall abundance of AMR in a sample. We furthermore determined the shift in bacterial community composition by high-resolution melt analysis and 16S ribosomal RNA (16S rRNA) gene sequencing. Depending on the initial intrinsic prevalence of class I integrons in the respective ex situ biofilm, benzalkonium chloride, alkylbenzene sulfonate, and cocamidopropyl betaine increased its prevalence by up to 6.5× on average. For fatty alcohol ethoxylate and the biosurfactants sophorolipid and rhamnolipid, the mean increase did not exceed 2.5-fold. Across all surfactants, the increase in class I integrons was accompanied by a shift in bacterial community composition. Especially benzalkonium chloride, cocamidopropyl betaine, and alkylbenzene sulfonate changed the communities, while fatty alcohol ethoxylate, sophorolipid, and rhamnolipid had a lower effect on the bacterial biofilm composition.

Evaluation of the effect of acid additives on rheological properties and technological efficiency of zwitterionic and anionic surfactant mixtures

Relevance. Various acid additives such corrosion inhibitors, iron stabilizers, demulsifiers, anti-precipitation agents are usually used to provide necessary technological properties to acid compositions. Adding the additives into the acid composition based on viscoelastic surfactants can have a significant impact on the efficiency of their subsequent use, since micelle formation and, consequently, rheology of their solutions are particularly sensitive to the presence of additional components in the system. Accordingly, determination of the acid additives influence on rheological properties and technological efficiency of acid compositions with surfactants is a vital task. Aim. To evaluate the effect of acid additives on rheological behavior of viscoelastic surfactants-based acid compositions (mixture of cocamidopropyl betaine and ethoxylated fatty alcohol sulfosuccinate). Object. Acidic composition based on viscoelastic surfactants (a mixture of anionic and zwitterionic surfactants) and a package of acidic additives – corrosion inhibitor, iron stabilizer, demulsifier and antisludge agent. Methods. Investigation of rheological properties using an MCR52 rheometer (Anton Paar GmBH) in the shear rate range from 1 to 100 s–1 at temperatures from 20 to 90°C, standard tests for selecting acid additives.  Results. The authors have determined the effect of acid additives on rheological properties of the developed self-diverting acid solution based on the viscoelastic surfactant (a mixture of anionic and zwitterionic surfactants). The obtained results confirmed that adding the acid additives into solutions leads to a decrease in partially neutralized solution viscosity. However, it expands the range of manifestation of viscoelastic properties. This will increase the efficiency of the developed composition during acid treatment. Also, the addition of acid additives reduces the initial viscosity, which facilitates acid injection into formation. A viscoelastic gel is not formed with hydrocarbons, which indicates that the treatment is effective in cleaning up the area after acidizing. The temperature test showed that the additives do not affect the temperature range of acid solution application.

Clinical relevance of doubtful reactions in patch testing: A single-centre retrospective study.

Doubtful reactions in patch testing are infrequently reported in the literature; however, recent reports have suggested they be assessed with the same scrutiny as stronger reactions. Assess the clinical relevance of doubtful reactions in patch testing. Retrospective study of 1514 patients comprehensively patch tested via the NACDG standard series and additional allergens based on history. The clinical relevance of each reaction was graded based on the NACDG scale: definite, probable, possible, past, unknown and irritant. Reactions were considered 'unique' if an additional mild-to-strong reaction to the same chemical at a different concentration was not observed. 68.9% (1043) of patients demonstrated at least 1 doubtful reaction. Of 4453 total doubtful reactions, 92.2% (4106) were unique. Only 3.3% (137) and 12.2% (500) of these were determined to be of definite or probable clinical relevance respectively. 'Fragrance' was the most common allergen family present among the unique definite doubtful reactions (37). However, 24 (64.9%) of these also had a stronger reaction to another fragrance. Cocamidopropyl betaine was the second most frequent allergen demonstrating definite doubtful reactions (27) and unique in 85.2% (23) of cases. Methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) was most prevalent (36) but less frequently unique (58.3%, 21). Doubtful reactions may not be as impactful to clinical decision making as theorised in the literature. Few demonstrate definite clinical significance, and many have related stronger reactions that capture them for clinical purposes. Identification of doubtful reactions to cocamidopropyl betaine and MCI/MI may be of greatest significance as they most frequently were not supported by stronger reactions.

Tuning the antimicrobial activity of microbial glycolipid biosurfactants through chemical modification.

Sophorolipids, glycolipid biosurfactants derived from microorganisms such as Starmerella bombicola, possess distinctive surface-active and bioactive properties, holding potential applications in cosmetics, pharmaceuticals and bioremediation. However, the limited structural variability in wild-type sophorolipids restricts their properties and applications. To address this, metabolic engineering efforts have allowed to create a portfolio of molecules. In this study, we went one step further by chemically modifying microbially produced sophorosides, produced by an engineered S. bombicola. Twenty-four new sophoroside derivatives were synthesized, including sophoroside amines with varying alkyl chain lengths (ethyl to octadecyl) on the nitrogen atom and their corresponding quaternary ammonium salts. Additionally, six different microbially produced glycolipid biosurfactants were hydrogenated to achieve fully saturated lipid tails. These derivatives, along with microbially produced glycolipids and three benchmark biosurfactants (di-rhamnolipids, alkyl polyglucosides, cocamidopropyl betaine), were assessed for antimicrobial activity against bacteria (Bacillus subtilis, Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Pseudomonas aeruginosa) and yeast (Candida albicans). Results indicated that microbially produced glycolipids, such as bola sophorosides, acidic sophorolipids and acidic glucolipids exhibit selective antimicrobial activity against the test organisms. Conversely, lactonic sophorolipids, sophoroside amines and quaternary ammonium salts display a broad antimicrobial activity. N-octyl, N-dodecyl and N-octadecyl derivatives exhibit the lowest minimal inhibitory concentrations, ranging from 0.014 to 20.0mgmL-1. This study demonstrates the potential synergy of thoughtful biotechnology and targeted chemistry to precisely tailor glycolipid biosurfactants to meet specific requirements across applications.

Allergic or Not: Final Interpretation of Doubtful Patch Test Reactions From the North American Contact Dermatitis Group, 2019-2020.

Background: Doubtful patch test reactions generally do not meet criterion for positivity in patch testing. However, the North American Contact Dermatitis Group (NACDG) allows for doubtful reactions to be coded with a final determination of "allergic/positive" based on the temporal pattern, appearance, known characteristics of the allergen, and/or other supportive patch test reactions. Objectives: To analyze NACDG data from the 2019-2020 patch test cycle to identify patterns in the interpretation and relevance of doubtful reactions. Methods: The frequency and proportions of doubtful reactions were tabulated and analyzed for patterns. Statistical analyses were limited to allergens with ≥30 doubtful reactions to ensure adequate sample size. Results: Of patch-tested patients, 31.9% (1315/4121) had ≥1 doubtful reaction. Of 2538 total doubtful reactions, 46% (n = 1167) had a final interpretation of "allergic/positive." The allergens with the highest proportion of doubtful reactions at the final visit were hydroperoxides of linalool 1% (4.5%), fragrance mix I 8.0% (3.9%), and cetrimonium chloride 0.5% (3.4%). Methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) 0.02% (P < 0.001), MI 0.2% (P < 0.001), nickel sulfate hexahydrate 2.5% (P = 0.001), and neomycin sulfate 20.0% (P = 0.003) doubtful reactions were more likely to be interpreted as allergic than nonallergic. Methyldibromoglutaronitrile/phenoxyethanol 0.2% (P < 0.001), oleamidopropyl dimethylamine 0.1% (P < 0.001), formaldehyde 2.0% (P < 0.001), cetrimonium chloride 0.5% (P < 0.001), benzophenone-4 (sulisobenzone) 10% (P < 0.001), iodopropynyl butylcarbamate 0.5% (P < 0.001), cocamidopropyl betaine 1.0% (P = 0.002), and benzisothiazolinone 0.1% (P = 0.012) doubtful reactions were less likely to be interpreted as allergic. Of the 1167 doubtful reactions interpreted as allergic, 84.9% had current relevance. Conclusions: Doubtful reactions were common and approximately one half were coded with a final interpretation of "allergic/positive." Of those, most were clinically relevant. MCI/MI, MI, nickel, and neomycin were more likely to be interpreted as allergic.

Saturated Micellar Networks: Phase Separation and Nanoemulsification Capacity

Different oils can be homogeneously dispersed in the network junctions of the separated bicontinuous micellar phases. Upon dilution, these dispersions spontaneously form nanoemulsions. The possibility of a micellar sponge phase formation in the case of mixtures with three anionic and two zwitterionic surfactants in the presence of divalent and monovalent salts is studied. The best results are obtained using sodium lauryl ether sulfate with 1 ethylene oxide group (SLES-1EO) and both cocamidopropyl betaine (CAPB) or N,N-dimethyldodecylamine N-oxide (DDAO) in the presence of an appropriate small amount of MgCl2 and CaCl2. Bicontinuous micellar phases can be produced also in high-salinity NaCl solutions. The bulk properties of these phases are independent of the concentration of the initial solutions from which they are separated, and their Newtonian viscosities are in the range from 0.3 Pa·s to 0.8 Pa·s. Both 8 wt% CAPB- and DDAO-containing sponge phases engulf up to 10 wt% limonene and spontaneously form nanoemulsion upon dilution with droplet sizes of 110–120 nm. Vitamin E can be homogeneously dispersed only in CAPB-containing saturated micellar network, and upon dilution, these dispersions spontaneously form nanoemulsions with smaller droplet sizes of 66 nm for both 8 diastereomers and 2 diastereomers mixtures of vitamin E.

FORMULATION AND PHYSICAL PROPERTIES TESTS OF FACIAL WASH FROM OLIVE OIL AND NIACINAMIDE

&lt;p class="MsoNormal" style="margin: 0in; margin-bottom: .0001pt; text-align: justify; text-indent: -.1pt; line-height: normal;"&gt;&lt;span style="font-size: 11.0pt; font-family: 'Calibri','sans-serif'; mso-fareast-font-family: Calibri;" lang="IN"&gt;Problems on facial skin that often occur are caused by free radicals. Free radicals can cause cell damage in the form of premature aging which is characterized by a lack of elasticity in the skin, black spots appear, skin looks duller and there is pigmentation. Free radicals can be counteracted by giving antioxidants. Antioxidants are molecular compounds that can release electrons and neutralize free radicals in order to prevent cell damage. One of the natural ingredients that can be used to treat premature aging is olive oil. Olive oil is believed to help maintain skin moisture and elasticity as well as expedite the skin regeneration process, so that the skin is not easily dry and wrinkled. The aim of the research was to determine the results of the physical properties test of olive oil and niacinamide facial wash preparations and to determine the right and optimum formula for the surfactant combination of sodium lauryl sulfate (SLS) and cocamidopropyl betaine. The type of research used is laboratory experimental with the Simplex Lattice Design (SLD) method. According to the results of the physical properties of the 8 formulas, the facial wash preparations met the physical properties tests such as organoleptic, homogeneity, pH, foam stability, spreadability and viscosity which met the requirements according to SNI. Olive oil and niacinamide facial wash preparations have an optimum formula at a concentration of 0.75% SLS and 0.25% cocamidopropyl betaine.&lt;/span&gt;&lt;/p&gt;&lt;em&gt;&lt;span style="font-size: 11.0pt; line-height: 115%; font-family: 'Calibri','sans-serif'; mso-fareast-font-family: Calibri; position: relative; top: .5pt; mso-text-raise: -.5pt; mso-ansi-language: IN; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;" lang="IN"&gt;Facial Washes; olive oil; Niacinamide&lt;/span&gt;&lt;/em&gt;

Natural-Origin Betaine Surfactants as Promising Components for the Stabilization of Lipid Carriers.

In the present work, we demonstrate studies involving the influence of the formulation composition on the physicochemical properties of nanocarriers: solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs). Novel lipid-origin platforms were prepared using two "green" betaine-based surfactants, cocamidopropyl betaine (ROKAmina K30) and coco betaine (ROKAmina K30B), in combination with three different solid lipids, cetyl palmitate (CRODAMOL CP), trimyristin (Dynasan 114), and tristearin (Dynasan 118). Extensive optimization studies included the selection of the most appropriate lipid and surfactant concentration for effective SLN and NLC stabilization. The control parameters involving the hydrodynamic diameters of the obtained nanocarriers along with the size distribution (polydispersity index) were determined by dynamic light scattering (DLS), while shape and morphology were evaluated by atomic force microscopy (AFM) and transmission electron microscopy (TEM). Electrophoretic light scattering (ELS) and turbidimetric method (backscattering profiles) were used to assess colloidal stability. The studied results revealed that both betaine-stabilized SLN and NLC formulations containing CRODAMOL CP as lipid matrix are the most monodisperse and colloidally stable regardless of the other components and their concentrations used, indicating them as the most promising candidates for drug delivery nanosystems with a diverse range of potential uses.

Mild but effective skin cleansing-Evaluation of laureth-23 as a primary surfactant.

Skin cleansing products are among the main reasons for the development of hand eczema. Therefore, a mild but effective skin cleansing product is of particular interest, especially in the work place, where various contaminations frequently have to be removed from hands. In this study, the potential of laureth-23 as a primary surfactant was evaluated and compared to other fatty alcohol ethoxylates (FAEO). Also, different laureth-23 surfactant combinations were compared to each other. Therefore, transepidermal water loss, erythema and visual scoring were measured after occlusive patch testing in 24 healthy subjects (aged 18-55). Afterwards, the results were ranked from low to high irritant potential and an irritation score was calculated. Furthermore, the cleaning performance was tested using an automated cleansing device in 10 healthy subjects (aged 18-55). The results confirmed the low irritant potential of laureth-23 and blends thereof. Within the different laureth-23 surfactant combinations, the combination of laureth-23 with a mild amphoteric and a mild anionic surfactant was superior to other laureth-23 surfactant combinations like laureth-23/anionic/anionic regarding skin compatibility as well as cleaning performance. In conclusion, laureth-23 showed very good performance as a primary surfactant. Especially, the combination of laureth-23, cocamidopropyl betaine and disodium laureth sulfosuccinate was mild to the skin while also showing good cleansing performance.

A green extraction process for the selective recovery of Sc(iii) based on hydrophobic betaine derivative ionic liquids.

The efficient extraction recovery of scandium (Sc(iii)) is crucial for its application in high-end technology. Two novel hydrophobic carboxylic acid ionic liquids (ILs), namely, [lauryl betaine][bis(trifluoromethanesulphonyl)imide] ([Laur][Tf2N]) and [cocamidopropyl betaine][bis(trifluoromethanesulphonyl)imide] ([Coca][Tf2N]), were synthesized using two inexpensive amphoteric surfactants as cation sources. [Laur][Tf2N] (257 °C) and [Coca][Tf2N] (251 °C) exhibited good thermal stability and strong hydrophobicity. The viscosity of [Coca][Tf2N] (4.29 × 103 mP s) was higher than that of [Laur][Tf2N] (2.55 × 103 mPa s) at 25 °C. The optimal extraction conditions were an extraction equilibrium time of 40 min, an initial Sc(iii) concentration of 0.001 mol L-1, a sodium nitrate concentration of 0.5 mol L-1, and a pH of 3. The extraction efficiency of [Laur][Tf2N] and [Coca][Tf2N] could even exceed 98.7% and 96.0%, respectively. The cation exchange extraction mechanism was studied by slope analysis, IR spectroscopy and 13C NMR spectroscopy. Sc(iii) extracted using [Laur][Tf2N] and [Coca][Tf2N] could be completely stripped with 0.1 mol L-1 and 0.2 mol L-1 HNO3 once, respectively. The structure of the ILs was not broken after stripping, and the extraction efficiency of the ILs remained almost unchanged after five cycles. In addition, the extraction differences at different pH levels made it possible to separate Sc(iii) from other rare earths using ionic liquids [Laur][Tf2N] and [Coca][Tf2N].

Cocamidopropyl betaine - a potential source of nitrogen-containing disinfection by-products in pool water.

Water treatment for most public pools involves disinfection with active chlorine leading to the formation of disinfection by-products (DBPs). Among them, nitrogen-containing compounds (N-DBPs) having increased toxicity and adverse effects on human health are of the greatest concern. Being the major component of various body washers for swimmers, cocamidopropyl betaine (CAPB) represents a potential and still underestimated anthropogenic precursor of N-DBPs in pool water. The purpose of this study was to investigate CAPB transformation pathways and mechanisms under the aqueous chlorination conditions. High-performance liquid and two-dimensional gas chromatography hyphenated with high-resolution mass spectrometry were used for the search and tentative identification of the primary and final CAPB transformation products. A wide range of DBPs containing up to five chlorine atoms including these in combination with hydroxyl and additional carbonyl groups has been revealed in model chlorination experiments for the first time. The proposed mechanism of their formation involves nucleophilic substitution of the secondary amide hydrogen atom at the first stage with subsequent free radical and electrophilic addition reactions resulting in non-selective introduction of halogen atoms and hydroxyl groups in the alkyl chain. The deep transformation products include short-chain chlorinated hydrocarbons and their oxidation products as well as dimethylcarbamoyl chloride possessing high toxicity and carcinogenic properties. Targeted analysis of real swimming pool water samples confirmed the results of model experiments enabling semi-quantitative determination of CAPB (0.8µg L-1) and 18 primary DBPs, including 10 chlorine-containing compounds with the total concentration of 0.1µg L-1. Among them, monochloro (50%) and hydroxydichloro (25%) derivatives predominate. The toxicity and health of the main DBPs has been estimated using QSAR/QSTR approach. Thus, the possibility of formation of new classes of potentially toxic chlorine-containing DBPs associated with the widespread use of detergents and cosmetics was shown.

Polymerization Behavior and Rheological Properties of a Surfactant-Modified Reactive Hydrophobic Monomer

The structures and properties of hydrophobic association polymers can be controlled using micelles. In this work, we synthesize a reactive hydrophobic surfactant monomer, KS-3, from oleic acid, N,N-dimethylpropylenediamine, and allyl chloride. A strong synergistic effect between KS-3 and cocamidopropyl betaine in aqueous solution enhances the hydrophilic dispersibility of KS-3, thereby transforming spherical micelles into cylindrical micelles. KS-3 was grafted onto a polyacrylamide chain via aqueous free-radical polymerization to obtain RES, a hydrophobic association polymer. Structural analysis revealed that the RES polymers assembled in wormlike micelles were more tightly arranged than those assembled in spherical micelles, resulting in a compact network structure in water, smooth surface, and high thermal stability. Rheological tests revealed that the synthesized polymers with wormlike and spherical micelles exhibited shear-thinning properties along with different structural strengths and viscoelasticities. Therefore, controlling the micellar state can effectively regulate the polymer properties. The polymers obtained through wormlike micelle polymerization have potential applications in fields with high demands, such as drug release, water purification, and oilfield development.

Prevalence of allergic contact dermatitis in children with and without atopic dermatitis: A multicenter retrospective case-control study.

As both allergic contact dermatitis and atopic dermatitis (AD) have similar clinical presentations and are characterized by spongiotic dermatitis on skin biopsy, many children with AD are not referred for patch testing and allergic contact dermatitis is underdiagnosed. To provide updated prevalence data of common contact allergens in children with and without AD. This is a retrospective case-control study using the Pediatric Allergic Contact Dermatitis Registry from 2018 to 2022. A total of 912 children were included (615 with AD and 297 without AD). Children with AD were more likely to have a longer history of dermatitis (4.1 vs 1.6years, P<.0001), have seen more providers (2.3 vs 2.1, P=.003), have greater than 1 positive patch test (PPT) result (P=.005), have a greater number of PPT results overall (2.3 vs 1.9, P=.012), and have a more generalized distribution of dermatitis (P=.001). PPT to bacitracin (P=.030), carba mix (P=.025), and cocamidopropyl betaine (P=.0007) were significantly increased in children with AD compared to those without AD. Technical variation between providers and potential for misclassification, selection, and recall biases. Children with AD are significantly more likely to have PPT reactions and should be referred for evaluation of allergic contact dermatitis and obtain patch testing.

An efficient separation for fluoride-ions from water supplies by ion precipitate flotation: Pilot scale study with generation of coagulative bubbles

Bubble surface modification is a promising technique that enables to increase the efficiency of a treatment that aims to remove a certain particle with lower consumption of chemical inputs. In this study, the so-called coagulative bubbles were generated from a mixed system consisting of amphoteric surfactant (Cocamidopropyl betaine, CAPB) and inorganic polymer coagulants (aluminum sulfate and calcium chloride) for the removal of fluoride ions present in groundwater destined for human supply. The critical micellar concentration (CMC) of CAPB was 0.26 mmol L−1. The coagulant bubbles (CB) were generated from pressurizing the coagulant solution in distilled water and applied continuously in a helical tubular reactor. The CB treatment method provided higher fluoride removal compared to conventional treatment with simple coagulant application. The CBs generated with Al made it possible to remove approximately 98 % of the initial amount of fluoride measured (3.5 mg L−1) with a dosage of 31 mg L−1 of Al; feed flow rate of 20 L min−1; pH 6 ± 0.5; and saturation pressure of 3 atm. This same operation, but without generation of CBs (regular atmospheric pressure), allowed the removal of 67 % of the initial fluoride concentration.

Facilitating desorption and diffusion of coalbed methane by wetting-corrosion: Perspectives from the change of pore structure

Surfactants and inorganic acids are usually added to fracturing fluids to improve CH4 desorption and diffusion by the wetting and corrosion effect. In this work, cocamidopropyl betaine (CAB) and H2SO4 were used to treat coal samples and then CH4 adsorption-desorption experiments and low-temperature liquid nitrogen experiments were carried out. The effects of CAB and H2SO4 and the composite solution on CH4 adsorption-desorption characteristics and pore structure of the coal samples were investigated. The results show that, after treated by the composite solution, the macropore volume of the coal samples increased while the specific surface area decreased, providing more channels for CBM diffusion and reducing CH4 adsorption sites. The decrease of fractal dimensions D1 and D2 indicates that the coal surface becomes smoother and the pore connectivity is enhanced. Therefore, the wetted-corroded coal samples had higher CH4 desorption rates and lower residual adsorption amounts compared to the coals treated with water and the single-component solution of CAB or H2SO4, and CH4 desorption rate of the wetted-corroded coal samples increases and the residual adsorption amount decreases as the acidity of the composite solution intensifies. This work will provide insights into the improvement of CBM desorption and diffusion using CAB and H2SO4 composite solutions.

The complex formed between Cocamidopropyl betaine (CAPB) – sulfonated polystyrene (PSS) via electrostatic and hydrophobic interactions

ABSTRACT This work produced a polyelectrolyte, sulfonated polystyrene (PSS) from polystyrene waste. The resulting PSS was characterized by FTIR spectrometry, which shows the bands of the sulfur trioxide group. Thermogravimetric analysis (TGA) confirms the material’s high stability compared to the starting material. The interactions between oppositely charged polyelectrolyte (PSS) and the surfactant cocamidopropyl betaine (CAPB) in an aqueous solution of three different pH values were also studied at 25°C, using conductimetry and viscometry techniques. The CMC of the surfactant is above the critical aggregation concentration (CAC) and well below the C2 (saturation concentration). PSS interacts strongly with the zwitterionic surfactant CAPB. At pH 2.5, the polymer is a strong polyanion, and binding is dominated by electrostatic charge neutralization with the cationic surfactant at this pH. At pH 5.2 and 9, the electrostatic attraction between CAPB and PSS weakens, and the hydrophobic interaction strengthens. The effect of salt concentration on the interaction between CAPB and PSS depends on the competition between increasing interaction and filtering interaction. The ionic strength is essential to these interactions after salt and acid injection. CAC and C2 are affected by the charge of the electrolyte and the medium due to the synergistic effects of alkali on the surfactant compared to the polymer system without alkali-surfactant and probably also due to the increase in the formed bond between the polyelectrolyte and the surfactant in the presence of salt.

PEMANFAATAN LIMBAH KULIT BAWANG PUTIH (Allium sativum L.) SEBAGAI BAHAN AKTIF PEMBUATAN SABUN CAIR

Utilization of household waste in Indonesia is still very rarely done, one of which is the use of garlic skin waste. From research by Allemann &amp; Baumann in 2008, garlic skin is rich in antioxidant compounds so it can protect skin cells from free radical damage if used as a skincare product, one of which is liquid bath soap for the body. This research aims to formulate garlic skin extract as liquid soap. The concentration used is 10%. The liquid soap formulation used was 17 g of SLS, 3 g of NaCl, 9 g of Cocamidopropyl Betaine, 9 g  of Glycerin, Fragrances, and Dyes to taste. Garlic skin extract liquid soap is evaluated for its physical quality consisting of organoleptic test results in the form of liquid, gum-scented and red-colored, pH test of 8.2, height test and foam stability of 79 mm, moisture content test of 51.12%, specific gravity test of 1.012 g/ml, and irritation test declared non-irritating. The results showed that garlic skin extract liquid soap with a concentration of 10 % had a physical quality that complied with their requirements. This research concludes that garlic skin extracts liquid soap meets the requirements of the physical quality test and safe for the skin because it does not cause irritation to the skin when used.