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Foam-assisted gas has been widely employed in enhanced oil recovery (EOR) by improving the volumetric sweep efficiency gas mobility of injected gas. However, the major obstacle of foam-assisted gas EOR is maintaining foam lamellae’s stability, especially in harsh reservoir conditions. As mentioned above, the study focused on the effect of silica nanoparticles (SiO2 NPs) in an anionic/nonionic surfactant mixture in enhancing the stability of foam film. The optimum concentration of silica nanoparticles was determined through various experimental approaches. The surface tension and interfacial tension in the presence and absence of SiO2 NPs were measured and recorded. The Bartsch shaking method was applied to analyse the foam half-life and foam static stability. Anionic surfactant Sodium Dodecyl Sulfate (SDS) was utilised with the nonionic surfactant Triton X100 (TX100) at a ratio of 4:1. Addition of various concentration (0.2 wt%, 0.4 wt%, 0.6 wt%, 0.8 wt% and 1.0 wt%) SiO2 NPs in two surfactant mixtures. The screening method was utilised to determine the optimum concentration of SiO2 NPs in SDS-TX100 surfactant mixture at 25 °C and 70 °C. The optimisation from the screening process demonstrated 0.4 wt% SiO2 NPs was suitable in SDS-TX100 surfactant mixture for stabilising the foam films.

Hypothesis: Common amphiphilic drug molecules often have a more rigid nonpolar part than conventional surfactants. The rigidity is expected to influence the self-assembling properties and possibly give rise to aggregation patterns different from that of regular surfactants. Experiments: We have investigated self-assembling properties of the hydrochloride salts of adiphenine (ADP), pavatrine (PVT), and amitriptyline (AMT) at concentrations up to 50 wt% using small-angle x-ray scattering, dynamic light scattering, cryo-transmission electron microscopy, and surface tension measurements. Findings: All drugs form small micelles of oblate spheroidal shape at concentrations above the critical micelle concentrations (CMC). The micelles grow weakly in size up to about 20 wt%, where the aggregation number reaches a maximum followed by a slight decrease in size at higher drug concentrations. We observe a correlation between the decrease in micelle size at high concentrations and an increasing charge of the micelles, as the degree of ionization increases with increasing drug concentration and decreasing pH. In contrast to what has previously been reported, the aggregation behavior of all studied drugs resembles the closed association behavior of conventional surfactants with a short aliphatic chain as hydrophobic tail group i.e. the micelles are always small in size and lack a second CMC. CMC values were determined with surface tension measurements, including also lidocaine hydrochloride (LDC) and chlorpromazine hydrochloride (CHL).

Hypothesis: Surfactants are widely used in agri-sprays to improve pesticide efficiency, but the mechanism underlying their interactions with the surface wax film on plants remains poorly understood. To facilitate physical characterisations, we have reconstituted wheat cuticular wax films onto an optically flat silicon substrate with and without octadecyltrimethoxysilane modification to control surface hydrophobicity. Experiments: Imaging techniques including scanning electron microscopy (SEM) unravelled morphological features of the reconstituted wax films similar to those on leaves, showing little impact from the different substrates used. Neutron reflection (NR) established that reconstituted wax films were comprised of an underlying wax film decorated with top surface wax protrusions, a common feature irrespective of substrate hydrophobicity and highly consistent with what was observed from natural wax films. NR measurements, with the help of isotopic H/D substitutions to modify the scattering contributions of the wax and solvent, revealed different wax regimes within the wax films, illustrating the impact of surface hydrophilicity on the nanostructures within the wax films. Findings: It was observed from both spectroscopic ellipsometry and NR measurements that wax films formed on the hydrophobic substrate were more robust and durable against attack by nonionic surfactant C 12E 6 solubilised with pesticide Cyprodinil (CP) than films coated on the bare hydrophilic silica. Thus, the former could be a more feasible model for studying the wax-surfactant-pesticide interactions.

Although we certainly benefit from modern communications and transportation technologies that are powered by lithium-ion batteries, it is necessary to concurrently bear responsibility for the environmental contamination associated with their production. Hence, our aim to develop an environmentally compatible/pollution-free green synthesis process is of particular importance. In this study, we employed pure water instead of an organic solvent as the reaction medium to realize the green synthesis of well-crystallized LiMnPO4/reduced graphene oxide (RGO) nanopowder at low temperature (102 °C) and constant atmospheric pressure, where the alkyl indican nonionic surfactant (APG06) plays a vital role in the reaction outcome.

The recovery of surfactants from organic mediums is of great economic and environmental interests in the field of petrochemicals sector. The aim of this study was to recover poly-dispersed nonionic surfactant (TX-100) from organic medium by the use of dehydrated and rehydrated kaolin. It was found that the presence of water after kaolin rehydration decreases considerably the amount of TX-100 adsorption from 28.7 μmol.g−1 onto dehydrated kaolin to 23.4 μmol.g−1 onto rehydrated kaolin. The estimation of the number of statistical layers of water deposited on kaolin was observed to be about 7 to 9. The effect of type of solvents (heptane, cyclohexane and benzene) on the adsorption onto rehydrated kaolin revealed a reduction in the adsorbed quantity; the adsorbed amounts were found to be 28.7 μmol.g−1, 26.7 μmol.g−1 and 24.2 μmol.g−1 in heptane, cycloheptane and benzene phases, respectively. On the other hand, it was observed that a temperature increased from 20 °C to 35 °C and 45 °C negatively affects the adsorption of TX-100 onto dehydrated and/or hydrated kaolin in heptane medium.

Foam fractionation is an effective separation technique in recovery of metal ions and surfactant from wastewater. In this paper, recovery of Cd(II) and surfactant in permeate from MEUF by foam fractionation with mixed anionic-nonionic surfactant were studied. Effects of the molar ratio of anionic-nonionic surfactant, Cd(II) concentration, pH on the foam properties and separation efficiency of the three matters were investigated. When the Cd(II) concentration of the feed solution was 10 mg/L, the molar ratio of Triton X-100/SDS was 0.1, the best Cd(II) removal percentage 99.1% was achieved. In addition, the removal percentages of the two surfactants were also relatively high at this condition. The mechanism of the effect of Triton X-100 on removal of Cd(II) by foam fractionation was also investigated by measurement of zeta potential and analysis of FTIR spectra. Results showed that a small amount of nonionic surfactant can significant enhance the removal percentage of Cd(II) by improvement of foam properties of anionic surfactant, while excessive nonionic surfactant may lower the removal percentage due to its negative effect on adsorption of Cd(II) at gas-liquid interface.

The emulsification and solubilization properties and detergency behaviors were investigated using homogeneous polyoxypropylene-polyoxyethylene (PO-EO) alkyl ether type nonionic surfactants (C12EOxPO3, where x represents EO chain lengths of 6 and 8, and C12 and PO3 indicate the dodecyl chain and single trioxypropylene chain, respectively) and polyoxyethylene (EO) alkyl ether type nonionic surfactants (C12EOx, x = 6 and 8). These nonionic surfactants possess single EO and PO chain lengths without a distribution. An oil-in-water (O/W) type emulsion prepared using mixtures of nonionic surfactant C12EOxPO3 or C12EOx solutions and squalane was shown to be stable in the order of C12EO6PO3

Silica nanofluid with silica nanoparticles and surfactants was prepared and used to enhance oil recovery through spontaneous imbibition. Nonionic surfactant (TX-100) as dispersant and synergistic enhancement agent was used to disperse silica nanoparticles into water. The silica nanofluid showed excellent anti-temperature and anti-salinity property. Because of synergistic effect, silica nanofluid has much better ability of oil detachment and wettability alteration than surfactant. The imbibition tests showed that silica nanofluid can improve oil recovery to about 16%, comparing with about 8% oil recovery of TX-100 solution, which improved the synergistic effect mechanism. The silica nanofluid has good application foreground for EOR.

This work aims at exploring the potential of nonionic surfactant octylphenol polyoxyethylene ether (OP-10) modified montmorillonites (NMts) as mycotoxins adsorbent. The resulting NMts has different structural configurations, organic carbon contents, surface hydrophobicity and textural properties at different surfactant loadings. The prepared NMts were used for adsorption of polar aflatoxin B1 (AFB1) and weak polar zearalenone (ZER) in both single and binary-contaminate systems by simulating conditions of gastrointestinal tract. The adsorption capacities of NMts to AFB1 and ZER increased up to 2.78 and 8.54 mg/g respectively from 0.51 and 0.00 mg/g of raw montmorillonite (Mt). High adsorption capacities of NMts to AFB1 and ZER could be reached at low surfactant loadings. There was little decrease from pH of 3.5 to 6.5 but became negligible with increasing the surfactant loadings. In binary-contaminate adsorption system, the adsorption of ZER was obviously affected by the existence of AFB1, while ZER had little effect on the adsorption process of AFB1 due to different adsorption mechanism. This study demonstrates that NMts could be a promising adsorbent for simultaneous detoxification of polar and non-polar mycotoxins.

A new type of high-density hydrophobic deep eutectic solvents (DESs) were synthesized with nonionic surfactants as hydrogen bond acceptors and hexafluoroisopropanol (HFIP) as hydrogen bond donor. Brij-35 was selected as the optimal nonionic surfactant for the preparation of Brij-35-HFIP-DES (molar ratio 1:20). A vortex-assisted DES-based liquid–liquid microextraction method was proposed for determination of Sudan dyes in tomato chili sauces. The whole pretreatment process only needs 5 min and 1.1 mL of organic solvent. The method with HPLC-DAD shows high efficiency (enrichment factors 89–176 and extraction rates 61.0–74.6%) and good performance with linearity (R ≥ 0.9997) in 0.04–2 μg g−1 range, detection limits of 0.0045–0.0118 μg g−1, recoveries of 91.6–104.5% and intra-/inter-day precision below 8.0%. A “DES in water in DES” aggregate microstructure was observed in DES-rich phase. The proposed method is simple, quick, eco-friendly, and suits for the efficient extraction and accurate determination of Sudan dyes in tomato chili sauces.

Winterization is one means of improving the low temperature flow properties of biodiesel fuel, by the separation of saturated FAMEs. Additives are also employed to improve separation in the winterization process by modifying the crystallization behavior. This process is referred to as additive winterization. In a previous study, we investigated a novel additive winterization method in which FAMEs are separated without agitation during cooling, allowing improved separation of saturated FAME and unsaturated FAME mixtures. This method is both facile and energy-efficient because vacuum filtration is not required. In this study, we examined the effects of additives (sorbitan mono fatty acids) and agitation on the separation of saturated FAMEs from saturated and unsaturated FAME mixtures via winterization. The additive winterization process resulted in significant improvements in the cloud points of the FAME mixtures following a single separation run, with the cloud point being decreased by 8 K under optimum conditions. In contrast, winterization based on agitation required at least two cycles of sequential cooling, agitation and filtration to obtain similar results. This study therefore highlights the potential of additive winterization using sorbitan mono fatty acid esters to enhance the low-temperature flow properties of biodiesel fuels based on a simple process with reduced energy expenditures.

In this article, the molecular level investigation on the detachment process of the alkane contaminant from the fused silica surface in nonionic surfactant solution is performed by using molecular dynamics simulation. Three important cleaning parameters including surfactant molecule structure, temperature and surfactant concentration are discussed. We found that the hydrophilic tail of the nonionic surfactant molecule plays a leading role in the desorption process of the oil droplet. The activated chemical activity in surfactant solution with the increasing temperature of solution facilitates the desorption of alkane contaminant. The critical surfactant concentration is vital for cleaning in a real situation. High surfactant concentration can facilitate the desorption of oil droplet in a static solution. The efficiency of water flooding decrease, when the concentration of surfactant is high. Our study can help to understand the cleaning mechanism in surfactant solution and is important for its application in industrial cleaning.

Using micellar medium as a solubilization technique is an influential approach for solubilization of drugs with high hydrophobicity. It may be combined with cosolvency to provide more solubility. This work reports the effects of Tween 80 as a nonionic surfactant and ethanol as a commonly used cosolvent on the solubilities of celecoxib, phenytoin and lamotrigine at 298.2 K. As experimental results approved the effect of Tween 80 on the solubility of celecoxib is more than the others. The experimental data points were fitted to the Jouyban-Acree, general single and modified Wilson models and then back-calculated solubilities were calculated where the mean percentage deviations were 9.7%, 13.3% and 14.0%, respectively.

Micellar medium as solubilization technique is an influential approach for solubilization of drugs with high hydrophobicity. In the current work, the effects of Tween 80 as a nonionic surfactant on the solubilities of lamotrigine in binary mixtures of ethylene glycol + water and propylene glycol + water at 298 K are investigated. To measure solubility of lamotrigine a lab-made setup was employed. This setup applies a synthetic-based method to measure the solubility of the candidate drugs using a three-step procedure to check the solution saturation point. Measured solubility data points were fitted to the common cosolvency models and then back-calculated solubilities were used to calculate the mean percentage deviation (MPD) as an accuracy measure of the models. The obtained MPDs for back-calculated and predicted solubilities using Jouyban-Acree model were 4.0 and 6.9%, respectively.

Montmorillonite (Mt) was modified with three nonionic surfactants, i.e., Span-80, Span-20 and OP-10. The influence of the structures and properties of nonionic surfactants on the structures and properties of organo-montmorillonite (OMt) was researched. X-ray diffraction results demonstrated that nonionic surfactants with low Hydrophile-Lipophile Balance (HLB) values could not intercalate into the interlayer space of Mt while surfactants with high HLB values could. Scanning electron microscope images indicated that the modified Mt was disaggregated into thin lamellas, instead of big particles. Surfactants were able to help to disperse Mt in water. Contact angle tests showed that the hydrophobicity of OMt was higher than raw Mt. However, the hydrophobicity of OMt was not as high as expected. The highest contact angle of OMt was 52°. With the increase of HLB values of nonionic surfactants, the hydrophobicity of OMt gradually decreased. The swelling ability of OMt in organic solvents was poor. The swelling ability of OMt was related to the structure of OMt and the HLB values of nonionic surfactants. Finally, the different mechanisms of OMt prepared with different nonionic surfactants were discussed.

Removal of hydrocarbons from sediments could be achieved using various techniques such as hydraulic flushing aided by surfactants, which works well for sand and gravel but not as effective for finer textured media, such as clay. Electrokinetics (EK) emerged as an effective method to remediate fine-grained soils, especially when combined with the application of surfactants. Here, we analyzed the removal efficiency of EK and a nonionic surfactant (Tween 80) when applied through a fine soil (80% clay) contaminated with n-hexadecane. The study compared the EK results with hydraulic flushing under the same surfactant concentration. After 18 days of treatment, EK removed 80%, which was significantly more efficient than hydraulic flushing which removed 52%. The investigation revealed that EK causes the surfactant to tackle the clayey soil from various directions due to the whole aquifer's electrification. This would be an advantage in field studies as it precludes the need to place numerous electrodes into the soil, as done in hydraulic flushing where multiple wells are placed to direct the surfactant's movement.

This study investigated the in vitro fermentation of three cereal straws (corn stover, wheat straw, and rice straw) with culture media containing two nonionic surfactants (alkyl polyglycoside and Tween 80) and variable surface tension (42, 48, and 54 mN/m) in a 2 × 3 factorial arrangement. The in vitro dry matter degradation of rice straw and corn straw linearly (P

Surfactants have ability to reduce the interfacial tension between residual oil and water and give high recovery factor. Adsorption of surfactant onto the solid surface makes it less effective in reduction of interfacial tension in enhanced oil recovery (EOR) applications. Adsorption of Trigoonella foenum-graceum (TFG) as a nonionic surfactant on crushed sandstone rock was investigated in this work. Conductivity technique was used to measure amount of surfactant adsorbed on crushed rock. Batch experiments were used to investigate the adsorption of surfactant on solid rock surface. In addition, different adsorption equilibrium and kinetic models were fitted to experimental data and parameters for each model were determined. Among the two and three equilibrium models, the Jovanovic and Brouers-Sotolongo models exhibited better predictions and were most suitable for prediction of surfactant adsorption. The kinetic adsorption of surfactant was best suited to pseudo-second order model. Furthermore, the experimental adsorption data were modeled using a method named GA-RBF. It was concluded that the proposed GA-RBF model is accurate in prediction of kinetic adsorption behavior of surfactant. The results of this study can be useful in surfactant selection in EOR processes especially for chemical flooding schemes.

Herein, we synthesized a nonionic surfactant namely, tetradecanoate mercapto acetate polyethylene glycol. We investigate the assembling of the synthesized surfactant on different types of prepared nanoparticles using ultraviolet (UV) and transmission electron microscope (TEM). The surface properties of the synthesized surfactant and its nanostructure were studied. The effect of the prepared nanoparticles on the antibacterial activity of the synthesized surfactant toward sulfated reducing bacteria (SRB) was described in this work. The results show the enhancement of the antibacterial activity of the synthesized surfactant with nanoparticles more than without nanoparticles.

Nonionic surfactants have broad applications such as cleaning and dispersion stabilization, which frequently are hampered by strong temperature sensitivities. As manifested by clouding and decreased solubility with increasing temperature, the interaction between water and the oligo(oxyethylene) head-groups is becoming less favorable. Different aspects of surfactant self-assembly, like the critical micelle concentration, micelle size and shape, intermicellar interactions and phase separation phenomena are reviewed as well as suggested underlying causes of the temperature dependence. Furthermore, the effect of cosolutes on clouding and the behavior of related systems, non-aqueous solutions and nonionic polymers, are examined. (C) 2016 Elsevier Ltd. All rights reserved.

This work demonstrates that based on a simple improved ternary nonionic surfactant templating system, hierarchically meso-mesoporous (HMM) silicas with ultra-large pores and pore volumes can be facilely prepared by combining hydrothermal treatments (HTT) with the partitioned cooperative self-assembly (PCSA) process. The obtained clew-like HMM silica particles contain bimodal pore size distributions. The disordered 1st mode mesostructures (pore sizes of 7–20 nm) form the ‘yarns’, while the 3D-interconnected 2nd mode intra-particulate pores (33–118 nm in sizes) exist between the ‘yarns’. The ultra-large pore volume reaching 3.22 cm 3 g −1 can be achieved. The formation of such HMM silicas arises from the HTT induced fragmentation of the 1st mode mesostructures.

Although nonionic surfactants have been widely employed as emulsifiers, their self-assembly behaviors in emulsion systems are not well understood. Herein, we report a multiscale molecular dynamics simulation study on the nonionic surfactant aggregations in alcohol ethoxylate (AEO)/water/octane/hexanol quaternary emulsion systems. By systematically examining the effects of chain length, degree of branching in surfactants and the addition of co-surfactants, we find that the stability of self-assembled emulsions is majorly affected by the hydrophilic chain length and chain distribution at the oil-water interfaces. The presence of branch chains in surfactants can promote the self-assembly. Moreover, the addition of co-surfactants benefits the formation of interface films and facilitates the formation of micro-emulsions. By unraveling the self-assembly mechanism of nonionic surfactants in emulsion systems from a multiscale perspective, this study provides fundamental insights towards the preparation and applications of nonionic-surfactant-based emulsions.

Niosomes are emerging drug delivery systems that maintain the drug targeting advantages of liposomes, while overcoming the problems of low drug encapsulation and instabilities usually associated with liposomes. The purpose of this study was to systematically develop and characterise the physicochemical and biological toxicological properties of prepared niosomes based on method of production, method of drug incorporation, construct composition and drug loading. Briefly, drug-free and model drug pilocarpine HCl-loaded niosomes were prepared using combinations of Tweens and Spans by either thin film hydration (TFH) or ether injection (EI) methods. The resulting niosomes were characterised based on vesicle size, polydispersity, zeta potential, structural microscopy and drug entrapment. Toxicity of optimised niosomes was tested on HCE-2 cell-line as a model of the corneal epithelium. Results indicated that EI method produced smaller niosomes than TFH method, although the latter method produces niosomes with better stability over time. Significant increase in drug entrapment was observed when pilocarpine HCl was incorporated into the organic phase during manufacture. No corneal cellular toxicity was observed with optimal Span-60 niosomes, with high drug encapsulation. This study provides a mechanistic insight to the design, evaluation and toxicological screening of niosomes with potential for ocular drug delivery to the elderly.

In this work, we studied the association and spectroscopic behaviour of amphiphilic drug, imipramine hydrochloride (IMP), and nonionic surfactant (TX-45), in the absence and presence of ionic liquid, 1-hexyl-3-methylimidazolium chloride (IL). IMP shows amphiphilic behaviour due to the presence of rigid tricyclic hydrophobic moiety in the body. Surface tension and absorbance measurements have been performed to study the nature of interactions between IMP and TX-45 mixtures in the nonattendance and attendance of IL. The diverse physical theories of mixed micellization (Clint, Rubingh, Motomura, and Maeda) were utilized to calculate the composition and interaction parameters. The Gibbs adsorption isotherm was adopted to compute the various surface parameters. The interaction between the two amphiphiles also evaluated via UV–visible spectroscopy.

In this study, a high shear-high pressure homogenization bonding technology, natural surfactant glycyrrhizic acid (GA), synthetic nonionic surfactant Tween 80 (T80) and synthetic ionic surfactant (SDS) were used to prepare the nanoemulsion of hesperidin (HDN-NE), and their solubilization, forming and stabilization mechanism were studied respectively. From the perspective of solubilization, the order of molar solublization ratio (MSR) was GA > T80 > SDS. From forming, there were a uniform appearance, smaller particle size (

The manufacture of detergent products such as laundry detergents, household cleaners and fabric softeners are of increasing interest to the consumer oriented chemical industry. Surfactants are the most important ingredient in detergent formulations, as they are responsible for the bulk of the cleaning power. In this research, a methodology has been developed to design a detergent product using computational tools. Different surfactant systems, such as single anionic, single nonionic, and binary mixtures of anionic-nonionic surfactants are covered in this work. Important surfactant properties such as critical micelle concentration (CMC), cloud point (CP), hydrophilic-lipophilic balance (HLB) and molecular weight (MW) have been identified. A group contribution (GC) method with the aid of computer modelling was used to determine the CMC, CP, and MW of surfactant molecules. The design of a surfactant molecule can be formulated as a multi-objective optimization problem that tradeoffs between CMC, CP, HLB and MW. Consequently, a list of plausible nonionic surfactant structures has been developed with the selected surfactant being incorporated into a binary surfactant mixture. Additives such as antimicrobial agents, anti-redeposition agents, builders, enzymes, and fillers were also considered and incorporated into a hypothetical detergent formulation together with the binary surfactant mixture. The typical ingredients and their compositions in detergent formulations are presented in the final stage of the detergent product design., Chemical engineering; Property prediction models; Chemical product design; Detergents; Surfactant design

In order to recycle TiO 2 photocatalysts and prevent TiO 2 from damaging polyvinylidene fluoride (PVDF) films, porous Zr x Si 1− x O 2 shell/void/TiO 2 core particles (Zr-SVTs) were firstly synthesized by the synergistic effect between nonionic surfactant P123 ((EO) 20 (PO) 70 (EO) 20 ) and oleic acid (CH 3 (CH 2 ) 7 CH = CH(CH 2 ) 7 COOH) and cohydrolysis between TEOS and ZrOCl 2 ·8H 2 O, and then embedded them into PVDF to prepare PVDF photocatalytic films (Zr-SVTP films) by phase inversion process. Zr-SVTs were characterized by SEM, TEM and EDX while Zr-SVTP films were characterized by SEM. The preparation condition and recycle of Zr-SVTP films were investigated and determined. The photocatalytic activities of Zr-SVTP films were investigated by cleaning oily wastewater. The results show that Zr-SVTs hold porous characteristic, and Zr-SVTP films perform the better photocatalytic activities compared with PVDF films (SVTP) embed by SiO 2 shell/void/TiO 2 core without doping Zr in SiO 2 shell, this is because the mass transfer inside channels of Zr-SVTs is promoted by Zr x Si 1− x O 2 shell, ensuring the better photocatalytic activities of Zr-SVTP films. Therefore, Zr-SVTP films structure characteristic will have a promising application in recycle of TiO 2 photocatalysts and cleaning oily wastewater.

Introducing the novel technique for enhancing oil recovery from available petroleum reservoirs is one of the important issues in future energy demands. Among of all operative factors, wettability may be the foremost parameter affecting residual oil saturation in all stage of oil recovery. Although wettability alteration is one of the methods which enhance oil recovery from the petroleum reservoir. Recently, the studies which focused on this subject were more than the past and many contributions have been made on this area. The main objective of the current study is experimentally investigation of the two nonionic surfactants effects on altering wettability of reservoir rocks. Purpose of this work is to change the wettability to preferentially the water-wet condition. Also reducing the residual oil saturation (Sor) is the other purpose of this work. The wettability alteration of reservoir rock is measured by two main quantitative methods namely contact angle and the USBM methods. Results of this study showed that surfactant flooding is more effective in oil-wet rocks to change their wettability and consequently reducing Sor to a low value. Cedar (Zizyphus Spina Christi) is low priced, absolutely natural, and abundantly accessible in the Middle East and Central Asia. Based on the results, this material can be used as a chemical surfactant in field for enhancing oil recovery.

In this work, environmentally friendly aqueous micellar two-phase systems containing nonionic surfactants (Triton X-114, Triton X-100 and Genapol X080) and organic salts (sodium citrate and sodium tartrate) were characterized. In order to accomplish this objective, the binodal diagrams (cloud point vs. surfactant concentration) were obtained for each condition. Additionally, critical micelle concentration (CMC) and micellar hydrodynamic diameter (DH) were determined for each system. According to the obtained results, it was found that the presence of salts lowered the CMC (ΔCMC up to 0.15 mM) and cloud point values (ΔCP up to 18 °C) following the sequence: sodium citrate > sodium tartrate. In addition, the hydrodynamic diameters of the micelles were notoriously increased in presence of the studied salts, showing the high sensitivity of the described aqueous micellar two-phase systems to the medium condition. These results open perspectives for the use of greener aqueous micellar two-phase systems for bioseparation purposes. Fil: Cordisco, Estefanía. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnol.conicet - Rosario. Instituto de Procesos Biotecnologicos y Quimicos Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina Fil: Haidar, Carla. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnol.conicet - Rosario. Instituto de Procesos Biotecnologicos y Quimicos Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina Fil: Goñi, Rocío. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnol.conicet - Rosario. Instituto de Procesos Biotecnologicos y Quimicos Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina Fil: Nerli, Bibiana Beatriz. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnol.conicet - Rosario. Instituto de Procesos Biotecnologicos y Quimicos Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina Fil: Pellegrini Malpiedi, Luciana. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnol.conicet - Rosario. Instituto de Procesos Biotecnologicos y Quimicos Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina

Aphrons are surfactant stabilized microbubbles with thick soapy shells. Stability is a key feature of microbubbles. Colloidal gas aphrons (CGAs), with an average diameter of 50 μm, offer particular advantages where the stability of microbubbles is of interest. Various factors that affect on CGA stability such as surfactant type, concentration, and processing parameters have been extensively studied. However, there is no simple and accurate stability index for characterizing the stability of microbubbles dispersion. In this study, the stability of CGAs dispersion has been examined based on the drainage curve by four stability indexes. The surfactant of choice was nonyl phenol ethoxylate (NPE), a nonionic surfactant. The results show that the one-tenth of drained liquid life ( T 0.1 ), the time elapsed when the drained liquid from CGA dispersion reaches ten percent of its final height is the best indicator among the other stability indexes for characterizing the CGAs dispersion.

The present work investigates the conjugation of flotation and photo-Fenton techniques on oil removal performance from oilfield produced water. The experiments were conducted in a column flotation and annular lamp reactor for induced air flotation and photodegradation steps, respectively. A nonionic surfactant was used as a flotation agent. The flotation experimental data were analyzed in terms of a first-order kinetic rate model. Two experimental designs were employed to evaluate the oil removal efficiency: fractional experimental design and central composite rotational design (CCRD). Overall oil removal of 99% was reached in the optimum experimental condition after 10 min of flotation followed by 45 min of photo-Fenton. The results of the conjugation of induced air flotation and photo-Fenton processes allowed meeting the wastewater limits established by the legislations for disposal.

Small-sized SAPO-34 was successfully synthesized by using Pluronic F127 nonionic surfactant as growth inhibitor and triethylamine (TEA)/morpholine (Mor) as structure-directing agents (SDA). It was proved that Si distribution and the crystal size changed with the addition of Pluronic F127 in the gel. It was found that the lifetime of the smallest size sample is about four times longer than that of conventional counterparts in the reaction of methanol to olefins (MTO).

In a nonionic polyoxyethylene type surfactant C i E j aqueous solution below the Krafft temperature, multilamellar vesicles which have a hollow including excess water are formed (Kawabata et al., 2009). In this study, we surveyed the critical vesicle concentration, CVC, and the formation of the vesicles by means of fluorescence microscopy and light scattering. We have found that disk-like layers are formed below the CVC, and they are transformed to vesicles via a coexisting region of vesicles and disks with increasing surfactant concentration. Furthermore, by varying temperature, the transformations are induced reversibly. These phenomena could be interpreted by taking into account the elastic energy of unilamellar vesicle formation.

Facile synthesis and 1D self-assembly of gold nanoparticles were achieved using a series of nonionic surfactants (Tween 20, Tween 40, and Tween 60). The assembly process can be controlled by adjusting the fine structures of surfactants. The effects of the molecular structures of capping agents were demonstrated and the formation mechanism based on the nonuniform distribution of capping ligands around gold nanoparticles was proposed. Systems with mixed capping agents (Tween 20 and Tween 60 or Triton X-100) were also investigated. Due to the different capping fashions of the mixed surfactants, the obtained gold nanostructures were changed from chains to particles. Besides, the diverse capping fashions can also interpret the different stabilities of the nanostructures in the saline solutions.

Highly ordered SBA-15 rods with tunable length and width have been synthesized by using nonionic surfactant P123 (EO20PO70EO20) as a structure-directing agent without any additives. SBA-15 rods with varying lengths (0.6–3.0 μm) and widths (0.26–0.40 μm) were tuned by simply adjusting the HCl concentration in the range of 0.5–2.5 M. The acidity was identified to be the key factor affecting the growing manner of the rod-like particles. It was found that the length of these SBA-15 rods decreased with the increase of the HCl concentration in the synthetic mixture, while the width increased slightly. Based on our results, a possible mechanism for the effect of the HCl concentration on the growing manner of the rod-like particles was proposed. Furthermore, adsorption of lysozyme (LYS) on these SBA-15 rods was investigated and the results showed that the shorter rods with shorter pore length demonstrated very rapid LYS adsorption (

International audience; The photocatalytic degradation of water pollutants using highly ordered mesoporous TiO2 particles is an emerging area of environmental remediation. Titania particles with a high hexagonal mesopore ordering and a large surface area have been synthesized by a new surfactant templating process that combined both the evaporation-induced self assembly method and the liquid crystal templating pathway. The transformation of the amorphous titanium dioxide walls into nanosized anatase walls is obtained by calcination. The photocatalytic oxidation of methyl orange has been investigated in mesoporous TiO2 aqueous suspensions irradiated by artificial UV-light. The effect of some physicochemical parameters such as time of adsorption prior to UV irradiation, initial methyl orange concentration, photonic flux, pH and amount of photocatalyst has been analyzed in details to optimize the experimental parameters. The efficiency of the process depends on the working conditions and the optimal conditions are: 1 h of dark adsorption, a TiO2 concentration of 0.5 g/L, an initial methyl orange concentration of 15 mg L-1 at acidic pH (pH 4) with an incident light intensity of 10(-5) Einstein L-1 s(-1). The rates of methyl orange decomposition follow Langmuir-Hinshelwood kinetics. The dependence of the reaction rate on the incident light intensity is first order. The reproducibility of the mesoporous TiO2 as photocatalyst for methyl orange degradation is investigated during several cycles experiments. No change in the activity of the catalyst is observed at the first 4 cycles which indicates that the TiO2 is able to use repeatedly.

Chemical penetration enhancers such as micelles can be formed from the solubilisation of the nonionic surfactants in the nanoemulsion system which may then provide an effective solution to the problems associated with drug delivery systems. The structural properties of micelles comprising 5, 20, and 30 molecules of the nonionic surfactant Tween80 were investigated by all-atom level molecular dynamics simulation in explicit water system. The micelles with higher aggregation numbers showed a prolate shape, with the surface being dominated by the polar hydrophilic moieties of surfactant molecules. The average radius of gyration was between 1.1-4.9 nm while the effective radius, determined from the radius of gyration was between 1.4-3.2 nm. The estimated structural properties of the micelles formed may give us a more detail insight in understanding the complexity of these classes of nonionic surfactants.

A laboratory study was conducted to assess the feasibility of a washing process with nonionic surfactant in combination with EDDS for the simultaneous mobilization of MTEs and PAH compounds from a field-contaminated soil. Unit processes consisting of complexometric extraction and surfactant-assisted mobilization were combined with reagent regeneration and detoxification steps to generate innocuous products. Thirty minutes of ultrasonic mixing of the soil with a combination of 20 mL L−1 surfactant suspension and a sparing quantity (2 mmol) of EDDS mobilized virtually all of the benzo[α] pyrene (B(a)P) and chrysene (Cry) and an appreciable portion of the burdens of Cd, Cr, Mn, Ni, Pb and Zn, lesser amounts of the As and Cu, but only small quantities of Al and Fe. Relative to individual reagents, combinations of surfactant (Brij98), with EDDS increased the recovery of B(a)P but seemingly did not influence Cry extraction efficiencies perceptibly. Nine sequential washes with the same initial dosage of mobilization aids decreased the quantities of both PAHs to levels in the soil that conformed to recommended maxima. What resulted was a soil that had been cleaned and a limited quantity of innocuous wash water.

In this paper, the normal-to-abnormal emulsion inversion induced by continuous stirring in a waxy crude oil, water and Triton X-100 emulsion was investigated. The emulsion inversion from the preferred O/W to W/O occurs through the formation of a w/O/W multiple emulsion, in which water from the external phase is continuously included as droplets in the dispersed oil phase drops until a critical dispersed phase value is reached and the inversion takes place. The inversion time, t inv , is an appropriate parameter to describe the emulsion inversion difficulty. And t inv increases with increasing emulsifier or NaCl concentrations while decreases with increasing stirring rate, meaning that the emulsion inversion becomes difficult with increasing emulsifier or NaCl concentrations while becomes easy with increasing stirring rate. The influence of φ o on t inv is complicate due to the increase of emulsion viscosity with increasing φ o . In general, increasing φ o favors the emulsion inversion thus decreasing t inv . However, the increased emulsion viscosity is adverse for the emulsion inversion thus increasing t inv . At high stirring rates (≥ 1500 rpm), the emulsion viscosity has little influence on the emulsion inversion and then t inv decreases with increasing φ o ; at low stirring rates (≤ 750 rpm), the stirring intensity is too low to trigger the emulsion inversion at every value of φ o ; at intermediate stirring rates, the value of t inv is influenced not only by φ o but also by the emulsion viscosity.

A nano-cerium dioxide hydrosol was synthesized via a sol-gel process at the range of room temperature to 65 degrees C with the nonionic surfactant PVP (polyvinylpyrrolidone). The mixture solution of cerium nitrate and urea turned out a visible chemical re

Fabrication of vesicles with the diameter of 4-30 mu m was achieved by mixing hydrophobic nonionic surfactant (Span 65) with a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer (Pluronic P123) in aqueous solutions at room temperature. Ring-shaped structure of the Plutonic P123/Span 65 mixture assemblies was confirmed by fluorescence microscopy. The presence of internal aqueous phase in the Pluronic P123/Span 65 mixture assemblies was determined by measuring the entrapment efficiency of calcein using fluorescence spectroscopy. On the other hand, Pluronic P123/Span 60 mixture system formed wire-like assemblies but not vesicles., Article, COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS. 389(1-3):82-89 (2011)

In the present work, in situ polymerization method was used to prepare nearly monodispersed microcapsules with long chain normal alkanes as core and melamine–formaldehyde (M–F) resin as shell at reaction temperature both above and below the cloud point of nonionic surfactant. A previously neglected point has been clarified, i.e., changing the reaction temperature is proved to be an effective way to tune the microcapsule size, surface pore size and density. Nano-scaled pores (from 5 to 200 nm) on the microcapsule surface were formed by the self-assembly template of nonionic surfactant micelles at different reaction temperatures. The dynamic morphological evolution in the encapsulation process was illustrated, for the first time, by scanning electron microscopy (SEM) at different reaction time. It is the alteration of the hydrophilic–lipophilic balance of crosslinked M–F preploymer in the polymerization process that leads the micelle droplets to migrate inside out, and consequently forms nano- or submicron-pores on the microcapsule surface. The prepared microcapsules have close inner space, providing a good 3-dimensional environment for the confined crystallization of alkanes within the polymeric shell. This methodology is versatile and effective for the synthesis of other porous microspheres, which can be applied potentially for encapsulating lipophilic functional materials.

The cloud point of nonionic surfactant polyoxyethylene (23) lauryl ether (Brij-35) was determined in the presence of various inorganic electrolytes. The measurements of cloud point (CP) were carried out with UV–vis spectrophotometer instead of visual observation. CP of Brij-35 could not be measured directly because its CP is more than 100 °C. Therefore, CP values of Brij-35 were lowered by the addition of electrolytes. In this study, NaF, NaCl, NaBr, KNO3, K2CO3, K3PO4, Li2SO4, Na2SO4, K2SO4, (NH4)2SO4, CuSO4, ZnSO4, CoSO4 were used as electrolytes. Linear lines which were drawn with CP values were extrapolated to zero electrolyte concentration. The real CP value of Brij-35 which is merely listed as >100 °C in the literature was found as 118.5 ± 0.5 °C for all samples. Furthermore, the effects of the nature of the cation and the anion and the valencies of the cations on CP were reported and the rate of decrease in CP with concentration is discussed.

Beta-cyclodextrin (CD) modified by 2-(9-anthracenecarboxamido)phenyl group (Ant-CD) was synthesized and their complexation behavior was investigated by UV and fluorescence spectroscopy. Fluorescence intensity of Ant-CD was dramatically enhanced ca. 10-fold by the addition of TritonX-100 (TX-100) in water below the critical micelle concentration. Ant-CD also showed ca. 4-fold fluorescence increasing in the addition of analogous materials, n-octylbenzenesulfonate in water. These results indicate that Ant-CD can act as a highly sensitive and selective chemosensor for TX-100. Ant-CD and TX-100 formed a pseudorotaxane supramolecular complex. This result was supported by (1)H-(1)H NOESY NMR measurement.

This study investigated the effect of nonionic and cationic surfactants on the dechlorination kinetics and products distribution of a series of chlorobenzenes (CBs) by Cu/Fe particles. Results showed that the reduction rates of CBs increased with the increase in chlorination. The rate constants were closely correlated to their lowest unoccupied molecular orbital (LUMO) energies and logarithmic octanol–water partition coefficients (Log K ow ). Lower LUMO energy and larger Log K ow value led to higher rate constant. The presence of nonionic surfactant of Triton X-100 (TX-100) greatly increased the dechlorination of CBs with higher hydrophobicity (>4Cl), and inhibited the dechlorination with lower hydrophobicity (

Nonionic surfactants, such as Triton X-100 and Tween-20, were shown in this study to improve the elec- trocatalytic activity of screen-printed carbon paste electrodes (SPCE). The electrochemical response of SPCE to hydrogen peroxide increased 8-10-fold with the modification of nonionic surfactants. In addi- tion, the glucose biosensors fabricated from nonionic surfactant-modified SPCE exhibited 6.4-8.6-fold higher response to glucose than that fabricated from unmodified SPCE. A concentration effect is pro- posed for nonionic surfactant to bring neutral reactants to the surface of electrode. Moreover, nonionic surfactant-modified SPCE exhibits a capability of repetitive usage and good reproducibility (R.S.D. < 5%) in the measurement of H2O2. Interestingly, the nonionic surfactant-modified SPCE exhibited an opposite effect to ascorbic acid, a common electroactive agent, which causes interference during clinical diagno- sis. The differential responses of nonionic surfactant-modified SPCE to H2O2 and ascorbic acid suggest its potential in the development of biosensors for clinical diagnosis.

International audience; The synthesis of amphiphilic lipid-polyoxazoline based on copolymers (CO-POxn) with narrow distribution has been achieved via cationic ring-opening polymerization of 2-methyl-2-oxazoline (MOx). Lipid-macroinitiator (COTs) was obtained from commercial castor oil (CO), widely renewable agricultural resource. CO-POxn with various length segments were synthesized from a macroinitiator COTs in order to investigate the effect of the length of the hydrophilic segment on the solution behavior of the nonionic polymer surfactants CO-POxn. The results showed that the critical micelle concentration rised with the increase of POx content and inversely surface tension decreased. The average size of aggregates of these structures suggested the formation of vesicles or nonspherical micelles. Star-shaped morphology of CO-POxn in solid state has also been observed using environmental scanning electron microscopy (ESEM). Addionally energy dispersive X-ray (EDX) analysis demonstrated the presence of POx block in the concentric stripes of the texture.