Search

The as‐synthesized MCM‐41 and its modified forms are used as adsorbents for the removal of nonylphenol ethoxylate (NP‐10) from aqueous solutions. The partial template containing MCM‐41 is prepared by treating the as‐synthesized sample with ethanolic ammonium nitrate solution. Complete removal of the template is performed using the calcination process. The prepared adsorbents are characterized by X‐ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy, and nitrogen physisorption techniques. The effect of adsorbent weight, pH, contact time, and initial concentration on the adsorption efficiency is studied. The equilibrium adsorption data are well defined, and they are fitted with Langmuir isotherm model. The maximum adsorption capacities (qm) and pseudo‐second‐order rate constants (k2) are calculated. The best adsorbent, in terms of removal efficiency, results to be the thermally treated MCM‐41, characterized by the highest surface area, and thus with the largest porosity. Specifically, the removal efficiency for NP‐10 is around 84% (558 mg g−1) with an initial concentration of 700 mg L−1, which is increased to 91% (455 mg g−1) for a 500 mg L−1 initial concentration. Thermodynamic studies depict that the adsorption of NP‐10 onto MCM‐41 is an endothermic process and the spontaneity is controlled by entropy. [ABSTRACT FROM AUTHOR]

Since traditional nonyl phenyl type nonionic surfactants have been known as destructive to the ecosystem, sorbitan nonionic surfactants (Tween 20, 40, 60 and 80) were used to make acrylic emulsion type pressure sensitive adhesives (PSA), and the type of effects they have on the adhesive properties were investigated. Also, their adhesive properties were compared with those synthesized using traditional nonyl phenyl nonionic surfactant (NP 40). As a result, PSA made using Tween60 showed higher initial tack and peel strength and a much higher holding power than those properties made using NP 40 at room temperature. PSA made by Tween 60, and cross-linked by DGEBA (Bisphenol A diglycidyl ether) and phenyl aziridine, exhibited over 12 h of holding power at 150 °C, and showed a holding state up to 180 °C during a SAFT test (Shear Adhesion Failure Temperature). [ABSTRACT FROM AUTHOR]

The inhibition effect of the synthetic nonionic surfactants (NIS) on the dissolution of carbon steel in 0.5 M H2SO4 solution has been demonstrated using different techniques. NIS compounds were characterized by IR and 1H NMR spectra. Corrosion parameters resulting from the techniques used confirm that inhibiting power of NIS compounds was increased with increasing NIS compounds, lowering temperature and surface properties e.g., surface tension, interfacial tension and critical micelles concentrations. Low values of surface properties increase the adhesive strength between NIS compounds and the carbon steel surface, which improves the adsorption process. Adsorption of NIS compounds is spontaneous and obeys Temkin's isotherm. The high inhibition efficiency of NIS compounds depends on the presence of more electron donor atoms, which increases the electron density at the adsorption center. Some thermodynamic functions have been identified and interpreted. [ABSTRACT FROM AUTHOR]

Interfacial interaction amongst the antidepressant drug-imipramine hydrochloride (IMP) and pharmaceutical excipient (triton X-100 (TX-100-nonionic surfactant)) mixed system of five various ratios in dissimilar media (H2O/50 mmol·kg−1 NaCl/250 mmol·kg−1 urea) was investigated through the surface tension method. In addition, in the aqueous solution, the 1H-NMR, as well as FT-IR studies of the studied pure and mixed system were also explored and deliberated thoroughly. In NaCl media, properties of pure/mixed interfacial surfaces enhanced as compared with the aqueous system, and consequently the synergism/attractive interaction among constituents (IMP and TX-100) grew, whereas in urea (U) media a reverse effect was detected. Surface excess concentration (Γmax), composition of surfactant at mixed monolayer (X1σ), activity coefficient (f1σ (TX-100) and f2σ (IMP)), etc. were determined and discussed thoroughly. At mixed interfacial surfaces interaction, parameter (βσ) reveals the attractive/synergism among the components. The Gibbs energy of adsorption (ΔGadso) value attained was negative throughout all employed media viewing the spontaneity of the adsorption process. The 1H NMR spectroscopy was also employed to examine the molecular interaction of IMP and TX-100 in an aqueous system. FT-IR method as well illustrated the interaction amongst the component. The findings of the current study proposed that TX-100 surfactant could act as an efficient drug delivery vehicle for an antidepressant drug. Gels can be used as drug dosage forms due to recent improvements in the design of surfactant systems. Release mechanism of drugs from surfactant/polymer gels is dependent upon the microstructures of the gels and the state of the drugs within the system.

Abstract In an aqueous buffer system, serious reverse and side reactions were found in the asymmetric reduction of 2-octanone with Saccharomyces cerevisiae. However, some nonionic surfactants added to the aqueous buffer system improved the bioreduction process by decreasing the reverse and side reaction rates in addition to effectively increasing the average positive reaction rate. Further, a shorter carbon chain length of hydrophilic or hydrophobic moieties in surfactants resulted in a higher yield of (S)-2-octanol. The alkylphenol ethoxylate surfactants had a less influence than polyoxyethylenesorbitan trialiphatic surfactants on the product e.e. It suggested that the product e.e. resulting from the change of carbon chain length of the hydrophobic moieties varied markedly compared with the change of carbon chain length of the hydrophilic moiety. Emulsifier OP-10 and Tween 20 markedly enhanced the yield and product e.e. at the concentration of 0.4 mmol L−1 with a yield of 73.3 and 93.2%, and the product e.e. of 99.2 and 99.3%, respectively, at the reaction time of 96 h.

Abstract Background Low concentrations of nonionic surfactants can change the physical properties of cell membranes, and thus and in turn increase drug permeability. Porcine circovirus 2 (PCV2) is an extremely slow-growing virus, and PCV2 infection of PK-15 cells yields very low viral titers. The present study investigates the effect of various nonionic surfactants, namely, Tween-20, Tween-28, Tween-40, Tween-80, Brij-30, Brij-35, NP-40, and Triton X-100 on PCV2 infection and yield in PK-15 cells. Result Significantly increased PCV2 infection was observed in cells treated with Tween-20 compared to those treated with Tween-28, Tween-40, Brij-30, Brij-35, NP-40, and Triton X-100 (p

[Display omitted] Nanodiamond dispersions in water and DMSO were stabilized with adsorbed layers of nonionic surfactant Igepal CA-630. Adsorption isotherms of Igepal CA-630 onto nanodiamonds from water and DMSO reveal the structure of the adsorbed layers. The stabilized aqueous dispersions retain their resistance to aggregation for at least 7 days, while the dispersions in DMSO are stable for 3 days. [ABSTRACT FROM AUTHOR]

We measured the self-diffusion coefficients of mixed micelles formed in binary mixtures of oxyethylated isononylphenols (neonols) AF9-2,3,4,6,8,9,10,12 by NMR diffusometry in aqueous 1 wt% solutions. The effective hydrodynamic radii of the micelles were calculated using the Stokes-Einstein relation. Cloud points of these solutions were determined visually and the relation between the cloud point and the composition of the mixture was suggested. Extraction of phenol from the solutions at their cloud points was also studied. [ABSTRACT FROM AUTHOR]

The relative mobility of weakly- and strongly-bound portions of hydrophobe-capped ethoxylate surfactants leads to discrepancies in NMR signal intensity which, surprisingly, increase with temperature. Nonionic surfactants have been widely used for many consumer products and industrial processes, and their applications often involve temperature-cycling across cloud point temperature (T cloud). To explore the behavior of nonionic surfactants across T cloud and when mixed with colloidal silica at a very dilute concentration around 0.1 wt%, a series of 1,2-epoxybutane-capped alcohol ethoxylates (BAEs) with various cloud points is used as a model system. BAEs with cloud points from 15 to 64 °C were successfully prepared by varying the lengths of 1,2-epoxybutane (BO) and ethylene oxide (EO) blocks and their phase behavior across T cloud was studied using nuclear magnetic resonance spectroscopy (NMR), dynamic light scattering (DLS) and differential scanning calorimetry (DSC). In the absence of silica, the NMR signals are not greatly affected by the cloud point transition, but both the water and surfactant exhibit a decrease in spin-spin relaxation time once the temperature reaches the T cloud. In the presence of silica, the NMR spectra indicate significantly reduced mobility of the EO portion relative to the alkyl and BO segments. Furthermore, our results suggest that the BAE surfactants are not fractionally clouding out or precipitating with a portion of the compositional distribution during the cloud point transition. [ABSTRACT FROM AUTHOR]

Wastewater treatments such as forward osmosis (FO) can be widely applied to separate or the reject substances from secondary treated effluents. Experimental studies have investigated the influence of membrane fouling and operating conditions. The performance of FO is affected by membrane fouling characteristics, composition of the feed solution and operating conditions. The experiments were performed using an osmotic membrane (FO-4040) to investigate the influences of operating conditions on water flux and reverse salt selectivity. The surfactant content, cross-flow velocity, and pH of the feed solution were systematically investigated for their effects on FO performance. The results showed that higher cross-flow velocities, increase of the pH of the feed solution, and adding surfactant into the feed solution yielded higher water fluxes. Reverse salt selectivity also increased after adding a surfactant to the feed solution but showed no significant increase at higher surfactant concentrations. [ABSTRACT FROM AUTHOR]

The Cloud Point Extraction (CPE) of Pb(II) ion, using Triton X-114/alanine and Triton X-114/phenyalanine as biodegradable systems, was carried out. The experimental results are expressed by four responses to surfactant concentration, amino acid concentration and temperature variations: extent of solute extraction (E), remaining solute (Xm,w) and surfactant (Xt,w) concentrations in dilute phase and volume fraction of coacervate (φC) at equilibrium. An empirical smoothing method was used, where the results were represented on three dimensional plots using the Box-Behnken design (BBD) and the response surface methodology (RSM). High extraction efficiencies (94 % with alanine and 98 % with phenylalanine) are reached in optimal conditions. Thereby, solute concentration reduction in the dilute phase is about 4 and 12 times with alanine and phenylalanine, respectively. The pH effect is also studied. Finally, the possibility of recycling the surfactant/amino acid system by pH change is proved. [ABSTRACT FROM AUTHOR]

Nonionic surfactants are highly stable and cost‐effective and receiving acceptance for applications in many diverse fields including drug delivery, due to their distinctive properties. Here, we report on the synthesis and characterization of sulfanilamide‐based nonionic surfactants for nanoscale vesicular drug loading applications. Nonionic surfactants were synthesized through alkylation of sulfanilamide with alkyl halides that possessed diverse degrees of lipophilicity. They were explored for their nanovesicular drug loading with Cefixime as a hydrophobic model drug. Drug‐loaded nanovesicles were characterized for surface morphologies, size, size distribution, surface charge, and drug loading efficiency using atomic force microscopy (AFM), dynamic light scattering (DLS), and UV–visible spectrophotometry. All of the synthesized nonionic surfactants revealed their CMC values in 0.055–0.035 mM range depending upon the lipophilic chain length of surfactants. They caused a decreased hemoglobin release and low toxicity against cell culture. They self‐assembled and loaded an increased amount of drug in the form of nanorange spherical shape niosomal vesicles. Results of the current study verify these synthesized nonionic surfactants are hemocompatible, nontoxic, and capable of self‐assembling into nanorange niosomal vesicles. These niosomal vesicles can be suggested as safe and highly efficient nanocarriers for hydrophobic drug loading and delivery. [ABSTRACT FROM AUTHOR]

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. 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. 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 12 E 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. [ABSTRACT FROM AUTHOR]

The kinetics of the reaction methionine+cumene hydroperoxide in the presence of nonionic surfactant was studied both in the pre-micellar and post-micellar regions at different temperatures by iodometry. It was established that the rate of the methionine + cumene hydroperoxide reaction depends on the molecular/ionic/micellar form of surfactant in the reaction system. In the post-micellar region the rate of methionine+cumene hydroperoxide reaction slows down due to solubilization of the reacting substances in the micelles. Quantification of solubilization of cumene hydroperoxide and methionine in the micelles has been studied by HPLC analysis. It was obtained that about 30% of cumene hydroperoxide, which is more hydrophobic than methionine, is solubilized in the micelles, as a result the concentration of cumene hydroperoxide in the reaction environment decreases and the rate of reaction in the post-micellar region also decreases. Based on the kinetic studies the reaction rate constant was determined and the value of activation energy was obtained. [ABSTRACT FROM AUTHOR]

The SAPO-34 catalysts were successfully synthesized with different amounts of a cheap and green nonionic surfactant (Triton X-100) as a mesoporogen additive and MOR/TEAOH as microporous mixed templates. The prepared samples were characterized and tested in the methanol to olefins (MTO) reaction under the industrial feed composition of 72 wt% methanol in water. The results revealed that the surfactant concentration affects the acidity, particle size, and textural properties which results in different catalytic performances. The sample prepared with the surfactant molar ratio of 0.02 exhibits a 12% improvement in the light olefins selectivity (90%) as well as the longer catalyst lifetime (more than 330 min) compared to the parent one (79.3% selectivity and 260 min lifetime). This could be attributed to the high crystallinity, smaller crystallite size, proper lower acidity, higher surface area, and the facilitation of reactants and product transportation through mesoporosity created in the structure of crystals. Highlights: SAPO-34 molecular sieve was synthesized with a new and cost-effective surfactant (Triton X-100) as a green route. Catalytic performance was carried out under severe feed composition (72 wt% methanol in water) which is close to industrial conditions. The sample SP-34 (0.02) showed a promising performance for MTO reaction with 90% total olefins selectivity and more than 330 min lifespan. Compared with the best catalyst synthesized with TX-100 by Rami et al. (Synthesis and characterization of a nano-sized hierarchical porous AuSAPO-34 catalyst for MTO reaction: Special insight on the influence of TX-100 as a cheap and green surfactant, 2019), SP-34 (0.02) showed more than 12% improvement in the catalyst lifetime with comparable olefins selectivity. [ABSTRACT FROM AUTHOR]

Synthesis of mesoporous MnFe 2 O 4 nanocomposites employing a simple one-pot approach of manganese acetate with ferric nitrate at varying surfactant F127 triblock copolymer molar ratios from 0.0075 to 0.020 was conducted, and their impacts on the physical properties, morphology, crystallinity, and photocatalytic performance were investigated. TEM images of the synthesized mesoporous MnFe 2 O 4 nanocomposites exhibit a quasi-spherical structure with 15–20 nm diameters. The lattice spacing of the MnFe 2 O 4 plane (311) was determined by ~ 0.256 nm, implying the construction of the cubic MnFe 2 O 4 lattice structure. Interestingly, the obtained mesoporous MnFe 2 O 4 nanocomposites have a large surface area of 227 m2/g for the first time. The total pore volume and average pore diameter were measured ~6.0 nm and 0.33 cm3/g, respectively. The photocatalytic performance of the mesoporous MnFe 2 O 4 nanocomposites for degradation of ciprofloxacin (CIP) was boosted from 50% to 100% by increasing surfactant F127 molar ratios from 0.0075 to 0.020. The photodegradation rate of the synthesized photocatalyst at 0.020 surfactant F127 molar ratio is higher two times than that of the synthesized one at 0.0075 molar ratio. Such high photocatalytic performance of mesoporous MnFe 2 O 4 nanocomposite at high surfactant F127 molar ratio as compared with other samples might be referred to some effects like generation high •OH concentration, reduction of light scattering as a result of large pore volume and high surface area, or a rapid diffusion of the CIP to the active sites through the mesoporous structure. [ABSTRACT FROM AUTHOR]

This paper presents a nonionic surfactant in the anionic surfactant pair (ternary mixture) that influences the hydrophobicity of the alkaline–surfactant–polymer (ASP) slug within low-salinity formation water, an environment that constrains optimal designs of the salinity gradient and phase types. The hydrophobicity effectively reduced the optimum salinity, but achieving as much by mixing various surfactants has been challenging. We conducted a phase behavior test and a coreflooding test, and the results prove the effectiveness of the nonionic surfactant in enlarging the chemical applicability by making ASP flooding more hydrophobic. The proposed ASP mixture consisted of 0.2 wt% sodium carbonate, 0.25 wt% anionic surfactant pair, and 0.2 wt% nonionic surfactant, and 0.15 wt% hydrolyzed polyacrylamide. The nonionic surfactant decreased the optimum salinity to 1.1 wt% NaCl compared to the 1.7 wt% NaCl of the reference case with heavy alcohol present instead of the nonionic surfactant. The coreflooding test confirmed the field applicability of the nonionic surfactant by recovering more oil, with the proposed scheme producing up to 74% of residual oil after extensive waterflooding compared to 51% of cumulative oil recovery with the reference case. The nonionic surfactant led to a Winsor type III microemulsion with a 0.85 pore volume while the reference case had a 0.50 pore volume. The nonionic surfactant made ASP flooding more hydrophobic, maintained a separate phase of the surfactant between the oil and aqueous phases to achieve ultra-low interfacial tension, and recovered the oil effectively. [ABSTRACT FROM AUTHOR]

Copyright of Detergent & Cosmetics is the property of Detergent & Cosmetics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Petroleum hydrocarbons are applied in various energy activities. If accidents happen, they may result in environmental contamination, especially in soil. Petroleum hydrocarbons have low evaporation rates and are adsorbed on the soil surface, making it necessary to treat contaminated soil before the pollutants spread to other areas. Soil washing with surfactant solution is a method used to treat petroleum hydrocarbon contamination. The process relies on surfactant properties which reduce surface tension and desorb diesel from soil particles prior to flushing out with water. The relationship between efficiency of diesel extraction from contaminated soil and factors of both single surfactants (Span20, Tween20, Tween80, Dehydol LS9) and mixed surfactants (Span20+Tween20, Span20+Tween80, Span20+Dehydol LS9) were investigated including hydrophile-lipophile balance (HLB) and interfacial tension (IFT) to select a suitable surfactant. Diesel was analyzed by GC-FID. Findings revealed that extraction efficiency significantly increased when the HLB of the surfactant increased in every solution pair (p = 0.05). Span20+Dehydol LS9 solution with HLB 12 showed the lowest IFT (17.767 ± 0.013 mN/m) and the highest diesel extraction efficiency (66.2%). The water washing process, repeated twice after washing with 1% (w/v) Span20+Dedydol LS9, resulted in less toxicity on germination and growth of tomato, rice, and green bean compared with diesel washing solution and fresh washing solution. Diesel-contaminated soil washing with mixed surfactant is an interesting alternative as an environmentally friendly soil treatment. [ABSTRACT FROM AUTHOR]

The supercritical fluid chromatography coupled with mass spectrometry (SFC‐MS) method and liquid chromatography coupled with mass spectrometry (LC‐MS) method were developed for the separation and characterization of poly (ethylene oxide) methyl glucose sesquistearate (PEO‐Glu‐sesquistearate). The products of PEO‐Glu‐sesquistearate are composed of complex oligomers. The relationship between molecular structure of these oligomers and chromatographic retention behavior in both SFC and LC were discussed and compared. As compared with LC, hydrophobic moieties of compounds favor the fast elution in SFC. The different series can be better separated by LC, while the homologues compounds in same series can be better separated by SFC, and SFC‐MS provided more comprehensive structural information. Different series such as PEO‐distearate, PEO‐stearate, PEO, PEO‐Glu‐tetrastearate, PEO‐Glu‐tristearate, PEO‐Glu‐distearate, PEO‐Glu‐stearate, and PEO‐Glu were identified by MS/MS. [ABSTRACT FROM AUTHOR]

One of the central challenges in producing water-in-diesel microemulsion fuels is to attain their thermal stability (to separate phases) for possible utilization and storage in various environmental and operating conditions. Thus, it should be possible to control the stability of the microemulsion systems at different temperatures. The present study discusses how to control the thermal stability of the microemulsion fuels in a temperature range from −21 °С to +73 °С. The effects of various alcohols, the concentration of ammonium acetate, and the surfactant/co-surfactant and diesel/water ratios are examined. Various C5-C9 alcohols can be used as co-surfactants to stabilize the microemulsions. An increase in the co-surfactant content and the usage of ammonium acetate brines as dispersed phase shifts the ranges of the thermal stability of the water-in-diesel microemulsion fuel towards lower temperatures. A decrease of the water fraction in the microemulsion fuel by 30% contributes to more than two-fold widening of the temperature band of stability. The optimum composition of the microemulsion fuel with the temperature bandwidth of thermal stability of about 86 °С is formulated. The thermal stability of the water–diesel–Neonol AF 9-6–2-ethylhexanol microemulsion system are compared with the known counterparts. [ABSTRACT FROM AUTHOR]

The nonionic surfactants DL-α-tocopherol methoxypolyethylene glycol succinates (TPGS-X-M, X represents the molecular weight of methoxypolyethylene glycols used and X is 750, 1000, 1500 or 1900) have been efficiently synthesized using DL-α-tocopherol as the hydrophobic end and polyethylene glycol(EO) as the hydrophilic end. Critical micelle concentrations (cmc), and the static and dynamic surface tensions of these four surfactants have been measured. These surfactants were used as dispersing agents in 20% etoxazole suspension formulation. The resulting dispersions were compared with the commercial dispersant FS3000 in various physical and chemical parameters. The static surface tensions of the surfactants indicated that the length of polyoxyethylene ether chain had little influence on the critical micelle concentrations of the surfactants. The results of dynamic surface tension tests showed that the surfactants TPGS-1000-M, TPGS-1500-M and TPGS-1900-M had a greater downward trend than that of FS3000 at 1 249.3 ms, which exhibited some advantages. The surfactants TPGS-1500-M and TPGS-1900-M were used as dispersing agents in 20% etoxazole suspension formulation for the test of their particle sizes, suspension rates, active ingredient contents, suspensibilities, thermal storage stabilities and low temperature stabilities. The results revealed that the suspension effects of new surfactants TPGS-1500-M and TPGS-1900-M were similar to that of FS3000 suspending agent. Therefore, surfactants TPGS-1500-M and TPGS-1900-M could be used as dispersing agents for suspension formulatio [ABSTRACT FROM AUTHOR]

The interaction between biological surfactant sodium deoxycholate (NaDC) and nonionic surfactants polyoxyethylene (n) nonylphenol ether (NPn) for the formation of micelles in aqueous solution were investigated. Surface tension, interfacial dilational viscoelasticity, and transmission electron microscopy (TEM) were characterized to systematically study the interaction between NaDC and NPn in buffer solution. At last, the mechanism of the interaction between NPn and NaDC were analyzed. The surface tension results show that the interaction between NaDC and NPn was displayed synergism action. The composition of the mixed systems has been estimated on account of the regular solution theory, Clint's equation, Rubingh theory and Rosen theory. The surface dilational rheology provided abundant effective information on the feature of adsorbed layers. From the oscillating barrier measurements, the peak values of the dilational modulus moved to lower concentrations in NaDC/NPn binary system compared to single surfactant. The dilational elasticity of the binary system decreased distinctly on the basis of the rigid structure of NaDC. The interaction of these two substances was proved directly by TEM images, that the boundaries of the aggregates are clearer due to the protection of NPn molecules. The new complex systems have potential application in environmental protection. Schematic illustration of the aggregation in NPn/NaDC mixed systems and concentration increased from left to right. [ABSTRACT FROM AUTHOR]

Alkyl glycosides were synthesised from starch and alcohols using Aspergillus oryzae a-amylase as catalyst. The surface plot of objective function is drawn by Minitab in order to more directly reflect the interaction between the various factors that affect the sugar conversion rate and the role of strength for interaction between the various experimental factors. The result shows that in the reaction with methanol, methyl maltoside and methyl maltotrioside were the main alcoholysis products. It is seen that there is strong interaction among the various experimental factors. When catalyst mass concentration is 10%, reaction time is 1 h, reaction ratio is 1, sugar conversion rate is 98.80%. Response surface methodology (RSM) could be effectively adopted to optimize the operating multifactor in synthesis of alkyl glycosides nonionic surfactant process. [ABSTRACT FROM AUTHOR]

The effect of several prevalent cations (including Na+, K+, Mg2+, Ca2+, Al3+, and Fe3+) on the adsorption of monochlorobenzene (MCB) onto bentonite was investigated at the coexistence of nonionic surfactant Tween 80 (T80) in surfactant-enhanced remediation (SER). They are all favorable for MCB and T80 adsorption, especially Mg2+ and Ca2+. Adsorption of MCB is strongly depended on T80 micelles. When its concentration exceeds the solubility, MCB is easier to bind with T80 micelles and be adsorbed by bentonite. Acidic environment can facilitate MCB and T80 adsorption, but the effect of cations on the adsorption is most significant under alkaline conditions. Adsorption capacity of MCB increases first followed by a slight decrease with increasing cations concentrations. The maximum adsorption rate of MCB determined is about 68.4% in a solution containing Mg2+ in the isothermal adsorption of MCB, while it is only 6.8% in a cation-free solution. Various characterizations showed that cations mainly changed the repulsion between bentonite particles and T80 micelles and the agglomeration and structure of bentonite, thus affecting the adsorption of MCB and T80 micelles. Our research demonstrated the nonnegligible promotion of MCB adsorption on bentonite by cations and acidic environment, which will adversely affect SER efficiency. [Display omitted] • Cations mainly promote the adsorption of T80 micelles rather than T80 monomers. • The higher the MCB dosage, the greater its adsorption rate in cations solutions. • MCB above its solubility is easier to bind with T80 and be adsorbed by bentonite. • T80 makes the zeta potential of bentonite particles rise and morphology smooth. • The particle size of bentonite decreases at higher cation concentrations. [ABSTRACT FROM AUTHOR]

Nonionic surfactants are reported as being able to enhance enzyme stability and increase the conversion of enzymatic reactions. Surfactant-assisted enzymatic hydrolysis conversion is affected by surfactant HLB values. This work investigated the influence of nonionic surfactants with different HLB values on chitosan enzymatic hydrolysis using cellulase enzyme by measuring the reducing sugars formation, viscosity, and molecular weight of hydrolyzed chitosan. A characterization analysis of hydrolyzed products was also carried out. A higher HLB value exhibits a better enzymatic chitosan hydrolysis performance, shown by the decrease in a solution’s viscosity and the increase in reducing sugar formation. Increasing the surfactant concentration will also increase the hydrolysis rate. Nonionic surfactants can protect cellulase enzyme from the denaturation of temperature and stirring influence. The higher the HLB value, the lower the molecular weight of the hydrolyzed chitosan. The result of UV–Vis demonstrated aldehyde groups formation during hydrolysis. The SEM analysis showed that the chitosan, hydrolyzed using different HLB values of surfactants, had different surface morphologies. However, it did not change the chemical structure of the hydrolysis product seen by the FTIR analysis. The XRD patterns showed that the relative crystallinity of raw chitosan decreased when hydrolyzed with surfactants.

It is a well-known fact that sirolimus (SRL) undergoes degradation process via hydrolysis in aqueous media, leading to incorrect assessment of drug amount and thus release characteristics of formulations. The main objective of the present study was to evaluate the effect of nonionic surfactants in media on in-vitro release profiles for sirolimus eluting stents (SES) coated with biodegradable polymeric matrix. Phosphate buffer and acetate buffer incorporating nonionic surfactants with varying concentrations were examined for adequate solubility and stability (by RP-HPLC). Good sink condition was achieved in phosphate buffer (at pH 4.0) with 1.0% Tween 20, 1.0% Brij 35% and 0.5% Brij 58. Hydrodynamic size (by DLS) and the micelle-water partition coefficient (P) with standard free energy of solubilization (∆Gs°) of drug were evaluated to get some understanding about the solubilization phenomena. About 80% of drug release during the period of 48 h was achieved in optimized drug release media which was 1.0% Tween 20 in phosphate buffer pH 4.0. The obtained accelerated SRL release profile in optimized medium correlated well with the real time in-vitro release in phosphate buffer (pH 7.4). Surface morphology changes (by SEM), changes in gravimetric weights and molecular weight change (by GPC) were examined before and after drug release to understand the drug release mechanism which explains that the polymer did not undergo degradation during the drug release.

This work has developed and evaluated a microemulsion-based drilling fluid formulation with characteristics to be applied in oil wells. The microemulsion was formulated with a solution of water/glycerol, pine oil, and Tween 80, a nonionic and biodegradable surfactant. The physical and chemical properties of the drilling fluid obtained in this work were investigated through rheology and filtration analysis, solids content, aging, lubricity, toxicity, and thermal degradation. A non-toxic microemulsion-based drilling fluid oil-in-water (O/W) with high lubricity (0.07638) and thermal stability was obtained with suitable viscosity, gel strength and low fluid loss (4.0 mL), low solids content (6%), stability in a wide range of salinity conditions, and the possibility of high water content (above 85% in mass fraction). The fluid presented a pseudoplastic behavior, and statistically significant Herschel–Bulkley parameters were obtained.

Surfactant-enhanced soil washing has been used for remediation of organic pollutants for an extended period, but its effectiveness and wide application was limited by the high concentration of surfactants utilized. In this work, the efficiency of conventional soil washing performance was enhanced by 12–25% through the incorporation of air bubbles into the low concentration surfactant soil washing system. Surfactant selection pre-experiment using aerated and conventional soil washing reveals Brij 35 > TX100 > Tween 80 > Saponin in diesel oil removal. Optimization of the effect of time, surfactant concentration, pH, agitation speed, and airflow rate in five levels were undertaken using Response Surface Methodology and Central composite design. The optimum degree of variables achieved was 90 min of washing time, 370 mg/l of concentration, washing pH of 10,535 rpm of agitation speed and 7.2 l/min of airflow rate with 79.5% diesel removal. The high predicted R2 value of 0.9517 showed that the model could efficiently be used to predict diesel removal efficiency. The variation in efficiency of aeration assisted and conventional soil washing was variable depending on the type of surfactant, organic matter content of the soil, particle size distribution and level of pollutant weathering. The difference in removal efficiency of the two methods increases when the level of organic matter increases and when the particle size and age of contamination decreases.

A new microspheres-surfactant flooding system consisting of polymer microspheres and nonionic surfactant has been detailed to enhance oil recovery of Bohai oilfield by increasing the sweep efficiency of water and the oil displacement efficiency of surfactant synchronously. The surface morphology and particle size distribution of polymer microspheres have been investigated through scanning electron microscopy and dynamic lighting scattering. In addition, plugging performance, oil displacement efficiency and the deep profile control process of combination system have been studied by utilizing assembled parallel double cores models and core displacement experiments. The experimental results have shown that the initial appearance of the polymer microspheres was regularly spherical; the particle size distribution was from 200 nm to 6 μm. The particle size of the microspheres after swelling was increased by nearly five times compared with the original particle size. The combination system could exhibit an effective injectivity and plugging effect for cores with different permeability from 0.5 μm2 to 3.0 μm2. This system could significantly reduce fractional flow through high permeability channel, and also present good profile control effect and oil displacement efficiency in parallel double cores. By the injection of the 2.5 PV microspheres solution, the microspheres flooding recovery could improve about 34% more than water flooding. The slug composition, with 400 mg/L polymeric microspheres and 0.3% nonionic surfactant, could obtain a higher oil recovery by 4 wt% original oil than the microspheres system. The combination system could be recommended as a potential combination for profile control in Bohai heterogeneous reservoirs. [ABSTRACT FROM AUTHOR]

The inhibiting action of nonionic surfactants, namely, propoxylated fatty esters (PFE) with different number of propylene oxide toward the corrosion of Zn in 0.1 M HCl solutions was investigated. Four techniques were used in this study such as weight loss, galvanostatic polarization, potentiodynamic anodic polarization and electrochemical impedance spectroscopy. The inhibition efficiency of PFE compounds increases by increasing the concentrations of PFE, number of propylene oxide unit and with lowering temperature. The inhibition was interpreted by adsorption of PFE molecules on the Zn surface according Temkin's isotherm. Galvanstatic polarization indicated that the PFE acts as a mixed type inhibitor. PFE molecules inhibit the pitting corrosion of Zn in a solution containing Cl– ions by moving the pitting potentials into a more noble direction. The activation thermodynamic parameters such as , ΔH* and ΔS* are calculated and explained. [ABSTRACT FROM AUTHOR]

The paper focuses on the behaviour of nonionic surfactants (NISs) for enhanced oil recovery (EOR) processes with special reference to its applicability in the reservoirs of Upper Assam. The present work specifically studies three NISs, viz. Tergitol 15-s-7(Tg7), Tergitol 15-s-9 (Tg9) and Triton X 405(TX), based on their surface tension (ST), dynamic interfacial tension, hydrophilic–lipophilic balance, emulsion stability, aqueous stability, particle size analysis and phase behaviour. Simultaneously, crude oil from an oil field of upper Assam Basin was characterized based on API gravity, kinematic and dynamic viscosities, pour point and acid number. Core flood studies were conducted in the reservoir core to determine the recovery of crude oil during secondary water flood and EOR by NISs. It was observed that Tergitol 15-S-7 when mixed with Triton X-405 (Tg7TX) had the least interfacial tension (IFT) as compared to individual NIS and their mixtures. The recovery was found to be as high as 25.67% after secondary water flood from the original oil in place when Tg7TX followed by chase water was used as an exotic fluid for EOR. This work is an attempt to identify NISs mixtures for EOR for Upper Assam Basin. [ABSTRACT FROM AUTHOR]

Extraction of adamantanes and diamantanes from petroleum source rock using nonionic surfactant was investigated and the optimum conditions for yields of the diamondoids were determined. The conventionally used accelerated solvent extraction method was compared to an innovative microwave-assisted nonionic surfactant extraction (MANSE). A three-level full factorial design of experiment (DoE) was adopted for the optimization of MANSE, involving solvent concentration, extraction temperature as well as extraction time. In-tube extraction (ITEX-2) using TENAX TA as sorbent in combination with gas chromatography-mass spectrometry (GC-MS) was used to determine the diamondoids in the extract. The results revealed that solvent concentration, extraction temperature and time have significant effects on extraction yields of the diamondoids. 0.04 M was the optimum surfactant concentration for extraction of both, adamantane and diamantane. The highest yields of the diamondoids were obtained at extraction temperature of 80 °C. The optimum extraction time for both adamantane and diamantane was 10 min. In comparison with the accelerated solvent extraction method, the results showed that MANSE is more efficient. This study has revealed that MANSE is a robust and efficient environmentally benign sample preparation method for geochemical evaluation of petroleum source rock. Image 1 • Nonionic surfactant has significant efficiency for extraction diamondoids from source rock. • Temperature and time interaction had significant effects on diamondoids yields. • The interactions of temperature/concentration and time/concentration had low influence on extraction yields. • The new method is environmentally friendly and efficient for extraction of diamondoids from source rock. [ABSTRACT FROM AUTHOR]

• The 9α-hydroxyandrost-4-ene-3,17-dione is a key intermediate of steroid drugs. • A nonionic surfactant is selected based on hydrophilic-lipophilic balance values. • Polyoxyethylene (10) nonylphenyl ether enhanced phytosterol solubility by 12.1-fold. • The 9α-hydroxyandrost-4-ene-3,17-dione molar yield increased to 42.5%. The 9α-hydroxyandrost-4-ene-3,17-dione (9α−OH-AD) is a key intermediate for synthetizing steroid pharmaceutical compounds. It is bioconverted by Mycobacterium sp. LY-1 from phytosterols. During biotransformation, the low solubility of phytosterols in water limits 9α−OH-AD production. In the present work, polyoxyethylene (10) nonylphenyl ether (TX-40), a nonionic surfactant, was first used to enhance phytosterol solubility during 9α−OH-AD biotransformation. In the presence of 0.7% TX-40, phytosterol solubility was increased 12.1-fold, and the 9α−OH-AD molar yield reached 42.5% at the phytosterols concentration of 15 g/L, an increase of 217.2% over controls. The improvement is sufficient to replace the traditional process of adding soybean oil. Scanning electron microscopy showed that the extracellular membrane-like structure was loosened by TX-40, but cells maintained their integrity. The fatty acid profile of Mycobacterium sp. LY-1 cells revealed that TX-40 altered the composition of the cell membrane and improved its permeability. The transcript levels of key enzymes involved in cell membrane lipid synthesis were downregulated significantly upon TX-40 addition compared with controls. These results demonstrated that the increase in product molar yield by TX-40 was primarily related to easier substrate transportation across the cell membrane of Mycobacterium sp. LY-1. [ABSTRACT FROM AUTHOR]

In this paper, epoxy methyl oleate (EMO) was used as the raw material to obtain the dihydroxyoleic acid methyl ester (DHOME) through ring-opening reaction. Then, the DHOME was reacted with ethylene oxide (EO) under Al-Mg composite oxide catalyst to synthesize a novel nonionic surfactant: dihydroxyoleic acid methyl ester ethoxylate (DHOMEE), which has both alcohol polyether and ester polyether chains. FT-IR was used to characterize the molecular structure of target product. Products with different EO addenda (DHOMEE-10, DHOMEE-15, DHOMEE-20) and conventional nonionic surfactants fatty acid methyl ester ethoxylate (FMEE) and methyl oleate ethoxylate (OMEE) were compared in terms of application performance. The results showed that DHOMEE is superior to conventional surfactants in terms of wetting, emulsification, foam and surface tension. In similar products, the performance of DHOMEE-15 is better than those of DHOMEE-10 and DHOMEE-20. [ABSTRACT FROM AUTHOR]

Understanding and predicting cloud point phenomena is important for the formulation of nonionic surfactant systems, and the design of cloud‐phenomena‐associated separation processes. There have been several approaches to fit and predict the cloud point phenomena, in most cases using bulk thermodynamic approaches. In this work, we introduced the hydrophilic–lipophilic‐difference and net‐average‐curvature (HLD‐NAC) as an interfacial (curvature) approach to predict cloud point values at different surfactant concentrations (cloud point curve). The HLD‐NAC method could fully predict the cloud point of alkyl ethoxylate of pure surfactants, typically within 4 °C of the experimental values, using published HLD constants, and the molecular structure of the surfactants. For commercial (polydispersed) surfactants, the same level of accuracy can be achieved if the experimental cloud point at 1 wt.% is used to adjust the HLD values. One additional benefit of using the HLD framework is the ability to predict changes in the cloud point curve with the introduction of electrolytes. While other models can fit the experimental data within 1 °C, the greater uncertainty of the HLD‐NAC (~4 °C) is a reasonable compromise given the simplicity of the approach. [ABSTRACT FROM AUTHOR]

The aqueous self‐assembly behavior of two homologous series of poly(ethylene oxide) (PEO)‐containing nonionic surfactants based on a C10‐Guerbet hydrophobe is reported. The two families of surfactants, alkyl ethoxylates and alkyl alkoxylates, are commercially available from BASF under the trade name Lutensol® XP‐series and XL‐series, respectively. The latter incorporate propylene oxide (PO) units in the surfactant chain. Dye solubilization was used to determine the critical micellization concentration (CMC) of each surfactant at 22 and 50 °C. The PO‐containing alkyl alkoxylates displayed lower CMC values, which were also more sensitive to temperature. The Gibbs free energy, enthalpy, and entropy of micellization were computed from the CMC data and used to identify the contribution of each surfactant moiety (alkyl chain, PO unit, and PEO block) in controlling the CMC. The micellization properties are compared with compositionally similar surfactants with linear alkyl chains, yielding information about the effects of the Guerbet alkyl chain on micellization. Isothermal titration calorimetry was also used to characterize the CMC and enthalpy of micellization which generally compare well with the dye solubilization results. Cloud point data reveal nonmonotonic relationships for the Lutensol® surfactants with respect to composition, unlike linear alkyl chain surfactants. Finally, dilute solution viscosity measurements performed on some Lutensol® surfactants show a change in the slope, suggesting a structural change that tends to be more pronounced for surfactants with longer PEO blocks. The data presented herein enhance the understanding of surfactant structure–property relationships required for industrial formulation. [ABSTRACT FROM AUTHOR]

Cu(II) oxide nanocorals were synthesized for the first time from a lyotropic liquid crystalline system formed from triton X-100 and water. The nanocorals were prepared based on a simple precipitation route, and then characterized by field emission scanning electron microscopy and X-ray diffraction patterns. The nanocorals provided a porous ensemble which comprised adhered nanorods of <50 nm in diameter. XRD pattern confirmed the crystalline structure of CuO with a grain size of ≈30 nm. Electrochemical behavior of the nanocorals was preliminary evaluated in an alkaline solution, and they represented a potential for hydrogen peroxide determination. [ABSTRACT FROM AUTHOR]

Metal nanoparticles have the ability to remove superoxide via changes in the surface electronic states at the large surface area. Gold, silver, and platinum nanoparticles were prepared in the presence of three sugar-based nonionic surfactants using NaBH4 as a reducing agent. The surfactants (glycosyloxyethyl methacrylate: xGEMA) contain sugar oligomers of various lengths (x), are biodegradable, and act as protecting groups for the nanoparticles. Three types of xGEMA were used: dodecyl and hexadecyl chains containing amphiphilic oligomers (C12-3.0GEMA and C16-3.2GEMA) and multi-dodecyl chain with multiple sugar side chains (1.8C12-4.7GEMA). We found that the type of nonionic surfactant affected the size of the nanoparticles. The average size of the gold, silver, and platinum nanoparticles ranged from 1.9 to 6.6 nm depending on the surfactant. The trend in the size of gold nanoparticles in relation to the chosen surfactants was different from that for the silver and platinum nanoparticles. Moreover, the gold nanoparticles did not show effective antioxidant activity for superoxide, whereas the silver and platinum nanoparticles removed superoxide to a certain extent. The general order for superoxide scavenging activity increased in the following order: gold < platinum < silver. In particular, the largest size of silver nanoparticles capped with C16-3.2GEMA had a similar ability for the removal of superoxide as superoxide dismutase (ca. 3999 unit/mg) on the basis of the mass concentration. [ABSTRACT FROM AUTHOR]