EO Groups Research Articles

Temperature Resistant Binary SLES/Nonionic Surfactant Mixtures at the Air/Water Interface.

Surface compositions of adsorbed monolayers at the air/water interface, formed from binary surfactant mixtures in equilibrium, have been studied using neutron reflectivity at three discrete temperatures: 10, 25, and 40 °C. The binary compositions studied are sodium lauryl dodecyl ether sulfate (SLES EO3)/C12E n, where n = 6 and 8, at a fixed concentration of 2 mM with and without the addition of 0.1 M NaCl. Without NaCl, the nonionic surfactant dominates at the interface and nonideal mixing behavior is observed. This is modeled using the pseudophase approximation with a quadratic expansion of the free energy of mixing. The addition of 0.1 M NaCl screens the charge interaction between the surfactants and drives the surface composition of each system closer to that of the bulk composition. However, model fits to both the micelles and surface layers suggest that nonideal mixing is still taking place, although it is difficult to establish the extent of nonideality due to the limited data quality. The effect of temperature changes on the surface adsorption and composition of the surfactant mixtures is minimal and within error, with and without NaCl, but the critical micelle concentrations are significantly affected. This indicates the dominant influence of steric hindrances and surfactant charge interactions in determining interfacial behavior for these surfactants, relative to the temperature changes. The study also highlights the delicate effect of a relatively small change in the number of EO groups on mixing behavior.

Experimental Investigation of Amine-Surfactant CO2 Foam Stability Enhanced by Silica Nanoparticles

The CO2 foam generated by the conventional surfactants usually does not show long-term stability due to the substantial solubility and diffusivity of CO2 in water. Silica nanoparticles with different wettability and high adsorption energy on the gas–water interface can be used as a stabilizer to enhance the stability of the CO2 foam. In this study, nine kinds of nonionic amine surfactants were employed to generate the CO2 foam, while three kinds of silica nanoparticles were selected and added to improve the CO2 foam stability. The influences of various factors, including pressure, temperature, pH, surfactant, and nanoparticle, on the CO2 foam stability have been investigated. The experimental results show that without nanoparticles, the CO2 foam stability decreases with the increase of the number of EO groups in the ethoxylated amine surfactant, especially under high-temperature and high-pressure (HTHP) conditions. In general, the nanoparticles with a low concentration (<0.5 wt %) have little influence on the CO2 foam stability, but when the concentration of nanoparticle is enhanced high enough (1.0 wt %), the CO2 foam stability can be improved significantly. In particular, by adding 1.0 wt % nanoparticle of QS-150 to 0.5 wt % surfactant of C18N(EO)2/10, the CO2 foam stability has been increased 5–6 times, while the volume of generated CO2 foam has been increased by 17–31%. Therefore, in this study, the synergetic mechanisms between the amine surfactants and the silica nanoparticles to generate and stabilize CO2 foam have been identified.

Synergy of surface-treated nanoparticle and anionic-nonionic surfactant on stabilization of natural gas foams

Positively charged surface-treated nanoparticle (S-AK) and anionic-nonionic surfactant sodium fatty alcohol polyoxyethylene ether sulfate (AES) mixture has been used to obtain natural gas foams. It was found that synergy occurs between S-AK and AES in generating stable natural gas foams due to the foam stability of the S-AK/AES mixture being better than that of either single component. It is important to control the contents of two species since there are optimum concentrations for S-AK and AES on stabilizing Natural gas foams. High salinity (≥50,000 mg L−1) is conducive to the stability of S-AK/AES natural gas foams at high temperature (50 °C). In addition to the electrostatic interaction, EO groups significantly promote the attraction between S-AK and AES. The stability of S-AK/AES natural gas foams may relate to two aspects: one is that AES-adsorbed nanoparticles migrate to the gas/liquid interface and enhance the interfacial dilatational elasticity, and the other is that a rigid skeleton structure forms in the natural gas foam films by the flocs consisting of S-AK and AES. Natural gas foams are most stable when the monolayer adsorption of AES molecules on the S-AK surface occurs in the dispersion.

Dilational surface visco-elasticity of CnEOm solutions under dynamic conditions

Harmonic surface oscillations of drops are used to study the dilational surface rheology of solutions of the oxyethylated alcohols C10ЕO8, C12ЕO5 and C14ЕO8 at the fixed oscillation frequency of 0.1 Hz for adsorption times between 200 and 5000 s. It was found that at shorter adsorption times the visco-elasticity modulus is lower than its value at longer adsorption times or in the equilibrium state of the adsorption layer at the same surface pressure. This mechanism is explained by the fact that an actual surfactant, characterized by a certain number of EO groups, is in fact a mixture of compounds with a quite wide range of these groups. As molecules with a smaller number of EO groups exhibit a higher visco-elasticity modulus, the changes in the composition of the adsorbed layer during the adsorption lead to the given situation. These considerations are supported by theoretical calculations of the adsorption for mixed surfactants solution.

Effect of dietary phytoextracts supplementation on growth performance and blood parameters of rainbow trout ( Oncorhynchus Mykiss W. ), cultivated in a recirculation system

The present research aimed to examine the effect of dietary phytoextracts supplementation on the growth performance, haematological (white blood cells, red blood cells, hemoglobin, hematocrit) and biochemical (glucose, urea, creatinine, total protein, albumin, ASAT, ALAT) blood parameters of rainbow trout (Oncorhynchus mykiss W.), cultivated in a recirculation system. The fish were divided into 6 groups: one control (C) and five experimental groups in whose food was added phytoextracts of curcumin (EC), paprika (EP), thyme (ET), oregano (EO) and garlic (EG). The inclusion of phytoextracts had no significant effect on growth parameters of fish from EC, EP, ET, EO and EG groups (P>0.05). Statistically significantly lower feed consumption per unit weight gain was observed in EO group vs C (Р<0.05). The phytoextract supplementation had significant influence on some of the haematological (white blood cells, red blood cells, hemoglobin) and biochemical (urea, creatinine, total protein, albumin, ASAT, ALAT) blood parameters of rainbow trout.

Poly(AN-co-PEGMA)/hBN/NaClO4 composite electrolytes for sodium ion battery

AbstractPolymer electrolytes composed of an acrylonitrile and polyethylene glycol methacrylate copolymer poly(AN-co-PEGMA) with addition of NaClO4 are studied by impedance spectroscopy, differential scanning calorimetry (DSC), fourier transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Hexagonal boron nitride (hBN) particles are having increasing interest owing to mechanical properties, thermal stability, chemical stability and good lubrication property. In this study, hBN was used as an inorganic filler. FTIR spectroscopy was used to examine the interactions between the host polymer and both NaClO4 salt and nano hBN particles. The thermal properties of the composites were studied using TGA and DSC tests. TGA results showed that all the composites membranes were thermally stable till 300°C with one step degradation. Surface morphology of the films was examined with SEM which also reveals the homogeneous dispersion of nano hBN in the polymer matrix. Ionic conductivity was studied with impedance spectroscopy, the results showed that the ionic conductivity increases with increasing PEGMA ratio. ANcoPEGMA 11 20Na (EO:Na ratio=20) sample showed maximum ion conductivity of approximately 3.6×10−4 S cm−1 at 100°C. This is because ANcoPEGMA 11 20Na has highest percentage of PEGMA and highest number of Na+ ion per EO groups.

Outcomes in diabetic foot ulcer patients with isolated T2 marrow signal abnormality in the underlying bone: should the diagnosis of "osteitis" be changed to "early osteomyelitis"?

To evaluate the variability of clinical treatment and outcomes based on reporting of diabetic foot ulcer MRI findings of adjacent marrow T2 hyperintensity with normal T1 signal. A retrospective review was conducted of 46 MRI examinations evaluating diabetic foot ulcers that demonstrated normal T1 marrow signal, but T2 marrow hyperintensity deep to the ulcer. The cohort was divided based on MRI report impressions into three groups; "osteitis without osteomyelitis" (OW), "osteitis but cannot exclude early osteomyelitis" (OCEO) and "early osteomyelitis" (EO). Patient demographics (age, gender) and accessory MRI findings of ulcer and sinus tract depth were recorded. Initial clinical assessment and medical treatment (route and duration of antibiotics), healing versus disease progression and histology or microbiology results were recorded. The isolated marrow T2 signal hyperintensity was reported as OW in 12 patients, OCEO in 18, and EO in 16. No statistical difference in clinical assessment was demonstrated between the OW, OCEO, and EO groups. Pathological condition was available in 15 patients within 0-7days (mean 2.4days) of the MRI examination, with 14 (93%) of these positive for osteomyelitis by histopathology or positive cultures. Initial diagnosis of or progression to osteomyelitis was shown in 28 patients (61%). Treatment of suspected osteomyelitis is heavily determined by clinical factors. Patients who initially demonstrate only T2 marrow signal abnormality under a diabetic ulcer are eventually diagnosed as osteomyelitis in 61% of cases and deserve aggressive treatment as early osteomyelitis when meeting clinical parameters.

Synthesis and characterization of alkyl, propoxy, ethoxy-based frothers

In this paper we describe the synthesis and characterization of a homologous series of linear polyglycol-based frothers comprising alkyl, propoxy (propylene oxide, PO), and ethoxy (ethylene oxide, EO) groups. The identities were confirmed by proton nuclear magnetic resonance spectroscopy and total organic carbon analysis. Characterization used three parameters, bubble size, gas holdup and water overflow rate, measured in a bubble column. The results indicate that increasing number of PO groups led to significant decrease in bubble size, and increase in gas holdup and water overflow rate. Increasing the alkyl chain length, gave similar but less pronounced trends; the least effect was increasing the number of EO groups. Changing the relative position of the PO and EO group had a significant effect on all three parameters. To account for the effect of PO/EO position, a mechanism based on effect of structure on molecule packing at the air/water interface is proposed.

Adsorption of anionic and non-ionic surfactants on carbon nanotubes in water with dissipative particle dynamics simulation.

The morphology of surfactants physically adsorbed on the surface of carbon nanotubes (CNTs) has a significant impact on the dispersion of CNTs in the solution. The adsorption of the surfactants alfoterra 123-8s (AF) and tergitol 15-s-40 (TG) on CNTs was investigated with dissipative particle dynamics (DPD) simulations, as well as the behavior of the binary surfactant system with CNTs. Properties of surfactants (i.e., critical micelle concentration, aggregation number, shape and size of micelle, and diffusivity) in water were determined to validate the simulation model. Results indicated that the assembly of surfactants (AF and TG) on CNTs depends on the interaction of the surfactant tail and the CNT surface, where surfactants formed mainly hemimicellar structures. For surfactants in solution, most micelles had spherical shape. The particles formed by the CNT and the adsorbed surfactant became hydrophilic, due to the outward orientation of the head groups of the surfactants that formed monolayer adsorption. In the binary surfactant system, the presence of TG on the CNT surface provided a considerable hydrophilic steric effect, due to the EO groups of TG molecules. It was also seen that the adsorption of AF was more favorable than TG on the CNT surface. Diffusion coefficients for the surfactants in the bulk and surface diffusion on the CNT were calculated. These results are applicable, in a qualitative sense, to the more general case of adsorption of surfactants on the hydrophobic surface of cylindrically shaped nanoscale objects.

High-Performance PEBA2533-Functional MMT Mixed Matrix Membrane Containing High-Speed Facilitated Transport Channels for CO2/N2 Separation

A novel mixed matrix membrane was fabricated by establishing montmorillonite (MMT) functionalized with poly(ethylene glycol) methyl ether (PEG) and aminosilane coupling agents in a PEBA membrane. The functional MMT played multiple roles in enhancing membrane performance. First, the MMT channels could be used as high-speed facilitated transport channels, in which the movable metal cations acted as carriers of CO2 to increase the CO2 permeability. Second, due to mobility of long-chain aminos and reversible reactions between CO2 and amine groups, the functional MMT could actively catch the CO2, not passively wait for arrival of CO2, which can facilitate the CO2 transport. At last, PEG consisting of EO groups had excellent affinity for CO2 to enhance the CO2/N2 selectivity. Thus, the as-prepared functional MMMs exhibited good CO2 permeability and CO2/N2 selectivity. The functional MMM doped with 40 wt % of MMT-HD702-PEG5000 displayed optimal gas separation with a CO2 permeability of 448.45 Barrer and a CO2/N2...

Telephone Problem-Solving Treatment Improves Sleep Quality in Service Members With Combat-Related Mild Traumatic Brain Injury: Results From a Randomized Clinical Trial.

Evaluate sleep quality, its correlates, and the effect of telephone-based problem-solving treatment (PST) in active duty postdeployment service members with mild traumatic brain injury (mTBI) SETTING:: Randomized clinical trial. Active duty service members with combat-related mTBI. Education-only (EO) and PST groups (N = 178 each) received printed study materials and 12 educational brochures. The PST group additionally received up to 12 PST telephone calls addressing participant-selected issues. Outcomes were evaluated postintervention (6 months) and at 12 months. Pittsburgh Sleep Quality Index. Sleep quality was manifestly poor in both groups at baseline (Pittsburgh Sleep Quality Index = 12.5 ± 4). Overall sleep quality was significantly different between the PST and EO groups at 6 months (P = .003) but not at 12 months. Longitudinally, PST significantly improved sleep quality at 6 months (P = .001) but not over the follow-up. Low sleep quality was associated with concussion symptoms, pain, depression, and posttraumatic stress disorder at all time points (P < .0001). Sleep disorders, common in postdeployment service members with mTBI, are strongly associated with the presence of pain, posttraumatic stress disorder, and depression. Telephone-based PST may be an effective therapeutic approach for reducing sleep disorders in this population. Research should focus on maintenance of treatment gains.

The preparation of SPEEK/phosphate salts membranes and application for CO2/CH4 separation

ABSTRACTSPEEK/phosphate salts membranes were prepared and utilized for CO2/CH4 separation. SPEEK with abundant –SO3H groups and EO groups on polymer chains would be beneficial for CO2 transport. The doped phosphate salts (NaH2PO4, Na2HPO4 and Na3PO4) with different acid‐base properties increased the water content in the membrane, and water was expected to increase both the solubility and diffusivity of CO2 in the membrane. All membranes were characterized by FTIR, TGA, and XRD. The CO2 permeability and CO2/CH4 selectivity of SPEEK/Na3PO4 membranes were higher than that of SPEEK/NaH2PO4 and SPEEK/Na2HPO4 membranes. Compared to the pure SPEEK membrane, the CO2 permeability and CO2/CH4 selectivity of SPEEK/Na3PO4−10 membrane were increased by 144% and 65%, respectively. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43399.

Enhanced CO2 separation performance of P(PEGMA-co-DEAEMA-co-MMA) copolymer membrane through the synergistic effect of EO groups and amino groups

PEDM copolymer membrane showed excellent gas separation performance through synergistic effect of EO and amino.

Constructing asymmetric membranes via surface segregation for efficient carbon capture

Novel asymmetric membranes consisting of polyethersulfone (PES) as the membrane matrix and poly(ethylene oxide) (PEO)-containing block-copolymer F68 as the versatile modifier are prepared via surface segregation. The membranes are then characterized by scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectra, X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC) and electronic tensile machine. The surface segregation of CO2-philic EO groups greatly enhance CO2 solubility in the membrane surface. Moreover, the increased PES chain mobility by the interaction between PES and F68 enhances the gas diffusivity in the bulk active layer. The membrane with 20wt% F68 exhibits CO2 permeance increment of 210% and CO2/N2 selectivity increment of 105%. Pressure, temperature and long term tests are conducted to get more integrated understanding of membrane performance. The strategy of constructing asymmetric membranes by surface segregation holds great promise for efficient carbon capture.

A new type of renewable surfactants for enhanced oil recovery: Dialkylpolyoxyethylene ether methyl carboxyl betaines

Abstract To avoid side effects in alkali-surfactant-polymer (ASP) flooding due to use of caustic alkalis, surfactant-polymer (SP) flooding free of alkali has been paid more attention in recently years. This calls surfactants more hydrophobic than those used in ASP flooding. A carboxyl betaine with double long alkyls, didodecylmethylcarboxyl betaine (diC 12 B), is such a candidate which behaves very well in reducing crude oil/water interfacial tension (IFT) but suffers from poor aqueous solubility and large adsorption loss by negatively charged sandstone. In this paper a new type of carboxyl betaines derived from renewable materials were synthesized by inserting EO groups between the long alkyl chains and head groups, and both homogenous compounds (diC 12 E n B, n = 2, 3, 4) and a mixture of homologues diC 12–14 E n B ( n = 2.2) derived from commercially available coconut alcohol polyoxyethylene ether were obtained and their properties as surfactants for SP flooding free of alkali were evaluated. The results show that with increasing EO number the solubility of the surfactants increases whereas the adsorption loss decreases, and accordingly the hydrophilicity of the surfactants increases, leading to a decrease of their preferred alkane carbon number ( N min ). Using these surfactants solely ultra low IFT ( 12 E 2 B, diC 12 E 4 B, and diC 12–14 E 2.2 B against C 13–15 , C 7–9 , and C 8–9 n -alkanes, respectively, and an order of 10 −2 mN/m IFT between Daqing crude oil and connate water can be achieved. However, ultra low IFT between Daqing crude oil and connate water can be achieved by using these surfactants via formulations. In comparison with diC 12 B the new surfactants with EO groups have both improved aqueous solubility and lower adsorption loss when employed in SP flooding free of alkali.

Modeling the Adsorption of Rheology Modifiers onto Latex Particles Using Coarse-Grained Molecular Dynamics (CG-MD) and Self-Consistent Field Theory (SCFT)

We model the adsorption of hydrophobically ethoxylated urethane (HEUR) thickeners onto two hydrophobic surfaces separated by a 50 nm gallery using coarse-grained molecular dynamics (CG-MD) with implicit solvent and three-dimensional self-consistent field theory (SCFT) with explicit solvent. The CG-MD simulations can be readily extended to encompass very long HEUR chains (up to 540 EO groups) but cannot with current computer speed simulate adsorption of HEURs with hydrophobes longer than 12 carbons (C12). The SCFT method can readily simulate HEURs with longer, C16, hydrophobes but has a greater challenge simulating very long EO chains. For HEURs with 180 EO units and C8 and C12 hydrophobes, both methods can be applied, allowing a combination of the two methods to span much of the parameter space of interest to experimentalists. It is demonstrated that depending on the hydrophobe strength and the HEUR concentration, HEUR chains can adsorb to the surfaces directly or indirectly (as adsorbed micelles or admic...

Effect of Cyclohexane on the Phase Behavior of L64/1-Butyl-3-Methylimidazolium Tetrafluoroborate System

The triblock copolymer poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (L64, PEO13PPO30PEO13) in 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]) can form lamellar liquid crystalline (Lα). The effect of apolar cyclohexane molecules on the Lα phase was investigated by using polarized optical microscopy (POM) and small-angle x-ray scattering (SAXS). The results of POM and SAXS show that a suitable amount of cyclohexane can contribute to the formation of lamellar liquid crystals, and the ordering of Lα phase is increased. For comparison, the effect of polar water on Lα phase was explored. After adding water, both EO groups and [BF4]– anion can form hydrogen bonds with water molecules, which weakens the electrostatic interactions between L64 and [Bmim][BF4] and therefore the ordering of lamellar structures is destroyed.

Sodium Alkyl Ether Sulfonates (SAES): Dual Anionic‐Nonionic Behavior in Synthetic Brine Having High Salinity and Hardness

AbstractDue to the presence of non‐sulfonated residual alkyl ether (AE), sodium alkyl ether sulfonate (SAES) may exhibit clear point‐cloud point solubilization behavior in brine. Accordingly, the effect of temperature on the compatibility of iC17EOxS (x = 7 and 10), nC17EO10S, along with their analogous nonionic surfactants iC17EOxH (x = 7 and 10) and nC17EO10, in addition to iC9EO14 in brine has been investigated. Depending on their molecular structures, these surfactants exhibited concentration‐dependent clear point and cloud point solubilization behavior. The cloud point was associated with the AE component whereas the clear point was attributed to the sulfonated one. Interestingly, an increase in the cloud point of the nonionic component with respect to the corresponding nonionic AE (100 % active) was observed. Adding iC9EO14 (100 % active) to iC17EO7S (xan = 0.0–0.362) resulted in a significant decrease in the clear point of iC17EO7S from above 100 °C to below 22 °C with a concomitant increase in iC17EO7/iC9EO14 mixture cloud point from 68 °C. (xan = 0) to 72 °C (xan = 0.325). This relatively modest increase by 4 °C was attributed to the interrelationship of different competitive mechanisms, namely an increase in mixed micelle charge with increasing xan, the dehydration of OE groups via ion (SO3−)‐dipole (O → CH2) interactions, and possible shielding of SO3− groups by iC9EO14 nearby extended EO groups. To the best of our knowledge, this is the first instance where dual anionic‐nonionic solubilization behavior of SAES in brine characterized by high salinity and hardness is being reported.

Ethanol-in-palm oil/diesel microemulsion-based biofuel: Phase behavior, viscosity, and droplet size

Increased environmental awareness and depletion of resources are driving industry to develop viable fuels from renewable resources. Vegetable oils are one alternative being considered for the production of renewable fuels. Surfactant reverse micelle microemulsions can be used as an alternative method for reducing high viscosities of vegetable oil without chemical wastes generated from the transesterification reaction. The objective of this research is to study the effects of surfactant saturation, unsaturation, and ethylene oxide groups on the phase behavior, kinematic viscosity, and microemulsion-droplet size with the goal of formulating optimized surfactant based biofuel. Four nonionic surfactants, stearyl alcohol (saturated), oleyl alcohol (unsaturated), methyl oleate (unsaturated with ester group), and Brij-010 (EO groups), were investigated in this research. It was found that the presence of methyl oleate unsaturated surfactant can greatly reduce the bulk viscosity and produce uniformly size of microemulsion droplets while use the least amount of surfactant for solubilizing ethanol-in-oil in the system. Thus, these results show that reverse micelle microemulsion can produce biofuels with desirable viscosity and fuel properties as compared to diesel.

Abstract 121: Role of Leukocyte Gpr120 in Atherosclerosis Development in Polyunsaturated Fatty Acid Diet Induced Atheroprotection in LDLrKO Mice

Introduction Diets enriched in polyunsaturated n-3 and n-6 fatty acids (PUFAs) are atheroprotective. FO, which is enriched in n-3 PUFAs, reduces plasma lipids and has anti-inflammatory effects. Recent studies have shown that GPR120 is the physiological n-3 PUFA receptor and its ligation by n-3 PUFAs blunts pro-inflammatory signaling pathways. However, the role of GRP120 in atherogenesis is unknown. Hypothesis We hypothesized that leukocyte GPR120 contributes to the atheroprotective effects of n-3, but not n-6, PUFUs by ligation of GRP120, resulting in decreased leukocyte inflammation. Methods Female LDLr-/- mice were transplanted with bone marrow from male wild type or GPR120 knockout mice. After recovery from transplantation, recipient LDLr-/- mice were fed atherogenic diets containing 0.2% cholesterol and enriched in saturated/monounsaturated fat (palm oil, PO), n-6 PUFA (borage, BO), a botanical n-3 PUFA (echium oil, EO) or FO for 16 weeks. Periodic blood samples were taken for lipid and lipoprotein measurements and aortas were harvested after 16 weeks of diet feeding to quantify atherosclerosis. Results Compared to the PO group, mice fed BO, EO and FO had significantly lower plasma total and very low density lipoprotein (VLDL) cholesterol concentrations. EO and FO groups also had lower plasma triglyceride concentrations compare to PO and BO fed mice. Compared to the PO group, mice fed BO and EO had significantly reduced aortic CE, comparable to the FO group. However, lack of leukocyte GPR120 did not significantly affect plasma lipids or atherosclerosis severity within any diet group. Conclusion Atherogenic diets enriched in n-6 and n-3 PUFAs derived from botanical oils (BO and EO) were as atheroprotective as FO compared to a diet containing saturated/monounsaturated fat (PO). Furthermore, lack of leukocyte GPR120 had minimal effect on plasma lipid/lipoprotein profile and atherosclerosis, suggesting that n-3 as well as n-6 PUFA associated atheroprotection is primarily due to reduction of VLDL-cholesterol in LDLr-/- mice.