Experimental investigation of the effects of oil asphaltene content on CO_(2) foam stability in the presence of nanoparticles and sodium dodecyl sulfate

Foam stability tests were performed using sodium dodecyl sulfate(SDS)surfactant and SiO2 nanoparticles as foaming system at different asphaltene concentrations,and the half-life of CO_(2) foam was measured.The mechanism of foam stability reduction in the presence of asphaltene was analyzed by scanning electron microscope(SEM),UV adsorption spectrophotometric concentration measurement and Zeta potential measurement.When the mass ratio of synthetic oil to foam-formation suspension was 1:9 and the asphaltene mass fraction increased from 0 to 15%,the half-life of SDS-stabilized foams decreased from 751 s to 239 s,and the half-life of SDS/silica-stabilized foams decreased from 912 s to 298 s.When the mass ratio of synthetic oil to foam-formation suspension was 2:8 and the asphaltene mass fraction increased from 0 to 15%,the half-life of SDS-stabilized foams decreased from 526 s to 171 s,and the half-life of SDS/silica-stabilized foams decreased from 660 s to 205 s.In addition,due to asphaltene-SDS/silica interaction in the aqueous phase,the absolute value of Zeta potential decreases,and the surface charges of particles reduce,leading to the reduction of repulsive forces between two interfaces of thin liquid film,which in turn,damages the foam stability.

Phase Behavior and Structural Transitions in Sodium Dodecyl Sulfonate Microemulsions

The forming mechanism of microemulsion of sodium dodecyl sulfonate, alcohols,water and isooctane was studied, with particular emphasis on the effect of molecular weight andconcentration of alcohols. Phase diagram of the four components, alcohol, sodium dodecyl sulfonate,water and isooctane, was used as a means of study, through which the microemulsion regions weredetermined. Phase diagram of sodium dodecyl sulfonate/n-pentanol/isooctane/water system at κ_m = 2(κ_m = W_(n-pentanol)/W_(SDS)) is presented. The variation of conductivities of differentmicroemulsion samples with water was measured. From the conductivities we investigated a change instructure from water droplets in oil (W/O) at low water content to liquid crystal at intermediatewater content and a stricture of oil droplets in water (O/W) at high water content.

Flotation separation of andalusite from quartz using sodium petroleum sulfonate as collector

The floatability of andalusite and quartz was studied using sodium petroleum sulfonate as collector, being successfully applied in the real ore separation. The collecting performance on minerals was interpreted by means of zeta potential measurement and infrared spectroscopic analysis. The single mineral experiments showed that andalusite got good floatability in acidic pH region while quartz exhibited very poor floatability in the whole pH range. At pH 3, the presence of Fe3+ obviously activated quartz, causing the identical flotation behavior of the two minerals, and calcium lignosulphonate exhibited good selective inhibition to quartz. The real ore test results showed that andalusite concentrate with 53.46% Al2O3 and quartz concentrate with 92.74% SiO2 were obtained. The zeta potential and infrared spectroscopic analysis results indicated that chemical adsorption occurred between sodium petroleum sulfonate and andalusite.

Curing of the Bacillus subtilis Plasmid Using Sodium Dodecyl Sulfate

Curing of Bacillus subtilis plasmid using sodium dodecyl sulfate (SDS)was studied in order to obtain a host strain. An overnight culture of Bacillus subtilis 24/pMX45 was used to inoculate fresh LB containing SDS (0-0.008%). No growth of 24/pMX45 was observed when LB contained an SDS concentration of 0.006% or greater, and the sublethal concentration (w/v) of SDS was 0.005% with a killing rate of 99%. Samples were diluted and plated on LB agar, individual colonies were randomly picked to a selective agar medium by tooth to screen for loss of plasmid-encoded erythomycin resistance. CsCl-EtBr gradient centrifugation and plasmid DNA profile demonstrated that plasmid-cured derivative A7 has completely lost its plasmid. A7 had a shorter lag, and its cell concentration was consistently higher than that of the 24/pMX45. Elimination of the plasmid was first observed after 24/pMX45 had been treated with SDS for 8 h. The percent elimination then continued to increase until about 22 h, after which the fraction of cured cell in the population remained constant. Plasmid cured cell numbers were measured in a separate control culture of 24/pMX45 untreated by SDS. No spontaneous loss of pMX45 was observed after 24/pMX45 were incubated for 24 h and 48 h with shaking at 37 ℃.These results suggested that SDS can be used as curing agent to eliminate the plasmid of Bacillus subtilis.

Water solubility enhancements of PAHs by sodium castor oil sulfonate microemulsions

Water solubility enhancements of naphthalene(Naph), phenantherene(Phen) and pyrene(Py) in sodium castor oil sulfonate(SCOS) microemulsions were evaluated. The apparent solubilities of PAHs are linearly proportional to the concentrations of SCOS microemulsion, and the enhancement extent by SCOS solutions is greater than that by ordinary surfactants on the basis of weight solubilization ratio(WSR). The log K em values of Naph, Phen, and Py are 3 13, 4 44 and 5 01 respectively, which are about the same as the log K ow values. At 5000 mg/L of SCOS conccentration, the apparent solubilities are 8 80, 121, and 674 times as the intrinsic solubilities for Naph, Phen, and Py. The effects of inorganic ions and temperature on the solubilization of solutes are also investigated. The solubilization is improved with a moderate addition of Ca 2+ , Na +, NH + 4 and the mixture of Na +, K +, Ca 2+ , Mg 2+ and NH + 4. WSR values are enhanced by 22 0% for Naph, 23 4% for Phen, and 24 6% for Py with temperature increasing by 5℃. The results indicated that SCOS microemulsions improve the performance of the surfactant enhanced remediation(SER) of soil, by increasing solubilities of organic pollutants and reducing the level of surfactant pollution and remediation expenses.

Intermolecular Interactions in Self-Assembly Process of Sodium Dodecyl Sulfate by Vertically Polarized Raman Spectra

Molecular self-assembly is extremely important in many fields, but the characterization of their corresponding intermolecular interactions is still lacking. The C-H stretching Raman band can reflect the hydrophobic interactions during the self-assembly process of sodium dodecyl sulfate （SDS） in aqueous solutions. However, the Raman spectra in this region are seriously overlapped by the OH stretching band of water. In this work, vertically polarized Raman spectra were used to improve the detection sensitivity of spectra of C-H region for the first time. The spectral results showed that the first critical micelle concentration and the second critical micelle concentration of SDS in water were 8.5 and 69 mmol/L, respectively, which were consistent with the results given by surface tension measurements. Because of the high sensitivity of vertically polarized Raman spectra, the critical micelle concentration of SDS in a relatively high concentration of salt solution could be obtained in our experiment. The two critical concentrations of SDS in 100 mmol/L NaCl solution were recorded to be 1.8 and 16.5 mmol/L, respectively. Through comparing the spectra and surface tension of SDS in water and in NaCl solution, the self-assembly process in bulk phase and at interface were discussed. The interactions among salt ions, SDS and water molecules were also analyzed. These results demonstrated the vertically polarized Raman spectra could be employed to study the self-assembly process of SDS in water.

Phase Behavior of Sodium Dodecyl Sulfate-n-Butanol-Kerosene-Water Microemulsion System

Experiments were carried out to investigate the influences of cation from electrolytes and acidity/alkalinity on the phase behavior of sodium dodecyl sulfate-n-butanol-organics-water （with electrolytes） microemulsion sys-tem. The organics used is commercial kerosene. The volume ratio of water to organics is 1︰1. The results show that the type and valence of electrolyte cations are important factors influencing the microemulsion behavior. Biva-lent Ca2＋is more effective than monovalent K＋and Na＋for the formation of Winsor type III and II microemulsion. For electrolytes with the same monovalent cation Na＋, i.e. NaCl and Na2CO3, anions in the electrolyte have some effect. Bivalent anion 23CO - leads to a lower activity of cation Na＋than monovalent anion Cl-. NaOH （or KOH） behaves similar with NaCl （or KCl）. When HCl is used as electrolyte, its acidity plays an important role. Phase in-version of microemulsion from type III （or II） to type I is observed through precipitation of Ca2＋using Na2CO3, neutralization of HCl by NaOH, and addition of water to the system, which releases the oil from the microemulsion.

Aggregation of Sodium Dodecyl Sulfonate in Poly-ethylene Glycol Aqueous Solutions Studied by Two-dimensional Nuclear Overhauser Enhancement Spectroscopy

Two-dimensional nuclear overhauser enhancement (2D NOESY)measurements show that sodium dodecyl sulfonate SDSN molecules co-aggregate with poly-ethylene glycol PEG in their aqueous solution at a concentration range of SDSN between the so-called co-aggregation concentration (cac) and the. Normal critical micellar concentration (cmc). SDSN micelles are formed when the cmc of SDSN is reached with PEG uniformly distributed in the interior.

The Antidotal Effects of High-dosage γ-Aminobutyric Acid on Acute Tetramine Poisoning as Compared with Sodium Dimercaptopropane Sulfonate

To investigate the therapeutic effect of nigh-dosage γ-aminobutyric acid （GABA） on acute tetramine （TET） poisoning, 50 Kunming mice were divided into 5 groups at random and the antidotal effects of GABA or sodium dimercaptopropane sulfonate （Na-DMPS） on poisoned mice in different groups were observed in order to compare the therapeutic effects of nigh-dosage GABA with those of Na-DMPS. Slices of brain tissue of the poisoned mice were made to examine pathological changes of cells. The survival analysis was employed. Our results showed that both high-dosage GABA and Na-DMPS could obviously prolong the survival time, delay onset of convulsion and muscular twitch, and ameliorate the symptoms after acute tetramine poisoning in the mice. Better effects could be achieved with earlier use of high dosage GABA or Na-DMPS. There was no significant difference in prolonging the survival time between high-dose GABA and Na-DMPS used immediately after poisioning. It is concluded that high-dosage GABA can effectively antagonize acute toxicity of terarnine in mice. And it is suggested that nigh-dosage GABA may be used as an excellent antidote for acute TET poisoning in clinical practice. The indications and correct dosage for clinical use awaits to be further studied.

Sodium dodecyl sulfate (SDS) as an effective corrosion inhibitor for Mg-8Li-3Al alloy in aqueous NaCl: A combined experimental and theoretical investigation

The corrosion inhibition behavior of Mg-8Li-3Al alloy in NaCl solution with sodium dodecyl sulfate(SDS)was investigated by hydrogen analysis,scanning electron microscopy(SEM),electrochemical test,scanning Kelvin probe force microscopy(SKPFM)and computational methods.Results showed that the corrosion resistance of Mg-8Li-3Al alloy in NaCl solution was effectively improved with SDS.The SEM and SKPFM results confirmed a dense,200 nm-thick SDS-adsorbed layer had formed on the alloy surface.The separation energy ΔE_(gap) and adsorption energy E_(ads) of SDS on the Mg surface were calculated by density functional theory and molecular dynamics simulations,respectively.And the corrosion inhibition mechanism was hypothesized and described.

STUDIES ON DERIVATIVE FLUORIMETRY Ⅲ. DETERMINATION OF TRACE AMOUNT OF TERBIUM IN THE PRESENCE OF SODIUM DODECYL SULFONATE

The derivative fluorimetric characteristics of Tb—SDS and Tb—SDS—phenanthroline systems have been studied. The optimum conditions were obtained. The 2nd—derivative spectrofluorimetric method in the systems has been applied to the determination of trace amounts of terbium, in rare earth ore and their oxides. The results are satisfactory.

Response of a Submersed Macrophyte Hydrilla verticillata (L.f) Royle,to Sodium Dodecylbenzene Sulfonate Stress

The acute toxicity of Sodium dodecylbenzene sulfonate （SDBS） to subcamersed macrophyte Hydrilla verticillata （L.f） Royle was studied. Chlorophyll contents and the activities of 3 antioxidant enzymes： superoxide dismutase （SOD, EC 1.15.1.1）, catalase （CAT, EC 1.11.1.6）, peroxidase （POD, EC 1.11.1.7） in the leaves were investigated under different concentrations of SDBS, The chlorophyll contents in leaves of experimental plants decreased gradually, while the electrical conductivity of culture solution increased gradually with the increased dose of SDBS. Under higher concentrations of SDBS （32 mg/L and 128 mg/L） treatment, SOD lost its activities completely after 24 h. The native PAGE analysis indicated the diversity of POD isoenzymes was obvious under different concentrations of SDBS stress.

Radiation-Induced Graft Polymerization of Sodium 4-Styrene Sulfonate onto Multiwalled Carbon Nanotubes and Their Application as Electrogenerated Chemiluminescence Biosensors

Sulfonate groups were introduced to the surfaces of multiwalled carbon nanotubes by the radiation-induced graft polymerization of sodium 4-styrene sulfonate for the use as biosensor supports. Alcohol dehydrogenase was immobilized onto a sulfonated nanotube-supporting electrode with tris（2,2＇-bipyridyl） ruthenium（II） complex to form an electrogenerated chemilluminesce sensor of alcohol. When it was used to detect alcohol in cyclic voltammetric measurements, the sensor showed the linearity over the range of 1.0 × 10^-4 M-5.0 ×10^-2 M, with a correlation coefficient of 0.992 and a detection limit of 1.9 ×10^-6 M. In electrogenerated chemilluminesce detection, it showed linearity over 5.0 × 10^-4 M-1.0 × 10^-2 M, with a correlation coefficient of 0.986 and a detection limit of 1.0 × 10^-6 M. The sensor was demonstrated to be able to detect ethanol in commercial drinks.

Observations on the Function of Mucous Cells in the Epidermis of the Cat-fish Clarias batrachus Exposed to Sodium Dodecyl Sulfate

Response of mucous cells, in the epidermis of the catfish Clarias batrachus, to a sublethal concentration of sodium dodecyl sulfate was studied and correlated with the alteration in the status of their secretory activity after different durations of the treatment. At 4h, 8h, 24h,48h and 72h of the detergent treatment, most mucous cells attained voluminous dimensions and appeared closely approximating to or even overlapping the adjacent ones. At 12h, 36h, and 60h, in contrast, the mucous cells appeared small and slender, and seemed to be located at greater intervals. These changes in dimensions were responsible for the apparent increase or decrease in the density of mucous cells after different durations of detergent treatment. Statistically, however, no significant change was observed in the total number of the mucous cells throughout the experiment.The mucous cells appeared enlarged towards the end of the experiment signifying increased mucus production. This is considered as an adaptation, for protection, assisting the fish to adjust to the changed environment.A shift in the histochemical nature of the secretory contents at the middle and basal parts of the mucous cells, from a mixture of neutral and acid glycoproteins to neutral glycoproteins, during the early stages of the treatment suggests that acid moities could not simultaneously be synthesized as an immediate response to enhanced mucous secretion. The apical parts of the mucous cells, however, showed no histochemical change throughout the experiment.

Changes of c-fos and c-jun mRNA Expression in Angiotensin Ⅱ-induced Cardiomyocyte Hypertrophy and Effects of Sodium Tanshinone ⅡA Sulfonate

The changes of proto-oncogene c-fos and c-jun mRNA expression in angiotensin Ⅱ （AngⅡ）-induced hypertrophy and effects of sodium tanshinone ⅡA sulfonate （STS） in the primary culture of neonatal rat cardiomyocytes were investigated. Twelve neonatal clean grade Wistar rats were selected. The cardiomyocytes were isolated, cultured and divided according to different treatments in the medium. The cardiomyocyte size was determined by phase contrast microscope, and the rate of protein synthesis was measured by [3H]-Leucine incorporation. The c-fos and c-jun mRNA expression in cardiomyocytes was detected by reverse transcription polymerase chain reaction （RT-PCR）. It was found after cardiomyocytes were treated with AngⅡ for 30 min, the c-fos and c-jun mRNA expression in cardiomyocytes was increased significantly （P〈0.01）. After treatment with AngⅡ for 24 h, the rate of protein synthesis in AngⅡ group was significantly increased as compared with control group （P〈0.01）. After treatment with AngⅡ for 7 days, the size of cardiomyocytes in AngⅡ group was increased obviously as compared with control group （P〈0.05）. After pretreatment with STS or Valsartan before AngⅡ treatment, both of them could inhibit the above effects of AngⅡ （P〈0.05 or P〈0.01）. It was suggested that STS could ameliorate AngⅡ-induced cardiomyocyte hy- pertrophy by inhibiting c-fos and c-jun mRNA expression and reducing protein synthesis rate of cardiomyocytes.

Enhancing the leaching effect of an ion-absorbed rare earth ore by ameliorating the seepage effect with sodium dodecyl sulfate surfactant

Ameliorating the problem of low leaching efficiency,long leaching period,and high agent consumption should be studied to efficiently exploit ion-absorbed rare earth ore resources.In this study,the surfactant sodium dodecyl sulfate(SDS) is used to enhance the leaching effect of an ion-absorbed rare earth ore by ameliorating the seepage effect for the first time.The effects of surfactant concentration,leaching agent dosage,solution flow velocity,and solution pH on the leaching rate were explored,and the mechanism of SDS was discussed.Under the optimum conditions,the addition of a small amount of SDS(mass fraction0.04%) can increase the leaching rate by about 5%,shorten the leaching period,and reduce the consumption of the leaching agent.SDS significantly ameliorates the seepage effect of the ore body by reducing the surface tension of the leaching agent and ameliorating the wettability of the mineral surface.This effect is the main factor that improves the leaching efficiency.DFT(density functional theory) calculation results show that SDS can react with rare earth ions,which reduces the adsorption strength on clay mineral surfaces.Hence,rare earth ions are easily exchanged by ammonium ions,and mass transfer is enhanced.

Protective Effect and Mechanism of Sodium Tanshinone ⅡA Sulfonate on Microcirculatory Disturbance of Small Intestine in Rats with Sepsis

To explore the protective effect of sodium tanshinone ⅡA sulfonate（STS） on microcirculatory disturbance of small intestine in rats with sepsis,and the possible mechanism,a rat model of sepsis was induced by cecal ligation and puncture（CLP）.Rats were randomly divided into 3 groups：sham operated group（S）,sepsis group（CLP） and STS treatment group（STS）.STS（1 mg/kg） was slowly injected through the right external jugular vein after CLP.The histopathologic changes in the intestinal tissue and changes of mesenteric microcirculation were observed.The levels of tumor necrosis factor-α（TNF-α） in the intestinal tissue were determined by using enzyme-linked immunoabsorbent assay（ELISA）.The expression of intercellular adhesion molecule-1（ICAM-1） in the intestinal tissue was detected by using immunohistochemisty and Western blot,that of nuclear factor κB（NF-κB） and tissue factor（TF） by using Western blot,and the levels of NF-κB mRNA expression by using RT-PCR respectively.The microcirculatory disturbance of the intestine was aggravated after CLP.The injury of the intestinal tissues was obviously aggravated in CLP group as compared with S group.The expression levels of NF-κB p65,ICAM-1,TF and TNF-α were upregulaed after CLP（P0.01）.STS post-treatment could ameliorate the microcirculatory disturbance,attenuate the injury of the intestinal tissues induced by CLP,and decrease the levels of NF-κB,ICAM-1,TF and TNF-α（P0.01）.It is suggested that STS can ameliorate the microcirculatory disturbance of the small intestine in rats with sepsis,and the mechanism may be associated with the inhibition of inflammatory responses and amelioration of coagulation abnormality.

Interaction of ciprofloxacin hydrochloride with sodium dodecyl sulfate in aqueous/electrolytes solution at different temperatures and compositions

Interactions of ciprofloxacin hydrochloride(CPFH)with sodium dodecyl sulfate(SDS)were investigated by conductivity measurement in H2O/electrolyte solutions(NaCl,Na2SO4&Na3PO4)over 298.15–318.15 K temperature range(with 5 K interval)considering the human body temperature.In all cases,two critical micelle concentrations(c*)were observed which are increased in the presence of drug and decreased in the presence of salts enunciating the presence of interaction amongst the studied components.For(CPFH+SDS)system in the presence of salt,the c*values at 303.15 K and I=0.50 mmol·kg^-1 followed the order:CNaCl>CNa2SO4>CNa3PO4.TheΔG1,m0 andΔG2,m0values are found to be negative for all systems that show that the micellization process is thermodynamically spontaneous.For(CPFH+SDS)system in water,theΔHm0&ΔSm0 values reveal that the micellization processes is both entropy dominated in almost all cases.In the occurrence of electrolytes,ΔHm0 andΔSm0 values indicate that micellization processes are both entropy&enthalpy restricted at upper temperature but it becomes totally entropy dependent at higher temperature.The higher positiveΔSm0 values indicate the enhanced hydrophobic interaction in presence of salts.The enthalpy-entropy compensation was determined from the linear relationship betweenΔHm0 andΔSm0 values in every state.Different transfer energies as well as compensation temperature and intrinsic enthalpy were also evaluated and the behaviors were comparable to other biological system.

3′-Daidzein sulfonate sodium protects against memory impairment and hippocampal damage caused by chronic cerebral hypoperfusion

3′-Daidzein sulfonate sodium（DSS） is a new synthetic water-soluble compound derived from daidzein,a soya isoflavone that plays regulatory roles in neurobiology.In this study,we hypothesized that the regulatory role of DSS in neurobiology exhibits therapeutic effects on hippocampal damage and memory impairment.To validate this hypothesis,we established rat models of chronic cerebral hypoperfusion（CCH） by the permanent occlusion of the common carotid arteries using the two-vessel occlusion method.Three weeks after modeling,rat models were intragastrically administered 0.1,0.2,and 0.4 mg/kg DSS,once a day,for 5 successive weeks.The Morris water maze test was performed to investigate CCH-induced learning and memory deficits.TUNEL assay was used to analyze apoptosis in the hippocampal CA1,CA3 regions and dentate gyrus.Hematoxylin-eosin staining was performed to observe the morphology of neurons in the hippocampal CA1,CA3 regions and dentate gyrus.Western blot analysis was performed to investigate the phosphorylation of PKA,ERK1/2 and CREB in the hippocampal PKA/ERK1/2/CREB signaling pathway.Results showed that DSS treatment greatly improved the learning and memory deficits of rats with CCH,reduced apoptosis of neurons in the hippocampal CA1,CA3 regions and dentate gyrus,and increased the phosphorylation of PKA,ERK1/2,and CREB in the hippocampus.These findings suggest that DSS protects against CCH-induced memory impairment and hippocampal damage possibly through activating the PKA/ERK1/2/CREB signaling pathway.

Determination of Trace Amounts of Zinc, Iron and Copper by Flame Atomic Absorption after Their Preconcentration Using Sodium Dodecyl Sulfate (SDS) Coated Alumina Nanoparticles Modified with 3-Mercapto-D-Valin from Environmental Samples

A sensitive and simple solid phase extraction method for the simultaneous determination of trace and toxic metals in environmental samples has been reported. The method is based on the adsorption of Zinc, Iron and Copper on SDS-coated alumina nanoparticles, which is also modified with 3-mercapto-D-valine. The retained analyte ions on modified solid phase were eluted using 5 mL of 4 mol·L﹣1 HNO3. The analyte determination was carried out by flame atomic absorption spectrometry. The influences of some metal ion and anions on the recoveries of understudy analyte ion were investigated. The influences of the analytical parameters including pH, ligand and SDS amount, eluting solution (type and concentrations) and sample volume on metal ions recoveries were investigated. The extraction efficiency was > 98% with relative standard deviation lower than 3% the method has been successfully applied for the extraction and determination of these ions content in some real samples. Prepared adsorbent was characterized by SEM and FT-IR measurements.