Amount Of Surface Active Agent Research Articles

Effects of surface active agents on DNAPL migration and distribution in saturated porous media

Dissolved surface active agents such as surfactant and natural organic matter can affect the distribution and fate of dense nonaqueous liquids (DNAPLs) in soil and groundwater systems. This work investigated how two common groundwater surface active agents, humic acid (HA) and Tween 80, affected tetrachloroethylene (PCE) migration and source zone architecture in saturated porous media under environmentally relevant conditions. Batch experiments were first conducted to measure the contact angles and interfacial tensions (IFT) between PCE and quartz surface in water containing different amount of surface active agents. Results showed that the contact angle increased and IFT decreased with concentration of surface active agent increasing, and Tween 80 was much more effective than HA. Five 2-D flow cell experiments were then conducted. Correspondingly, Tween 80 showed strong effects on the migration and distribution of PCE in the porous media due to its ability to change the medium wettability from water-wet into intermediate/NAPL-wet. The downward migration velocities of the PCE in three Tween 80 cells were slower than those in the other two cells. In addition, the final saturation of the PCE in the cells containing surface active agents was higher than that in the water-only cell. Results from this work indicate that the presence of surface active agents in groundwater may strongly affect the fate and distribution of DNAPL through altering porous medium wettability.

Первичные средства пожаротушения для Арктики

For Arctic Region of Russian Federation a stored pressure extinguisher generating a water mist flow with antifreeze and gallogen-including foam agent and fluorine SAA (surface active agent) added should be applied as the first-aid fire equipment. It is a special priority-task to use water mist at Arctic Region facilities, where high extinguishing capacity is required, there is limited water supply and transportation, FEA-spill-caused collateral damage minimization is necessary. It is advantageous to use LiCl or CaCl 2 salt solutions as antifreeze while employing the above extinguisher in Arctic Region. A certain amount of fluorine SAA (AFFF-type) practically does not increase the SAA freezing temperature without lowering extinguishing capacity. A developed analytical description of the process in a stored pressure extinguisher allows to define optimal correlation with respect to gas filled volume V 0 and total (summarized) extinguisher volume V £ . At present in world practice an opinion has formed of limiting service bottle pressurization level up to 2 MPa (20 bar). Arctic Region designed 6 l capacity extinguisher tests performed on A Class (solid combustibles) and B Class (flammable fluid) model fire sites have demonstrated high efficiency under lower temperatures (-52 °C) equal to present-day extinguisher efficiency at positive temperatures: A Class - 6A, B Class - 183B. The results of experiments made determine a possibility of atomized solution flow application for extinguishing energized electric sets, as current leak would not exceed 0.25 mA. Negligible conductivity of atomized FEA flows is explained by a small solution volume proportion (< 0,05) in the air.

Determination of surfactants and levoglucosan from selected vegetation by spectroscopic colorimetric method

ABSTRACTVegetation is one of the natural sources which contribute to the amount of surface active agent into the environment. It is believed that surfactants can be derived from various kinds of sources such as biomass burning or soil and these excessive level of surfactants emitted into the atmosphere can influence both cloud formation and climate. The objective of this study was to determine the concentration of both anionic and cationic surfactants as well as levoglucosan from vegetation and soot and at different weather conditions around the tin mine lakes environment. The samples were prepared by cutting several parts of tropical plant species, namely Cinnamomum Iners, Gliricidia Sepium and Hopea Odorata, which were mainly leaves and stems. After that, samples were allowed to dry in an oven at a temperature of 40°C for 2 h. The concentrations of levoglucosan and surfactant such as methylene blue active substance (MBAS) and disulphine blue active substance (DBAS) were analysed through the colorimetric method. The results showed that higher concentrations for both anionic and cationic surfactants were found in C. Iners leaves which give the concentrations of 86.92 ± 38.99 and 22.33 ± 10.59 µg/g. It was noted that the concentrations of anionic and cationic surfactants in this research were correlated to each other, indicating the possibility of similar sources that affect both levels of surfactants in the vegetation. In addition, the highest level of levoglucosan was dominated by the leaves from G. Sepium species with the concentration of 25.62 ± 12.65 mg/g, respectively. A positive significant correlation (r = 0.8447, 0.8355 and p = 0.0001 < 0.05) between anionic surfactants and levoglucosan was also discovered in this study.

A single-step aerosol process for in-situ surface modification of nanoparticles: Preparation of stable aqueous nanoparticle suspensions

HypothesisSurface modification of nanoparticles during aerosol or gas-phase synthesis, followed by direct transfer into liquid media can be used to produce stable water-dispersed nanoparticle suspensions. ExperimentThis work investigates a single-step, aerosol process for in-situ surface-modification of nanoparticles. Previous studies have used a two-step sublimation–condensation mechanism following droplet drying, for surface modification, while the present process uses a liquid precursor containing two solutes, a matrix lipid and a surface modifying agent. A precursor solution in chloroform, of stearic acid lipid, with 4 %w/w of surface-active, physiological molecules [1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-dipalmitoyl-sn-glycero-3-phospho-(1′-rac-glycerol)-sodium salt (DPPG) or 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy (polyethylene glycol) 2000]-ammonium salt (DPPE-PEG)] was processed in an aerosol reactor at a low gas temperatures. The surface modified nanoparticles were characterized for morphology, surface composition and suspension properties. FindingsSpherical, surface-modified lipid nanoparticles with median mobility diameters in the range of 105–150nm and unimodal size distributions were obtained. Fourier transform infra-red spectroscopy (FTIR) measurements confirmed the presence of surface-active molecules on external surfaces of modified lipid nanoparticles. Surface modified nanoparticles exhibited improved suspension stability, compared to that of pure lipid nanoparticles for a period of 30days. Lowest aggregation was observed in DPPE-PEG modified nanoparticles from combined electrostatic and steric effects. The study provides a single-step aerosol method for in-situ surface modification of nanoparticles, using minimal amounts of surface active agents, to make stable, aqueous nanoparticle suspensions.

Formation of Breath Figure Arrays in Methanol Vapor Assisted by Surface Active Agents

Breath figure (BF) process is a promising technique for fabricating honeycomb polymer films. It is usually conducted in water vapor. While, in organic vapors only unique polymer can be used to prepare BF arrays as reported in our previous article (Breath Figure in Nonaqueous Vapor. Soft Matter, 2013, 506-514), although new structure features are induced in the film. In this paper, a universal modified BF processing is devised for preparing porous films in methanol vapor with conventional polymers, by adding a small amount of surface active agent into the casting solution, such as siloxane- and fluorine-containing block copolymers. The pores in the PS films prepared with this method are of cylindrical shape with large depth-diameter aspect ratio, and the diameter and depth of pores can be well controlled by the experiment conditions. Based on these results, the formation mechanism of honeycomb structure in methanol vapor is discussed.

Preparation and characterization of nanometer-sized barium titanate powder by complex-precursor method

A new complex-precursor method was proposed to prepare nanometer-sized BaTiO3 powder. Firstly, [Ti2O(O2)2(ta)2]4− complex ions were prepared by the reaction of H2O2, Ti4+ and ta3− (ta=[C6H6O6N]3−) with a desirable amount of surface active agent, and then the Ba2[Ti2O(O2)2(ta)2]·2H2O precursor was obtained by reaction between [Ti2O(O2)2(ta)2]4− and Ba2+. Finally, the precursor was annealed at 800 °C for 2 h to obtain BaTiO3 powder. The morphology, the particle size distribution, the purity and the molar ratio of Ba to Ti of BaTiO3 powder were investigated systematically by TEM, XRD, IR, Raman and chemical analysis, respectively. The results show that the BaTiO3 powders with the grain size of about 40 nm have a tetragonal crystalline structure at room temperature and a spherical morphology.

Factors Affecting the Oil Agglomeration of Sivas-Divriği Uluçayır Lignite

In the coal industry, the coal particles need to be decreased to a very fine size because of the need of removing inorganic materials from coal. Oil agglomeration is a kind of coal cleaning technique that is used for separation of organic and inorganic parts of fine sized coal. In this study, the oil agglomeration of Sivas-Divriği (S-D) Uluçayır lignite was carried out by using kerosene, diesel oil, fuel oil, poppy oil, and sunflower oil. The amount of bridging oil was varied from 5% to 25% of the amount of lignite. The effect of oil amount, oil type, solid content, agitation rate and time, pH on agglomeration performance was investigated. Maximum recovery value of 98.18% was observed by using poppy oil. In order to investigate the effect of pH on agglomeration NaOH and HCl is added to the slurry in various amounts. It is decided that the best agglomeration condition is obtained at low pH values. The effect of nonionic surface active agent (Igepal-CA 630) on agglomeration is investigated by adding to the slurry and it is observed that the grade is increased with the amount of surface active agent.

Studies on the adsorption of Brij-35 and CTAB at the coal–water interface

The adsorption behavior of polyoxyethylene (23) lauryl ether (Brij-35) and cetyl trimethyl ammonium bromide (CTAB) on coal sample has been studied. The adsorption process is found to be sensitive to pH, temperature, electrolyte concentration, and the amount of surface active agent. An attempt has been made to explain the adsorption behavior of the surfactants using the Langmuir equation. The extent of adsorption of Brij-35 on coal is found to be the highest at pH 2, which decreases with increase in pH and remains constant in the neutral and alkaline pH regions. But, the adsorption of CTAB exhibits the opposite behavior of that of Brij-35. Adsorption of any of the surfactant at the coal/water interface sharply decreases the apparent viscosity of 55 wt% coal–water slurry (CWS) at a shear rate of 100 s −1. Electrostatic adsorption of the surfactants on the coal surface decreases the surface charge and renders the coal surface hydrophobic which is manifested in the form of high apparent viscosity of the coal–water slurry under the test conditions.

界面活性剤を用いた糖類のフルフラール誘導体への変換（原標題は英語）

This paper presents a method for the industrial preparation of 5-substituted furfurals, potential as agricultural chemicals, dehydrating saccharides with hydrochloric acid in the presence or catalytic amounts of surface active agents.

Surfactant Effects on the Equipment Performance of Extraction Columns.

A small amount of surface active agent in a extraction column has the effect of decreasing mass transfer coefficient, while increasing the mass transfer area. The overall mass transfer efficiency is thus varied complicatedly with the surfactant concentration and the hydrodynamic behavior of the two phase in the extraction columns. In this work, spray-tower and packed-tower are used as extraction columns to obtain the overall performance of the equipment. The effects of surfactant on the mass transfer efficiency and interfacial area in the two apparatuses are studied. The results show that the effects of SLS on the decreasing of mass transfer coefficient is more prominent than that on the increasing of mass transfer area in the both apparatuses. In the packed-tower, a higher efficiency is obtained due to the effect of the packing. However, at the presence of SLS, the dispersion effect can not raise the interfacial area high enough to overcome the simultaneous decrease in mass transfer coefficient. The mechanisms to increase interfacial area by the surfactant are different at various concentrations of SLS and different between the two apparatuses, which are also discussed in this article.

Operation of Rhodamine 6G Dye Laser in Water Solution

The ethanolic solution of Rhodamine 6G is used for dye lasers in the atomic vapor laser isotope separation (AVLIS) system. However, the water solution is preferable from the standpoint of easy treatment and safety. In this paper, we systematically investigated the laser efficiency of a Rhodamine 6G dye laser pumped by a frequency-doubled Nd:YAG laser, for various water-based solutions with surface-active agents and alcohols. By adding an appropriate amount of surface-active agent (Triton X or Emulgen) or alcohol (ethanol or propanol), we obtained almost the same level of laser efficiency as in the pure ethanolic solution. The improvement in the laser efficiency with these additives was attained by the deaggregation of nonradiative dimers. It was also confirmed that the water-based solution showed better performance against thermal distortion than the ethanolic solution, and was suitable for copper vapor laser (CVL) pumping.

水性塗料を用いた表面浮遊法による熱交換器内部の流れの可視化

In order to understand the internal flow pattern of a heat exchanger, new method flow visualization is developed using water paint instead of the aluminum powder or saw dust in conventional way. A mixture of water and white water paint adding a little amount of surface active agent is adopted to obtain the internal flow pattern of heat exchanger without sticking of tracer to the model surface. The mixture liquid having weight ratio of water, white water paint and surface active agent 4:1:1/2000 shows the best condition for visualization. Using this tracer, it is possible to trace the time-line and the streak-line around the model clearly. Various kinds of fin arrangement of the exchanger are tested.

Quick Dyeing of Substrates such as Carbons Being Hard to Dye

A substrate being hard to dye can be easily dyed a desire color, by applying a special dyebath containing concentrated sulfuric acid. All inorganic and organic materials may be instantly dyed a desire color, so far as those having a greater surface area are concerned.The substrates being most hard to dye such as carbon black, polypropylene, polyvinyl chloride, polyvinilidene chloride, etc., may be quickly dyed a beautiful color, by this dyeing process.Insoluble coloring materials, such as vat and sulfur colors, or pigments, are the most suitable for this process. These can be applied as molecular solutions. Therefore, a beautiful color can be satisfactly developed. Also, this new dyeing process can be applied to soluble coloring materials. In this case, an organic acid is useful as a component in the dye bath.A special dyebath consisting of concentrated sulfuric acid and with the regular amounts of surface active agent and organic solvent which have an emulsified state may be used effectively for quick dyeing on the most hard to dye. This special dyebath has a greater dye-accessibility for the substrates being hard to dye.

On the interaction of vortex rings and pairs with a free surface for varying amounts of surface active agent

Observations are reported of the interaction with a free surface of vortex rings and vortex pairs moving normal to the surface when different amounts of surface active agents are present on the surface. At a vortex ring Reynolds number Γ/ν≈3800, the interaction with a contaminated free surface results in the generation of secondary and tertiary vortex rings that limited the outward motion of the vortex ring core. When the experiment was repeated with a cleaner surface the formation of the secondary vortex ring was delayed so that the outward motion and stretching of the vortex ring core was much more than for the contaminated surface. At a Reynolds number Γ/ν≈18 000, the vortex pair was observed to rebound from the free surface contrary to what one would expect for an inviscid flat boundary. When the surface was cleaned by draining away a portion of the contaminated surface water the amount of rebound was reduced. These changes in interaction are believed to be caused by the reduction in concentration of the surface active agent which, in turn, results in a reduced generation of secondary vorticity ahead of the vortex ring or pair before and during the interaction with the surface.

Effect of Surface Active Agent on Direct Atomic Absorption Spectrophotometric Determination of Metals in Waste Water Containing Fatty Oil

The effect of the addition of surface active agents was studied for the direct flame atomic absorption spectrophotometric determination of metals such as cadmium, chromium, copper, lead, and nickel in waste water containing fatty oil.Absorbances of the elements were increased by the addition of oleyl-12, hexadecyltrimethylammonium bromide, Tween-20, sodium dodecylbenzenesulfonate and Brij-35 for emulsifying fatty oil in aqueous solution. The enhancing of absorbance was independent of the type of surface active agents used, but was dependent on the stability of emulsion.It was found that the effective amount of surface active agents was about 0.21.0% region for a sample solution containing less than 10% of fatty oil, but in the case of large content of fatty oil (More than 20%), this method is carried out after diluted with water to a suitable concentration.

A Comparison of Pad-Dry-Cure and Low Add-On Reactant Application on Cotton Fabrics

The unfavorable effect of reactant migration in padded cotton fabrics during.drying on the balance of crease recovery and abrasion weight loss was confirmed once more. The influence of fabric type and pretreatments such as scouring and bleaching was studied. With the aid of a low add-on method making use of an engraved roller it can be shown that if the add-on is kept under a level of 30-40%, migration is largely prevented. Consequently, the balance of properties approaches that of a fabric with a uniform reactant distribution. The effect of the surface-active agents in low add-on methods was studied. The interaction between pretreatment and amount of surface active agent applied is clearly illustrated.

Experimental studies of drop dynamics in shear fields: Role of dynamic interfacial effects

The behavior of drops in shear fields is experimentally studied and the roles of interfacial viscous effects and interfacial tension gradients are investigated. Specifically, drop deformation, orientation, and internal and external circulation tests are reported and these are compared with various theoretical predictions. Only in the case of systems with very high bulk viscosities were dynamic interfacial effects found to be negligible. In lower viscosity systems, even those with only contaminant amounts of surface active agents, significant interfacial shear viscosities and apparent dilatational viscosities were obtained. The experimental results are consistent with the previous theoretical predictions of Flumerfelt, and the latter theory provides a basis for interfacial viscous property measurements.

鉛電極表面反応におよぼす電解液および表面活性剤の影響

In this experiment, the authors studied the influence of the amounts of Pb and H2SiF6, and the influence of surface active agents in the lead electrolyte on the deposited potential, current density, dissolved potential and peak current density of the lead, and the following results were obtained.1) The starting potential of the dissolution of the lead, EO, increased with the amount of Pb in the electrolyte, but it decreased with the amount of H2SiF6. EO did not vary with changes in the amount of surface active agents.2) When the surface active agents were added in the electrolyte, the starting potential of the lead deposition, Ep, except for the addition of KSCN in the electrolyte, became lower than it had been in the case of non addition.3) The starting current density of lead deposition, Ip, reached its highest level with the addition of KSCN to the electrolyte. But, with the addition of glue to the electrolyte, Ip decreased.4) The peak potential, EA, and the peak current density, IA, of the lead dissolution were varied according to the concentration of Pb and H2SiF65) The peak potential of the lead dissolution, EA, increased as KSCN was added and also as the surface active agents phenol and polypepton were added to the electrolyte. Especialy, when KSCN was added in the electrolyte, the potential variedl argely.6) The peak current density, IA, of the lead dissolution generally decreased as the surface active agents are added to the electrolyte.7) From these results, it considered that the optimum for the electrolysis is Pb: 80g/l, H2SiF6: 80g/l and gelatin or glue: 1g/l-1.5g/l.

Radiotracer Studies on the Amount of Surface Active Agents remained on Fruit and Vegetables

The amounts of polyoxyethlene (20) sorbitane laurate SL (EO) remained on the fruit and vegetables such as strawberry, cabbage, cucumber and spinach washed by the detergent solution of SL (EO) have been determined by means of the radiotracer method using SL (EO) labeled with radioisotope 14C. Further studies on sodium dodecylbenzene sulfonate (DBS) and sodium triethyleneglycol dodecylether sulfate (ES) have been carried out and compared with SL (EO).The measurement was chiefly made for cabbage leaf under the various conditions. Under the condition of dipping in 0.1% detergent solution for ten minutes at 1618°C, following by rinsing twice with 100ml of water for 20sec., the amout of residual SL (EO) observed were 0.18γ/cm2 for the surface and 0.54γ/cm along the section of cabbage leaf. The amount of SL (EO) remained on cucumber and strawberry were nearly the same as that on cabbage, but that on cabbage, and spinach were four or five times larger than that on cucumber and strawberry when compared in the unit of the amount of residual SL (EO) per weight. The tendency for the amount of the various surface active agents in this study was about the same between fruit and vegetables, and the residual amount of DBS, SL (EO) and ES decreased in that order listed.

Influence of surface active agents on oxygen absorption to the free interface in a stirred fermentor

AbstractLiquid phase coefficients were measured for the absorption of oxygen from air to the free interface in stirred vessels. Coefficients for absorption into soft water were independent of the instantaneous dissolved oxygen concentration. Coefficients for absorption into soft water containing a surface active agent were strongly dependent on the instantaneous dissolved oxygen level. The degree of nonlinearity of the coefficients was a function of the rate of agitation of the liquid. The coefficients were independent of the amount of surface active agent added above a very low level. Absorption coefficients for bubble aeration in the same vessels were independent of dissolved oxygen concentration even when the surface active agent was present.