Water Surfactant Solutions Research Articles

In Vitro Cytotoxicity and Pharmacokinetic Study for Bosutinib Solid Lipid Nanoparticles.

Bosutinib (BST) is a Biopharmaceutics Classification System Class II drug having very low solubility and high permeability. Low aqueous solubility and poor dissolution of BST lead to poor bioavailability, Thus, limited aqueous solubility is the bottleneck for the therapeutic outcome of BST. Animal data suggest that the absolute bioavailability of BST is about 14-34% due to an extensive first-pass effect. To overcome hepatic first-pass metabolism and to enhance oral bioavailability, lipid-based drug delivery systems such as solid lipid nanoparticles (SLNs) can be used. SLNs are submicron colloidal carriers having a size range of 50-1000 nm. These are prepared with physiological lipid and dispersed in water or aqueous surfactant solution. BST can be conveniently loaded into SLNs to improve the oral bioavailability by exploiting the intestinal lymphatic transport. An optimal system was evaluated for bioavailability study in rats compared with that of BST suspension (SUS). An in vitro cytotoxicity study was done by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay method through ATCC cell lines; the percent inhibition was more in SLN when compared with SUS. The pharmacokinetics of BST-SLNs after oral administration in male Wistar rats was studied. The bioavailability of BST was increased by 2.28 fold when compared with that of a BST SUS. The results are indicative of SLNs as suitable lipid-based carrier system for improving the oral bioavailability of BST.

A Review on Solid Lipid Nanoparticles as Nano Drug Delivery Transporters

Abstract: Solid lipid nanoparticles (SLN) have several potential uses in research for medicine such as drug discovery and drug delivery, an area at the forefront of evolving area of nanobiotechnology. In general, SLNs were created to address the drawbacks of conventional colloidal carriers, including emulsions, liposomes, and polymeric nanoparticles since they provide various advantages such as favourable release profiles and tailored drug delivery with outstanding physical-chemical stability. Solid lipid nanoparticles are spherical solid lipid particles that are distributed in water or an aqueous surfactant solution and are in the nanometer size range. Therefore, SLN is used to deliver hydrophilic and lipophilic drugs. The review article focuses on various aspects of SLN including the structure, the influence of excipients, the drug incorporation model, the principle of release, the method of preparation, characterization, the route of administration and biodistribution, and the application of SLN.

Molecular simulation study of the influence of different surfactants on the wetting characteristics of anthracite

The reduction of dust pollution in coal mines is of great importance both for protection of the environment and for the occupational safety and health of coal mine workers. The reduction of dust from anthracite has been a challenge due to its inherent hydrophobicity and high metamorphism. As a result, surfactants are commonly added to water to improve the wettability of coal, thereby improving the dust reduction efficiency of a water spray system. To clarify from a microscopic perspective the effect of different surfactants on the wettability of anthracite, models for the anthracite-surfactant-water system were established, and adsorption configuration, relative concentration distribution, and the diffusion coefficients of water molecules in the systems were thoroughly investigated with molecular simulations. The results showed the directional arrangement of surfactants in the simulation systems after 150 ps of equilibration, resulting in the reduced surface tension of the water-surfactant solution and enhanced wettability of anthracite. Along the (001) normal direction, the relative concentration of sodium dodecylbenzenesulfonate (SDBS) (15.32), the anthracite-water overlapping area, the diffusion rate of water molecules, and the activity (DSDBS = 0.97 × 10-8 m2·s−1) were maximized, indicating the excellent wettability effect of SDBS. The results of the study are of practical significance for improving the wetting effect of anthracite, improving the dust reduction efficiency, and safeguarding the occupational safety and health of personnel.

Influence of anionic surfactant on stability of nanoparticles in aqueous solutions

Dispersion and aggregation of nanoparticles in aqueous solutions are important factors for safe and effective application of nanoparticles, for instance, in the oil industry. As conventional oil reserves are depleted, it is necessary to advance chemical enhanced oil recovery (cEOR) techniques to develop unconventional oil reservoirs. Nanoparticles modified by surfactants can be a promising reagent in cEOR. These nanomaterials can reduce interfacial tension and change the wettability of reservoir rock, which leads to an increase in oil recovery. However, the application of nanoparticles is limited by their substantial aggregation in aqueous solutions. The purpose of this work is to select nanoparticles for obtaining stable sols in water in the presence of an anionic surfactant and to optimize the conditions (pH) for further modifying the nanoparticles with the anionic surfactant. Sodium dodecyl sulfate (SDS) is used as an anionic surfactant. The aggregation of oxide and carbon nanoparticles in water and anionic surfactant solutions was studied by laser diffraction, dynamic and electrophoretic light scattering methods. Most of the studied nanoparticles in water form aggregates with bi-, three- and polymodal particle size distributions. TiO2 nanoparticles obtained by plasma dynamic synthesis form the most stable sols in anionic surfactant solutions. The range of 5–7 pH is defined as optimal for their modification with surfactants. The stability of carbon nanoparticles in aqueous solutions increases significantly in the presence of a surfactant. The obtained results form the basis for further research on the modification of marked nanoparticles in surfactant solutions.

Pushing the Limits of Capillary Assembly for the Arbitrary Positioning of Sub-50nm Nanocubes in Printable Plasmonic Surfaces.

The fabrication of high quality nanophotonic surfaces for integration in optoelectronic devices remains a challenge because of the complexity and cost of top-down nanofabrication strategies. Combining colloidal synthesis with templated self-assembly emerged as an appealing low-cost solution. However, it still faces several obstacles before integration in devices can become a reality. This is mostly due to the difficulty in assembling small nanoparticles (<50 nm) in complex nanopatterns with a high yield. In this study, a reliable methodology is proposed to fabricate printable nanopatterns with an aspect ratio varying from 1 to 10 and a lateral resolution of 30 nm via nanocube assembly and epitaxy. Investigating templated assembly via capillary forces, a new regime was identified that was used to assemble 30-40 nm nanocubes in a patterned polydimethylsiloxane template with a high yield for both Au and Ag with multiple particles per trap. This new method relies on the generation and control of an accumulation zone at the contact line that is thin as opposed to dense, displaying higher versatility. This is in contrast with conventional wisdom, identifying a dense accumulation zone as a requirement for high-yield assembly. In addition, different formulations are proposed that can be used for the colloidal dispersion, showing that the standard water-surfactant solutions can be replaced by surfactant-free ethanol solutions, with good assembly yield. This allows to minimize the presence of surfactants that can affect electronic properties. Finally, it is shown that the obtained nanocube arrays can be transformed into continuous monocrystalline nanopatterns via nanocube epitaxy at near ambient temperature, and transferred to different substrates via contact printing. This approach opens new doors to the templated assembly of small colloids and could find potential applications in various optoelectronic devices ranging from solar cells to light-emitting diodes anddisplays.

Mixing carbon nanotubes with asphalt binder through a foaming process toward high-performance warm mix asphalt (WMA)

ABSTRACT This paper investigates mixing carbon nanotubes (CNTs) with asphalt binder through a foaming process to produce high-performance warm mix asphalt (WMA). Two different solvents of ethanol and a water-based surfactant are used to disperse the multi-walled CNTs. Initial morphological assessment of the two CNT solutions showed that a more homogenous dispersion of the CNTs was achieved using the water surfactant solution. The foaming performance, thermal, and rheological properties of the foamed asphalt mixed with different percentages of CNTs are further investigated. The test results showed that a very small amount of CNTs (0.06% ∼ 0.1% in weight of the binder) can effectively enhance the foaming performance for bubble stability without tangibly increasing the rheological properties of the foamed asphalt. The specific heat capacity of the foamed samples was smaller than the neat binder, whereas the glass transition temperature of the foamed samples shifted to a lower temperature as compared to that of the neat binder. The thermal conductivity of the 6% CNTs sample (0.24% wt. in asphalt binder) was improved by two-fold compared with the foamed unmodified asphalt, which indicates the potential of using CNTs in the binder for enhancement of thermal properties in asphalt pavements.

Friction dynamics of human hair treated with water or cationic surfactant aqueous solution

AbstractCationic surfactants are adsorbed on the surface of human hair and exhibit a lubricating effect. Here, we evaluated the friction when the hair treated with water or 1 wt% cationic surfactant (cetyltrimethylammonium bromide) aqueous solution was rubbed by a contact probe equipped in a sinusoidal motion friction evaluation system. Because of the rough structure of the cuticle on the human hair surface, an oscillatory phenomenon with a frequency of 50–70 Hz was observed when untreated hair was rubbed with a contact probe. On the other hand, the oscillatory phenomenon was not observed when the hair contained a large amount of water because stick–slip phenomena were inhibited on the soft, swollen hair surface. Furthermore, the change in kinetic friction coefficient and delay time, which is a normalized value of the time difference between the reaction of the friction force to accelerated motion, from untreated hair, Δμk and Δδ, was almost zero. However, we found a large difference in Δμk and Δδ for the hair treated with cationic surfactant aqueous solution. The treatment with cationic surfactant reduced both friction parameters, Δμk and Δδ, indicating that the treatment induced not only the frictional force but also the profile at the beginning of frictional sliding. The significant lubrication is due to cationic surfactant adsorption on the hair surface. These data imply that the smoothness of hair treated with a cationic surfactant is related to a reduction in friction coefficient and delay time δ.

Experimental study on the imbibition mechanism of the Winsor type Ⅰ surfactant system with ultra-low IFT in oil-wet shale oil reservoirs by NMR

Surfactants enhanced spontaneous imbibition is an effective method to improve the oil recovery of shale reservoirs. The popular perspective believes that the wettability alteration and the capillary force are the primary mechanisms. Thus a water-wet condition and a relatively high interfacial tension (IFT) are required. However, in this work, we found that the Winsor type I surfactant solution with ultra-low IFT performed better than other relatively higher-IFT solutions with the capillary effect in oil-wet shale reservoirs. The contact angle, spontaneous imbibition recovery and phase behavior of the Winsor type I surfactant solutions were measured and compared with the solutions with relatively high IFT, including water, nonionic, and anionic surfactant solutions. The results demonstrated that anionic surfactants and Winsor type I surfactant solutions could alter the wettability to a water-wet condition, while the nonionic surfactants could only change to an intermediate-wet state. Both the anionic surfactants and Winsor type I surfactant solutions could displace the oil from micropores and mesopores. Still, the Winsor type I surfactant solutions with ultra-low IFT showed a better performance than the anionic surfactants with relatively high IFT. The interfacial micrographs of the Winsor type I surfactant solutions in contact with the oil phase manifested that the Winsor type I surfactant solutions changed the recovery patterns from two-phase flow driven by capillary force to the migration of microemulsions and emulsions driven by diffusion and gravity. The over-equilibrium Winsor type Ⅲ microemulsions and emulsions are rapidly formed near the oil-water interface. After that, the over-equilibrium Winsor type Ⅲ microemulsions are gradually diluted to Winsor type Ⅰ microemulsions and dissolved in a fresh surfactant solution. At the same time, the emulsions diffuse firstly, then coalesce and migrate out of the pore mediums driven by buoyancy. The water-wet condition and capillary force are not significant for this flow pattern, thus the Winsor type I surfactant solutions with ultra-low IFT are especially effective in recovering the oil of oil-wet micropores and mesopores. This work provides a new way of exploiting the oil in organic matter pores that can barely change to water-wet conditions.

Experimental study on the characteristics of temperature dependent surface/interfacial properties of a non-ionic surfactant aqueous solution at quasi-thermal equilibrium condition

The surface/interfacial properties of liquid at elevated temperatures are fundamental issues for wide applications where the surface force matters. The dynamic characteristics of wetting behavior and surface tension (ST) of surfactant solutions remain unclear at thermal equilibrium, especially at high temperature. Utilizing a quasi-thermal equilibrium setup, the temperature dependence of the surface/interfacial properties of liquids (ultra-pure water and aqueous surfactant solutions) at temperature ranging from 10 to 90 °C (1 atm) are studied, by the sessile drop method and pendant drop method, respectively. A decreasing trend of the initial ST and contact angle (CA) is observed with the increase of temperature. During evaporation, the increase of the local relative humidity around the droplet has a crucial influence on CA. The obtained ST and CA are based on the thermodynamic model with modified coefficients, which can well describe the general trends for different temperatures and concentrations. For the ultra-pure water, the droplets will be pinned suddenly on the heating surface, until a sudden contraction occurs with evaporation. However, the surfactant-laden droplet shows different dynamical behaviors from ultra-pure water. Three different stages, named spreading-controlled Stage I, evaporation-controlled Stage II, and depinning-controlled Stage III are found for the dynamic evolution of surfactant-laden droplet. In what follows, the different droplet behaviors are also analyzed for surfactant solution and ultra-pure water.

Experimental and modeling study of enhanced oil recovery from carbonate reservoirs with smart water and surfactant injection

Many studies have been performed in the field of smart water injection and its combination with chemical methods to improve oil recovery. However, there has been less previous evidence for the efficiency of a mixture of cationic and nonionic surfactants combined with smart water for enhanced oil recovery in carbonate reservoirs. Therefore, in the current study, we aimed to investigate the effects of such a combination to enhance oil recovery from a fractured carbonate reservoir. Phase behavior experiments, IFT, and contact angle measurements were performed to design the optimal solution for EOR experiments. Then, through a series of flooding experiments, imbibition tests and simulations, and dimensionless analysis, the efficiency of the designed smart water-surfactant solution was examined. The results demonstrate a strong synergy between low salinity water and surfactant for recovering oil from carbonate reservoirs, as their optimal combination could recover up to 51.1% and 41.25% of the original oil-in-place in the core flood and imbibition experiments, respectively.

An experimental study on heat transfer of different aqueous surfactant solutions horizontal impinging jet using infrared thermography

This paper reports the effect of surface wettability on heat transfer characterizes of the impinging jet using the infrared thermography. Tests are performed on a heated vertical stainless steel foil of 0.15 mm thickness (SS-304) by circular horizontal impinging jets of pure water and various aqueous surfactant solutions such as 2-Ethyl Hexanol (2-EH), 1-Octanol (1-Oct) and Sodium-Dodecyl Sulfate (SDS) at varied surfactant concentration (100–400 ppm). The effect of wettability enhancement in heat transfer is disclosed by the heat transfer study using the thermal image detected by the infrared thermography system (A655sc, FLIR System). At a similar time period (t = 0.2 sec) after impingement, the liquid spreading is found to grow by a maximum of 3.1 times for 2-EH and 2.4 times for SDS. New empirical correlations are presented using regression analysis for the enhancement of radial impingement zone (Ra/Ro) and the ratio of heat transfer coefficient of water with additives (had) with the heat transfer coefficient for pure water (hpw).

An experimental investigation of hydrodynamic and heat transfer characteristics of surfactant-water solution and CNT nanofluid in a helical coil-based heat exchanger

Nanofluids are gaining attention due to their excellent heat transfer characteristics as compared to conventional basefluids. In this study, CNT nanofluid was prepared using double distilled water (as basefluid) and mixed surfactant (a mixture of surfactant SDBS and GA) keeping the Surfactant/CNT ratio 1. Hydrodynamics as well as heat transfer characteristics of water, surfactant-water solution and CNT nanofluid were investigated in coil tube heat exchanger. Thermo-physical properties of surfactant-water solution and CNT nanofluid were also examined. Results showed no difference in viscosity of surfactant-water solution in comparison to water but a slight increment in density of the surfactant-water solution compared to water. Also, it was found that friction factor was increased with increase in Reynolds number for water, surfactant-water solution and CNT nanofluid. The overall heat transfer coefficient was 62.62% higher for CNT nanofluid at 5000 Reynolds number as compared to water. No enhancement was observed in heat transfer coefficient for surfactant-water solution in comparison to water. These results concluded that CNT nanoparticles play a major role to enhance the heat transfer rate of nanofluid in contrast to water.

Experimental study on pool boiling regime transitions of vertical rod quenched in aqueous surfactant solutions using inverse heat transfer analysis

In this study, the effect of surfactants and liquid temperature on boiling regime transitions of high-temperature rod during quenching was examined using inverse heat transfer analysis. Liquid pools of the aqueous sodium dodecyl sulfate (SDS) and Triton X-100 solutions were used with pure water. In the present experimental range, the critical heat flux (CHF) and minimum film boiling (MFB) point for all test fluids increased as the liquid temperature decreased. On the other hand, the SDS and Triton X-100 surfactants suppressed the CHF and MFB point, which might be due to the enhancement of vapor film stability caused by reduced surface tension. Some previous experimental studies have reported that the surfactants enhance the boiling regime transitions, but their results seem to be contradictory to the present ones. Considering the present study with the previous works, the surfactants seem to have different effect on boiling phenomena depending on the boiling regime. In other words, in the aqueous surfactant solution, the boiling regime transition points seem to be markedly influenced by a path of boiling regime. In addition, boiling mode diagrams were presented for pure water and aqueous surfactant solutions.

Taming Troublesome Suzuki–Miyaura Reactions in Water Solution of Surfactants by the Use of Lecithin: A Step beyond the Micellar Model

The use of water solutions of industrial and designer surfactants enables performing a wide variety of chemical transformations on hydrophobic precursors. Most reactions are clean, fast, and effici...

Bubble behaviors during subcooled pool boiling in water and nonionic surfactant aqueous solution

A visualization study of the bubble behavior in pool boiling of ultra-pure water and surfactant aqueous solution (Triton X-114) under different heat fluxes was performed, using a narrow transparent bare FTO heating surface with various subcooling degrees of 5°C, 25°C and 35°C, respectively. It is shown that with the decrease of liquid subcooling, bubble coalescence in ultra-pure water becomes obvious. Whilst with the increase of liquid subcooling, the bubble surface gets rough and unstable. In contrast, a newly discovered phenomenon of bubble-bubble (BB) penetration occurs in the surfactant solution under the same working condition as that in water. BB penetration behavior is a bubble interaction without coalescence. This bubble behavior is believed to be the results of micro-convection due to the shrinkage of the bubble root, and the Marangoni effect due to the surface tension gradient. Combination of Marangoni effect and bubble surface movement causes the surfactant molecules to aggregate toward the bubble root, and it effectively promotes the nucleation of the next bubble. Owe to the rapid growth of newly nucleated bubbles, the bubble-bubble penetration and piercing behaviors happen during the growth stage. The newly nucleated bubble partially accelerates the first bubble departure, also interacts with the first bubble by forming a tiny vapor channel. This phenomenon should be one of the reasons of enhanced heat transfer using surfactant solutions.

Preparation of Long Duration Stable CNT Nanofluid Using SDS

CNT nanofluid shows better heat transfer rate due to their high thermal conductivity. Due to hydrophobic nature of CNT, preparation of stable nanofluid is a major challenge. Here nanofluid was prepared using modified two-step method using multi-walled CNT as nanomaterial, double distilled water as base fluid and SDS as surfactant. CNT concentration was varied from 0.1 to 0.3 wt%, surfactant/CNT ratio from 1 to 3 and ultrasonication time from 0 to 180 min. The results indicate that ultrasonication time and surfactant/CNT ratio have a significant effect on the dispersion of CNT in surfactant water solution. Prepared CNT nanofluid was found to be stable for a longer duration.

Detonation in the hydrogen-oxygen microfoam on the aqueous base

In the paper, the propagation of the detonation wave in the hydrogen-oxygen microfoam on the aqueous base is considered. Microfoam represents a two-phase system containing micron-sized gas bubbles filled with the hydrogen-oxygen mixture. These bubbles are dispersed in the water solution of surfactant (sodium dodecyl sulfate). The dependencies of detonation speed on the equivalence ratio and on the water content in the foam are obtained with the use of high-speed filming. It is found that the detonation speed slightly increases with the decrease in water content in the foam. Based on the pressure measurements, it is established that the detonation propagation in the foam is driven by relatively weak shock waves, which by themselves are not able to induce ignition of the hydrogen-oxygen mixture. To substantiate the fact of detonation existence in the microfoam a hypothesis of the cumulative collapse of gas bubbles under the shock wave action is proposed. The estimation for detonation speed in microfoam is analytically derived on the basis of simple phenomenological representations.

Comparing electrowettability and surfactants as tools for wettability enhancement on a hydrophobic surface

Surfactants and electrowetting (EW) are widely used for wettability enhancement of water. While numerous studies have examined the use of surfactants and EW individually, there are very few studies on electrowettability of surfactant-infused droplets. Furthermore, comparative analyses of the extent of wettability alteration via the use of surfactants and via EW are very limited. This study fills such gaps, and presents a systematic and detailed comparison of wettability control via EW and surfactants on a smooth hydrophobic surface. Nine surfactants were chosen in three categories: anionic, cationic and zwitterionic. Contact angle (CA) measurements of surfactant-infused water droplets were conducted with and without EW, at pre and post-critical micelle concentration limits (CMC).Many fundamental insights on the interplay between surfactants and electric fields are uncovered. While surfactants enhance wettability till CMC limits, EW can enable additional CA reduction (in surfactant-infused droplets) of as much as 35°. Conversely, surfactants enhance (by as much as 27°) the EW-induced CA reduction of water-surfactant solutions, as compared to EW-induced CA reduction of water alone. Interestingly, the influence of EW in enabling CA reduction is weakened by the addition of surfactants at pre-CMC levels. In contrast, the influence of EW in enabling CA reduction is increased at higher surfactant concentrations. It is noted that the extent of wettability enhancement via EW is limited by contact angle saturation beyond a certain electric field. At post CMC levels, the saturation CAs resulting from EW are independent of surfactant concentration.

Numerical study of coal dust behaviors and experimental investigation on coal dust suppression efficiency of surfactant solution by using wind tunnel tests

ABSTRACT Coal dust is one of the most serious hazards on mine sites. Water spray with surfactant added is an effective way to control the coal dust. In this study, wind tunnel experiments were designed to evaluate the surfactant on coal dust suppression efficiency. A CFD modeling was first constructed in to investigate the coal dust particles movement characteristics, and the stimulation results were provided for the wind tunnel design. The CFD results indicated that the location of the nozzle placement and the time for the water spraying start time. The coal dust suppression efficiency was then evaluated in the presence of different surfactants. The experiment results suggest that the anionic and non-ionic surfactants are helpful to improve the suppression efficiency while the cationic surfactant failed to increase it. For the SDBS at various concentrations, the highest suppression efficiency is achieved when at 0.20%. Compared with the larger coal dust particles, the finer ones are more difficult to capture for both water and SDBS surfactant solution. The results also demonstrate the potential application of this surfactant on coal mine industries.

Study of the displacement of floating diamagnetic bodies by a magnetic field

The authors analyzed the motion of diamagnetic bodies that float on diamagnetic liquids. The motion was inspired by the deformation of the diamagnetic liquid surface by a magnetic field, called the ‘Moses effect’. The influence of the surface tension on the shape of the well pushed out by the steady magnetic field (B ≅ 0·35T) acting on the surface of the liquid was studied both experimentally and theoretically for water, silicone oil and aqueous surfactant solution. The suggested mathematical approach accurately predicted the shape of the well, depending on the surface tension of the liquid. Qualitative analysis is reported regarding the motion of floating diamagnetic polymers and metallic objects driven by the Moses effect. The impact of the bulk magnetic force on the motion is minor for all of the studied diamagnetic rafts. The influences of gravity and interfacial forces on the displacement of rafts may be of a comparable order of magnitude.