Preparation of Continuous Mesoporous Films on Porous and Dense Substrates

1996 ◽  
Vol 431 ◽  
Author(s):  
J. Liu ◽  
J. R. Bontha ◽  
A. Y. Kim ◽  
S. Baskaran
Keyword(s):  
Surfactant Solution ◽  
Silicate Solution ◽  
Diffusion Cell ◽  
Transparent Film ◽  
Mesoporous Films ◽  
Porous Support ◽  
Surfactant Solutions ◽  
Mesoporous Film ◽  
Cell Reactor ◽  
Porous Supports

AbstractHigh quality, continuous mesoporous films are prepared on both porous and dense substrates. An interfacial reaction mechanism is used to grow mesoporous films within the pores of porous supports using a diffusion cell reactor. The porous support was placed between two compartments containing a silicate solution in one compartment and a surfactant solution in the other. The silicate and surfactant solutions diffused into the support to form a mesoporous film at the liquid-liquid interface. This method produces a transparent film free from large defects. Spincoating technique is also used to prepare mesoporous films on dense substrates. These films have uniform thickness and show well-defined interference depending on the film thickness.

A New Dynamic Wettability-Alteration Model for Oil-Wet Cores During Surfactant-Solution Imbibition

SPE Journal ◽  
2013 ◽  
Vol 18 (05) ◽  
pp. 818-828 ◽  
Author(s):  
M. Hosein Kalaei ◽  
Don W. Green ◽  
G. Paul Willhite
Keyword(s):  
Experimental Data ◽  
Oil Recovery ◽  
History Matching ◽  
Mechanistic Model ◽  
Surfactant Solution ◽  
Experimental Tests ◽  
Quantitative Agreement ◽  
Wettability Alteration ◽  
Porous Rock ◽  
Surfactant Solutions

Summary Wettability modification of solid rocks with surfactants is an important process and has the potential to recover oil from reservoirs. When wettability is altered by use of surfactant solutions, capillary pressure, relative permeabilities, and residual oil saturations change wherever the porous rock is contacted by the surfactant. In this study, a mechanistic model is described in which wettability alteration is simulated by a new empirical correlation of the contact angle with surfactant concentration developed from experimental data. This model was tested against results from experimental tests in which oil was displaced from oil-wet cores by imbibition of surfactant solutions. Quantitative agreement between the simulation results of oil displacement and experimental data from the literature was obtained. Simulation of the imbibition of surfactant solution in laboratory-scale cores with the new model demonstrated that wettability alteration is a dynamic process, which plays a significant role in history matching and prediction of oil recovery from oil-wet porous media. In these simulations, the gravity force was the primary cause of the surfactant-solution invasion of the core that changed the rock wettability toward a less oil-wet state.

Drag Reduction of the Flow Past a Circular Cylinder in Surfactant Solution

2001 ◽  
Author(s):  
Satoshi Ogata ◽  
Keizo Watanabe
Keyword(s):  
Circular Cylinder ◽  
Drag Reduction ◽  
Sodium Salicylate ◽  
Tap Water ◽  
Pressure Coefficient ◽  
Surfactant Solution ◽  
Reduction Ratio ◽  
Number Range ◽  
Surfactant Solutions ◽  
Maximum Drag Reduction

Abstract The flow around a circular cylinder in surfactant solution was investigated experimentally by measurement of the pressure and velocity profiles in the Reynolds number range 6000 < Re < 50000. The test surfactant solutions were aqueous solutions of Ethoquad O/12 (Lion Co.) at concentrations of 50, 100 and 200 ppm, and sodium salicylate was added as a counterion. It was clarified that the pressure coefficient of surfactant solutions in the range of 10000 < Re < 50000 at the behind of the separation point was larger than that of tap water, and the separation angle increased with concentration of the surfactant solution. The velocity defect in surfactant solutions behind a circular cylinder was smaller than those in tap water. The drag coefficients of a circular cylinder in surfactant solutions were smaller than those of tap water in the range 10000 < Re < 50000, and no drag reduction occurred at Re = 6000. The drag reduction ratio increased with increasing concentration of surfactant solution. The maximum drag reduction ratio was approximately 35%.

Surfactant Effects on Picloram Adsorption by Soils

Weed Science ◽  
1976 ◽  
Vol 24 (6) ◽  
pp. 549-552 ◽  
Author(s):  
J. D. Gaynor ◽  
V. V. Volk
Keyword(s):  
Organic Matter ◽  
Cationic Surfactant ◽  
Anionic Surfactant ◽  
Organic Matter Content ◽  
Clay Content ◽  
Surfactant Solution ◽  
Matter Content ◽  
Adsorption Sites ◽  
Surfactant Solutions ◽  
Extractable Al

The effects of soil organic matter, clay, extractable Al, cation exchange capacity, and pH on the adsorption of picloram (4-amino-3,5,6-trichloropicolinic acid) from aqueous and surfactant solutions were investigated. Linear adsorption isotherms for the soils were obtained with the Freundlich equation. Of the five soil properties investigated, Freundlich K values correlated with extractable Al and clay content. Picloram adsorption from aqueous solutions and from the non-ionic and anionic surfactant solutions was greater on the soils at pH 5 than at pH 7. The anionic surfactant competed with picloram for adsorption sites on the soils at pH 5. Picloram adsorption from solutions containing 0.1 and 1% cationic surfactant was greater than that from aqeuous and anionic and nonionic surfactant solutions. Picloram adsorption from the 10% cationic surfactant solution was similar on soils with pH 5 and 7 and increased with decreased organic matter content.

Boiling of Water and Surfactants in Confined Space

2008 ◽  
Author(s):  
G. Hetsroni
Keyword(s):  
Heat Flux ◽  
High Speed ◽  
Video Recording ◽  
Surfactant Solution ◽  
Time Behavior ◽  
Gap Size ◽  
Confined Space ◽  
Annular Channels ◽  
Surfactant Solutions ◽  
Nucleation Sites

Natural convection boiling of water and surfactant solutions at atmospheric pressure in narrow horizontal annular channels was studied experimentally. The Alkyl (8–16) Glucoside with molecular weight of 390 g/mol was used in the experiments. It is a nonionic surfactant with negligible environmental impact. The length of the horizontal channels was 24 mm and 36 mm, the gape size was in the range of 0.45–3.7 mm, the heat flux was in the range of 20–500 kW/m2, the concentration of surfactant solutions was varied from 10 to 600 ppm. The gap size of the vertical channels was changed in the range of 1–80 mm. The flow pattern was visualized by high-speed video recording to identify the different regimes of boiling of water and surfactant solutions with different concentrations. At heat flux q<100 kW/m2 the rapid growth of elongated bubble was observed in the water. The rapid bubble growth pushes the liquid-vapor interface on both open sides of the channel. When a bubble departs from a nucleus cavity, its cavity is then recovered by liquid, and next bubble will appear on the heated tube after a certain interval. The behavior of the long vapor bubbles occurring in small size annular channels is not similar to annular flow with intermitted slugs between two vapor trains. Surfactant solution promotes activation of nucleation sites in a clustered mode. The cluster contains a number of small bubbles, the location of nucleation sites and time behavior of each bubble cannot be traced exactly. At higher values of heat flux coalescence process was observed during boiling of water and surfactant solutions. For water boiling in horizontal channels at Bond numbers Bo<1 the CHF in restricted space is lower than that in unconfined apace. This effect increases with increasing the channel length. For water at Bond number Bo = 1.52, boiling can be considered as unconfined. Additive of surfactant led to enhancement of heat transfer compared to water boiling in the same gap size, however, this effect decreased with decreasing gap size. For the same gap size, CHF in surfactant solutions was significantly lower than that in water. Hysteresis was observed for boiling in degraded surfactant solutions.

Confined Swirling Flows of Aqueous Surfactant Solutions Due to a Rotating Disc in a Cylindrical Casing

2007 ◽  
Author(s):  
S. Tamano ◽  
M. Itoh ◽  
M. Yoshida ◽  
K. Yokota
Keyword(s):  
Reynolds Number ◽  
Surfactant Solution ◽  
Swirling Flows ◽  
Visualization Technique ◽  
Rotating Disc ◽  
Constant Frequency ◽  
First Normal Stress Difference ◽  
Surfactant Solutions ◽  
Aqueous Surfactant Solution ◽  
Cylindrical Casing

In this study, confined swirling flows of an aqueous surfactant solution due to a rotating disc in a cylindrical casing were investigated using a sectional flow visualization technique and a two-component laser Doppler velocimetry (LDV) system. The concentrations of aqueous surfactant solutions (C14TASal) are 0.4, 0.8, and 1.2 wt%. Rheological properties such as a shear viscosity and a first normal stress difference of the surfactant solution were measured with a rheometer. The patterns of the secondary flow were classified using the Reynolds and elastic numbers. We revealed that the projection formed near the center of the rotating disc was moving up and down at a constant frequency for C14TASal 0.8 and 1.2 wt%, which has not been reported as far as we know. The effects of the Reynolds number, elastic number, and aspect ratio on the velocity profiles were clarified. It was also found that the region of rigid body rotation existed at the higher Reynolds number tested for C14TASal 0.4 wt%.

scholarly journals Complexes of Ectoine with the Anionic Surfactants as Active Ingredients of Cleansing Cosmetics with Reduced Irritating Potential

Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1433
Author(s):  
Tomasz Bujak ◽  
Martyna Zagórska-Dziok ◽  
Zofia Nizioł-Łukaszewska
Keyword(s):  
Antioxidant Activity ◽  
Systems Analysis ◽  
Anionic Surfactants ◽  
Surfactant Solution ◽  
Model Systems ◽  
Surfactant Solutions ◽  
Atopic Skin ◽  
Cytotoxic Studies ◽  
Skin Care Products ◽  
Selection Of

For many years, an increasing number of diagnosed atopy and skin problems have been observed. For people affected by the problem of atopy, the selection of skin care products, including cosmetics, is extremely important. Cleansing cosmetics, due to their ability to cause skin irritations and disturb the hydrolipidic barrier, can increase problems with atopic skin. New solutions to reduce the effects of these products on the skin are very important. In this work, the effect of ectoine on the properties of anionic surfactants was analyzed. Based on model systems, analysis of the effect of ectoine on the irritating effect of four anionic surfactants and their ability to solubilize model sebum was performed. Antioxidant activity was also evaluated, and cytotoxic studies were performed on cell cultures. It was shown that the addition of ectoine to the anionic surfactant solutions improves its safety of use. After introducing ectoine to the surfactant solution, a decrease of irritant potential (about 20%) and a decrease in the ability to solubilize of model sebum (about 10–20%) was noted. Addition of ectoine to surfactant solutions also reduced their cytotoxicity by up to 60%. The obtained results indicate that ectoine may be a modern ingredient that improves the safety of cleansing cosmetics.

scholarly journals Association of neutral red with micelles and its effect on the pKa

1993 ◽  
Vol 71 (11) ◽  
pp. 1785-1791 ◽  
Author(s):  
Robin K. Dutta ◽  
Subray N. Bhat
Keyword(s):  
Equilibrium Constants ◽  
Sodium Dodecyl ◽  
Surfactant Solution ◽  
Neutral Red ◽  
Association Constants ◽  
Alkyltrimethylammonium Bromides ◽  
Surfactant Solutions ◽  
Constant Ph ◽  
Apparent Association Constants ◽  
Apparent Association

The interactions of neutral red with cationic surfactants, viz., N-hexadecylpyridinium chloride and alkyltrimethylammonium bromides; a nonionic surfactant, viz., Triton X100; and an anionic surfactant, viz., sodium dodecyl sulfate, were investigated spectroscopically. The equilibrium constants for the association of the indicator with the micelles were determined from the apparent association constants at constant pH at 298 K. The effects of the indicator-micelle association on the apparent pKa of the indicator in aqueous surfactant solutions are discussed. It was shown that the apparent pKa of the indicator in cationic surfactant solution can be predicted from knowledge of the indicator-micelle association constant.

Synthesis and Characterization of a Novel Class of Zwitterionic Fluorocarbon Surfactants Based on Perfluorobutyl

2021 ◽  
Vol 58 (2) ◽  
pp. 136-145
Author(s):  
Xuhong Jia ◽  
Rui Huang ◽  
Xiaoguang Yang ◽  
Wan Tao ◽  
Xinhua Zhu
Keyword(s):  
Surface Tension ◽  
Surface Activity ◽  
High Efficiency ◽  
Pure Water ◽  
Surfactant Solution ◽  
Carbon Chain ◽  
Surfactant Solutions ◽  
Minimum Surface Tension ◽  
Fluorocarbon Chain ◽  
Ph Range

Abstract Perfluorooctane sulfonate (PFOS) and its derivatives had been banned due to their potential environmental hazards, although they possessed excellent surface activity. An effective method to solve this problem was to shorten the fluorocarbon chain of these surfactants from C°H17 to C4F9. As previous studies had shown, zwitterionic surfactants possess higher surface activity but have lower toxicity compared to other types of surfactants. In view of this, a class of novel zwitterionic fluorocarbon surfactants (n-CFNA-Br) with perfluorobutyl moiety was synthesized in this work. Their structures were characterized by FTIR, 1H NMR, 13C NMR, 19F NMR and MS. The results showed that all synthesized n-CFNA-Br had almost the same minimum surface tension, but their critical micelle concentration (CMC) decreased with increasing length of hydrophobic carbon chain. In pure water, the surface tension at the CMC (γCMC) of the four n-CFNA-Br were about 20 mN/m, and the CMC values were 7.73 mmol/L for 1-CFNA-Br, 4.70 mmol/L for 2-CFNA-Br, 4.13 mmol/L for 3-CFNA-Br, and 3.36 mmol/L for 4-CFNA-Br, indicating high efficiency and effectiveness. In 0.1 mol/L NaCl, the CMC values reduced to less than half of the CMC values measured in the pure aqueous surfactant solution, while the surface tensions γCMC remained almost unchanged, indicating good salinity tolerance of the synthesized surfactants. The acidic surfactant solutions exhibited similar CMC values to the saline solutions, but the surface tension γCMC increased slightly to 25 mN/m. However, further investigation showed that the n-CFNA-Br surfactants exhibited poor surface activity in alkaline solution (0.1 mol/L NaOH). In the pH range of 6.6 to 10.4, white precipitates appeared in the surfactant solutions after some time, indicating that the n-CFNA-Br are not suitable for use in alkaline systems with pH greater than 6.6.

Bubble Growth in Surfactant Solutions

2010 ◽  
Author(s):  
G. Hetsroni ◽  
A. Mosyak
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Bubble Growth ◽  
High Speed ◽  
Surfactant Solution ◽  
Life Time ◽  
Channel Length ◽  
Gap Size ◽  
High Speed Video ◽  
Surfactant Solutions

The presence of surfactant additives in water was found to enhance significantly the boiling heat transfer. The objective of the present investigation was to compare the bubble growth in water to that of a surfactant solution with negligible environmental impact. The study was conducted to clarify the effect of the heat flux on the dynamics of bubble nucleation. The bubble growth under condition of pool boiling in water and surfactant solutions was studied using high speed video technique. The bubble generation was studied on a horizontal flat surface; where the natural roughness of the surface was used to produce the bubbles. At heat flux of q= 10 kW/m2 the life-time and the volume of bubble growth in surfactant solution did not differ significantly from those of water. The time behavior of the contact angle of bubble growing in surfactant solution is qualitatively similar to that of water. At a heat flux of q= 50 kW/m2, boiling in surfactant solution, when compared with that of pure water, was observed to be more vigorous. Surfactant promotes activation of nucleation sites; the bubbles appeared in a cluster mode; the life-time of each bubble in the cluster is shorter than that of a single water bubble. The detachment diameter of water bubble increases with increasing heat flux, whereas analysis of bubble growth in surfactant solution reveals the opposite effect: the detachment diameter of the bubble decreases with increasing heat flux. Natural convection boiling of water and surfactants at atmospheric pressure in narrow horizontal annular channels was studied experimentally in the range of Bond numbers Bo = 0.185–1.52. The flow pattern was visualized by high-speed video recording to identify the different regimes of boiling of water and surfactants. The channel length was 24mm and 36mm, the gap size was 0.45, 1.2, 2.2, and 3.7mm. The heat flux was in the range of 20–500 kW/m2, the concentration of surfactant solutions was varied from 10 to 600 ppm. For water boiling at Bond numbers Bo&lt;1 the CHF in restricted space is lower than that in unconfined space. This effect increases with increasing the channel length. For water at Bond number Bo = 1.52, boiling can almost be considered as unconfined. Additive of surfactant led to enhancement of heat transfer compared to water boiling in the same gap size, however, this effect decreased with decreasing gap size. For the same gap size, CHF in surfactant solutions was significantly lower than that in water. Hysteresis was observed for boiling in degraded surfactant solutions.

Confined Swirling Flows of Aqueous Surfactant Solutions Due to a Rotating Disk in a Cylindrical Casing

2008 ◽  
Vol 130 (8) ◽  
Author(s):  
Shinji Tamano ◽  
Motoyuki Itoh ◽  
Mitsunori Yoshida ◽  
Kazuhiko Yokota
Keyword(s):  
Reynolds Number ◽  
Surfactant Solution ◽  
Rotating Disk ◽  
Swirling Flows ◽  
Visualization Technique ◽  
Constant Frequency ◽  
First Normal Stress Difference ◽  
Surfactant Solutions ◽  
Cylindrical Casing ◽  
Elasticity Number

In this study, confined swirling flows of an aqueous surfactant solution due to a rotating disk in a cylindrical casing were investigated using a sectional flow visualization technique and a two-component laser Doppler velocimetry system. The concentrations of aqueous surfactant solutions (C14TASal) are 0.4wt%, 0.8wt%, and 1.2wt%. Rheological properties such as shear viscosity and first normal stress difference of the surfactant solution were measured with a rheometer. The patterns of secondary flow were classified using the Reynolds and elasticity numbers. We revealed that the projection formed near the center of the rotating disk moved up and down at a constant frequency for C14TASal0.8wt% and 1.2wt%, which has not been reported as far as we know. The effects of the Reynolds number, elasticity number, and aspect ratio on the velocity profiles were clarified. It was also found that the region of rigid body rotation existed at the higher Reynolds number tested for C14TASal0.4wt%.

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