The Influences of Polymers and Temperature on the Foam Properties of 3‐Dodecylalkoxyl‐2‐hydroxylpropyl Trimethylammonium Chloride

The foam performances of 3‐dodecoxy‐2‐hydroxypropyl trimethylammonium chloride (C₁₂TAC) have been determined in the existence of different relative amount of polymer. The experimental results show that the foaming ability of the mixture systems of the C₁₂TAC/PEG and C₁₂TAC/PVP is stronger than that of the surfactant solutions in the absence of polymer, and with the increase of relative amount of polymer both foaming efficiency and foam stability of the surfactant solutions are evidently enhanced. For the aqueous solution of the surfactant, effect of temperature on foaming properties has also been examined. The results show that both the foaming ability and stability of the foams of the surfactant solutions are highest (or strongest) at 30°C.     

The Effect of Macromolecules on Foam Stability in Sodium Dodecyl Sulfate/Cetylpyridinium Bromide Mixtures

Abstract

The effects of macromolecules, gelatin, and polyvinylpyrrolidone (PVP), on the properties of foam comprising sodium dodecyl sulfate (SDS) and cetylpyridinium bromide (CPDB) have been studied by measurements of foamability, foam stability, surface tension, and solution specific viscosity. The results indicate that foamability and foam stability are significantly improved when macromolecules are added into mixed systems. Both gelatin and PVP associate with SDS/CPDB surfactants and form aggregates. Electrostatic repulsion and steric stabilization between the two sides of the foam lamellae, due to aggregation, and prevention of drainage in the lamellae, achieved by the long chains of macromolecules are the reasons for increasing foamability and foam stability. The interactions between PVP and surfactants is weaker than those between gelatin and surfactants. The strongest association between macromolecules and surfactants occurs when the molar ratio of SDS/CPDB is 1:1. By comparing PVP with gelatin, the former is favored to increase foamability, and the latter is favored to increase foam stability.     

PEP与阴离子表面活性剂复配体系泡沫性能的研究

研究了PEP型非离子表面活性剂分别与十二烷基苯磺酸钠（DBS）,十二烷基硫酸钠（SDS）形成复配体系的泡沫性能,讨论了浓度及配比的变化对泡沫性能的影响,结果表明起泡性和稳泡性皆随混合表面活性剂的浓度的上升而增强;在一定浓度下,随着PEP比例下降,起泡性和稳泡性也随着增大,并达到稳定值。     

Protein foam application for enhanced oil recovery

Protein foam was explored as a foaming agent for enhanced oil recovery application in this study. The influence of salinity and oil presence on bulk stability and foamability of the egg white protein (EWP) foam was investigated. The results were compared with those of the classical surfactant sodium dodecyl sulfate (SDS) foam. The results showed that the EWP foam is more stable than the SDS foam in the presence of oil and different salts. Although, the SDS foam has more foamability than the EWP foam, however, at low to moderate salinities (1–3 wt% NaCl), both foam systems showed improvement in foamability. At a NaCl concentration of 4.0 wt% and above, foamability of the SDS foam started to decrease drastically while the foamability of the EWP foam remained the same. The presence of oil has a destabilizing effect on both foams but the EWP foam was less affected in comparison to the SDS foam. Moreover, increasing the aromatic hydrocarbon compound percentage in the added oil decreased the foamability and stability of the SDS foam more than EWP foams. This study suggests that the protein foam could be used as an alternative foaming agent for enhanced oil recovery application due to its high stability compared to the conventional foams.     

Thermodynamics of interaction between sodium bis(2‐ethylhexyl) sulfosuccinae and polymers in aqueous solutions by isothermal titration microcalorimetry

The interactions between sodium bis(2‐ethylhexyl) sulfosuccinae (AOT) and two nonionic water‐soluble polymers, including polyvinyl pyrrolidone (PVP) and polyethylene glycol (PEG) have been investigated by using isothermal titration microcalorimetry in aqueous solutions at 298.15 K. The results show that the critical aggregation concentration, which corresponding to the first turning point in the curve of experimental interaction heat versus concentration of the surfactant, is lower than the critical micellar concentration (cmc), confirming the existence of polymer‐surfactant interactions. The value of cac is not sensitive to the relative amount of polymer in low concentration range of the polymer. The mono‐layer saturated adsorption concentration, which corresponding to the second turning point, rises as the polymer concentration is increased. The interaction between PVP and AOT is stronger than that between PEG and AOT. The results also indicate that the aggregation of AOT in water and polymers solutions is entropically driven. The observed thermal effects have been interpreted in terms of the interactions of the polymer molecules with AOT monomers or the molecular clusters. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 275–283, 2006     

Investigations on foamability of surface-chemically pure aqueous solutions of functionalized alkylaldonamides

The foamability of the aqueous solutions of functionalized, surface-chemically pure surfactants of the nonionic saccharide-type: N,N-di-n-alkylaldonamides, N-alkyl-N-(2-hydroxyethyl)aldonamides, and N-cycloalkylaldonamides, derivatives of D-glucono-1,5-lactone and/or D-glucoheptono-1,4-lactone, were investigated. The approach of Lunkenheimer and Ma?ysa for the characterization of the foamability and foam stability of these surfactant solutions was applied for these investigations. Using standard parameters related to the different physical stages of the foaming process, foam stability can be described in a simple and easy manner. In general, the investigated alkylaldonamides form foams of medium stability. However, for some homologues a transition from unstable to stable foam systems is observed with increasing concentration. Modifications of the molecular structure of the alkylaldonamides are distinctly reflected in their foam properties. This fact concerns not only changes of the hydrophobic moiety and its functionalization but also slight variations of the saccharide residue. Each homologous series reveals an exceptional foam behavior. In the case of the N,N-di-n-alkylaldonamides the increase of the n-alkyl chain length is accompanied by an increase of the foam stability. The aqueous solutions of the N-alkyl-N-(2-hydroxyethyl)aldonamides reveal most favorable foaming properties for homologues with average alkyl chain lengths. Moreover, it was found that the occurrence of a phase transition in the adsorption layers of the N-cyclooctylgluconamides previously observed by surface tension and surface potential measurements is also remarkably reflected in their foam stability.     

A multi point conductivity measurement system for characterisation of protein foams

Protein foams play an important role in both food and biotechnological processes. A sound understanding of foaming properties of proteins relevant to such processes is useful e.g. to allow adequate control of unwanted foams and appropriate choice of protein-physical system when foams of certain characteristics are required. In general, measurements of changes in foam volume (volumetric method) are used for foam characterisation. However, recently there has been increased interest in the use of measurement methods based on conductivity and capacitance. Simple relative techniques based on electrical conductivity measurements provide information on both foamability and foam stability. A multi point conductivity measurement system has been designed and used for characterisation of model protein foams (0.1 and 1.0 mg ml⁻¹ Bovine serum albumin, BSA). The solution of BSA was sparged with nitrogen or carbon dioxide gas at constant flow rate (90 cm³ min⁻¹) via a stainless steel sinter (0.5 or 2.0 μm in pore size). A comparison of foaming properties determined by volumetric and conductimetric techniques is provided. Both methods show that more stable foams are obtained for solutions at higher BSA concentrations. At all BSA concentrations, higher foamability and stability are achieved with a smaller sinter pore size. When nitrogen rather than carbon dioxide is used as a dispersed phase, higher foamability and foam stability are obtained. The conductivity measurements indicate that foamability is dependent on gas type, whereas, volumetric measurements do not show such differences.     

Stability of Polymer and Surfactant Mixture Enhanced Foams in the Presence of Oil Under Static and Dynamic Conditions

Three different types of foaming agents including hydrocarbon surfactant TQ01, partial fluorinated surfactant BF01, and per-fluorinated surfactant QF01 exhibited good foaming ability and foam stability under 95°C high temperature and 32,325 ppm salinity conditions. The oil-tolerance ability order with respect to Malaysia Off-shore (MOS) crude oil for surfactant TQ01, BF01, and QF01 is TQ01 < BF01 < QF01. Introduction of polymer into the foam formula could significantly increase foam stability. Different polymers show different abilities of increasing foam stability. Spreading coefficient and entering coefficient are close to zero for surfactant BF01 foaming system and much less than zero for surfactant QF01 foaming system, so the oil-resistance ability of foam generated by surfactant QF01 is the strongest. For surfactant TQ01 foaming system, the calculated spreading coefficient and entering coefficient are greater than zero; therefore, the TQ01 foam system is more sensitive to MOS crude oil and its oil-resistance ability is the poorest. Core flooding test indicated that using the 0.4% BF01 and 0.2% YH1096 combined foaming formula could increase the pressure drop across the porous media significantly, indicating that strong foam was generated in the presence of MOS crude oil.     

Stabilization of nonaqueous foam with lamellar liquid crystal particles in diglycerol monolaurate/olive oil system

Nonaqueous foams stabilized by lamellar liquid crystal (L alpha) dispersion in diglycerol monolaurate (designated as C12G2)/olive oil systems are presented. Foamability and foam stability depending on composition and the effects of added water on the nonaqueous foaming behavior were systematically studied. It was found that the foamability increases with increasing C12G2 concentration from 1 to 3 wt% and then decreases with further increasing concentration, but the foam stability increases continuously with concentration. Depending on compositions, foams are stable for a few minutes to several hours. Foams produced by 10 wt% C12G2/olive oil system are stable for more than 6 h. In the study of effects of added water on the foaming properties of 5 wt% C12G2/olive oil system, it was found that the foamability and foam stability of 5 wt% C12G2/olive oil decreases upon addition of 1 wt% water, but with further increasing water, both the foamability and foam stability increase. Foams with 10% water added system are stable for approximately 4 h. Phase behavior study of the C12G2 in olive oil has shown the dispersion of L alpha particles in the dilute regions at 25 degrees C. Thus, stable foams in the C12G2/olive oil system can be attributed to L alpha particle, which adsorb at the gas-liquid interface as confirmed by surface tension measurements and optical microscopy. Laser diffraction particle size analyzer has shown that the average particle diameter decreases with increasing the C12G2 concentration and, hence, the foams are more stable at higher surfactant concentration. Judging from foaming test, optical micrographs, and particle size, it can be concluded that stable nonaqueous foams in the studied systems are mainly caused by the dispersion of L alpha particles and depending on the particle size the foam stability largely differs.     

Influence of Electrolytes on Foaming of Sodium Lauryl Sulfate

The influence of various electrolytes on the foamability of an anionic surfactant, sodium lauryl sulfate was studied. Foamability was measured by using a recently designed method for foam testing of surfactant solutions. The results are discussed in terms of foaming efficiency and foaming effectiveness. The addition of NaCl increases foaming efficiency whereas foaming effectiveness increased only marginally. The effect of cations on foaming efficiency and foaming effectiveness increased in the order, Li⁺< Na⁺<Cs⁺. This observation is explained in terms of the hydrated size of cations which decreases as Li⁺> Na⁺> Cs⁺.     

Foaming and foam stability for mixed polymer-surfactant solutions: effects of surfactant type and polymer charge

Solutions of surfactant-polymer mixtures often exhibit different foaming properties, compared to the solutions of the individual components, due to the strong tendency for formation of polymer-surfactant complexes in the bulk and on the surface of the mixed solutions. A generally shared view in the literature is that electrostatic interactions govern the formation of these complexes, for example between anionic surfactants and cationic polymers. In this study we combine foam tests with model experiments to evaluate and explain the effect of several polymer-surfactant mixtures on the foaminess and foam stability of the respective solutions. Anionic, cationic, and nonionic surfactants (SDS, C(12)TAB, and C(12)EO(23)) were studied to clarify the role of surfactant charge. Highly hydrophilic cationic and nonionic polymers (polyvinylamine and polyvinylformamide, respectivey) were chosen to eliminate the (more trivial) effect of direct hydrophobic interactions between the surfactant tails and the hydrophobic regions on the polymer chains. Our experiments showed clearly that the presence of opposite charges is not a necessary condition for boosting the foaminess and foam stability in the surfactant-polymer mixtures studied. Clear foam boosting (synergistic) effects were observed in the mixtures of cationic surfactant and cationic polymer, cationic surfactant and nonionic polymer, and anionic surfactant and nonionic polymer. The mixtures of anionic surfactant and cationic polymer showed improved foam stability, however, the foaminess was strongly reduced, as compared to the surfactant solutions without polymer. No significant synergistic or antagonistic effects were observed for the mixture of nonionic surfactant (with low critical micelle concentration) and nonionic polymer. The results from the model experiments allowed us to explain the observed trends by the different adsorption dynamics and complex formation pattern in the systems studied.     

Foams stabilized by mixed cationic gemini/anionic conventional surfactants

The mixed adsorption of a cationic gemini surfactant, ethanediyl-1,2-bis(dodecyldimethylammonium bromide) (abbreviated as 12-2-12), and an anionic conventional surfactant, sodium dodecyl sulfate (SDS), was examined using surface tension measurements. The viscoelastic properties of the mixed films were investigated by dilational interfacial rheology technique. The results showed that the addition of SDS promoted the close packing of adsorbed molecules at the interface, which increased the dilational elasticity of the mixed films. The stability of the foams was determined by the half-life of foam height collapse. The foams generated by 12-2-12/SDS mixtures were more stable than that formed by pure 12-2-12. In the presence of sodium bromide, the foam stability was further enhanced and the surfactant concentration required to attain the maximum effect in stabilizing foams was greatly reduced. The high foam stability could well relate to the high elasticity of the film.     

表面活性剂和聚乙烯吡咯烷酮在ZrO2上的吸附对其悬浮体稳定性的影响

研究了水溶液中十二烷基苯磺酸钠（ＳＤＢＳ）、溴代十四烷基吡啶（ＴＰＢ）和聚乙烯吡咯烷酮（ＰＶＰ）在ＺｒＯ２上的吸附及对ＺｒＯ２水悬浮体稳定性的影响。结果表明：ｐＨ＝２．４时ＳＤＢＳ在ＺｒＯ２上的吸附等湿线为ＬＳ型，ｐＨ＝７．０时ＴＰＢ的吸附等温线为Ｓ型，吸附等温线与ＺｒＯ２粒子ζ电势变化同线有大体一致的关系。在最大吸附量时ＺｒＯ２粒子ζ电势较大，且吸附的表面活性剂离子形成大部分亲水基朝向水相的表面     

Prediction of the Properties of a Binary Surfactant Mixture of Arlacel‐165 and Myrj‐59 in Aqueous System

Foamability and foam stability, emulsifying power, surface tension, and interfacial tension were investigated for different ratios of binary surfactant system of Arlacel‐165 (glyceryl stearate (and) PEG‐100 stearate) and Myrj‐59 (polyoxyethylene 100 stearate). Among all the ratios tested for their foaming power and foamabilty, the ratios 8:2, 5:5, 4:6, 2:8, and 1:9 of Arlacel‐165 and Myrj‐59 showed the best results. At these ratios, the foaming power and foamability was found to be 100%. The surfactants having foam stability more than 50% can be considered as metastable and those less than 50% are considered as low‐stability foams. In case of surface tension and interfacial tension property measurements, 8:2 and 9:1 showed the best results. At 8:2 and 9:1 of Arlacel‐165 and Myrj‐59, the surface tension was found to be 37.7 dynes/cm and 1.33 dynes/cm respectively at 30°C ambient temperature. Also, 7:3 of this binary mixture was found to exhibit the best emulsifying power among all the ratios tested. At 30°C, the emulsifying property of the binary mixture was 6 hours.     

Synergism and foaming properties in mixed nonionic/fatty acid soap surfactant systems

The synergism and foaming behavior of a mixed surfactant system consisting of a nonionic surfactant (polyethoxylated alkyl ether C(n)E(m)) and a fatty acid soap (sodium oleate) were studied. The micellar interaction parameter (the beta-parameter) was determined from the cmc following the approach of Rubingh's regular solution theory. For both the C(12)E(6)/sodium oleate and the C(14)E(6)/sodium oleate mixtures, the results indicate a fairly strong attractive interaction (negative beta-values), which were in agreement with previous data reported for other nonionic/anionic surfactant systems. The characteristics of the foam produced from the surfactants were evaluated using a glass column equipped with a series of electrodes measuring the conductance of the foam, which enabled the water content of the foam to be determined. From these measurements, since the total foam volume was almost the same for all concentrations and surfactants, we compared the amount of liquid in the foam produced under dynamic foaming and the ability of the foam to entrain the liquid after the airflow was switched-off (static foam stability). The amount of liquid in the foam 100 s after the air was switched-off followed the order NaOl > C(12)E(6) > C(14)E(6). Also, the mixtures had the same foam volumes as the pure surfactants at the same concentration. However, both mixtures had higher concentrations of liquid in the foam when the mole fraction of the nonionic surfactant in the mixed surfactant system was greater than about >0.3 in the solution.     

Mixed adsorption of poly(vinylpyrrolidone) and sodium dodecylbenzenesulfonate on kaolinite

The mixed adsorption of the nonionic polymer poly(vinylpyrrolidone) (PVP) and the anionic surfactant sodium dodecylbenzenesulfonate (SDBS) on kaolinite has been studied. Both components adsorb from their mixture onto the clay mineral. The overall adsorption process is sensitive to the pH, the electrolyte concentration, and the amounts of polymer and surfactant. Interpretation of the experimental data addresses also the patchwise heterogeneous nature of the clay surface. In the absence of PVP, SDBS adsorbs on kaolinite by electrostatic and hydrophobic interactions. However, when PVP is present, surfactant adsorption at 10(-2) M NaCl is mainly driven by charge compensation of the edges. The adsorption of PVP from the mixture shows similar behavior under different conditions. Three regions can be distinguished based on the changing charge of polymer-surfactant complexes in solutions with increasing SDBS concentration. At low surfactant content, PVP adsorbs by hydrogen bonding and hydrophobic interactions, whereas electrostatic interactions dominate at higher surfactant concentrations. Over the entire surfactant concentration range, polymer-surfactant aggregates are present at the edges. The composition of these surface complexes differs from that in solution and is controlled by the surface charge.     

Adsorption of sodium dodecyl sulfate at the hydrophobic solid/aqueous solution interface in the presence of poly(ethylene glycol): dependence upon polymer molecular weight

The polar orientation and degree of conformational order of sodium dodecyl sulfate (SDS) adsorbed at the hydrophobic octadecanethiol/aqueous solution interface in the presence of poly(ethylene glycol) (PEG) has been investigated as a function of the surfactant concentration and the molecular weight of the polymer. Sum frequency generation (SFG) vibrational spectroscopy was employed to obtain spectra of interfacial surfactant; weak SFG signals from interfacial polymer were also detected for polymer molecular weights of 900 and above. The phase of the SFG spectra indicated that both the surfactant and polymer had a net orientation of their CH2 and/or CH3 groups toward the hydrophobic surface. Spectra of SDS in the presence of mixed polymer/surfactant solutions showed increasing conformational order as the surfactant concentration was raised. At the lowest surfactant concentrations, the spectra of SDS were weaker in the presence of the polymer than in its absence. All PEG molecular weights investigated, with the exception of PEG 400, gave rise to significant inhibition of ordered surfactant adsorption below the critical micelle concentration. The greatest inhibitory effect was noted for PEG 900. Probing interfacial PEG specifically through the use of perdeuterated SDS revealed that the polymer spectral intensity decreased monotonically as the surfactant concentration was increased for all polymer molecular weights where a PEG spectrum was apparent. These findings are interpreted in terms of the displacement of preadsorbed polymer as the surfactant concentration increases. This result is compatible with observations of adsorption from SDS/PEG solutions at solid/solution and solution/air interfaces made using other techniques.     

评价表面活性剂溶液泡沫性能的方法—真球气泡法北大核心CSCD

通过真球气泡法测定了不同价数和浓度的无机盐体系下十二烷基硫酸钠(SDS)表面活性剂溶液的表面张力和表面扩展黏度;通过Ross-Miles法测定了相应同一溶液的发泡力和泡沫稳定性;结果表明:SDS溶液的表面张力值随着各种无机盐浓度的增加而减小至不变,此时的无机盐浓度作为相对浓度100%来考察时,发现临界胶束浓度(CMC)值与添加盐的种类无关,只随无机盐的相对浓度的增加而减少;即CMC值随着无机盐的相对浓度的增加从不含无机盐时的8.3 mmol/L均收敛至最小值3.0 mmol/L;表面张力值和对应的发泡力值呈负线性关系,由此推断表面张力值可以评价发泡力;表面扩展黏度值和对应的泡沫稳定性值呈正线性关系,由此推断表面扩展黏度可以评价泡沫稳定性;无机盐种类对SDS表面活性剂发泡力和泡沫稳定性的影响力随阳离子价数(Na^(+)、Cu^(2+)、Fe^(3+))增加而增加。     

Effect of water on foaming properties of diglycerol fatty acid ester-oil systems

We have studied the effect of added water on the nonaqueous foaming properties of diglycerol fatty acid ester nonionic surfactant systems. Diglycerol monomyristate (designated as DGM) could not foam in nonpolar oils squalane and hexadecane at normal room temperature. Nevertheless, addition of a small amount of water induces a dramatic change in foaming properties. Both the foamability and foam stability increases with the amount of added water within the studied concentration range. Phase behavior study showed that in the dilute regions there is dispersion of solid surfactant in the aforementioned oils in the DGM systems. The particle size of the dispersed solid phase was found to be several tens of microns in the water free system, and hence it tends to coagulate and precipitate. In the case of shorter alkyl chain length, diglycerol monolaurate (DGL) surfactant-oil systems, dispersion of lamellar liquid crystal (Lalpha) is observed at room temperature, and the poor foaming properties were attributed to the large particle size of the liquid crystal. In both the DGL and DGM-oil systems, we observed a tendency of the particle size to decrease with the increasing concentration of added water. At higher temperature, the solid surfactant transforms to lamellar liquid crystal phase, and foaming is improved in the DGM/squalane system. Foams are stable for several minutes. Judging from the foaming test and particle size distribution data it can be concluded that the poor foaming in the diglycerol fatty acid esters-oil systems may possibly be due to bigger particle size, which causes precipitation. Addition of water results in the dispersion of smaller particles and improves the foaming behavior.     

SDS与PVP对碘化银溶胶稳定性的影响

研究了SDS、PVP及二者的混合物对AgI溶胶稳定性的影响。SDS主要通过表面活性负离子在AgI质点表面上的吸附使ζ电势升高,提高溶胶的稳定性。低浓度的PVP使AgI溶胶敏化,高浓度时又通过吸附层的空间稳定效应使其稳定。在PVP与SDS的混合溶液中,AgI溶胶的稳定性显著增加。根据PVP与SDS在固液界面上的相互作用讨论了这一增效作用。