Surface Tension Of Surfactant Research Articles

Correction: The equilibrium and dynamic surface tension of polymeric surfactants based on epoxidized soybean oil grafted hydroxyethyl cellulose

Correction for ‘The equilibrium and dynamic surface tension of polymeric surfactants based on epoxidized soybean oil grafted hydroxyethyl cellulose’ by Xujuan Huang et al., RSC Adv., 2016, 6, 64121–64128.

The equilibrium and dynamic surface tension of polymeric surfactants based on epoxidized soybean oil grafted hydroxyethyl cellulose

Analysis of the equilibrium and dynamic surface tension of epoxidized soybean oil grafted hydroxyethyl cellulose (H-ESO-HEC) surfactants with different molecular weights were carried out at pH values that ranged from 8 to 13.

Effects of Added Salts on Surface Tension and Aggregation of Crown Ether Surfactants.

Two crown ether surfactants, dodecanoyloxymethyl- (C11Φ6) and octanoyloxymethyl-18-crown-6 (C7Φ6), were synthesized and the surface tension dependence on surfactant concentration of their aqueous solutions was measured both in the absence and presence of alkali chlorides to confirm the critical micelle concentration (CMC) is highest for the added cation that have an ionic diameter comparable to the hole size of the crown ether ring and that several break points on the surface tension vs. concentration curves occur for these crown ether surfactants. For C11Φ6 and C7Φ6, in the absence of salt, the surface tension vs. concentration curves had two break points. Using the solubilization of a water-insoluble dye as an indicator, we found that the break point at the higher concentration (m0) for C7Φ6 was due to micelle formation. Two break points were also observed for the aqueous solution of C11Φ6 in the presence of NaCl, KCl, RbCl, and CsCl salts at concentrations of 0.22 mol kg(-1) and for C7Φ6 with 0.22 mol kg(-1) KCl added. The CMC (m0) was found to be the highest for solutions containing K(+) salts because K(+) has an ionic diameter comparable to the hole size of 18-crown-6 ring. Furthermore, the CMC decreased as the ionic diameters of the added cations deviated from the hole size. The molecular areas at two break points, estimated by the Gibbs adsorption isotherm, except for that at the break point at mI of C7Φ6, were very small for an adsorbed monolayer. Further investigation is required to elucidate the reason for the break point at mI.

In Vitro Evaluation of a Device for Intra-Pulmonary Aerosol Generation and Delivery.

For infants born with respiratory distress syndrome (RDS), liquid bolus delivery of surfactant administered through an endotracheal tube is common practice. While this method is generally effective, complications such as transient hypoxia, hypercapnia, and altered cerebral blood flow may occur. Aerosolized surfactant therapy has been explored as an alternative. Unfortunately, past efforts have led to disappointing results as aerosols were generated outside the lungs with significant pharyngeal deposition and minimal intrapulmonary instillation. A novel aerosol generator (Microjet™) is evaluated herein for intrapulmonary aerosol generation within an endotracheal tube and tested with Curosurf and Infasurf surfactants. Compared with other aerosol delivery devices, this process utilizes low air flow (range 0.01-0.2 L/min) that is ideal for limiting potential barotrauma to the premature newborn lung. The mass mean diameter (MMD) of the particles for both tested surfactants was less than 4 μm, which is ideal for both uniform and distal lung delivery. As an indicator of phospholipid function, surfactant surface tension was measured before and after aerosol formation; with no significant difference. Moreover, this device has an outside diameter of <1mm, which permits insertion into an endotracheal tube (of even 2.0 mm). In the premature infant where intravenous access is either technically challenging or difficult, aerosol drug delivery may provide an alternative route in patient resuscitation, stabilization and care. Other potential applications of this type of device include the delivery of nutrients, antibiotics, and analgesics via the pulmonary route.

Surfactants at the Design Limit.

This article analyzes how the individual structural elements of surfactant molecules affect surface properties, in particular, the point of reference defined by the limiting surface tension at the aqueous cmc, γcmc. Particular emphasis is given to how the chemical nature and structure of the hydrophobic tails influence γcmc. By comparing the three different classes of surfactants, fluorocarbon, silicone, and hydrocarbon, a generalized surface packing index is introduced which is independent of the chemical nature of the surfactants. This parameter ϕcmc represents the volume fraction of surfactant chain fragments in a surface film at the aqueous cmc. It is shown that ϕcmc is a useful index for understanding the limiting surface tension of surfactants and can be useful for designing new superefficient surfactants.

PENGARUH JENIS PELARUT DAN TEMPERATUR REAKSI PADA SINTESIS SURFAKTAN DARI ASAM OLEAT DAN n-METIL GLUKAMINA DENGAN KATALIS KIMIA

Surfactants are molecules that also has a hydrophilic group and a lipophilic group that can unify a mixture consisting of water and oil. Alkanolamide is one type of nonionic surfactants are widely used in everyday life. In this study, will be observed the influence of the type of solvent and reaction temperature on the synthesis of surfactant alkanolamide n -methyl glukamine and oleic acid from palm oil with sodium methoxide catalyst. This study aims to determine the value of the hydrophilic lipophilic balance (HLB), pH and surface tension of surfactant, by observing the effect of the type of solvent and reaction temperature. This research was conducted by using a flask at 90 ° C, 110 ° C, 130 ° C for 3 hours reaction time, substrate ratio of 1: 2, the stirring speed of 150 rpm and a catalyst concentration of 0.4% (w/w). In the amidation reaction samples taken from the flask every 1 hour for 3 hours and then the results of this amidation reaction was washed with acetone solvent to separate the catalyst. Results washing then purified by heating at 90°C to evaporate the solvent surfactant products hexane and butanol. Results containing surfactant in the analysis with Hydrophilic Liphophilic Balance Method, surface tension and FT-IR spectrophotometry. Based on this research, the optimal conditions at a temperature of 110oC, reaction time 3 hours at the solvent ratio 2: 1. From the analysis of surfactant oleoil n-Methyl glukamine values obtained HLB in the range of 11,53 HLB in accordance with the standard detergent.

Nanobubbles: a new paradigm for air-seeding in xylem.

Long-distance water transport in plants relies on a system that typically operates under negative pressure and is prone to hydraulic failure due to gas bubble formation. One primary mechanism of bubble formation takes place at nanoporous pit membranes between neighboring conduits. We argue that this process is likely to snap off nanobubbles because the local increase in liquid pressure caused by entry of air-water menisci into the complex pit membrane pores would energetically favor nanobubble formation over instant cavitation. Nanobubbles would be stabilized by surfactants and by gas supersaturation of the sap, may dissolve, fragment into smaller bubbles, or create embolisms. The hypothesis that safe and stable nanobubbles occur in plants adds a new component supporting the cohesion-tension theory.

An axisymmetric model for the analysis of dynamic surface tension

An axisymmetric model accounts for dynamic surface tension of non-ionic surfactants under consideration of diffusive adsorption behaviour with a finite diffusion length.

Dynamic surface tension and adsorption kinetics of a siloxane dicephalic surfactant

The dynamic surface tension (DST) of a siloxane dicephalic surfactant was measured by using the maximum bubble pressure method. By using the classical Ward and Tordai equation, the diffusion coefficient for each bulk surfactant concentration was calculated. The results show that at the initial adsorption stage and at the end of the adsorption process, the dynamic surface tension data were all consistent with this diffusion-controlled mechanism. Their diffusion coefficient was slightly lower than that for conventional hydrocarbon surfactants.

Biophysical inhibition of pulmonary surfactant function by polymeric nanoparticles: Role of surfactant protein B and C

The current study investigated the mechanisms involved in the process of biophysical inhibition of pulmonary surfactant by polymeric nanoparticles (NP). The minimal surface tension of diverse synthetic surfactants was monitored in the presence of bare and surface-decorated (i.e. poloxamer 407) sub-100nm poly(lactide) NP. Moreover, the influence of NP on surfactant composition (i.e. surfactant protein (SP) content) was studied. Dose-elevations of SP advanced the biophysical activity of the tested surfactant preparation. Surfactant-associated protein C supplemented phospholipid mixtures (PLM-C) were shown to be more susceptible to biophysical inactivation by bare NP than phospholipid mixture supplemented with surfactant protein B (PLM-B) and PLM-B/C. Surfactant function was hindered owing to a drastic depletion of the SP content upon contact with bare NP. By contrast, surface-modified NP were capable of circumventing unwanted surfactant inhibition. Surfactant constitution influences the extent of biophysical inhibition by polymeric NP. Steric shielding of the NP surface minimizes unwanted NP–surfactant interactions, which represents an option for the development of surfactant-compatible nanomedicines.

Application of Green Surfactants Developing Environment Friendly Foam Extinguishing Agent

The green surfactants were used to develop environment friendly foam extinguishing agent instead of fluorocarbon surfactant. The surface tension and foam property of a variety of green surfactants were studied by orthogonal experiments. Alkyl glucose amide and organosilicone surfactant were selected. The foam property of alkyl glucose amide and surface tension of organosilicone surfactant were experimentally studied. And finally, the content of two surfactants were determined by considering the interaction of orthogonal experiments. The fire extinguishing performance of 2.5% alkyl glucose amide and 2% organosilicone surfactant containing foam extinguishing agent met the national standard requirements. Conclusion: alkyl glucose amide and organosilicone surfactant can replace fluorocarbon surfactant in foam extinguishing agent. This fire extinguishing agent is completely in conformity with “Stockholm Convention”, and environment friendly foam extinguishing agent.

Effect of Surfactant Type and Concentration on Surfactant Migration, Surface Tension, and Adhesion of Latex Films

The effect of surfactant type and concentration on the migration behavior of surfactant in a latex film was investigated. Two types of surfactant, including an anionic (sodium lauryl sulfate, SLS) and a non-ionic (nonylphenol ethoxylate, average number of ethylene oxide units = 40, NP-40) surfactant, were used in an emulsion polymerization of methyl methacrylate butyl acrylate copolymer (MMA–BA). The total amount of surfactant was varied in three levels, i.e., 1.5, 3, and 4.5 wt%, and the surfactants were used both pure and in a mixture state. The surfactant migration to the film–air (F–A) and film–substrate (F–S) interfaces of the latex films was determined by using an attenuated total reflection-Fourier transform infrared (ATR-FTIR) method. In addition, the adhesion of the latex films to glass substrates was measured by a pull-off test. The results showed that the migration of anionic surfactant to the interfaces was greater than the non-ionic one. It was also found that the use of non-ionic surfactant along with anionic surfactant could decrease the migration of the anionic surfactant to the interfaces.

Shampoos Then and Now : Synthetic versus Natural *#

Hair care has been important to mankind from times immemorial. The market today is replete with synthetic hair care products, pushing natural materials to the background. These natural materials, being produced from plants, are bio-degradable and non-toxic. In a bid to investigate natural products, we studied the surface tension, foaming and relevant parameters of natural surfactants extracted from Shikakai (Acacia concinna) and Seto Siris (Albizia procera), traditionally used in hair care. In order to get a better understanding, Johnson's Baby Shampoo has also been studied. Shikakai showed very prominent surface tension reduction and high foaming, showing that it can be a potential candidate for good hair care. These effects are not so prominent for Seto Siris. However, as it is widely available in the hills, large quantities can be used. Qualitative measurement of their cleaning properties and subsequent comparison with commercial shampoo show that both plants have a large potential in providing nontoxic natural hair care products.

Effects of Branched-Chain Alcohols on Surface Activity and Micellization of Gemini Surfactants

Gemini surfactants are a kind of novel and efficient surfactants and alcohols are one of the most widely used additives to surfactant products in industries and daily life. Understanding the effects of alcohols on surface activities and micellization of gemini surfactants will promote the applications of gemini surfactants. Effects of linear-chain alcohol (1-pentanol) and branched-chain alcohols (2-hexanol and 3-heptanol) with the same main chain as 1-pentanol on the surface activity and micellization of cationic ammonium gemini surfactants C12CSC12Br2 (S=2, 4, 6, 8, 10, 12) in aqueous solution have been investigated by surface tension, electrical conductivity, isothermal titration microcalorimetry (ITC), cryogenic transmission electron microscopy (Cryo-TEM), and NMR techniques. The branched-chain alcohols have not shown obvious effects on the critical micelle concentration of surfactants (CMC), the size and the morphology of micelles due to loose microstructure and weak interactions between the alcohols and the gemini surfactant molecules. However, the addition of branched-chain alcohols greatly decreases the surface tension of surfactants and the surface tension decreases with the increase of the branching factor of the alcohols. In addition, the surfactant concentration required to reduce the surface tension of the solvent by 20 mN/m (C20) and the surface tension values of the surfactants at CMC (γCMC) decrease obviously with the increment of the branching factor of the alcohols at a fixed alcohol concentration due to the increase of the hydrophobic chain density at the air/solution interface. The results suggest that the branched-chain alcohols influence the self-assembly of surfactants more obviously at the air/solution interface than in micelles. Moreover, there is a second critical concentration in the surface tension curves of C12C10C12Br2 and C12C12C12Br2 with a longer spacer, indicating that the hydrophobic chains of these gemini surfactants are not packed tightly even above CMC due to the flexibility of their spacers and low CMC, and are packed more tightly with the increase of the surfactant concentration. The addition of alcohols decreases the second critical concentration remarkably with the increase of their branching factor, which means that the branched alcohols have a more obvious effect on the surface activity of gemini surfactants with a longer spacer. This work helps us to understand the effects of branched-chain alcohols on the self-assembly of gemini surfactants at air/solution interface and in bulk solution, and may provide some guidance on how to choose alcohols to adjust surface activities and micellization of gemini surfactants.

New Measurements of Lung Surfactant Interfacial Tension with Micropipette Manipulation Technique

Approximately 50,000-190,000 adults and 24,000 newborn per year in the U.S. develop Acute- and Neonatal-Respiratory Distress Syndrome (ARDS&NRDS), respectively. For more than a couple of decades, many researchers have been tackling the problem of how to investigate lung surfactant behavior, especially of the relationships between the lipids and the natural lung surfactant proteins, by using techniques such as the Langmuir-Trough or Pulsating Bubble Surfactometer (PBS). Currently, we are developing a new method of the micropipette manipulation technique for lung surfactant surface tension measurement. The technique builds on previous studies that used a simple tapered micropipet to measure liquid-gas and liquid-liquid interfacial tension [1-2]. Working with micropipettes that contain the aqueous phase but viewed in air allows us to measure interfacial tensions at controlled pressures and interfacial radii when lung surfactant material is introduced, as in delivery of liquids to the lung alveoli. The new measurements of calf lung surfactant, Infasurf, at the aqueous-air interface showed how the interfacial tension γ at 37 degree Celsius was rapidly reduced from 70.3 to 21.1 ± 0.1 mN/m. One of the advantages of this technique is that by using a second delivery pipette it can be used to observe kinetic processes like adsorption, condensation and desorption of interfacial materials. In order to provide a reversed cone shape for the delivery measurements, we modified the pipette shape to be trumpet-shaped. We will present more details at the meeting regarding lung surfactants and synthetic systems that have been studied.References[1–2] Lee, S., D. H. Kim, and D. Needham, Langmuir, 2001. 17: 5537 & 5544.

Research on the Performance of Polyether-Modified Trisiloxane Surfactant

The surface tension, CMC, HLB, emulsifying ability and hydrolytic stability of the polyether-modified trisiloxane surfactants were tested. The hydrolytic stability of different products was compared.

Thermodynamics and micellization of cetyltrimethyl ammonium bromide in the presence of lysozyme

To study the structural changes in lysozyme (cationic protein) on the addition of N-cetyl-N,N,N-trimethyl ammonium bromide (CTAB) and to understand the mechanism underlying aggregation of resulting protein–surfactant complex, surface tension, density and sound velocity measurements of lysozyme–CTAB solutions were carried out over a temperature range of 25–40°C. The critical micelle concentration (cmc) of CTAB has been calculated from surface tension measurements and is found to increase with increase in lysozyme concentration as well as with temperature. Surface tension data have been further used to calculate the interfacial parameters; maximum surface excess concentration (Γmax), minimum area per molecule (Amin), standard free energy of adsorption (ΔGoad), surface pressure at cmc (Πcmc) and standard free energy of transfer (ΔGotr), that have direct bearing on the consequences of such interactions at the molecular level. The negative values of standard Gibbs energy changes indicate spontaneity of micellization. Apparent molar volume (ϕv) and apparent molar adiabatic compressibility (ϕκ) have also been calculated using density and velocity of sound. These parameters have been examined as a function of surfactant concentration, lysozyme concentration and temperature to understand the consequences of interactions between these two components. A good qualitative correlation is found to exist with regard to the surfactant–lysozyme interaction obtained from the experimental data from different techniques.

Properties of the ternary mixtures of fluorocarbon and hydrocarbon nonionic surfactants at the water–air interface

Surface tension measurements of aqueous solutions of ternary surfactant mixtures of ethoxylated tert-octylphenol with 10 and 16 ethylene oxide groups, called Triton X-100 (TX100) and Triton X-165 (TX165), respectively, with the fluorocarbon surfactant Zonyl FSN-100 (FSN100) were carried out at 293K. Based on the surface tension isotherms, the Gibbs surface excess of surfactants concentration at the water–air interface was determined. Then the mole fractions of surfactants in the surface layer were compared with those in the bulk phase. Considering the different composition of the mixed monolayer at the water–air interface, calculated with and without the water content, the molecular interaction parameters of surfactants, their activity coefficients, activity toward water and binary mixtures and the free enthalpy of their mixing were also calculated. As follows from the measurements and calculations, among others, the values of the surface tension of the studied ternary mixture of surfactants at the concentrations corresponding to the saturated monolayer at the water–air interface can be predicted. It is possible to obtain these values on the basis of the monomer mole fraction of TX100, TX165 and FSN100 calculated without the water content at this interface and the values of the surface tension of single surfactants studied at an appropriate concentration.

Surfactant Surface Tension Effects on Promoting Hydrate Formation: An Experimental Study Using Fluorocarbon Surfactant (Intechem-01) + SDS Composite Surfactant

The investigation of surface tension is a very important task for gas hydrate studying. Surfactants can effectively reduce the surface tension, improve the gas storage capability of hydrate and increase the formation rate, shorten the induction time. The objective of this study were to obtain a better understanding of the role of surface tension on hydrate formation and build gas hydrate models involve surfactant. In this study it was highlighted that the surface tension of Intechem-01 + SDS composite surfactants in natural gas hydrate promotion system and the change rules at different temperatures, concentration and proportion. According to the results of experiment, the surface tension of composite surfactants decreased with the increase of Intechem-01. The best cooperating effect was observed in proportion (Intechem-01 content) of 0.6 - 0.7, where the surface tension was the lowest. In this proportion range, the composite surfactants showed the same effect to pure fluorine carbon surfactant. The study shown the surface tension of composite surfactants decreased with the rise of temperature, and they were in a linear relationship within a certain range. Surface tension of composite surfactants decreased with the increase of surfactant concentration, however, it was no longer decreased above critical micelle concentration (CMC). The fitting equation of surface tension with various factors has been obtained.

Micellization and Adsorption Behaviors of New Reactive Polymerizable Surfactants Based on Modified Nonyl Phenol Ethoxylates

AbstractThe synthesis and characterization of a series of polymerizable surfactants based on alkyl phenol ethoxylate backbone and carboxylic or anhydride chain ends were investigated. Surface activities of these polymerizable surfactants were investigated to correlate their structure and their performances. The new bifunctional surfmers were prepared by reacting polyoxyethylene 4‐nonyl‐2‐propylene‐phenol nonionic reactive surfactants with maleic anhydride. The chemical structure of the prepared surfactants was characterized by 13C and 1H NMR analyses. The surface activities of the modified polymerizable surfactants were measured from the adsorption isotherm measurements which were determined from the relationship between the concentrations and surface tension of surfactants in aqueous medium at different temperatures. Critical micelle concentration (CMC) values were determined for water soluble surfactants. It was found that CMC decreases with the incorporation of the anhydride and acid groups in the chemical structure of polyoxyethylene 4‐nonyl −2‐propylene‐phenol nonionic surfactant. surface‐active parameters such as area per molecule at the interface (Amin), surface excess concentration (Γmax) and the effectiveness of surface tension reduction (πCMC) were measured from the adsorption isotherms of the modified surfactants. Some thermodynamic data for the adsorption process were calculated and discussed. The data indicated that the new surfmers are more reactive than the simple polyoxyethylene 4‐nonyl‐2‐propylene‐phenol and more adsorbed at interfaces. We have performed a preliminary experiment to explore the emulsification efficiency of the newly synthesized reactive surfactants in equal volume oil–water emulsions. Different emulsion types and stabilities were obtained.