Surfactant Addition
Surfactant Addition - Related Videos
09:34
Extraction and Characterization of Surfactants from Atmospheric Aerosols
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Cited by 26 •
2017
Methods are presented for the targeted extraction of surfactants present in atmospheric aerosols and the determination of their absolute concentrations and surface tension curves in water, including their Critical Micelle Concentration (CMC).
01:27
Conjugate Addition (1,4-Addition) vs Direct Addition (1,2-Addition)
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2025
α,β-Unsaturated carbonyl compounds with two electrophilic sites, the carbonyl carbon, and the β carbon, are susceptible to nucleophilic attack via two modes: conjugate or 1,4-addition and direct or 1,2-addition. Conjugate addition results in a thermodynamically stable product. The reaction retains the stronger C=O bond at the expense of the weaker C=C π bond. The process is slow as the β carbon is less electrophilic than the carbonyl carbon. Direct addition products are formed faster owing to...
07:20
Lavage-induced Surfactant Depletion in Pigs As a Model of the Acute Respiratory Distress Syndrome (ARDS)
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Cited by 21 •
2016
Repeated pulmonary lavages in anesthetized pigs induce lung injury resembling major aspects of human acute respiratory distress syndrome (ARDS). For this purpose the lungs are repeatedly lavaged with 0.9% saline at 37 °C. The goal of the protocol is a reproducible mitigation of gas exchange and hemodynamics for research in ARDS.
10:28
Experimental Measurement of Settling Velocity of Spherical Particles in Unconfined and Confined Surfactant-based Shear Thinning Viscoelastic Fluids
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Cited by 15 •
2014
This paper demonstrates the experimental procedure to measure terminal settling velocities of spherical particles in surfactant-based shear thinning viscoelastic fluids. Fluids over a wide range of rheological properties are prepared and settling velocities are measured for a range of particle sizes in unbounded fluids and fluids between parallel walls.
01:08
Conjugate Addition of Enolates: Michael Addition
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2023
The attack of a nucleophile at the β carbon of an α,β-unsaturated carbonyl compound is called conjugate addition. Conjugate addition reactions of active methylene compounds, such as β-diketones, β-keto esters, β-keto nitriles, and α-nitro ketones, are called Michael addition reactions. The reaction is catalyzed by a base that abstracts the acidic methylene hydrogen, generating a doubly-stabilized enolate ion that serves as the nucleophile or the Michael donor. The base employed depends on the...
FAQs
Amphiphilic molecules orient their hydrophilic regions toward water and their hydrophobic regions toward less-water-compatible environments at an interface. This adsorption changes the forces operating at the boundary and lowers surface tension. As concentration rises beyond the critical micelle concentration, excess molecules assemble into micelles, creating a different environment for dispersed substances and experimental interactions.
Concentration determines whether molecules mainly modify an interface or also form micelles. The critical micelle concentration marks the point above which these structures develop. Increasing the amount is therefore not automatically beneficial. An unsuitable or excessive concentration may disturb biological membranes and affect cell viability, so the intended outcome must guide the amount used.
Selection should reflect the desired interfacial outcome and the biological material being exposed. A surfactant may be useful for wetting, dispersion, emulsion stabilization, membrane studies, protein studies, or compound delivery, yet an unsuitable choice can disrupt membranes or reduce cell viability. Matching both surfactant type and concentration helps balance function against biological compatibility.
Begin by identifying the intended purpose, such as improving wetting, dispersing materials, stabilizing an emulsion, studying membranes or proteins, or delivering a poorly water-soluble compound. Select a compatible surfactant, introduce it in a controlled amount, and assess whether the desired interfacial change occurs without membrane disruption or loss of cell viability.
Micelles and related interfacial structures can help accommodate poorly water-soluble compounds within a system that otherwise disperses them poorly. This can support delivery by improving dispersion, but the formulation still requires careful control of surfactant type and concentration. Excess or unsuitable material may create biological problems, including membrane disruption or effects on cell viability.
They should examine both the intended physical effect and the biological response. Relevant outcomes include improved wetting or dispersion, emulsion stabilization, and useful behavior in membrane or protein studies, alongside evidence of whether membranes are disrupted and cells retain viability. This paired evaluation matters because an interfacial improvement can be accompanied by biological disruption.