Structure of zwitterionic surfactant micelles: micellar size and intermicellar interactions

1992 ◽  
Vol 96 (21) ◽  
pp. 8614-8619 ◽  
Author(s):  
Yves Chevalier ◽  
Flavien Melis ◽  
Jean Pierre Dalbiez
Keyword(s):  
Zwitterionic Surfactant ◽  
Surfactant Micelles ◽  
Micellar Size

Photoluminescent and pH-responsive supramolecular structures from co-assembly of carbon quantum dots and zwitterionic surfactant micelles

2018 ◽  
Vol 6 (43) ◽  
pp. 7021-7032 ◽  
Author(s):  
Xiaofeng Sun ◽  
Mengjun Chen ◽  
Yiqiang Zhang ◽  
Yanji Yin ◽  
Linwen Zhang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Carbon Quantum Dots ◽  
Supramolecular Structures ◽  
Zwitterionic Surfactant ◽  
Ph Responsive ◽  
Surfactant Micelles

Mixing negatively charged carbon quantum dots with a zwitterionic surfactant in water produces a variety of supramolecular structures, which are photoluminescent and show a reversible response to pH.

Structure and Dynamics of Spherical and Rodlike Alkyl Ethoxylate Surfactant Micelles Investigated Using NMR Relaxation and Atomistic Molecular Dynamics Simulations

2019 ◽  
Author(s):  
Allison Edwards ◽  
Abdolreza Javidialesaadi ◽  
Katie Weigandt ◽  
George Stan ◽  
Charles Eads
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Nmr Relaxation ◽  
Cross Relaxation ◽  
Relaxation Rates ◽  
Surfactant Micelles ◽  
Cylindrical Micelles ◽  
Spherical Micelles ◽  
Dynamics Simulations ◽  
Relative Motions

We study molecular arrangements and dynamics in alkyl ethoxylate nonionic surfactant micelles by combining high field (600 and 700 MHz) NMR relaxation measurements with large-scale atomistic molecular dynamics simulations. For spherical micelles, but not for cylindrical micelles, cross relaxation rates are positive only for surfactant alkyl tail atoms connected to the hydrophilic head group. All cross relaxation rates are negative for cylindrical micelles. This effect is reproducible either by changing composition (ratios of the nonionic surfactants) or changing temperature of a single surfactant in order to change the micelle shape. We validate the micelle shape by SANS and use the results as a guide for our simulations. We calculate parameters that determine relaxation rates directly from simulated trajectories, without introducing specific functional forms. Results indicate that relative motions of nearby atoms are liquid-like, in agreement with 13C T1 measurements, though constrained by micelle morphology. Relative motions of distant atoms have slower components because the relative changes in distances and angles are smaller when the moving atoms are further apart. The slow, long-range motions appear to be responsible for the predominantly negative cross relaxation rates observed in NOESY spectra. The densities of atoms from positions 1 and 2 in the boundary region are lower in spherical micelles compared to cylindrical micelles. Correspondingly, motions in this region are less constrained by micelle morphology in the spherical compared to the cylindrical cases. The two effects of morphology lead to the unusual occurrence of positive cross relaxation involving positions 1 and 2 for spheres.

Transformations of wormlike surfactant micelles induced by a water-soluble monomer

2021 ◽  
Author(s):  
Alexander S. Ospennikov ◽  
Alexey A. Gavrilov ◽  
Oleksandr P. Artykulnyi ◽  
Alexander I. Kuklin ◽  
Valentin V. Novikov ◽  
...  
Keyword(s):  
Water Soluble ◽  
Surfactant Micelles

scholarly journals Inhibition of Escherichia coli O157:H7 and Salmonella enterica Isolates on Spinach Leaf Surfaces Using Eugenol-Loaded Surfactant Micelles

Foods ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 575
Author(s):  
Songsirin Ruengvisesh ◽  
Chris R. Kerth ◽  
T. Matthew Taylor
Keyword(s):  
Escherichia Coli ◽  
Salmonella Enterica ◽  
Limit Of Detection ◽  
Sodium Dodecyl ◽  
Microbial Pathogens ◽  
Escherichia Coli O157 ◽  
Human Pathogens ◽  
Surfactant Micelles ◽  
Leaf Surfaces ◽  
Spinach Leaf

Spinach and other leafy green vegetables have been linked to foodborne disease outbreaks of Escherichia coli O157:H7 and Salmonella enterica around the globe. In this study, the antimicrobial activities of surfactant micelles formed from the anionic surfactant sodium dodecyl sulfate (SDS), SDS micelle-loaded eugenol (1.0% eugenol), 1.0% free eugenol, 200 ppm free chlorine, and sterile water were tested against the human pathogens E. coli O157:H7 and Salmonella Saintpaul, and naturally occurring microorganisms, on spinach leaf surfaces during storage at 5 °C over 10 days. Spinach samples were immersed in antimicrobial treatment solution for 2.0 min at 25 °C, after which treatment solutions were drained off and samples were either subjected to analysis or prepared for refrigerated storage. Whereas empty SDS micelles produced moderate reductions in counts of both pathogens (2.1–3.2 log10 CFU/cm2), free and micelle-entrapped eugenol treatments reduced pathogens by >5.0 log10 CFU/cm2 to below the limit of detection (<0.5 log10 CFU/cm2). Micelle-loaded eugenol produced the greatest numerical reductions in naturally contaminating aerobic bacteria, Enterobacteriaceae, and fungi, though these reductions did not differ statistically from reductions achieved by un-encapsulated eugenol and 200 ppm chlorine. Micelles-loaded eugenol could be used as a novel antimicrobial technology to decontaminate fresh spinach from microbial pathogens.

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