scholarly journals Quantum-chemical investigation of interactions in supramolecular systems: cholesterol - bile acids - silica in aqueous solutions

Surface ◽  
2021 ◽  
Vol 13(28) ◽  
pp. 39-46
Author(s):  
O.O. Kazakova ◽  
Keyword(s):  
Aqueous Solutions ◽  
Bile Acids ◽  
Water System ◽  
Distribution Coefficients ◽  
Supramolecular Systems ◽  
Solvation Model ◽  
Free Gibbs Energy ◽  
Screening Model ◽  
Energy Of Interaction ◽  
Hydrophobized Silica

Hypercholesterolemia significantly increases the risk of myocardial infarction associated with COVID-19. Along with pharmacological treatment, the possibility of the excretion of excess cholesterol from an organism by adsorption is also of great interest. The interaction of cholesterol with the surface of partially hydrophobized silica in aqueous solutions of bile acids was investigated by the PM7 method using the COSMO (COnductor-like Screening MOdel) solvation model. The distribution of electrostatic and hydrophobic potentials of molecules and complexes was calculated. The values of free Gibbs energy adsorption of bile acids on the surface of silica correlate with the distribution coefficients in the n-octanol-water system. The energy of interaction of cholesterol with bile acids affects its adsorption on silica. The stronger the bond of cholesterol with the molecules of bile acids, the less it is released from the primary micelles in solution and adsorbed on the surface.

Predicting cyclohexane/water distribution coefficients for the SAMPL5 challenge using MOSCED and the SMD solvation model

2016 ◽  
Vol 30 (11) ◽  
pp. 1007-1017 ◽  
Author(s):  
Sebastian Diaz-Rodriguez ◽  
Samantha M. Bozada ◽  
Jeremy R. Phifer ◽  
Andrew S. Paluch
Keyword(s):  
Water Distribution ◽  
Distribution Coefficients ◽  
Solvation Model

Development and creation of zeta potential reference material of the particles in a liquid medium

2021 ◽  
pp. 58-62
Author(s):  
Dmitrii I. Belenkii ◽  
Dmitry V. Averkin ◽  
Dmitry V. Vishnevetskii ◽  
Svetlana D. Khizhnyak ◽  
Pavel M. Pakhomov
Keyword(s):  
Bovine Serum Albumin ◽  
Zeta Potential ◽  
Serum Albumin ◽  
Aqueous Solutions ◽  
Bovine Serum ◽  
Polystyrene Latex ◽  
Powder Materials ◽  
Silver Acetate ◽  
Supramolecular Systems ◽  
Standard Samples

A comprehensive study to develop and create standard samples of the zeta potential unit of particles in a liquid in accordance with the requirements of GOST ISO 13099-2-2016 in the range of measured values from minus 150 mV to plus 150 mV was carried out. The existing standard samples of zeta potential in Russia and the world have been investigated; the analysis of the applicability of the starting materials and components for the creation of new standard samples has done. Samples based on modified polystyrene latex microspheres, bovine serum albumin and supramolecular systems based on aqueous solutions of L-cysteine, N-acetylcysteine, and silver acetate were considered as promising standard samples of the zeta potential of particles. All studies were carried out on equipment from the State Primary Standard of Dispersed Parameters of Aerosols, Suspensions and Powder Materials GET 163-2020 using the method of electrophoretic light scattering and measuring the pH value. It was found that polystyrene latex microspheres do not correspond to the requirements of the work in terms of developing a set of standard samples. Samples based on suspensions of bovine serum albumin do not correspond to the requirements of GOST ISO 13099-2-2016. Supramolecular systems based on aqueous solutions of L-cysteine, N-acetylcysteine, and silver acetate were proposed as standard samples. Such systems are characterized by the ability to modify the initial potential-determining layer of particles without changing their aggregate stability. Studies of the long-term stability of the developed standard samples of the zeta-potential unit of particles in a liquid have been carried out.

The distribution coefficients of phenol and substituted phenols in the ammonium sulfate-poly-N-vinylpyrrolidone-water system

2011 ◽  
Vol 85 (4) ◽  
pp. 568-572 ◽  
Author(s):  
E. V. Churilina ◽  
P. T. Sukhanov ◽  
Ya. I. Korenman ◽  
A. N. Il’in ◽  
G. V. Shatalov ◽  
...  
Keyword(s):  
Ammonium Sulfate ◽  
Water System ◽  
Distribution Coefficients ◽  
Substituted Phenols

scholarly journals Investigation of Surfactant AOT Mediated Charging of PS Particles Dispersed in Aqueous Solutions

Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 471 ◽  
Author(s):  
Huiying Cao ◽  
Baichao An ◽  
Yong Wang ◽  
Kun Zhou ◽  
Naiyan Lu
Keyword(s):  
Zeta Potential ◽  
Aqueous Solutions ◽  
Particle Surface ◽  
Water System ◽  
Submicron Particles ◽  
Foam Formation ◽  
Preferential Adsorption ◽  
Aqueous Salt Solutions ◽  
Air Water Interface ◽  
Charging Mechanism

Nano/submicron particles can be activated by surfactants and aggregate at the air-water interface to generate and stabilize foams. Such systems have been applied extensively in the food, medicine, and cosmetic industries. Studying particle charging behavior in a particle/surfactant/water system is a fundamental way to understand the activation of the particle surface. This paper presents an investigation of the charging behavior of polystyrene (PS) particles dispersed in aqueous solutions of the surfactant sodium di-2-ethylhexylsulfosuccinate (AOT). The results showed that zeta potential of PS was related to the AOT concentration with two different concentration regions. Below the critical micelle concentration (CMC), the charging of PS particles was effected by AOT ions; while above the CMC, it came from both AOT ions and AOT micelles. This behavior was different from that observed for PS in aqueous salt solutions. Additionally, the particle concentration and size were found to affect the zeta potential differently in the two AOT concentration regions. By analyzing these results, the charging mechanism of the PS/AOT/water system was revealed to be preferential adsorption. In summary, the study disclosed the internal connection between the PS charging in aqueous AOT solution and the activation of PS particles, as well as their influence to foam formation and stability.

scholarly journals Distribution coefficients for chemical components of a coal-oil/water system

1988 ◽  
Vol 22 (9) ◽  
pp. 1189-1199 ◽  
Author(s):  
Kurt C. Picel ◽  
Vassilis C. Stamoudis ◽  
Milagros S. Simmons
Keyword(s):  
Water System ◽  
Distribution Coefficients ◽  
Chemical Components ◽  
Oil Water

Effect of amino acid (glycine) on the distribution of transition metal (Co-Ni-Zn-Cu) and magnesium divalent ions between silicate gels and aqueous solutions: an experimental study

Clay Minerals ◽  
1988 ◽  
Vol 23 (1) ◽  
pp. 45-54 ◽  
Author(s):  
M. Dabira ◽  
F. Delbove ◽  
A. Perruchot ◽  
J. Trichet
Keyword(s):  
Amino Acid ◽  
Aqueous Solutions ◽  
Distribution Coefficients ◽  
Complexing Agent ◽  
Divalent Ions ◽  
Reference Distribution ◽  
Original Distribution ◽  
Image Position ◽  
Distribution Equilibria ◽  
Amino Acid Glycine

AbstarctThe study of M and Mg ion exchange (M = Co, Ni, Cu, Zn), between silicate gels SiO2.q(M, Mg)O.nH2O and amino acid (glycine) saline aqueous solutions (M, Mg)SO4, shows that the introduction of the complexing agent completely upsets the original distribution equilibria of M and Mg between the two types of phases. The values of the measured bulk distribution coefficientare lowered considerably relative to the inorganic reference distribution coefficients. The lowering of D may be accounted for by calculating the contents of the different species, MA, MA+, M2+, under which the metallic element M is present in the solutions. The values ofresulting from the calculated M2+ contents are identical to the values of Dref, determined in systems without a complexing agent.

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