Синтезированы новые биамфифильные поверхностно-активные вещества (БПАВ) на основе катиона алкилметилморфолиния и додецилсульфат-аниона (Мор-n(ДС), n = 4, 6, 8, 10). С привлечением методов ИК-спектроскопии, спектроскопии ЯМР 1Н, масс-спектрометрии, элементного анализа охарактеризована структура биамфифилов. Методами тензиометрии, кондуктометрии, флуоресцентной спектроскопии (с использованием зонда пирена), динамического и электрофоретического рассеяния света проведена оценка агрегационного поведения биамфифилов в водных растворах. Показано, что увеличение длины углеводородного радикала на два углеродных атома у амфифильного катиона приводит к увеличению поверхностной активности ПАВ ~ на 5 единиц и к снижению порога агрегации систем в 1.5–2 раза. Установлено, что происходит формирование агрегатов с гидродинамическим диаметром 20–120 нм в зависимости от длины радикала у катиона алкилметилморфолиния и от концентрации БПАВ. Дзета-потенциал систем находится в диапазоне от –25 до –100 мВ и снижается с увеличением концентрации биамфифилов. Методом спектрофотомерии показана значительная солюбилизационная способность биамфифилов по отношению к гидрофобному красителю Оранж ОТ. Полученные соединения могут представлять интерес для биомедицинского применения и других высокотехнологичных направлений.

The hydrolytic decomposition of the organophosphorus ecotoxicant paraoxon in alkaline micellar solutions of a cationic surfactant with a carbamate fragment (CB-2-16) has been investigated by means of spectrophotometry. The stronger catalytic effect of micellar solutions aged during several days in comparison with freshly prepared ones has been associated with alkaline hydrolysis of the carbamate surfactant and the formation of a mixed system of CB-2-16 with its decomposition product cetyl(2-hydroxyethyl)dimethylammonium bromide (1H NMR spectroscopy data). In the absence of alkali, the decomposition products of the carbamate surfactant have not been detected for more than four months, indicating its hydrolytic stability in a neutral environment.

New morpholinium surfactants with a carbamate fragment between the amphiphile head group and its hydrophobic tail (CnMB-carb, where n = 8, 10, 12, 14, 16) were synthesized. The cmc values obtained by tensiometry for dodecyl, tetradecyl, and hexadecyl homologues are 3–4 times lower than those of 4-alkyl-4-methylmorpholinium bromides. The introduction of a carbamate fragment can be considered as tool for controlling cmc values. The calculation of the thermodynamic parameters of micellization, i.e., Gibbs free energy of micellization (∆Gmic), enthalpy of micellization (ΔHmic), entropy of micellization (ΔSmic), were carried out based on the temperature dependences of specific electrical conductivity as a function of surfactant concentration. It was determined that the aggregation of cationic surfactants is driven by the entropy and ΔG(CH2) is equal to 3.26 kJ/mol. The cmc values determined by fluorimetry were approximately two times lower than those obtained by tensiometry and conductometry, probably due to the ability to identify premicellar aggregates. Using the spectrophotometry, a twofold increase in the solubilization capacity of C16MB-carb (0.036 molOOT/molsurf) was established in comparison with a non-functionalized morpholinium surfactants with the same tail length (0.019 molOOT/molsurf). The “closed bottle test” showed that the degree of CnMB-carb biodegradation reaches 56.7–62.3

New biamphiphilic surfactants (BSs) have been synthesized based on alkylmethylmorpholinium cation and dodecyl sulfate anion (Mor- n (DS), n = 4, 6, 8, 10). The structure of the biamphiphiles has been characterized by IR spectroscopy, 1 H NMR spectroscopy, mass spectrometry, and elemental analysis. The aggregation behavior of the biamphiphiles in aqueous solutions has been assessed by tensiometry, conductometry, fluorescence spectroscopy (using a pyrene probe) and dynamic and electrophoretic light scattering. It has been shown that an increase in the hydrophobic tail length by two carbon atoms in an amphiphilic cation leads to an increase in the surface activity of the surfactant by ~5 units and a decrease in the aggregation threshold of the systems by 1.5–2 times. It has been established that the formation of aggregates with hydrodynamic diameters of 20–120 nm depending on the alkyl chain length of the alkylmethylmorpholinium cation and BS concentration. The zeta potential of the systems ranges from –25 to –100 mV and decreases with increasing biamphiphile concentration. Spectrophotometry has been employed to show a significant solubilization capacity of the biamphiphiles with respect to a hydrophobic dye Orange OT. The compounds obtained may be of interest for biomedical applications and other high-tech areas.

— This paper examines the feasibility of using acoustic emission (AE) for gaining insight into solvation processes in liquids. In particular, we demonstrate that, during solvation of various salts, acoustic emission parameters are determined by the chemical composition of the salt. Our results make it possible to predict the application field of AE measurements for probing the salt dissolution process.

Liposome surface potential effect on cellular uptake and cytotoxicity is evaluated using liposomes, modified with cationic lipid DOTAP, a series of cationic gemini surfactants with two carbamate fragments, and an amphiphilic peptide SSRGD. The surfactants used are novel representatives of the gemini family with improved self-assembling activity coupled with potential biodegradable properties and displayed increasing antibacterial activity and cytotoxicity with the shortening of hydrophobic alkyl tails. The longest alkyl tail surfactant, 14-6-14(Et), was the most biocompatible of the series, which was chosen for liposome modification. Prepared liposomes of various compositions are characterized from morphological and physicochemical standpoints in order to optimize their biocompatibility and stability. The carbamate gemini surfactants were also twice as effective at providing positive charge to liposomes and less toxic compared to DOTAP. On their own, carbamate surfactants were able to increase cellular uptake of liposomes by 190%. The mixed composition of 14-6-14(Et) surfactant and SSRGD amphiphilic peptide was the most readily absorbed formulation among different tested neutral, cationic and RGD-modified liposomes. The comparison between the cellular uptake promotion is conducted as to what is the most selective and efficient approach to enhance lipid nanoparticle uptake by cancerous cells.

В работе рассмотрена возможность использования метода акустической эмиссии (АЭ) для изучения процессов сольватации, проходящих в водной среде. В частности, показано, что в процессе растворения различных солей параметры акустической эмиссии определяются химическим составом соли. Полученные данные позволяют спрогнозировать сферу применения метода АЭ для изучения процесса растворения солей.

Complexation ability of the imidazolium surfactants with a methoxyphenyl fragment towards a model protein, bovine serum albumin, has been investigated by means of physico-chemical methods (tensiometry, fluorescence spectroscopy, and dynamic as well as electrophoretic light scattering). The addition of bovine serum albumin has led to a decrease in the aggregation threshold of surfactants by 1.5–2 times. The imidazolium surfactants have formed stable complexes with the protein. The components binding has occurred primarily via the tyrosine amino acid fragments, involving hydrogen bonding and van der Waals interactions. Additional contribution of electrostatic forces and hydrophobic effect in the surfactant–albumin system has been revealed by means of dynamic and electrophoretic light scattering.

The interaction between a number of cationic surfactants bearing the head group with different structures (triallyl, morpholinium, including hydroxyethyl-substituted) with oppositely charged biomolecules (amino acids and sodium adenosine triphosphate (ATP)) was studied. The amino acid additives (glycine, lysine, histidine, arginine) do not affect the aggregation behavior of the tested cationic surfactants. However, in some combinations, they can significantly increase their solubilization capacity. The ATP additive already in a minimum amount decreases the critical micelle concentration of the surfactant by an order of magnitude, and the solubilization capacity depends on the structure of the surfactant head group.

Data characterizing the effect of electrolyte additives (sodium chloride and salicylate, polyacrylic acid) on the critical micelle concentration and the size of hexadecylpiperidinium surfactant aggregates, including those containing one or two hydroxyl groups, were obtained by tensiometry and dynamic light scattering methods. The solubilization effect of surfactant—electrolyte systems with respect to the hydrophobic dye probe Orange OT was evaluated. The conditions (pH, ratio of components) for the formation of soluble (nonstoichiometric) and insoluble (stoichiometric) polymer-colloidal complexes were determined for a surfactant—polyacrylic acid system.

Quantitative data characterizing the aggregation behavior, antimicrobial activity and toxicity of hexadecyl cationic surfactants with two carbamate fragments in the head group (CB-n,n-16; where n is the number of carbon atoms in alkyl group of carbamate fragment) have been obtained. It has been established that these compounds exhibit high bactericidal and fungicidal activity against a wide range of pathogenic microorganisms, including their resistant forms. Binary systems CB-2, 2-16/Tween 80 have been prepared and investigated. Under the varying the ratio of components, the critical micelle concentration values were determined, which indicated their negative deviation from the model of ideal mixing (synergistic effect). Membranotropic properties of dicarbamate surfactants and their binary compositions with Tween 80 were studied using dipalmitoylphosphatidylcholine liposomes as a cell membrane model. The effect of surfactants on the main phase transition temperature of lipid bilayer characterizing its transition from liquid crystalline to gel state was determined by the turbidimetric method.

New surfactants based on borneol (BA- n ) with various alkyl tail lengths ( n = 10, 12) were synthesized and studied as permeation enhancers for transdermal delivery of hydrophilic substrates. New modified liposomes based on BA- n and the lipid phosphatidylcholine (PC) were obtained and characterized by various physicochemical methods. The composition of liposomes was optimized by varying the surfactant/lipid molar ratio. It was shown that modification of PC liposomes with borneol surfactants increases their stability over time. The modified liposomes were loaded with a hydrophilic probe, rhodamine B. The release of the substrate from the resulting systems was monitored in vitro. The liposomal forms with the encapsulated probe were evaluated as potential systems for transdermal delivery using Franz cells. The application of the modified liposomes was found to enhance the transdermal diffusion.

The aggregation behavior of new cationic hexadecyl surfactants with one or two alkylcarbamate fragments in the head group in water was studied using conductometry, spectrophotometry, fluorescence spectroscopy, and dynamic light scattering, and their catalytic action in hydrolytic processes was examined. Kinetic parameters of the alkaline hydrolysis of carboxylic acid esters (p-nitrophenyl acetate and p-nitrophenyl caprinate) were obtained upon the variation of the structures of surfactant head groups and the pH of solution. It was shown that the catalytic effect of micelle-forming surfactants with a single carbamate fragment is higher than that of the corresponding dicarbamate compounds, and it decreases with the alkyl chain length of substituents in head groups. It was found that carbamate surfactants capable of vesicle formation accelerate the hydrolysis of the test esters to a greater extent than their analogs forming micelles: the observed acceleration of the process can exceed two orders of magnitude in the case of a compound with the decyl substituent in a carbamate fragment.

This review is devoted to self-organizing systems based on amphiphilic compounds of different types, i.e., open-chain and macrocyclic ones. Conventional colloidal surfactants have been considered both in the individual form and in the presence of modifiers, including electrolytes and cosurfactants. Special attention has been focused on the role of structural factors, in particular, an analysis has been performed for the cases of the most pronounced influence of surfactant structure (the nature of head groups and counterions, the passage to dicationic surfactants, and the occurrence of calix[4]arene cores) on the aggregation characteristics, morphological behavior, and functional activity of the systems. Macrocyclic amphiphiles are typical objects of supramolecular chemistry. The final part of the review presents the comparison between two types of the systems: (1) amphiphilic calixarenes (covalent functionalization of macrocycles with alkyl fragments) and (2) calixarene–surfactant binary composites (noncovalent modification of the macrocyclic platform).

New piperidinium surfactants with a benzyl fragment in the head group were synthesized and characterized. The critical micelle concentrations, degrees of binding of counterions, and aggregation numbers were determined for aqueous solutions of these surfactants by tensiometry, conductometry, and spectrophotometry. The wetting action of the synthesized surfactants was characterized, and their solubilization capacity with respect to the hydrophobic dye Orange OT and fungicide carbendazim was estimated. Antimicrobial activity of the surfactants to a number of plant pathogenic strains was revealed, which is especially pronounced with respect to gram-positive bacteria Clavibacter michiganensis, Curtobacterium flaccumfaciens, and Rathayibacter iranicus (minimum bactericidal concentration 0.5–4 µg mL−1).

The forming and study of cationic surfactant/polyelectrolyte (PE) polymer colloid systems has been done at different concentrations of an amphiphilic compound and fixed polymer concentration. An imidazolium amphiphilic compound with a tetradecyl radical (IA-14) served as the surfactant; polyacrylic acid (PAA) characterized by a molecular weight of 1800 Da was used as component of the polymer. The aggregation characteristics of the systems have been examined via tensiometry, conductometry and fluorescence spectroscopy. It is shown that introducing of polyelectrolyte initiates the formation of polymer colloid complexes (PCC) at a 50 times lower concentration than the one required for an individual IA-14 system. Dynamic light scattering analysis has shown that the values of the hydrodynamic parameters of PCC lied in the range of 100–120 nm and did not depend on the concentration of the PE or the surfactant. It has been estimated via electrophoretic light scattering that electrostatic interactions make the main contribution to the formation of complexes.

Three 40 wt % Pt/C electrocatalysts prepared using two different approaches—the polyol process and electrochemical dispersion of platinum under pulse alternating current—and a commercial Pt/C catalyst (Johnson Matthey prod.) were examined via X-ray diffraction (XRD) and transmission electron microscopy (TEM). The stability characteristics of the Pt/C catalysts were studied via long-term cycling, revealing that, for all cycling modes, the best stability was achieved for the Pt/C catalyst with the largest platinum nanoparticle sizes, which was synthesized via electrochemical dispersion of platinum under pulse alternating current. Our results show that the mass and specific electrocatalytic activities of Pt/C catalysts toward ethanol electrooxidation are determined by the value of the electrochemically active Pt surface area in the catalysts.

The work shows that the dangerous vulnerability of renewable energy sources is the imperfection of materials and design of energy storage devices. A study of the charge-discharge cycles’ effect on the batteries’ stability in a specially developed installation showed that if even the most promising lithium-ion devices are used, due to the microdamage accumulation, all electric energy storage devices will not be durable and will necessarily fail. In addition, it is shown that the materials used in the manufacture of solar panels and wind turbine blades can harm the environment. It is concluded that the Technosphere safety problems of alternative energy can be solved only if the technology for the efficient utilization of used solar batteries and blades of wind-powered generators is created.