Исследовано влияние g-облучения на острую токсичность промышленной редкосшитой полиакриловой кислоты, торговой марки "Карбомер 141G" и геля на ее основе при внутрибрюшинном, накожном и пероральном способе введения подопытным мышам линии Balb/c и C57BL/6. Предварительное g-облучение карбомера снижает токсичность его водной дисперсии при внутрибрюшинном введении. При этом динамика массы тела экспериментальных животных показывает достоверное ( р = 0.05) снижение средней массы тела ко 2–3 суткам после введения водной дисперсии как необлученного, так и облученного карбомера с тенденцией к восстановлению массы тела к 14 суткам, дисперсии с высоким содержанием карбомера приводят к летальному исходу. В отличие от перорального введения гелей, когда наблюдается снижение массы подопытных животных, в случае накожного введения гелей с первых же дней эксперимента наблюдается прибавление в весе подопытных животных, и не происходит их гибели. Добавление углеродных нанотубок УНТ (0.07 мас. %) и фуллерена С٦0 (0.10 мас.%) в гели приводит к уменьшению привеса средней массы животных как при пероральном, так и накожном введении гелей, не вызывая токсического действия на организм. Исследования острой токсичности исходного карбомера и его g-облученного до 1000 кГр аналога позволяют их отнести к 3-му классу опасности для внутрибрюшинного способа введения в соответствии с ГОСТ 12.1.007–76. Результаты исследования указывают на то, что полимерные гели на основе редкосшитой полиакриловой кислоты (в облученной и необлученной формах) могут быть использованы в качестве носителей активных компонентов лекарственных средств для адресной доставки при терапии социальнозначимых заболеваний.

The effect of γ-irradiation on the acute toxicity of commercial lightly crosslinked polyacrylic acid of the trademark Carbomer 141G and a gel based on it has been studied by intraperitoneal, cutaneous, and oral administration to experimental Balb/c and C57BL/6 mice. Preliminary γ-irradiation of the carbomer decreased the toxicity of its aqueous dispersion upon intraperitoneal administration. At the same time, the dynamics of body weight of experimental animals showed a significant decrease (p = 0.05) in average body weight 2–3 days after the introduction of aqueous dispersions of both nonirradiated and irradiated carbomer with a tendency to restore body weight by 14 days; dispersions with a high carbomer content led to death. Unlike the oral administration of gels, when a decrease in the weight of experimental animals was observed, an increase in the weight of the experimental animals was observed from the very first days of the experiment in the case of cutaneous administration of gels, and their death did not occur. The addition of carbon nanotubes (CNTs) (0.07 wt

A systematic study has been performed for the effect of nonionic surfactants (NSs), i.e., ethoxylated higher fatty alcohols with different ethoxylation degrees, on the ultrasonic dispersion of carbon nanotubes in aqueous solutions and on the colloid-chemical properties of the resulting dispersions, namely, their optical density and the sizes and electrokinetic potentials of the particles in the colloidal systems. A non-linear dependence of the characteristics of dispersions on the ethoxylation degree has been revealed. This dependence is associated with structural transformations in NS molecules. The most efficient ethoxylation degree and concentration of nonionic surfactants in a solution, which have the highest disaggregating and stabilizing effects upon the preparation of carbon nanotube (CNT) dispersions, have been determined. The influence of the ethoxylation degree of the ethoxylated higher fatty alcohols on the electrokinetic properties of CNT dispersions has been revealed. It has been shown that carbon nanotube dispersions can be used to modify the rheological and electrical properties of gel systems based on rarely crosslinked poly(acrylic acid). The effects of NSs and CNTs on the viscosity, shear yield stress, consistency index, mechanical stability, relaxation time, and viscous flow activation energy of the polymer gels have been studied. It has been shown that the incorporation of nanotubes increases the electrical conductivity of the gels. The ultrastructure of the gel samples has been studied by transmission electron microscopy.

The effect of γ-irradiation on the surface properties of polypropylene (PP) has been studied as a function of the absorbed dose. It has been established that γ-irradiation leads to an increase in the free surface energy of the polymer, its acid–base component, and the surface polarity. An analysis of the IR spectra of γ-irradiated PP samples indicated the formation of oxygen-containing groups in the composition of PP macromolecules, which was confirmed by the values of the surface acidity parameter. An increase in the dose led to an increase in the concentration of products of radiation-induced conversion. A significant increase in the melt flow index (MFI) of polypropylene up to an absorbed dose of 150 kGy also evidenced the occurrence of oxidation and destruction processes. The MFI decreased at radiation doses above 150 kGy, and this fact indicates that such doses of ionizing radiation lead to the predominance of the processes of polymer structuring or crosslinking.

The effect of γ-irradiation of the gelling agent Carbomer 141G, which is lightly crosslinked polyacrylic acid, on the rheological properties of gels based on the carbomer has been studied. It has been found that an increase in the dose of γ-irradiation in air has a destructive effect on the polymer, leading to a decrease in rheological parameters, such as viscosity, yield strength, and hysteresis area. Irradiation of the carbomer in air with doses greater than 300 kGy leads to a significant decrease or the complete loss of its gel-forming properties. At the same time, irradiation of the carbomer with the same dose in vacuum causes as small a decline in viscosity as 2% compared to the initial systems. It has been established that the optimal gelling agent for obtaining stable antibacterial gels is the carbomer irradiated with a dose of 30 kGy.

Collagen is a biodegradable polymer with many beneficial properties, such as high biocompatibility with skin, excellent film-forming ability, antimicrobial and antioxidant actions, etc. It has received increasing attention in various research and practical fields for its potential applications. However, the use of collagen can be problematic due to its high molecular weight, which can be resolved by hydrolysis into smaller polypeptides. Efforts have also been made to find alternative sources of collagen and its hydrolysates. One such promising source is poultry by-products rich in type I collagen, the most important collagen for practical use. This article analyzes the physico-chemical properties of collagen hydrolysates isolated from the superficial soft tissues of chicken paws. The results obtained show that the use of Neutrase yields a hydrolysate that exhibits greater surface activity at the liquid-gas interface, enhanced wetting ability, and better adhesion to hydrophobic surfaces. Therefore, it can be recommended as a multifunctional ingredient for skin care cosmetics. A cream formula with collagen hydrolysate was developed. Cream is characterized as a multiple emulsion with a moisturizing effect.

A new multifunctional biologically active ingredient—a polymer chitosan–melanin complex from Hermetia illucens black lion fly—has been studied comprehensively to obtain a stable photoprotective cosmetic cream that exhibits additionally the hydrating properties.

The surface energy characteristics of polyvinylidene fluoride irradiated with accelerated helium ions have been investigated. The bombardment of the polymer with helium ions leads to an increase in the acid–base component of the surface free energy and surface polarity due to the appearance of polar functional groups in the surface layer. Determination of the acidity parameters of the irradiated polymer surface indicates the predominance of acidic functional groups on the surface layer as a result of irradiation. It is likely that a decrease in the dispersion component of the surface free energy with the energy of ions and radiation dose is associated with the carbonization of irradiated polymer surface.

О.Н. Голодков 1) , Ю.А. Ольхов 1) , С.Р. Аллаяров 1) , П.Н. Гракович 2) , Г.П. Белов 1) , Л.Ф. Иванов 2) , Л.А. Калинин 2) 1) Институт проблем химической физики Российской академии наук 142432, Черноголовка, пр. Академика Семенова, 1, e-mail: sadush@icp.ac.ru 2) Институт механики металлополимерных систем им. В.А. Белого НАН Беларуси 246050, Гомель, Беларусь, ул. Кирова, 32а, e-mail: grapn@rambler.ru

The effect of γ-radiation dose on the surface energy characteristics of commercial polytetrafluoroethylene (PTFE) of five different grades has been studied. In the course of PTFE irradiation in air, radiation oxidation leads to the appearance of functional groups and an increase in the acid–base component of the free surface energy and surface polarity; in this case, the dispersive component of the free surface energy decreases with dose because of the radiation-induced loosening, amorphization, and degradation of the polymer. The effect of γ-irradiation of PTFE on its wetting with aqueous solutions of the anionic surfactant sodium dodecyl sulfate has been studied for the first time. It has been found that irradiation increases the wetting and the work of adhesion of the surfactant solution due to the appearance of polar groups in the surface layer.

One of the approaches to solving the problem of carbon nanotubes dispersions obtaining is the use of nonionic surfactants in the processes of ultrasonication of carbon nanostructures in aqueous solutions. The effect of nonionic surfactants on dispersing and stabilizing is determined by the adsorption interaction of surfactant molecules with a graphene surface, the study of which can reveal important patterns of stable carbon nanotubes dispersions obtaining during ultrasonic treatment in liquid media. The aim of this work was to study the adsorption of ethoxylated isononylphenols with a variable average degree of ethoxylation on single-walled and multi-walled carbon nanotubes from aqueous solutions. The value of adsorption of nonionic surfactants on carbon nanotubes was calculated on the basis of changes in the equilibrium concentration of ethoxylated isononylphenols in the solution at presence of carbon nanotubes. The equilibrium concentration of nonionic surfactants was determined by absorption spectroscopy. It was found that the shape of adsorption isotherms of the ethoxylated isononylphenols on carbon nanotubes from aqueous solutions before ultrasonic treatment corresponds to the Langmuir adsorption isotherm L2. The values of maximum adsorption of ethoxylated isononylphenols were shown to decrease with an increase in the average degree of ethoxylation. Obviously, this is due to conformational changes in the polar chain, showed in the sizes of ethoxylated isononylphenols micelles, in the structure of the adsorption layer. It has been established that the hydrophobic interaction of the surfactants hydrocarbon radical with a graphene surface is the main mechanism for the adsorption of ethoxylated isononylphenols on carbon nanotubes. The dispersions of carbon nanotubes in micellar solutions of nonionic surfactants were obtained and studied. It was shown that ultrasonic treatment leads to a change in the mechanism of nonionic surfactants adsorption on carbon nanotubes.

The action of accelerated 1–4-MeV protons on polychlorotrifluoroethylene in vacuum was accompanied by a preferential rupture of the main polymer chain with the release of more than 30 gaseous products, most of which were tetrafluoroethylene and chlorine- and fluorine-containing compounds. As a result of proton bombardment, the concentration of carbon on the polymer surface decreased and the concentrations of fluorine and chlorine increased. It has been shown that the incorporation of chlorine atoms into the structure of a perfluoropolymer changes the mechanism of its proton bombardment and helps to protect its macromolecule from the reaction of fluorine abstraction by accelerated protons with the formation of hydrogen fluoride. It has been found that irradiation with accelerated protons leads to changes in surface energy characteristics.