Центральная Научная Библиотека УрО РАН

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   H 43


    Heavy metals removal by flocculation/precipitation using N-(2-carboxyethyl)chitosans [Text] / S. YU. Bratskaya, A. V. Pestov, Yu. G. Yatluk, V. A. Avramenko // Colloids and Surfaces A: Physicochemical and Engineering Aspects. - 2009. - Vol. 339, № 1-3. - P140-144

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Аннотация: Here we report on solution properties and flocculation performance of polyampholyte chitosan derivatives - N-carboxyethylated chitosans (CEC) - synthesized "in gel" by treatment of chitosan with acrylic acid. We show that carboxyethylation with the substitution degrees (DS) from 0.7 to 1.6 yields water-soluble derivatives, whose isoelectric points (IEP) range from 6.30 to 3.55. At pH 7.5 interaction of negatively charged CEC derivatives with positively charged colloids of the heavy metal hydroxides (Zn2+, Cu2+, Ni2+), serving as a model of postgalvanic wastewaters, results in lowering of electrokinetic potential of the hydroxide colloids and their precipitation at appropriate flocculant dose. Investigations of CEC flocculation performance depending on pH and DS show that the efficiency of metal removal decreases in the row Cu2+ Zn2+ Ni2+ corresponding to the row of the hydroxocomplex stability for these metals. The higher was pH of the system and DS of CEC derivative, the narrower was the flocculation window and the stronger was negative effect of flocculant overdosing on the efficiency of heavy metal removal. Based on the estimation of floc settling rates and the residual metal concentrations, we have concluded that the optimal DS of CEC derivatives for the precipitation of metal hydroxides is 0.7-1.0

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   T 44


    The effect of super- and nanodispersed powders of zinc and copper alloys in plastic greases on the structure and triboengineering properties of steel surfaces / L. V. Zolotukhina, A. Ya. Zapevalov, S. V. Zhidovinova, I. G. Arefiev, B. R. Gelchinsky // Journal of Friction and Wear. - 2011. - Vol.32, №2. - С. 107-112

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
LUBRICATING COMPOSITIONS -- TRIBOENGINEERING PROPERTIES -- STEEL SURFACES
Аннотация: It is demonstrated that the wear rate of tribocouples can be reduced significantly with the use of lubricating compositions obtained by added super- and nanodispersed zinc or Cu-Sn powders to the Lithol-24 plastic grease. When the superdispersed powders of copper alloys interact with tribosurfaces, the copper and tin diffuse into the base metal, producing secondary composite superdispersed structures. The alloyed elements penetrate into the base metal more deeply if the powder contains the nanodispersed fraction. The films of polyfluorinated oligomers based on particles of zinc and copper alloy powders with functional substitutes reduce substantially the friction coefficient of kinematic couples when they are lubricated with these lubricating compositions and expand the temperature range of application of plastic greases

\\\\Expert2\\nbo\\Journal of Friction and Wear\\2011, v. 32, p. 107-112.pdf
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   P 41


    Pentacyanoferrate(II) complexes with N-containing derivatives of chitosan and polyallylamine: Synthesis and cesium uptake properties [Electronic resource] / S. YU. Bratskaya, V. V. Zheleznov, Y. O. Privar, A. Mechaev, A. V. Pestov // Colloids and Surfaces A: Physicochemical and Engineering Aspects. - 2014. - Vol. 460. - С. 145-150

ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
SODIUM AMINOPRUSSIDE -- POLYMER LIGANDS (CHITOSAN) -- POLYALLYLAMINE
Аннотация: Here we report on synthesis of new organic–inorganic materials based on products of interaction between sodium aminoprusside and polymer ligands (chitosan (CS), N-2-(2-pyridyl)ethylchitosan (2-PC), N-2-(4-pyridyl)ethylchitosan (4-PC), N-(4-methyl-5-imidazolyl)methylchitosan (IC), N-(2-cyanoethyl)chitosan (CC), polyallylamine (PA), N-(2-pyridyl)methyl-polyallylamine (PMPA), N-2-(2-pyridyl)ethyl-polyallylamine (PEPA), N-(4-methyl-5-imidazolyl)methyl-polyallylamine (IPA) and poly(2-vinylpyridine) (PVP)). The composition of the obtained materials was characterized using the element analysis and X-ray diffraction; the Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric analysis data were used to propose the structure of the formed complexes. It was established that ion and ligand exchange were the main reactions, through which sodium aminoprusside interacts with water-soluble polymer salts. Reactivity in complex formation reaction of unmodified polymers changes in a row: PA > CS > PVP. Modification of chitosan with 2-(4-pyridyl)ethyl and 2-cyanoethyl moieties enhances reactivity of chitosan to the level of PA, while introduction of 2-(2-pyridyl) and (4-methyl-5-imidazolyl)methyl moieties, on the contrary, decreases reactivity of chitosan to that of PVP. At the same time, functionalization of PA with 2-pyridylalkyl groups decreases its reactivity in reaction with aminoprusside ion. Thus, reactivity of all studied polymeric matrices changes in the row: PA ≈ 4-PC ≈ CC > CS > 2-PC ≈ IPA ≈ IC > PMPA > PVP > PEPA. The distribution coefficients with respect to cesium ions have been determined for the synthesized complexes in cobalt(II) form. It has been shown that the complex of chitosan with pentacyanoferrate(II) has higher distribution coefficient with respect to Cs+ ions, as compared to its N-derivatives and synthetic polymers. Organic–inorganic materials obtained in the matrix of synthetic polymers have shown higher tendency to peptization and, therefore, lower sorption capacities and distribution coefficients

\\\\expert2\\nbo\\Colloids and Surfaces A\\2014, v.460, p.145-150.pdf
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   E 27


    Effect of polarity of solvent on silanization of halloysite nanoclay using (3-glycidyloxy propyl) trimethoxy silane / A. M. Abu el-Soad, A. V. Pestov, N. A. Martemyanov [et al.] // Journal of inorganic and organometallic polymers and materials. - 2021. - № 31. - P2569–2578

ББК Г
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Аннотация: The grafting of silane groups on clay surfaces has been recently investigated in order to fabricate versatile compounds with new potential applications in materials science and ecological engineering. This work explored the influence of variety of solvents with variable polarity on the silanization of halloysite nanoclay (HNT) surface by (3-Glycidyloxy propyl) trimethoxy silane. To this purpose, the functionalization of HNT by 3-Glycidyloxypropyltrimethoxysilane (GOPTMS) has been conducted in Ethanol (polar protic solvent), Tetrahydrofuran (THF) and Acetonitrile (polar aprotic solvents), and Hexane, 1,4-Dioxane and Toluene (non polar solvents). The silane grafted materials were characterized by using several techniques, including Fourier Transform Infrared Spectroscopy (FT-IR), elemental analysis, Scanning Electron Microscopy (SEM), Thermogravimetry (TGA), X-ray Diffraction Analysis (XRD) and Nitrogen adsorption/desorption isotherms. The largest silane loading has been detected for the hybrid nanomaterials prepared in Hexane as a dispersing medium.

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   S 98


    Synthesis of Fe@C nanoparticles containing sulfo groups on their surfaces and study of their aggregation behavior in aqueous media / I. A. Bakhteeva, I. V. Medvedeva, I. V. Byzov [et al.] // Russian chemical bulletin. - 2021. - Vol. 70, № 4. - P722-731

ББК Г
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
MAGNETIC NANOPARTICLES -- IRON-CARBON -- BENZENESULFONIC ACID -- IR SPECTROSCOPY
Аннотация: Magnetic iron nanoparticles (MNPs) encapsulated in a carbon shells and containing sulfo groups on the surface (Fe@C-SO3H) were synthesized. The aggregative stability of aqueous suspensions of the Fe@C-SO3H nanoparticles was studied in solutions of bovine serum albumin and calcium chloride and in phosphate-buffered saline, which simulate blood plasma. It is shown that the Fe@C-SO3H particles practically do not aggregate in the phosphate buffer saline for a long time (several days). On the contrary, MNPs encapsulated in a protein shells using ultrasonic treatment form aggregates up to 110–120 nm in size under these conditions. Suspensions of the Fe@C-SO3H particles are stable in aqueous solutions of calcium chloride in the range of the solid phase concentration between 0.05 and 0.10 g L−1. The results obtained indicate the possibility of using the functionalized Fe@C-SO3H nanoparticles in vitro experiments in biological media.

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    Peptide ligands on the PEGylated nanoparticle surface and human serum composition are key factors for the interaction between immune cells and nanoparticles / A. G. Pershina, A. M. Demin, N. A. Perekucha [et al.] // Colloids and Surfaces B: Biointerfaces. - 2023. - Vol. 221. - P112981
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Аннотация: The architecture of a nanoparticles' surface formed due to a modification with a ligand and protein corona formation in biofluids is critical for interactions with cells in vivo. Here we studied interactions of immune cells with magnetic nanoparticles (MNPs) covalently modified with polyethylene glycol (PEG) and their counterparts conjugated with peptides: a pH (low) insertion peptide (pHLIP) and cycloRGD as a targeting ligand in human serum. The conjugation of MNPs-PEG with pHLIP, but not with cycloRGD, enhanced the association of these particles with mononuclear phagocytic cells in vitro and in vivo. We did not find a clear difference in protein corona composition between the pHLIP-modified and parental PEGylated nanoparticles. Analysis of the effect of autologous human serum on MNP uptake by monocytes showed that the efficiency of endocytosis varies among healthy donors and depends on intrinsic properties of serum. Nevertheless, using classic blood, coagulation, biochemical tests, and anti-PEG IgG serum level, we failed to identify the cause of the observed interdonor variation. These individual differences should be taken into consideration during testing of nanotherapeutics.

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