Yu. G. Yatluk

Synthesis in a gel as a new procedure for preparing carboxyethyl chitosan

A fundamentally new procedure of synthesis of carboxyethyl chitosan in a physical gel, ensuring higher degree of substitution at lower temperatures and lower consumption of time and chemicals, compared to the existing procedures, was developed. The structure of the resulting products was examined by diffuse reflection IR and 1H NMR spectroscopy in solutions and also 1H and 7Li broad line NMR.

Imidazole-containing chitosan derivative: a new synthetic approach and sorption properties

A novel method for the synthesis of a hetaryl-containing chelate amino polymer, namely, N-(4(5)-imidazolylmethyl)chitosan (IMC), with a degree of substitution up to 0.3 was proposed. The “synthesis in gel” approach involves direct substitution of the hydroxyl group in 4(5)-imidazolylmethanol. The structures of these polymers were confirmed by 1H NMR data. For sorption studies, IMC samples were crosslinked with epichlorohydrin and diglycidyl ethers of ethylene glycol and diethylene glycol. The degrees of swelling and sorption properties of the polymers largely depend on the crosslinking agent and the degree of crosslinking. The sorption capacities of IMC for AuIII, PtIV, and PdII ions are higher than those of the nonmodified polymer. The extraction of noble metal ions from chloride solutions becomes more selective with increasing degree of crosslinking. The sorption capacity of IMC for CoII and NiII ions is higher than those of chitosan and its known N-heterocyclic derivatives.

Synthesis in a gel and sorption properties of N-2-sulfoethyl chitosan

A new procedure was developed for preparation of chelate amino-containing polymer N-2-sulfoethyl chitosan by synthesis in a gel through the reaction between chitosan and sodium 2-bromoethanesulfonate, yielding a polymer with the degree of substitution of up to 0.5. The structure of the resulting polymers was confirmed by 1H NMR spectroscopy. The sorption characteristics with respect to transition and alkaline-earth metal ions were determined for the cross-linked polymers.

N-2-(2-pyridyl)ethyl chitosan: Synthesis in gel and sorption properties

A procedure was developed for preparing a new heterocyclically substituted chelating aminopolymer, N-2-(2-pyridyl)ethyl chitosan, by direct addition of 2-vinylpyridine to chitosan under the conditions of synthesis in gel. The resulting polymer has the degree of substitution of up to 1. The ability of the samples obtained to sorb transition and noble metal ions was evaluated.

Gel-synthesis, structure, and properties of sulfur-containing chitosan derivatives

The possibility of using the thermochemical approach to thermal decomposition of solids, previously developed by the author, to interpretation of the mechanism and kinetics of reduction of metal oxides with hydrogen was studied. Many properties of NiO reduction with hydrogen, including formation of metal nuclea, the nature of induction period, autocatalysis effect, equimolar and isobaric periods of reduction, the character of the effect of hydrogen pressure on reduction rate, and the nanocrystalline structure of a reduced metal, were explained in terms of the given approach.

Effect of the titanium glycerolate precursor heat treatment procedure on the morphology and photocatalytic properties of TiO2 nanopowder

We have studied the effect of titanium glycerolate precursor heat treatment on the morphology, structure, and photocatalytic properties of titanium dioxide nanopowders.

Sorbents based on modified polysiloxanes

Organic-inorganic hybrid sorbents based on a polysiloxane modified with amino and thiourea groups have been synthesized for the first time by a sol-gel process. The structure of the sorbents has been determined by X-ray photoelectron spectroscopy and IR spectroscopy. Their thermal stability has been assessed and the mechanism of their degradation has been elucidated. The structural and adsorption parameters of the sorbents have been evaluated. The results demonstrate that the introduction of amino groups into the structure of the polysiloxane yields an effective sorbent for Pb(II) extraction and enables Cu(II) and Zn(II) separation from Co(II) and Ni(II). The thiourea-modified polysiloxane selectively sorbs Bi(III) (0.1–2 M HCl), Pt(IV) (pH 2), and Pb(II) (pH > 3). Divalent Co, Ni, Cu, and Zn can be sorbed from alkaline solutions.

The first cubane-like complex of copper based on N-carboxyethyl-tris(hydroxymethyl)aminomethane: Synthesis and crystal structure

AbstractThe interaction of acrylic acid with tris(hydroxymethyl)aminomethane (I) was studied. A simple method was suggested for preparing N-carboxyethyl-tris(hydroxymethyl)aminomethane (homotricin) (II). On the basis of compound II, the 1:1 Cu complex, [Cu(OCH2C(CH2OH)2NHCH2CH2COO)]4·nH2O (n = 4–11.25) (III), which is alkoxycarboxylate, was synthesized. The crystal structure of III was found to correspond to a cubane-like tetranuclear cluster (an automated Bruker X8Apex diffractometer with CCD detector (MoKα radiation, graphite monochromator, ϑ = 1.11°−27.5°), 8016 reflections, space group P

Synthesis of poly[N-(2,3-dihydroxypropyl)aminostyrene], a new sorbent for boron(III) ions

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