А 43 Активность гидрогеля диоксида циркония в реакции жидкофазного окисления 2,3,5-триметил-1,4-гидрохинона =The activity of zirconium (IV) oxide hydrogel in liquid phase oxidation of 2.3.5-threemetyl-1.4-hydroquinon [] / О. В. Кузнецова, В. Г. Харчук, О. В. Корякова, Л. А. Петров // Аналитика и контроль. - 2006. - Т. 10, № 2. - С. 126-130. - Библиогр.: с. 130 (10 назв.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Методом начальных скоростей изучено влияние гидрогеля оксида циркония (IV) на процесс жидкофазного окисления дегидрирования 2,3,5-триметил-1,4-гидрохинони в водно-метанольном растворе. Отмечено, что введение гидрогеля ингибирует реакцию, зависимость начальных скоростей от содержания геля в реакции имеет нелинейный характер. Методом ИК спектроскопии изучены ассоциативные взаимодействия между ингредиентами реакции |
S 98 Synthesis of hydrogels based on silicon polyolates [Electronic resource] / T. G. Khonina, E. V. Shadrina, A. A. Boyko, O. N. Chupakhin, L. P. Larionov, A. A. Volkov, V. D. Burda // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 2010. - Vol. 59, № 1. - P75-80 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ORGANOSILICON COMPOUNDS -- DIOLS -- GLYCEROL Аннотация: Biologically active hydrogels based on silicon polyolates, which are the products of reactions of tetraethoxy- and methyltriethoxysilanes with polyols (1,2-propanediol, glycerol, polyethylene glycol), were synthesized. The optimal conditions for hydrogel formation and hydrogel composition were determined. The acute toxicity and transcutaneous and wound-healing activities of the synthesized compounds were studied. The experimental results show that hydrogels based on silicon polyolates can be recommended for further preclinical and clinical tests with the purpose of their use in medical practice both as self-sufficient agents and ointment bases of pharmaceutical compositions with wound-healing, regenerative, and transcutaneous action \\\\Expert2\\nbo\\Russian Chemical Bulletin\\2010, 59 (1), 75-80.pdf |
M 45 Mechanism of structural networking in hydrogels based on silicon and titanium glycerolates / T. G. Khonina, A. P. Safronov, E. V. Shadrina, M. V. Ivanenko, A. I. Suvorova, O. N. Chupakhin // Journal of Colloid and Intrface Science. - 2012. - Vol. 365, № 1. - С. 81-89 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): HOFMEISTER SERIES -- TITANIUM–GLYCEROL HYDROGELS -- SCHULTZE–HARDY RULE Аннотация: Formation of organic/inorganic hydrogels based on silicon– and titanium–glycerol precursors synthesized by transesterification of alkoxy derivatives in excess of glycerol was investigated. The precursors in excess of glycerol and obtained gels were studied by chemical and physical methods including gelation kinetics, IR spectroscopy, XRD, dynamic and electrophoretic light scattering, mechanical deformation, which disclosed the basic difference in the gelation mechanism and structure of network in the hydrogels. Due to this difference, the gelation time of silicon– and titanium–glycerol precursors depended on pH or electrolyte addition in an opposite way. In the wide pH range, silicon–glycerol hydrogel was a polymeric single-phase system formed by the polymeric network homogeneously swollen in liquid water/glycerol medium. Flory–Rehner theory applied to the elastic modulus of these gels gave 40–180 monomer base units in the subchains of the network depending on water content in the gel. The mechanism of networking was three-dimensional polycondensation promoted by the electrically charged functional groups attached to the flexible polymeric chains. Electrolyte solutions provided the gelation according to Hofmeister series. Titanium–glycerol hydrogels were heterogeneous colloid systems at pH > 1.5 and single-phase polymeric gels at lower pH. Electrolyte solutions provided the gelation according to Schultze–Hardy rule \\\\Expert2\\nbo\\Journal of Colloid and Interface Science\\2012, v.365, p.81.pdf |
S 98 Synthesis of pharmacologically active hydrogels [Electronic resource] / M. V. Ivanenko, T. G. Khonina, O. N. Chupakhin, L. P. Larionov // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 2012. - Vol.61, №11. - С. 2163-2171. - Bibliogr. : p. 2171 (30 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): SILICON POLYOLATES -- TITANIUM POLYOLATES -- WOUND-HEALING Аннотация: The target synthesis of new biologically active hydrogels based on combined silicon and titanium polyolates was carried out. The optimum conditions for hydrogel formation and their composition were determined. The type of hydrogels and mechanisms of gelation depend on the nature of polyols: gels based on combined silicon and titanium polyethylene glycolates are polymeric and formed via the polycondensation mechanism, whereas gels based on combined silicon and titanium glycerolates are colloidal and formed via the coagulation—condensation mechanism. The combined hydrogels based on silicon dimethyl glycerolates and titanium tetraglycerolate exhibit enhanced transcutaneous, wound healing, and regenerating activity \\\\expert2\\NBO\\Russian Chemical Bulletin\\2012, 61 (11), 2163-2171.pdf |
Chitosan cross-linking with acetaldehyde acetals / A. Pestov, Y. Privar, A. Slobodyuk [et al.] // Biomimetics. - 2022. - Vol. 7, № 1. - Ст. 10 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): CHITOSAN -- ACETALDEHYDE ACETALS -- HYDROGEL Аннотация: Here we demonstrate the possibility of using acyclic diethylacetal of acetaldehyde (ADA) with low cytotoxicity for the fabrication of hydrogels via Schiff bases formation between chitosan and acetaldehyde generated in situ from acetals in chitosan acetate solution. This approach is more convenient than a direct reaction between chitosan and acetaldehyde due to the better commercial availability and higher boiling point of the acetals. Rheological data confirmed the formation of intermolecular bonds in chitosan solution after the addition of acetaldehyde diethyl acetal at an equimolar NH2: acetal ratio. The chemical structure of the reaction products was determined using elemental analysis and 13C NMR and FT-IR spectroscopy. The formed chitosan-acetylimine underwent further irreversible redox transformations yielding a mechanically stable hydrogel insoluble in a broad pH range. The reported reaction is an example of when an inappropriate selection of acid type for chitosan dissolution prevents hydrogel formation. |