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Information × Registration Number 0221U106444, 0120U100725 , R & D reports Title Development of redox-active nanomaterials with controlled pro-/antioxidant activity based on oxide nanocrystals. popup.stage_title Head Seminko Vladyslav V., Кандидат фізико-математичних наук Registration Date 07-12-2021 Organization Institute for scintillation materials NAS Ukraine popup.description2  2. It was shown that both the rate and specific mechanisms of neutralization of reactive oxygen species by cerium oxide nanocrystals depend on the pH value of aqueous solutions. pH increasing leads to an increase in the rate of decomposition of hydrogen peroxide by nanocrystals. Two different pathways for the decomposition of hydrogen peroxide by cerium oxide nanocrystals were identified: the first with the formation of superoxide anions predominating at high pH values, and the second one with formation of hydroxyl radicals predominating at low pH values. It was shown that the efficiency of neutralization of hydroxyl radicals by cerium oxide nanocrystals decreases with decreasing pH value, which leads to the predominance of prooxidant properties of nanocrystals at low pH values. It was shown that the effect of reducing the efficiency of neutralization of hydroxyl radicals with decreasing pH is common to different types of oxide nanocrystals with ions of variable valence (cerium oxide, orthovanadate nanocrystals). It was shown that while UV irradiation of aqueous solutions of cerium oxide nanocrystals during the reduction of Ce4+ to Ce3+ ions leads to acceleration of these processes, the introduction of rare earth ions slows down the process of regeneration of antioxidant properties of nanocrystals due to binding of oxygen vacancies by rare earth ions. Using these results, general conclusions are made about the role of pH of aqueous solutions, type and content of impurity ions and UV irradiation in the mechanisms of formation of pro- / antioxidant activity of oxide nanocrystals. Product Description popup.authors Grygorova Ganna V. Hubenko Kateryna О. Maksimchuk Pavlo О. Seminko Vladyslav V. popup.nrat_date 2021-12-07 Close