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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Bonding of alkaline and alkaline earth cations in Na-Ca-Sr polyphosphate glasses

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Autor(es):
Morguetto, Gabriel Felipe [1] ; Bins Tsunaki, Lucas Ely [1] ; Schneider, Jose [1]
Número total de Autores: 3
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, CeRTEV, Inst Fis Sao Carlos, Sao Carlos, SP - Brazil
Número total de Afiliações: 1
Tipo de documento: Artigo Científico
Fonte: INTERNATIONAL JOURNAL OF APPLIED GLASS SCIENCE; SEP 2019.
Citações Web of Science: 1
Resumo

Dissolution of phosphates bioglasses, for bone regeneration or controlled ion release, is a key property to be tuned by adequate selection of chemical species. Mixed Na-Sr and Na-Ca polyphosphate glasses exhibit definite bonding preferences of the stronger cations to O from chain-end phosphates (Q(1)) instead of random bonding to the network (Q(1) and Q(2)). This behavior is important for the control of dissolution, as hydration starts from the reaction of H with O in Q(1). To analyze this bonding preference in glasses with two alkaline earths competing for O, mixed Na-Ca-Sr polyphosphates (0.57-x) Na2O center dot x/2 SrO center dot x/2 CaO center dot 0.43 P2O5 (0 <= x <= 0.30 molar fraction) were considered. P-31 nuclear magnetic resonance was used to analyze the short-range environments of Q(n) groups, detecting preferential bonding of Ca and Sr to Q(1). To probe variations in the medium-range organization of the network induced by Ca or Sr, glasses with compositions (0.57-x) Na2O center dot x MO center dot 0.43 P2O5 (M = Ca,Sr; 0 <= x <= 0.30 molar fraction), were analyzed using P-31-double-quantum techniques. An increase in mutual Q(2) self-connectivity relative to the base Na-polyphosphate network was detected as Ca or Sr were added, indicating conversion of linear phosphate chains into rings. (AU)

Processo FAPESP: 13/07793-6 - CEPIV - Centro de Ensino, Pesquisa e Inovação em Vidros
Beneficiário:Edgar Dutra Zanotto
Linha de fomento: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs