{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,23]],"date-time":"2026-02-23T10:55:52Z","timestamp":1771844152416,"version":"3.50.1"},"reference-count":36,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2025,7,14]],"date-time":"2025-07-14T00:00:00Z","timestamp":1752451200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Surfaces"],"abstract":"<jats:p>Bioactive glasses are known for their surface reactivity and ability to bond with bone tissue through the formation of hydroxyapatite. This study investigates the effects of substituting ultrapure water with natural geothermal waters from the Azores in the sol\u2013gel synthesis of 45S5 and MgO-modified bioglasses. Using high-resolution X-ray photoelectron spectroscopy (XPS), we examined how the mineral composition of the waters influenced the chemical environment and network connectivity of the glass surface. The presence of trace ions, such as Mg2+, Sr2+, Zn2+, and B3+, altered the silicate structure, as evidenced by binding energy shifts and peak deconvolution in O 1s, Si 2p, P 2p, Ca 2p, and Na 1s spectra. Thermal treatment further promoted polymerization and reduced hydroxylation. Our findings suggest that mineral-rich waters act as functional agents, modulating the reactivity and structure of bioactive glass surfaces in eco-sustainable synthesis routes.<\/jats:p>","DOI":"10.3390\/surfaces8030050","type":"journal-article","created":{"date-parts":[[2025,7,15]],"date-time":"2025-07-15T09:45:52Z","timestamp":1752572752000},"page":"50","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["XPS Investigation of Sol\u2013Gel Bioactive Glass Synthesized with Geothermal Water"],"prefix":"10.3390","volume":"8","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5935-870X","authenticated-orcid":false,"given":"Helena Cristina","family":"Vasconcelos","sequence":"first","affiliation":[{"name":"Faculty of Science and Technology, University of the Azores, S. Miguel, Azores, 9500-321 Ponta Delgada, Portugal"},{"name":"Laboratory of Instrumentation, Biomedical Engineering and Radiation Physics (LIBPhys, UNL), Department of Physics, NOVA School of Science and Technology, 2829-516 Caparica, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9356-3045","authenticated-orcid":false,"given":"Maria","family":"Meirelles","sequence":"additional","affiliation":[{"name":"Faculty of Science and Technology, University of the Azores, S. Miguel, Azores, 9500-321 Ponta Delgada, Portugal"},{"name":"Research Institute of Marine Sciences, University of the Azores (OKEANOS), Faial, Azores, 9901-862 Horta, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5893-0660","authenticated-orcid":false,"given":"Re\u015fit","family":"\u00d6zmente\u015f","sequence":"additional","affiliation":[{"name":"Vocational School of Health Services, Bitlis Eren University, Bitlis 13100, T\u00fcrkiye"}]}],"member":"1968","published-online":{"date-parts":[[2025,7,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1487","DOI":"10.1111\/j.1151-2916.1991.tb07132.x","article-title":"Bioceramics: From Concept to Clinic","volume":"74","author":"Hench","year":"1991","journal-title":"J. Am. Ceram. Soc."},{"key":"ref_2","first-page":"657","article-title":"FTIR and XRD evaluation of carbonated hydroxyapatite powders synthesized by wet methods","volume":"744\u2013747","author":"Paszkiewicza","year":"2005","journal-title":"J. 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