Increased surface area during sintering of calcium phosphate glass and sodium chloride mixtures. Issue 1 (January 2015)

• Record Type: Journal Article
• Authors: Davim, E.J.C.; Fernandes, M.H.V.; Senos, A.M.R.
• Is Part Of: Journal of the European Ceramic Society. Volume 35:Issue 1(2015:Jan.)
• Page Start: 329
• Page End: 336
• Publication Date: 2015-01
• Subjects: Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2014.08.009
• Languages: English
• ISSNs: 0955-2219

Abstract

<abstract abstract-type="author" id="abs0005"> <title id="sect0005">Abstract</title> <sec> <p id="spar0005">Glass scaffolds were obtained by the salt sintering method, using mixtures of calcium phosphate glass, 25.42%SiO₂–10.89%P₂O₅–32.68%CaO–31%MgO(mol%), and salt, NaCl, pressed and sintered bellow the salt melting point, followed by leaching of the salt in water.</p> <p id="spar0010">The sintering behaviour of glass/salt powder mixtures was followed by dilatometry, BET and SEM. It was found that the specific surface area (SSA) of supports sintered between 700–750 °C and leached, can be 15–50 times higher than that of the glass precursor powder, a very surprising behaviour because it presents the opposite tendency of a typical sintering process.</p> <p id="spar0015">Dilatometric curves showed an unusual expansion from ∼450 °C until ∼700 °C, followed by shrinkage at higher temperatures. This expansion accompanies the observed increase of SSA and the microstructures showed a clear effect of reaction between the glass and the salt with remarkable wrinkling of the glass particle surfaces. This phenomenon was further investigated by using DTA, XRD and FTIR.</p> </sec> </abstract>