caa a22 4500 605545847 CHVBK 20210128100937.0 cr unu---uuuuu 210128e20151001xx s 000 0 eng 10.1007/s00723-015-0701-4 doi (NATIONALLICENCE)springer-10.1007/s00723-015-0701-4 Firing-Induced Microstructural Properties of Quasi-Diamagnetic Carbonate-Based Porous Ceramics: a 1H NMR Relaxation Correlation Study [Elektronische Daten] [Camilla Terenzi, Cinzia Casieri, Francesco De Luca, Raimondo Quaresima, Giovanni Quarta, Valentina Tudisca] This study deals with the application of two-dimensional proton nuclear magnetic resonance relaxometry (2D 1H NMR-R) to the characterization of porous ceramics nearly free of magnetic compounds. Different microstructural properties were obtained by firing a diamagnetic mixture of kaolin, calcium, and magnesium carbonate over a wide range of maximum temperatures (600-1100°C) and firing times at the maximum temperature (soaking times) (0-10h). The 2D 1H NMR-R method relies on the correlated measurement of 1H longitudinal (T 1) and transverse (T 2) relaxation times of pore-filling water by which the properties of the interconnected pore space may be investigated. In the absence of significant magnetic susceptibility effect due to para- and ferro-magnetic compounds, the 2D 1H NMR-R maps allow studying the conjoint effects on pore size distribution and inter-pore coupling due to the variations in both time and temperature of firing. The NMR experiments were performed with a low-field 1H NMR sensor, which allows non-destructive and in situ analysis. For ceramic specimens fired at 600 and 700°C, the fraction of smallest pores increases with firing time at the expenses of those with intermediate size. The pore shrinkage occurring at this stage, and likely associated with the transformation of kaolinite in metakaolinite, is affected in a similar way by soaking time and firing temperature, in line with the concept of equivalent firing temperature. At temperatures from 800 to 1100°C, the structural modifications involving interconnectivity and average pore size are driven primarily by firing temperature and, secondarily, by soaking time. The 2D 1H NMR-R results are confirmed by more traditional, but destructive, mineralogical, and structural analyses like X-ray powder diffraction, helium pycnometry, mercury intrusion porosimetry, and nitrogen adsorption/desorption method. Springer-Verlag Wien, 2015 Terenzi Camilla Dipartimento di Fisica, Sapienza Università di Roma, P.le A. Moro 2, 00185, Rome, Italy aut Casieri Cinzia Dipartimento di Scienze Fisiche e Chimiche, Università de L'Aquila, Via Vetoio 10, 67010, Coppito, L'Aquila, Italy aut De Luca Francesco CNR-IPCF UOS Roma and Dipartimento di Fisica, Sapienza Università di Roma, P.le A. Moro 2, 00185, Rome, Italy aut Quaresima Raimondo Dipartimento di Ingegneria Civile, Edile-Architettura, Ambientale, Università de L'Aquila, 67040, Roio, L'Aquila, Italy aut Quarta Giovanni Istituto per i Beni Archeologici Monumentali, IBAM, CNR, 73100, Lecce, Italy aut Tudisca Valentina Dipartimento di Fisica, Sapienza Università di Roma, P.le A. Moro 2, 00185, Rome, Italy aut Applied Magnetic Resonance Springer Vienna 46/10(2015-10-01), 1159-1178 0937-9347 46:10<1159 2015 46 723 https://doi.org/10.1007/s00723-015-0701-4 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00723-015-0701-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Terenzi Camilla Dipartimento di Fisica, Sapienza Università di Roma, P.le A. Moro 2, 00185, Rome, Italy aut NATIONALLICENCE 700 1- Casieri Cinzia Dipartimento di Scienze Fisiche e Chimiche, Università de L'Aquila, Via Vetoio 10, 67010, Coppito, L'Aquila, Italy aut NATIONALLICENCE 700 1- De Luca Francesco CNR-IPCF UOS Roma and Dipartimento di Fisica, Sapienza Università di Roma, P.le A. Moro 2, 00185, Rome, Italy aut NATIONALLICENCE 700 1- Quaresima Raimondo Dipartimento di Ingegneria Civile, Edile-Architettura, Ambientale, Università de L'Aquila, 67040, Roio, L'Aquila, Italy aut NATIONALLICENCE 700 1- Quarta Giovanni Istituto per i Beni Archeologici Monumentali, IBAM, CNR, 73100, Lecce, Italy aut NATIONALLICENCE 700 1- Tudisca Valentina Dipartimento di Fisica, Sapienza Università di Roma, P.le A. Moro 2, 00185, Rome, Italy aut NATIONALLICENCE 773 0- Applied Magnetic Resonance Springer Vienna 46/10(2015-10-01), 1159-1178 0937-9347 46:10<1159 2015 46 723