scholarly journals Thermal analysis, nuclear magnetic resonance spectroscopy, and impedance spectroscopy of N,N-dimethyl-pyrrolidinium iodide: An ionic solid exhibiting rotator phases

2005 ◽  
Vol 97 (9) ◽  
pp. 093904 ◽  
Author(s):  
Josefina Adebahr ◽  
Aaron J. Seeber ◽  
Douglas R. MacFarlane ◽  
Maria Forsyth
Keyword(s):  
Thermal Analysis ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Impedance Spectroscopy ◽  
Magnetic Resonance Spectroscopy ◽  
Nuclear Magnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
Ionic Solid ◽  
Nuclear Magnetic

scholarly journals Monitoring hydration in lime-metakaolin composites using electrochemical impedance spectroscopy and nuclear magnetic resonance spectroscopy

Clay Minerals ◽  
2014 ◽  
Vol 49 (3) ◽  
pp. 341-358 ◽  
Author(s):  
G. L. Pesce ◽  
C. R. Bowen ◽  
J. Rocha ◽  
M. Sardo ◽  
G. C. Allen ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Electrochemical Impedance Spectroscopy ◽  
Magnetic Resonance ◽  
Impedance Spectroscopy ◽  
Magnetic Resonance Spectroscopy ◽  
Calcium Hydroxide ◽  
Nuclear Magnetic Resonance Spectroscopy ◽  
Electrochemical Impedance ◽  
Resonance Spectroscopy ◽  
Nuclear Magnetic

AbstractThis paper describes a study of the hydraulic reactions between metakaolin (MK) and air lime using electrochemical impedance spectroscopy (EIS) and nuclear magnetic resonance spectroscopy (NMR). Tests were carried out at 20, 25 and 30°C on lime-MK pastes with 10:1 w/w ratio. Tests over 28 days allowed identification of relevant changes in the EIS signals and characterization of pastes using thermal analysis (TGA/DSC), scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP) and uni-axial compressive tests. Tests over shorter periods of time (up to 42 h) allowed more detailed studies of the hydraulic phases formed at the very beginning of the reactions.Results of thermal analyses demonstrate formation of hydraulic compounds such as CSH, C4AH13 and C3ASH6 and show their evolution over time. MIP analysis demonstrates changes in pore size distribution related to the formation and trasformation of hydraulic phases. Variations of impedance response with time are shown to be associated with reaction kinetics. Changes in the NMR signal within the first 42 h of reaction are shown to be associated with the dissolution of calcium hydroxide in the pore solution. Overall, this paper demonstrates the importance of NMR in the study of hydraulic reactions in lime based materials and the ability of EIS to detect the formation of hydraulic compounds and the end of the calcium hydroxide dissolution process.

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