Application of Si-29 and Al-27 magic angle spinning nuclear magnetic resonance to studies of the building materials of historical monuments

We report the application of Si-29 and Al-27 magic angle spinning nuclear m agnetic resonance (MAS NMR) studies on building stones from historical monu ments to obtain direct information about the degree of degradation and to o bserve the changes in the consolidated material after treatment with tetrae thoxysilane (TEOS). Using the data obtained from deteriorated materials, a diagnostic laboratory, a suitable treatment and recommendations for buildin g conservation may infer. A case study is presented using stones from Guana juato City Main Church (Central Mexico). X-ray diffraction patterns to char acterize the species present in the stones agree with the solid state NMR r esults. (C) 1999 Elsevier Science B.V. All rights reserved.