Solid State NMR Spectroscopy: A multiscale "lens" for understanding complex materials

Complexity is a common feature intrinsic to many materials playing a key role in in biology, chemistry and industry. Complexity can arise from many factors as the coexistence of different chemical components and phases and an overall structural disorder and heterogeneity. Because of complexity it is often difficult to obtain a detailed characterization of interesting materials, while, on the other hand, such a knowledge is crucial for understanding the functional performances of materials and orienting their design, synthesis and optimization. Solid State NMR spectroscopy is an extremely powerful technique, which can effectively bridge this gap. Indeed, it can be applied to substantially every kind of material and, by exploting a plethora of nuclear probes and properties, it allows structural and dynamic properties to be characterized on very wide spatial (0.1 - 100 nm) and frequency (Hz - GHz) scales.(1-4) In this contribution I will try to highlight the power and significance of this technique, going through several studies, carried out in our research group, in which Solid State NMR has allowed a multiscale understanding of innovative complex materials.(5-7) (1) M. Geppi, S. Borsacchi, G. Mollica, C. A. Veracini, Appl. Spectr. Rev. 44 (2009), 1. (2) M. Geppi, S. Borsacchi, G. Mollica, Encyclopedia of Magnetic Resonance, Wiley, 2008. (3) F. Martini, M. Geppi, S. Borsacchi, Clay-Polymer Nanocomposites (2017), 307. (4) M. Geppi, S. Borsacchi, E. Carignani, Disordered Pharmaceutical Materials (2016), 427. (5) F. Martini, M. Tonelli, M. Geppi, F. Ridi, S. Borsacchi, L. Calucci, Cem. Concr. Res. 102 (2017), 60. (6) S. Borsacchi, U. P. Sudhakaran, L. Calucci, F. Martini, E. Carignani, M. Messori, M. Geppi, Polymers 10 (2018), 822. (7) E. Passaglia, F. Cicogna, F. Costantino, et al., Chem. Mater. 30 (2018), 2036.