Recent Applications of Unilateral NMR to Objects of Cultural Heritage

Although nuclear magnetic resonance (NMR) is recognized as a powerful tool in many areas of research, among the investigative techniques used in the field of cultural heritage its application is still largely unknown. One of the reasons for this is that artifacts are complex heterogeneous systems whose analysis requires a multi-disciplinary approach. In addition, major drawbacks in the analysis of objects belonging to cultural heritage are their limited quantity, number of samples collected from the artifact, and their immovability. Consequently, a methodological approach where non-destructive, and possibly non-invasive techniques are used, is advisable. In recent years, thanks to the development of portable instruments, there has been an increasing use of the NMR methodology in the cultural heritage field. The use of portable NMR has allowed us to study several materials in the cultural heritage, such as frescoes, stones, wood, paper, and paintings, to address the challenges in monitoring dampness in historical masonries, to evaluate the penetration depth of a hydrophobic treatment into a porous material, and to study of the effect of cleaning procedures on artifacts. In this paper, recent studies illustrating the potential of NMR portable methodologies in this field of research are reported.