NMR and MRI techniques as alternative non-destructive tests for microstructure analysis of natural bamboo

Understanding bamboo microstructure and fluid transport is essential not only for improving preservative treatments, and bonding performance but also for minimizing cracks during drying and storage after harvest and defining its mechanical characteristics. While various techniques can be applied, nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) remain underexplored for bamboo analysis. In this study, NMR relaxation times effectively distinguished microstructural features of Guadua angustifolia. Three components were identified using the Carr-Purcell-Meiboom-Gill (CPMG) distribution, and two using the Logarithmically distributed Aperiodic-Pulse-Sequence Saturation Recovery (LAPSR) method. Based on the LAPSR distribution, two surface relaxivity values similar to those reported for wood were estimated by correlating with mercury intrusion porosimetry: rho 1 = 0.067 mu m/ms and 0.113 mu m/ms for the shorter and longer components, respectively. MRI demonstrated the potential for spatially visualizing water distribution within the bamboo structure under varying moisture conditions. These findings highlight the usefulness of NMR and MRI as non-destructive, non-invasive and fast tools for assessing bamboo microstructure and fluid transport behavior.