Nuclear magnetic resonance (NMR), as an advanced non‐destructive and rapid measurement technology, has shown unique advantages in the evaluation of unconventional shale reservoirs. This paper systematically introduces the fundamental principles of NMR spectroscopy and relaxation theory in porous media and comprehensively analyzes the experimental techniques and analytical methodologies for NMR and magnetic resonance imaging (MRI) applications in shale characterization. The content aims to provide substantive reference value for researchers and practitioners engaged in shale NMR investigations. Notably, despite existing technical challenges in expository relaxation mechanisms and capturing nanoscale pore signals within shale matrices, NMR applications present novel possibilities for developing emerging research frontiers. For instance, there is significant synergy between NMR technology and emerging fields such as supercritical CO ₂ enhanced recovery, carbon capture, utilization and storage (CCUS), and underground hydrogen storage. This paper methodological framework exhibits extensibility to studies of tight sandstones, hydrate‐bearing sediments, and other porous media systems, thereby offering cross‐disciplinary technical support for establishing carbon neutrality‐oriented energy development paradigms.

Metal–organic frameworks (MOFs) typically exist in the form of powders or dispersed crystals, which limits their direct application in practical engineering scenarios that require monolithic structures and processability. To address this issue, the present study successfully anchored MOF (zeolitic imidazolate framework-8, ZIF-8) nanocrystals within a porous silicon carbide (p-SiC) substrate via a facile in situ growth strategy, achieving both stable macroscopic loading and intimate microscopic interfacial bonding. The resulting ZIF-8/p-SiC composite exhibits a hierarchical porous structure, with a specific surface area approximately 183 times higher than that of the raw p-SiC, alongside a substantially enhanced CO₂ adsorption capacity. By utilizing a low-cost p-SiC support and mild ZIF-8 synthesis conditions, this work demonstrates excellent reproducibility and scalability, providing a facile and effective pathway for fabricating MOF/porous media composite systems that possess both superior mechanical properties and tailored pore structures. Additionally, the developed MOF/p-SiC composites can serve as controllable rock-analog porous media, offering new perspectives for investigating MOF-rock interfacial interactions and CO₂ geological sequestration mechanisms, thereby establishing an organic link between fundamental materials science and geological engineering applications.

This study employed time domain nuclear magnetic resonance by using inversion recovery and Carr–Purcell–Meiboom–Gill pulse sequences to identify the relaxation properties of bound water in elm and pine wood under various relative humidity levels. Results showed that the sizes of micropores and mesopores in elm and pine increased with water accumulation. Furthermore, the sizes of micropores and mesopores in sapwood were larger than those in heartwood of both elm and pine wood. Hydroxyl bound water (OH bound water) molecules were tightly bound to the primary sorption sites of the polymers. More freely bound water occupied the void spaces between microfibrils within the cell wall. Elm wood exhibited higher T₁/T₂ ratios for bound water than pine, suggesting that elm had less mobility than pine. Moreover, OH bound water exhibited higher T₁/T₂ ratios than more freely bound water in pine and elm, indicating greater molecular mobility constraints and stronger interactions with the wood polymer. Notably, OH bound water mobility increased significantly with water accumulation.

Distributions of nuclear magnetic resonance (NMR) relaxation times provide detailed information about the water in wood. This study documents the water dynamics analysis of T₂ and T₁ distributions for saturated delignified sapwood (DSW), delignified heartwood (DHW) and lignocellulose (LC) samples at different temperatures. Results indicate that below the freezing point of bulk water, free water freezes, causing its signal to disappear from the distribution. Then, the low temperature distributions of the unfrozen bound water contain more information about its components, with DSW, DHW and LC containing two distinct states of bound water (OH bound water (B-water) and more freely bound water (C-water)). Furthermore, it was observed that within the temperature range of −3°C to −60°C, B-water in DSW, DHW and LC maintained a higher unfrozen water content (UWC) value than C-water, and the T₁/T₂ ratios for B-water were consistently higher than that for C-water, indicating that B-water has a greater antifreeze capacity. T₂ and T₁ distributions offer different kinds of information about water components, and all peaks within the distribution have been assigned.