Solid‐State NMR Spectroscopy

Abstract

Solid‐state NMR spectroscopy is an indispensable tool for probing detailed structures and dynamics of polymers at an atomic level due to its capability to selectively manipulate various types of anisotropic spin interactions in solids and its nondestructive property. Herein, this article mainly describes the properties of those anisotropic spin interactions in solids, and how they are used to extract structural and dynamic information via sophisticated one‐ and multidimensional solid‐state NMR spectroscopy. We hope this article can be a good tutorial for the researchers interested in using solid‐state NMR to study polymers.

Elucidations of Structure and Molecular Dynamics of Complex Polymers by State-of-the-Art Solid-State NMR Spectroscopy

“…( ) xx yy zz iso (4) In polymers, the Haeberlen−Mehring−Spiess convention 16−18 is often adapted to define the three principal values according to their separation from the isotropic value, namely…”

“…The interplay of hierarchical structures and heterogeneous dynamics in polymers typically poses a significant challenge on the molecular-level understanding of polymer properties . Solid-state nuclear magnetic resonance (ssNMR) represents one of the most powerful approaches to address this challenge due to the presence of versatile time- and space-dependent NMR spin probes, namely spin interactions, such as chemical shift anisotropy (CSA), homonuclear/heteronuclear dipolar couplings, quadrupolar interactions, and so on. , The appropriate choice and ingenious manipulation of various spin interactions enable quantitative determination of structures on a length scale from angstroms to a few hundred nanometers and dynamics on a time scale from picoseconds to tens of seconds. − Specifically, ssNMR spectroscopy offers several unique advantages that are particularly well-suited for the study of structures and molecular dynamics of polymers. First, the presence of different isotopes in polymers, including 1 H, 2 H, 13 C, 14 N, 15 N, etc., often affords ssNMR with site selectivity and enables utilization of an abundant variety of spin interactions governing the NMR spectra and signal evolution with specific experimental parameters.…”

Chain Dynamics of Partially Disentangled UHMWPE around Melting Point Characterized by 1H Low-Field Solid-State NMR

“…The following supporting information can be downloaded at: https:// www.mdpi.com/article/10.3390/polym15081910/s1, Figure S1: DSC plots of four samples with a heating rate of (a): S1: PE used in experiments and their corresponding characteristics, including weight-average molar mass (M w ), polydispersity (PDI), viscosity-average molar mass (M η ) and [η]c; Table S2: The melting point (T m ) and the crystallinity (X c ) obtained by DSC plots. References [56][57][58][59][60] are cited in the Supplementary Materials.…”