1H NMR Trajectories for Analyzing the Growth and Purification of 2D Polyaramids
Journal
Journal of the American Chemical Society
Journal Volume
147
Journal Issue
7
Start Page
5921
End Page
5932
ISSN
0002-7863
1520-5126
Date Issued
2025-02-19
Author(s)
Abstract
The recent synthesis of two-dimensional (2D) polyaramid (PA) polymers has shown that they exhibit remarkable mechanical and gas barrier properties. However, new methods are necessary to enable the efficient measurement of discoidal sizes of 2D polyaramids and tracking of their growth over time during reaction. Herein, we employ 1H NMR peak analysis of the aromatic and proton end group regions to characterize 2D-PA growth from monomeric precursors, alongside purification using two-stage filtration and washing steps. The ratio of aromatic to end group protons yields the molecular weight and discoidal size, while the skewness of the NMR peaks in the aromatic region provides a relative weighting between dendritic, small, and larger polycyclic domains. These two metrics delineate a distinct two-dimensional 1H NMR trajectory that we show to be valuable for analyzing the results of differing synthetic and processing conditions. Theoretical bounds corresponding to dendrimer and polycyclic limits as a function of repeat unit size are derived as an aid in trajectory analysis. These results establish an analytical framework for evaluating 2D-PA and its variants, facilitating the exploration of the synthetic landscape.
Subjects
Air purification
Alkylation
Microfiltration
aromatic polyamide
dendrimer
dimethyl sulfoxide
metal organic framework
trifluoroacetic acid
polymer
proton
Dendritics
End groups
Gas barrier properties
Measurements of
Mechanical barrier
Monomeric precursors
NMR peaks
Peak analysis
Two-dimensional
Washing steps
Article
atomic force microscopy
biocompatibility
calculation
chromatography
growth
hydrophobicity
kinetics
molecular dynamics
molecular imaging
monitoring
nonhuman
nuclear magnetic resonance
proton nuclear magnetic resonance
purification
scanning electron microscopy
transmission electron microscopy
two-dimensional imaging
X ray diffraction
article
benchmarking
controlled study
drug analysis
filtration
molecular weight
synthesis
Aromatization
Publisher
American Chemical Society (ACS)
Type
journal article