Super-resolution imaging reveals resistance to mass transfer in functionalized stationary phases
Abstract
Chemical separations are costly in terms of energy, time, and money. Separation methods are optimized with inefficient trial-and-error approaches that lack insight into the molecular dynamics that lead to the success or failure of a separation and, hence, ways to improve the process. We perform super-resolution imaging of fluorescent analytes in five different commercial liquid chromatography materials. Unexpectedly, we observe that chemical functionalization can block more than 50% of the material's porous interior, rendering it inaccessible to small-molecule analytes. Only in situ imaging unveils the inaccessibility when compared to the industry-accepted ex situ characterization methods. Selectively removing some of the functionalization with solvent restores pore access without substantially altering the single-molecule kinetics that underlie the separation and agree with bulk chromatography measurements. Our molecular results determine that commercial "fully porous" stationary phases are over-functionalized and provide an alternative avenue to characterize and direct separation material design from the bottom-up.
Repository Citation
Neria, Ricardo Monge, Muhammad Zeeshan, Aman Kapoor, et al. 2025. "Super-resolution imaging reveals resistance to mass transfer in functionalized stationary phases." Science Advances 11(7).
Publisher
American Association for the Advancement of Science
Publication Date
2-14-2025
Publication Title
Science Advances
Department
Chemistry and Biochemistry
Document Type
Article
DOI
https://doi.org/10.1126/sciadv.ads0790
Keywords
Performance liquid-chromatography, Pore-size distributions, Exchange adsorbents, Single, Adsorption, Separation, Flourescence, Diffusion, Accessibility, Purification
Language
English
Format
text
