Tailoring dynamic hydrogels by controlling associative exchange rates
Name
nihms-1904148.pdf
Description
Accepted version
Size
1.62 MB
Format
Adobe PDF
Checksum (MD5)
adea1672a7246f92c9854b2baaa21845
Author(s)
Zhang, Vivian
Accardo, Joseph V
Kevlishvili, Ilia
Woods, Eliot F
Chapman, Steven J
Eckdahl, Christopher T
Stern, Charlotte L
Kulik, Heather J
Kalow, Julia A
Date Issued
August 10, 2023
Journal
Chem
Publisher
Elsevier BV
Citation
Tailoring dynamic hydrogels by controlling associative exchange rates. Zhang, Vivian et al. Chem, Volume 9, Issue 8, 2298 - 2317
Version
Author's final manuscript
Abstract
Dithioalkylidenes are a newly developed class of conjugate acceptors that undergo thiol exchange via an associative mechanism, enabling decoupling of key material properties for sustainability, biomedical, and sensing applications. Here, we show that the exchange rate is highly sensitive to the structure of the acceptor and tunable over four orders of magnitude in aqueous environments. Cyclic acceptors exchange rapidly, from 0.95 to 15.6 M−1s−1, whereas acyclic acceptors exchange between 3.77 × 10−3 and 2.17 × 10−2 M−1s−1. Computational, spectroscopic, and structural data suggest that cyclic acceptors are more reactive than their acyclic counterparts because of resonance stabilization of the tetrahedral exchange intermediate. We parametrize molecular reactivity with respect to computed descriptors of the electrophilic site and leverage this insight to design a compound with intermediate characteristics. Lastly, we incorporate this dynamic bond into hydrogels and demonstrate that the characteristic stress relaxation time (τ) is directly proportional to molecular kex.
MIT Department
Massachusetts Institute of Technology. Department of Chemical Engineering
Massachusetts Institute of Technology. Department of Chemical Engineering
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Creative Commons Attribution-Noncommercial-ShareAlike
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DOI of Published Version
https://doi.org/10.1016/j.chempr.2023.05.018
