TY - JOUR
T1 - Modulating Noncovalent Cross-links with Molecular Switches
AU - Epstein, Eric S.
AU - Martinetti, Luca
AU - Kollarigowda, Ravichandran H.
AU - Carey-De La Torre, Olivia
AU - Moore, Jeffrey S.
AU - Ewoldt, Randy H.
AU - Braun, Paul V.
N1 - Funding Information:
This research was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Award DE-FG02-07ER46471, through the Materials Research Laboratory at the University of Illinois. E.E. also acknowledges support of a National Science Foundation Graduate Research Fellowship under Grant No. 2012141509, as well as support of a Beckman Institute Graduate Research Fellowship through the Arnold and Mabel Beckman Foundation. Notes The authors declare no competing financial interest.
Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/2/27
Y1 - 2019/2/27
N2 - Spiropyran molecular switches, in conjunction with transition metal ions, are shown to operate as reversible polymer cross-linkers. Solutions containing a spiropyran-functionalized polymer and transition metal ions underwent reversible thermally triggered (light-triggered) transient network formation (disruption) driven by the association (dissociation) of metal-ligand cross-links. Heat triggers metal-ion-mediated cross-linking via thermal isomerization of spiropyran to its open, merocyanine form, and exposure to visible light triggers dissociation of polymer cross-links. Cross-linking is found to depend on both the valence of the ion as well as the molar ratio of spiropyran to metal salt. We envision this to be a starting point for the design of many types of reversible, stimuli-responsive polymers, utilizing the fact that spiropyrans have been shown to respond to a variety of stimuli including heat, light, pH, and mechanical force.
AB - Spiropyran molecular switches, in conjunction with transition metal ions, are shown to operate as reversible polymer cross-linkers. Solutions containing a spiropyran-functionalized polymer and transition metal ions underwent reversible thermally triggered (light-triggered) transient network formation (disruption) driven by the association (dissociation) of metal-ligand cross-links. Heat triggers metal-ion-mediated cross-linking via thermal isomerization of spiropyran to its open, merocyanine form, and exposure to visible light triggers dissociation of polymer cross-links. Cross-linking is found to depend on both the valence of the ion as well as the molar ratio of spiropyran to metal salt. We envision this to be a starting point for the design of many types of reversible, stimuli-responsive polymers, utilizing the fact that spiropyrans have been shown to respond to a variety of stimuli including heat, light, pH, and mechanical force.
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U2 - 10.1021/jacs.8b12762
DO - 10.1021/jacs.8b12762
M3 - Article
C2 - 30661352
AN - SCOPUS:85061938707
SN - 0002-7863
VL - 141
SP - 3597
EP - 3604
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 8
ER -