1 research outputs found
Photolabile SI-PET-RAFT Initiators for Wavelength-Selective Grafting and De-grafting of Polymer Brushes
Polymer
brushes offer a wide array of applications in surface modification.
While recent advances have made these chemistries more user-friendly,
scientific questions about fundamental polymer properties often remain
unanswered. For example, copolymer brush composition, chain end fidelity,
and dispersity often remain prohibitively challenging to characterize.
This conundrum produces a need for chemically precise pathways to
evaluate polymer brushes. To this end, this contribution describes
the synthesis of an o-nitrobenzyl-based photolabile
initiator for surface-initiated reversible deactivation radical polymerization.
The product can be immobilized on surfaces, enable growth of polymer
brushes under visible light, and be cleaved under ultraviolet (UV)
irradiation. Wavelength selectivity is confirmed using a combination
of ellipsometry, tensiometry, and X-ray photoelectron spectroscopy,
and patterning experiments indicate good spatial control over photocleaving.
Finally, nuclear magnetic resonance spectroscopy indicates visibility
of characteristic peaks for both chain ends after degrafting of the
polymer brush