2 research outputs found
Rapid Visible Light-Mediated Controlled Aqueous Polymerization with In Situ Monitoring
We report a simple procedure for
rapid, visible light-mediated,
controlled radical polymerization in aqueous solutions. Based on the
photoelectron transfer reversible addition–fragmentation chain
transfer (PET–RAFT) polymerization, fast chain propagation
at room temperature in water was achieved in the presence of reductant
and without prior deoxygenation. A systematic study correlating irradiation
intensity and polymerization kinetics, enabled by in situ nuclear
magnetic resonance spectroscopy, provided optimized reaction conditions.
The versatility of this procedure was demonstrated through a rapid
triblock copolymer synthesis, and incorporation of water-labile activated
esters for direct conjugation of hydrophilic small molecules and proteins.
In addition, this technique boasts excellent temporal control and
provides a wide range of macromolecular materials with controlled
molecular weights and narrow molecular weight distributions
Metal-Free Removal of Polymer Chain Ends Using Light
A light-mediated method for the facile
removal of polymer end groups that are common to controlled radical
polymerization techniques is presented. This metal-free strategy is
general, being effective for chlorine, bromine, and thiocarbonylthio
moieties as well as a number of different polymer families (styrenic,
acrylic, and methacrylic). In addition to solution reactions, this
process is readily translated to thin films, where light mediation
allows the straightforward fabrication of hierarchically patterned
polymer brushes