2 research outputs found
Controlled RAFT Polymerization and Zinc Binding Performance of Catechol-Inspired Homopolymers
Incorporation of catechols into polymers
has long been of interest
due to their ability to chelate heavy metals and their use in the
design of adhesives, metalâpolymer nanocomposites, antifouling
coatings, and so on. This paper reports, for the first time, the reversible
additionâfragmentation chain transfer (RAFT) polymerization
of a protected catechol-inspired monomer, 3,4-dimethoxystyrene (DMS),
using commercially available trithiocarbonate, 2-(dodecylthiocarbonothioylthio)-2-methylpropionic
acid (DDMAT), as a chain transfer agent. Our identified RAFT system
produces well-defined polymers across a range of molecular weights
(5â50 kg/mol) with low molar mass dispersities (<i><i><i>Ä</i></i></i>, <i>M</i><sub>w</sub>/<i>M</i><sub>n</sub> < 1.3). Subsequent facile
demethylation of polyÂ(3,4-dimethoxystyrene) (PDMS) yields polyÂ(3,4-dihydroxystyrene)
(PDHS), a catechol-bearing polymer, in quantitative yields. Semiquantitative
zinc binding capacity analysis of both polymers using SEM/EDXA has
demonstrated that both PDMS and PDHS have considerable surface binding
(65% and 87%, respectively), although the films deposited from PDMS
are of a better quality and processability due to solubility and lower
processing temperatures
The Relationship between Charge Density and Polyelectrolyte Brush Profile Using Simultaneous Neutron Reflectivity and In Situ Attenuated Total Internal Reflection FTIR
We
report on a novel experimental study of a pH-responsive polyelectrolyte
brush at the silicon/D<sub>2</sub>O interface. A polyÂ[2-(diethylamino)Âethyl
methacrylate] brush was grown on a large silicon crystal which acted
as both a substrate for a neutron reflectivity solid/liquid experiment
but also as an FTIR-ATR spectroscopy crystal. This arrangement has
allowed for both neutron reflectivities and FTIR spectroscopic information
to be measured in parallel. The chosen polybase brush shows strong
IR bands which can be assigned to the NâD<sup>+</sup> stretch,
D<sub>2</sub>O, and a carbonyl group. From such FTIR data, we are
able to closely monitor the degree of protonation along the polymer
chain as well as revealing information concerning the D<sub>2</sub>O concentration at the interface. The neutron reflectivity data allows
us to determine the physical brush profile normal to the solid/liquid
interface along with the corresponding degree of hydration. This combined
approach makes it possible to quantify the charge on a polymer brush
alongside the morphology adopted by the polymer chains