The synthesis and
thermoresponsive properties of surface-attached
poly(
N
-isopropylacrylamide)-
co
-
N
,
N
′-methylene bisacrylamide (PNIPAM-
co
-MBAM) networks are investigated. The networks are formed
via
SI-ARGET-ATRP (“grafting-from”) on thiol-based
initiator-functionalized gold films. This method is reliable, well
controlled, fast, and applicable to patterned surfaces (
e.g.
, nanopores) for networks with dry thicknesses >20 nm. Surface-attached
PNIPAM-
co
-MBAM gels are swollen below their volume
phase transition temperature but above collapse without complete expulsion
of water (retain ∼50 vol %). The swelling/collapse transition
is studied using complementary SPR and QCMD techniques. The ratio
between swollen and collapsed heights characterizes the thermoresponsive
behavior and is shown to not depend on network height but to vary
with MBAM content. The higher the proportion of the crosslinker, the
lower the magnitude of the phase transition, until all responsiveness
is lost at 5 mol % MBAM. The temperature range of the transition is
broadened for more crosslinked PNIPAM-
co
-MBAM gels
but remains centered around 32 °C. Upon reswelling, less crosslinked
networks display sharp transitions, while for those containing ≥3
mol % MBAM, transitions remain broad. This tunable behavior persists
for gels on nanostructured gold surfaces. Investigating PNIPAM-
co
-MBAM networks on gold plasmonic nanowell arrays is a
starting point for expanding their scope as thermo-controlled nanoactuators.