  Temperature-sensitive hydrogels based on polymers such as
poly(N-isopropylacrylamide) (PNIPAM) undergo a volume phase transition in
response to changes in temperature. During this transition, distinct changes in
both thermal and mechanical properties are observed. Here, we illustrate and
exploit the inherent thermodynamic link between thermal and mechanical
properties by showing that the compressive elastic modulus of PNIPAM hydrogels
can be probed using differential scanning calorimetry. We validate our approach
by using conventional osmotic compression tests. Our method could be
particularly valuable for determining the mechanical response of
thermosensitive submicron-sized and/or oddly shaped particles, to which
standard methods are not readily applicable.
