TY  - JOUR
AB  - The effect of deuteration on the volume phase transition (VPT) temperature of poly (N-isopropylmethacrylamide) (pNIPMAM) microgels in aqueous suspension is determined via IR spectroscopy and size measurements by photon correlation spectroscopy (PCS). We study the effect of a hydrogenated and a deuterated solvent (H2O/D2O), and of the hydrogenated and (partially) deuterated monomer. Deuteration of the monomer or copolymerization with deuterated monomers shifts the volume phase transition temperature (VPTT) by up to 8.4 K to higher temperatures, in good agreement with known results for pNIPAM microgels. Moreover, the shape of the swelling curve is found to depend on deuteration, with the highest deuteration leading to the sharpest VPT. Finally, the quantitative agreement between FTIR spectroscopy and PCS evidences the spatial homogeneity of the microgel particles. Our results are rationalized in terms of the effect of deuteration on hydrogen bonding. They shall be of primary importance for any experimental measurements close to the VPT involving isotopic substitution, and in particular contrast variation small angle neutron scattering.
DA  - 2019
DO  - 10.3390/polym11040620
KW  - microgel
KW  - deuteration
KW  - isotope effect
KW  - NIPMAM
KW  - VPTT shift
LA  - eng
IS  - 4
PY  - 2019
SN  - 2073-4360
T2  - Polymers
TI  - Deuteration-Induced Volume Phase Transition Temperature Shift of PNIPMAM Microgels
UR  - https://nbn-resolving.org/urn:nbn:de:0070-pub-29347691
Y2  - 2024-11-22T03:24:47
ER  -