TY - JOUR
T1 - Phase Transition Kinetics of Doubly Thermoresponsive Poly(sulfobetaine)-Based Diblock Copolymer Thin Films
AU - Kreuzer, Lucas P.
AU - Widmann, Tobias
AU - Bießmann, Lorenz
AU - Johannes, Nuri Hohn
AU - Raphael Markl, Pantle
AU - Moulin, Jean Francois
AU - Hildebrand, Viet
AU - Laschewsky, Andre
AU - Papadakis, Christine M.
AU - Müller-Buschbaum, Peter
N1 - Publisher Copyright:
© 2020 American Chemical Society.
PY - 2020/4/28
Y1 - 2020/4/28
N2 - The swelling and phase transition behavior upon increasing temperature of a doubly thermoresponsive diblock copolymer thin film in steps above the characteristic cloud points (CPs) of the blocks is studied. An upper critical solution temperature (UCST)-type zwitterionic poly-(sulfobetaine), poly(N,N-dimethyl-N-(3-methacrylamidopropyl)-ammoniopropane sulfonate) (PSPP, CPUCST = 31.5 °C), is combined with a lower critical solution temperature (LCST)-type nonionic poly(N-isopropyl-/ methacrylamide) (PNIPMAM, CPLCST = 49.5 °C) block. Using time-of-flight neutron reflectivity (ToF-NR), we observe the swelling in D2O vapor at a constant temperature of 20 °C, followed by two subsequent temperature jumps, from 20 to 40 °C (above CPUCST) and from 40 to 60 °C (above CPLCST). The observed response of the diblock copolymer films deviates from the aqueous solution behavior, which is mainly attributed to the increased polymer concentration. Temperature-induced changes in the thin-film nanostructure are investigated with ToF grazing-incidence small-angle neutron scattering (GISANS). Alterations in the chain conformation and hydrogen bonding are probed by Fourier transform infrared (FTIR) spectroscopy. The ionic SO3− groups (in the PSPP block) and the nonionic hydrophilic amide groups (in both blocks) are found to affect the mechanisms of D2O uptake and release significantly.
AB - The swelling and phase transition behavior upon increasing temperature of a doubly thermoresponsive diblock copolymer thin film in steps above the characteristic cloud points (CPs) of the blocks is studied. An upper critical solution temperature (UCST)-type zwitterionic poly-(sulfobetaine), poly(N,N-dimethyl-N-(3-methacrylamidopropyl)-ammoniopropane sulfonate) (PSPP, CPUCST = 31.5 °C), is combined with a lower critical solution temperature (LCST)-type nonionic poly(N-isopropyl-/ methacrylamide) (PNIPMAM, CPLCST = 49.5 °C) block. Using time-of-flight neutron reflectivity (ToF-NR), we observe the swelling in D2O vapor at a constant temperature of 20 °C, followed by two subsequent temperature jumps, from 20 to 40 °C (above CPUCST) and from 40 to 60 °C (above CPLCST). The observed response of the diblock copolymer films deviates from the aqueous solution behavior, which is mainly attributed to the increased polymer concentration. Temperature-induced changes in the thin-film nanostructure are investigated with ToF grazing-incidence small-angle neutron scattering (GISANS). Alterations in the chain conformation and hydrogen bonding are probed by Fourier transform infrared (FTIR) spectroscopy. The ionic SO3− groups (in the PSPP block) and the nonionic hydrophilic amide groups (in both blocks) are found to affect the mechanisms of D2O uptake and release significantly.
UR - http://www.scopus.com/inward/record.url?scp=85083188967&partnerID=8YFLogxK
U2 - 10.1021/acs.macromol.0c00046
DO - 10.1021/acs.macromol.0c00046
M3 - Article
AN - SCOPUS:85083188967
SN - 0024-9297
VL - 53
SP - 2841
EP - 2855
JO - Macromolecules
JF - Macromolecules
IS - 8
ER -