TY  - GEN
A1  - Niebuur, Bart-Jan
A1  - Puchmayr, Jonas
A1  - Herold, Christian
A1  - Kreuzer, Lucas P.
A1  - Hildebrand, Viet
A1  - Müller-Buschbaum, Peter
A1  - Laschewsky, André
A1  - Papadakis, Christine M.
T1  - Polysulfobetaines in aqueous solution and in thin film geometry
T2  - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2  - Polysulfobetaines in aqueous solution show upper critical solution temperature (UCST) behavior. We investigate here the representative of this class of materials, poly (N,N-dimethyl-N-(3-methacrylamidopropyl) ammonio propane sulfonate) (PSPP), with respect to: (i) the dynamics in aqueous solution above the cloud point as function of NaBr concentration; and (ii) the swelling behavior of thin films in water vapor as function of the initial film thickness. For PSPP solutions with a concentration of 5 wt.%, the temperature dependence of the intensity autocorrelation functions is measured with dynamic light scattering as function of molar mass and NaBr concentration (0–8 mM). We found a scaling of behavior for the scattered intensity and dynamic correlation length. The resulting spinodal temperatures showed a maximum at a certain (small) NaBr concentration, which is similar to the behavior of the cloud points measured previously by turbidimetry. The critical exponent of susceptibility depends on NaBr concentration, with a minimum value where the spinodal temperature is maximum and a trend towards the mean-field value of unity with increasing NaBr concentration. In contrast, the critical exponent of the correlation length does not depend on NaBr concentration and is lower than the value of 0.5 predicted by mean-field theory. For PSPP thin films, the swelling behavior was found to depend on film thickness. A film thickness of about 100 nm turns out to be the optimum thickness needed to obtain fast hydration with H 2 O.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 713 
KW  - polyzwitterions
KW  - polysulfobetaines
KW  - dynamic light scattering
KW  - phase behavior
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427363
SN  - 1866-8372
IS  - 713
ER  - 
TY  - JOUR
A1  - Kreuzer, Lucas P.
A1  - Widmann, Tobias
A1  - Hohn, Nuri
A1  - Wang, Kun
A1  - Biessmann, Lorenz
A1  - Peis, Leander
A1  - Moulin, Jean-Francois
A1  - Hildebrand, Viet
A1  - Laschewsky, André
A1  - Papadakis, Christine M.
A1  - Müller-Buschbaum, Peter
T1  - Swelling and exchange behavior of poly(sulfobetaine)-based block copolymer thin films
JF  - Macromolecules : web edition
N2  - The humidity-induced swelling and exchange behavior of a block copolymer thin film, which consists of a zwitterionic poly(sulfobetaine) [poly(N,N-dimethyl-N-(3-(methacrylamido)propyl)ammoniopropanesulfonate) (PSPP)] block and a nonionic poly(N-isopropylacrylamide) (PNIPAM) block, are investigated by time-of-flight neutron reflectometry (TOF-NR). We monitor in situ the swelling in the H2O atmosphere, followed by an exchange with D2O. In the reverse experiment, swelling in the D2O atmosphere and the subsequent exchange with H2O are studied. Both, static and kinetic TOF-NR measurements indicate significant differences in the interactions between the PSPP80-b-PNIPAM(130) thin film and H2O or D2O, which we attribute to the different H- and D-bonds between water and the polymer. Changes in the chain conformation and hydrogen bonding are probed with Fourier transform infrared spectroscopy during the kinetics of the swelling and exchange processes, which reveals the key roles of the ionic SO3- group in the PSPP block and of the polar amide groups of both blocks during water uptake and exchange.
Y1  - 2019
U6  - https://doi.org/10.1021/acs.macromol.9b00443
SN  - 0024-9297
SN  - 1520-5835
VL  - 52
IS  - 9
SP  - 3486
EP  - 3498
PB  - American Chemical Society
CY  - Washington
ER  -