TY  - JOUR
AU  - Meier-Koll, Andreas
AU  - Pipich, Vitaliy
AU  - Busch, Peter
AU  - Papadakis, Christine M.
AU  - Müller-Buschbaum, Peter
TI  - Phase Separation in Semidilute Aqueous Poly( N -isopropylacrylamide) Solutions
JO  - Langmuir
VL  - 28
IS  - 23
SN  - 1520-5827
CY  - Washington, DC
PB  - ACS Publ.
M1  - FZJ-2015-03370
SP  - 8791 - 8798
PY  - 2012
AB  - The phase separation mechanism in semidilute aqueous poly(N-isopropylacrylamide) (PNIPAM) solutions is investigated with small-angle neutron scattering (SANS). The nature of the phase transition is probed in static SANS measurements and with time-dependent SANS measurements after a temperature jump. The observed critical exponents of the phase transition describing the temperature dependence of the Ornstein–Zernike amplitude and correlation length are smaller than values from mean-field theory. Time-dependent SANS measurements show that the specific surface decreases with increasing time after a temperature jump above the phase transition. Thus, the formation of additional hydrogen bonds in the collapsed state is a kinetic effect: A certain fraction of water remains as bound water in the system. Moreover, H–D exchange reactions observed in PNIPAM have to be taken into account.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000305092700024
DO  - DOI:10.1021/la3015332
UR  - https://juser.fz-juelich.de/record/201060
ER  -