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Stimuli‐Responsive Polymers in Solution Investigated by NMR and Infrared Spectroscopy
Author(s) -
Spěváček Jiří,
Dybal Jiří
Publication year - 2011
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.201150503
Subject(s) - polymer , solvent , phase (matter) , infrared spectroscopy , spectroscopy , nuclear magnetic resonance spectroscopy , relaxation (psychology) , analytical chemistry (journal) , chemistry , molecule , size exclusion chromatography , materials science , organic chemistry , psychology , social psychology , physics , quantum mechanics , enzyme
Summary: Temperature‐induced and solvent composition‐induced phase separation in solutions of poly( N ‐isopropylmethacrylamide) (PIPMAm) and other thermoresponsive polymers as studied by NMR and infrared (IR) spectroscopy is discussed. The fraction p of phase‐separated units (units with significantly reduced mobility) and subsequently, e.g., thermodynamic parameters characterizing the coil‐globule phase transition induced by temperature, were determined from reduced integrated intensities in high‐resolution 1 H NMR spectra. This approach can be especially useful in investigations of phase separation in solutions of binary polymer systems. Information on behaviour of water during temperature‐induced phase transition was obtained from measurements of 1 H NMR relaxation times of HDO molecules. NMR and IR spectroscopy were used to investigate PIPMAm solutions in water/ethanol (D 2 O/EtOH) mixtures where the phase separation can be induced by solvent composition (cononsolvency). Some differences in globular‐like structures induced by temperature and solvent composition were revealed by these methods.