NMR investigations of temperature-induced phase transition in aqueous polymer solutions

0363237 - ÚMCH 2012 RIV DE eng J - Journal Article
Spěváček, Jiří
NMR investigations of temperature-induced phase transition in aqueous polymer solutions.
Macromolecular Symposia. Roč. 305, č. 1 (2011), s. 18-25. ISSN 1022-1360
R&D Projects: GA ČR GA202/09/1281
Institutional research plan: CEZ:AV0Z40500505
Keywords : aqueous polymer solutions * cooperative effects * NMR
Subject RIV: CD - Macromolecular Chemistry

The different dynamics of polymer segments forming phase-separated globular structures in aqueous (D2O) solutions affects both the shape of NMR spectra and NMR relaxation times of polymer and solvent. Two types of the approach are discussed. The first one is based on the reduction of integrated intensities of polymer NMR lines in high-resolution NMR spectra in the system undergoing the coil-globule phase transition. The fraction p of phase-separated units (units with significantly reduced mobility) and subsequently, e.g., thermodynamic parameters DH and DS characterizing the coil-globule phase transition can be determined. The second approach is based on measurements of 1H NMR relaxation times of water (HDO) which provide information on behaviour of water during phase transition. The power of both approaches is demonstrated on results obtained with solutions of several thermoresponsive homopolymers and copolymers.
Permanent Link: http://hdl.handle.net/11104/0199244