ISSN:
1435-1536
Keywords:
Key words Solid/fluid interface processes
;
Amorphous and polymeric materials
;
Magnetic resonance and relaxation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Poly(ethylene oxide) chains of molecular weight 2000 have been grafted on pyrogenic silica, spin-labelled at their free end and put into contact with cyclohexane. The electron paramagnetic resonance of the nitroxide free radical gives evidence of two specific environments: namely, trains adsorbed on the solid with a restricted motion and loops and tails protruding into solution with a high mobility. The dynamic parameters such as the rotational correlation time and the static ones such as the fraction of each population have been evaluated. Under a flow of solvent the unwinding of the chains has been observed with increasing flow rate in our experimental range. Some mechanisms are proposed to explain this behaviour.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s003960050476
