Publications - 1983
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Self-diffusion and nuclear spin relaxation of benzene adsorbed on graphitized carbon
T. Cosgrove, B. W. Copping and R. A. Jarvis
School of Chemistry, University of Bristol, Bristol, UK.
J. Colloid Interface Sci. (1983), 96(1), 214-21
Abstract
Self-diffusion coeffs. and nuclear spin relaxation times were measured as functions of coverage in the multilayer region for C6H6 adsorbed on graphitized carbon. The diffusion coeffs. increase and the spin lattice relaxation times decrease with decreasing coverage. The results are interpreted in terms of exchange between regions of different mobility. The spin-spin relaxation times, however, are independent of coverage.
An experimental study of polymer conformations at the solid/solution interface
Terence Cosgrove, Trevor L. Crowley and Brian Vincent
Department of Physical Chemistry, University of Bristol, Bristol, UK
Editor(s): Ronald Harry Ottewill, Colin H. Rochester and Alec L. Smith Adsorpt. Solution, Symp. (1983), Meeting Date 1982, 287-97. Publisher: Academic, London, UK
Abstract
A model for the conformation of polyoxyethylene (I) physisorbed to polystyrene (II) latex particles is suggested in which most of the I segments is contained in loops or trains within 4-5 nm from the II surface and with long tails extending as far as 20 nm into the soln. (H2O). The model was derived using the information on the fraction of bound segments, the normalized segment d. distribution normal to the solid/soln. interface, and the 2nd moment of the segment d. distribution, which was obtained by combined NMR and small-angle neutron scattering studies. The adsorption isotherm of I on II latex was also obtained. The comparison with the previously reported (C.; et al., 1982) exptl. data for poly(vinyl alc.) adsorbed on II latex showed a similar conformation for both systems.
Self and mutual diffusion measurements in dilute and semi-dilute polystyrene solutions
T. Cosgrove and J. M. Sutherland
School of Chemistry, University of Bristol, Bristol, UK.
Polymer (1983), 24(5), 534-6
Abstract
Self-diffusion coeffs. were detd. for polystyrene (mol. wt. 37,000) in toluene-d8 and cyclohexane-d12 by pulsed field gradient NMR at 303 K. Mutual diffusion coeffs. were detd. by photon correlation spectroscopy (PCS). In a poor solvent (cyclohexane), both methods showed a monotonic decrease in diffusion coeff. with increasing concn. In a good solvent (PhMe), NMR showed a monotonic decrease in the diffusion coeff. while PCS showed an increase. The results are discussed in terms of self and mutual diffusion.
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