TY  - JOUR
AU  - Gold, Barbara
AU  - Pyckhout-Hintzen, W.
AU  - Wischnewski, A.
AU  - Radulescu, A.
AU  - Monkenbusch, M.
AU  - Allgaier, J.
AU  - Hoffmann, I.
AU  - Parisi, D.
AU  - Vlassopoulos, D.
AU  - Richter, D.
TI  - Direct Assessment of Tube Dilation in Entangled Polymers
JO  - Physical review letters
VL  - 122
IS  - 8
SN  - 1079-7114
CY  - College Park, Md.
PB  - APS
M1  - FZJ-2019-01999
SP  - 088001
PY  - 2019
AB  - A key ingredient within theories focusing on the rheology of entangled polymers is the way how the topological constraints of an entangled chain are lifted by unconstrained segments, i.e., how the constraining tube is dilated. This important question has been addressed by directly measuring the tube diameter d at the scale of the tube by neutron spin echo spectroscopy. The tube diameter d and plateau modulus G0N of highly entangled polyethylene oxide (PEO) chains of volume fraction c that are diluted by low molecular PEO show a concentration dependence d∝ca/2 and G0N∝c1+a with an exponent a close to 4/3. This result allows the clear discrimination between different theoretical models that predict 4/3 or other values between 1 and 2 and provides an important ingredient to tube model theories.
LB  - PUB:(DE-HGF)16
C6  - pmid:30932610
UR  - <Go to ISI:>//WOS:000459919700011
DO  - DOI:10.1103/PhysRevLett.122.088001
UR  - https://juser.fz-juelich.de/record/861548
ER  -