Issue
EPL
Volume 87, Number 6, September 2009
Article Number 68003
Number of page(s) 5
Section Interdisciplinary Physics and Related Areas of Science and Technology
DOI http://dx.doi.org/10.1209/0295-5075/87/68003
Published online 08 October 2009
EPL, 87 (2009) 68003
DOI: 10.1209/0295-5075/87/68003

Topological changes at the gel transition of a reversible polymeric network

J. Billen1, M. Wilson1, A. Rabinovitch2 and A. R. C. Baljon1

1   Department of Physics, San Diego State University - San Diego, CA 92128, USA
2   Department of Physics, Ben-Gurion University of the Negev - Beer-Sheva, 84105, Israel

abaljon@mail.sdsu.edu

received 19 May 2009; accepted in final form 9 September 2009; published September 2009
published online 8 October 2009

Abstract
We investigate how the network topology of an ensemble of telechelic polymers changes with temperature. The telechelic polymers serve as “links" between “nodes", which consist of aggregates of their associating end groups. Our analysis shows that the degree distribution of the system is bimodal and consists of two Poissonian distributions with different average degrees. The number of nodes in each of them as well as the distribution of links depend on temperature. By comparing the eigenvalue spectra of the simulated gel networks with those of reconstructed networks, the most likely topology at each temperature is determined. Topological changes occur at the transition temperatures reported in our previous study (BALJON A. R. C. et al., J. Chem. Phys., 126 (2007) 044907). Below the micelle transition the topology can be described by a robust bimodal network in which superpeer nodes are linked among themselves and all peer nodes are linked only to superpeers. At even lower temperatures the peers completely disappear leaving a structure of interconnected superpeers.

PACS
89.75.Fb - Structures and organization in complex systems.
83.80.Qr - Surfactant and micellar systems, associated polymers.
82.70.Gg - Gels and sols.

© EPLA 2009