Wrapping threads around spheres
Condensed Matter lunchtime seminar
Wrapping threads around spheres
- Event time: 1:00pm
- Event date: 9th July 2001
- Speaker: Matthias Fuchs (University of Edinburgh)
- Location: Room 2511, James Clerk Maxwell Building (JCMB) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB
Event details
Free polymers which are added to suspensions of colloidal hard sphere
particles induce attractions among the particles. These depletion
attractions are rather well understood as long as the polymer coils are
much smaller than the particles. Considering the opposite limit in size
ratios, polymer coils which are much larger than the spheres, strikingly
contradictory predictions can be found in the literature.
Whereas de Gennes predicted that only weak attractions are induced which
cannot lead to phase separation, Sear recently predicted that phase
separation takes place at smaller and smaller colloid concentrations for
increasing polymer size.
Experimental observations and some theoretical arguments will be given
trying to disentangle the threads, and to stress the need for more
studies.
P.G. de Gennes, C. R. Acad. Sci. Paris 288B, 359 (1979)
R. Sear, Phys. Rev. Lett. 86, 4696 (2001)
other references can be found here.
R. Sear, Phys. Rev. Lett. 86, 4696 (2001)
other references can be found here.
About Condensed Matter lunchtime seminars
This is a weekly series of informal talks given primarily by members of the institute of condensed matter and complex systems, but is also open to members of other groups and external visitors. The aim of the series is to promote discussion and learning of various topics at a level suitable to the broad background of the group. Everyone is welcome to attend..