Description: Polymer-mediated melting in ultrasoft colloidal gels

This title appears in the Scientific Report : 2002

Polymer-mediated melting in ultrasoft colloidal gels

Star polymers with a high number of arms, f = 263, become kinetically trapped when dispersed in an athermal solvent at concentrations above the overlapping one, forming physical gels. We show that the addition of linear chains at different concentrations and molecular weights reduces the modulus of...

Personal Name(s):	Stiakakis, E.
	Vlassopoulos, D. / Likos, C. / Roovers, J. / Meier, G.
Contributing Institute:	Weiche Materie; IFF-WM
Published in:	Physical review letters, 89 (2002) S. 208302-1 - 208302-4
Imprint:	College Park, Md. APS 2002
Physical Description:	208302-1 - 208302-4
DOI:	10.1103/PhysRevLett.89.208302
Document Type:	Journal Article
Research Program:	Kondensierte Materie
Series Title:	Physical Review Letters 89
Subject (ZB):	J
Link:	OpenAccess
	Publikationsportal JuSER

Please use the identifier: http://hdl.handle.net/2128/1599 in citations.
Please use the identifier: http://dx.doi.org/10.1103/PhysRevLett.89.208302 in citations.

Star polymers with a high number of arms, f = 263, become kinetically trapped when dispersed in an athermal solvent at concentrations above the overlapping one, forming physical gels. We show that the addition of linear chains at different concentrations and molecular weights reduces the modulus of the gel, eventually melting it. We explain this linear polymer-induced gel-liquid transition in terms of effective interactions and star depletion. In the limit of very high linear-chain molecular weight a "reentrant gelation" is detected and attributed to bridging flocculation, analogous to that observed in colloidal dispersions.