title: Gelation transitions of colloidal systems with bridging attractions.
abstract: Gelation transitions in a colloidal system, where there is a strong reversible attraction between small, soft microgels and large, hard spheres, are systematically investigated. Different from widely studied depletion attraction systems that are also two-component systems, the strong attraction between small solvent and large solute particles introduces bridging attractions between large solute particles. We conclusively demonstrate that the formation of physical gels at the intermediate volume fraction of our bridging attraction system follows more closely with the percolation line that is in stark contrast to what is observed in depletion attraction systems, where the gelation transition is related with the frustrated spinodal separation, not a purely kinetic phenomenon. Our results introduce a different way to control gelation transitions in spherical colloidal systems, and imply that people need to be prudent when generalizing the physical picture of the gelation transitions obtained from systems with different origins of effective attraction as the solvent molecule may play important roles.
authors.affiliation: Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.|Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.|Department of Polymer Engineering, University of Akron, Akron, Ohio 44325, USA.
authors.forename: Guangcui
authors.initials: G
authors.lastname: Yuan
authors.affiliation: Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Junhua
authors.initials: J
authors.lastname: Luo
authors.affiliation: Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Charles C
authors.initials: CC
authors.lastname: Han
authors.affiliation: Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.|Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, USA.
authors.forename: Yun
authors.initials: Y
authors.lastname: Liu