A new route to the formation ofcolloidal gels • Playing with • Short Range Attractions and Long Range Repulsions • Stefano Mossa, Francesco Sciortino, Piero • Tartaglia, Emanuela Zaccarelli
The quest for the ideal (thermoreversible) gel….model The quest 1) Long Living reversible bonds 2)No Phase Separation 3) No Crystallization Are 1 and 2 mutually exclusive ? Low Temperature Long Bond Lifetime Condensation
Phase Diagram for Square Well (3%) Repulsive Glass Iso-diffusivity lines Percolation Line Spinodal AHS (Miller&Frenkel) A3 Attractive Glass Liquid+Gas
How to stay at low T without condensation ? Reasons for condensation (Frank, Hill, Coniglio) Physical Clusters at low T if the infinite cluster is the lowest energy state How to make the surface more stable than the bulk ? The quest
The case of an attractive potential Cluster Ground State for the 2n-n potential (Lekkerkerker)
ADD HERE SOMETHINGDISNMORE • AND POON......
How to make negative ? Upper Limit Optimal Size Groenewold and Kegel
Molecular Dynamics Data for Repulsive Yukawa Potential Several number densities n
The Optimal Size Controls if the system is going to be a cluster phase or an arrested disordered state (Wigner Glass) Are the simulation data providing support for this picture ?
The T-dependence of S(q) =0.15
A case in which clustering is.... home made ! Star Polymers low f high f
Cluster Phase stabilized by the competition of Short-Ranged and Repulsive-Long-Ranged interactions The disordered arrest problem has been expressed in term of glass transition of cluster Colloidal Gels = Wigner Glasses