Stability and anomalous entropic elasticity of subisostatic random-bond networks.

Fluctuation-stabilized marginal networks and anomalous entropic elasticity.

We study the elastic properties of thermal networks of Hookean springs. In the purely mechanical limit, such systems are known to have a vanishing rigidity when their connectivity falls below a critical, isostatic value. In this work, we show that thermal networks exhibit a nonzero shear modulus G well below the isostatic point and that this modulus exhibits an anomalous, sublinear dependence o...

The role of proline in the elastic mechanism of hydrated spider silks.

This study used thermoelastic measurements to investigate the role of proline in the elastic mechanism of hydrated, spider major ampullate (MA) and flagelliform (FL) silks. Experiments on hydrated MA silk from Araneus diadematus (proline content 16%) reveal that conformational entropy elasticity accounts for about 90% of the elastic force at small extensions, but entropy elasticity drops to abo...

Entropic elasticity of phantom percolation networks

– A new method is used to measure the stress and elastic constants of purely entropic phantom networks, in which a fraction p of neighbors are tethered by inextensible bonds. We find that close to the percolation threshold pc the shear modulus behaves as (p−pc) , where the exponent f ≈ 1.35 in two dimensions, and f ≈ 1.95 in three dimensions, close to the corresponding values of the conductivit...

Temperature - dependent structure , elasticity , and entropic stability of Bi phases on Cu { 111 }

Entropic Elasticity at the Sol-Gel Transition

The sol-gel transition is studied in two purely entropic models consisting of hard spheres in continuous three-dimensional space, with a fraction p of nearest neighbor spheres tethered by inextensible bonds. When all the tethers are present (p = 1) the two systems have connectivities of simple cubic and face-centered cubic lattices. For all p above the percolation threshold pc, the elasticity h...