Physical properties dilation

A system with a complex microstructure is a critical system if its large-scale physical properties depend only on very few macroscopic parameters, and if their dependence with respect to these parameters presents universal features. In the critical domain, a critical system depends (normally) on only one length, and at the critical point it becomes completely scale invariant, i.e. invariant for space dilatations ... 

Because protein-ba sed foams depend upon the intrinsic molecular properties (extent and nature of protein-protein interactions) of the protein, foaming properties (formation and stabilization) can vary immensely between different proteins. The intrinsic properties of the protein together with extrinsic factors (temperature, pH, salts, and viscosity of the continuous phase) determine the physical stability of the film. Films with enhanced mechanical strength (greater protein-protein interactions), and better rheological and viscoelastic properties (flexible residual tertiary structure) are more stable (12,15), and this is reflected in more stable foams/emulsions (14,33). Such films have better viscoelastic properties (dilatational modulus) ( ) and can adapt to physical perturbations without rupture. This is illustrated by -lactoglobulin which forms strong viscous films while casein films show limited viscosity due to diminished protein-protein (electrostatic) interactions and lack of bulky structure (steric effects) which apparently improves interactions at the interface (7,13 19). 

Physical Effects of Filler. Dispersion of any hard particulate matter in a soft matrix will yield a composite with quite different properties. The two main causes for these effects are load sharing of the filler particles and strain dilatation of filled elastomers. 

As has been noted in Sect. 8.1 the renormalization group is closely connected to the group of spatial dilatations. We therefore first discuss some general properties of the dilatation group, translating the results to physics in the next sections. 

Rate-state models assume that the friction depends on the rate and a small number of state variables that describe the properties of the interface. Different physical interpretations of the microscopic properties that these state variables describe have been proposed, such as the amount of dilation at the interface [46] or the degree of crystallinity of an intervening film [47,48]. Most approaches leave the nature of the state variable unspecified and merely assume that it depends on some average of recent velocities [49 51]. The coefficients of... 

Bourbon, D., Y. Kamiya, and K. Mizoguchi, Sorption and dilation properties of poly(para-phenylene sulfide) uruJer high-pressure carbon-dioxide. Journal of Polymer Science Part B-Polymer Physics, 1990. 28(11) p. 2057-2069. 

The two basic types of mechanical deformation, from a physical and molecular standpoint, are shear and dilatation. The experimental methods described in the preceding three chapters yield information primarily about shear only in extension measurements on hard solids does a perceptible volume change influence the results. By combining shear and extension measurements, the bulk properties can be calculated by difference, as for example in creep by equation 55 of Chapter 1, but the subtraction is unfavorable for achieving a precise result. Alternatively, bulk properties can be measured directly, or they can be obtained by combining data on shear and bulk longitudinal def ormations (corresponding to the modulus M discussed in Chapter 1), where the subtraction does not involve such a loss of precision. Methods for such measurements will now be described. They have been reviewed in more detail by Marvin and McKinney. ... 

There are various direct measurements of micellar solutions giving access to the dynamics rate constants - mainly based on disturbance of the equilibrium state by imposing various types of perturbations, such as stop flow, ultrasound, temperature and pressure jump [14,15[. This aspect is also not further elaborated here we focus instead on the impact of micellar kinetics on interfacial properties, to demonstrate that tensiometry and dilational rheology are suitable methods to probe the impact of micellar dynamics. The first work on this subject was published by Lucassen already in 1975 [16[ and he showed that the presence of micelles in the bulk have a measurable impact on the adsorption kinetics, and hence on the dilational elasticity, when measured by a longitudinal wave damping technique. Subsequent work demonstrated the effect of micellar dynamics on non-equilibrium interfacial properties [17-29]. The physical idea of the impact of micellar dynamics on the dynamic properties of interfacial layers can be easily understood from the scheme given in Figure 13.1. 

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