Supermolecular fluids

Parker JL, Richetti P, Kekicheff P, Sarman S (1992) Direct measurement of structural forces in a supermolecular fluid. Phys Rev Lett 68 1955-1958... 

Maher JY, Goidburg WI, Pohl DW, Lanz M (1984) Phys Rev Lett 53 60 Goh MC, Goldburg WI, Knobler CM (1987) Phys Rev Lett 58 1008 Goldburg WI (1987) lit Safran SA, Clark NA (eds) Physics of complex and supermolecular fluids. John Wiley, New York, p 475... 

For a survey of several areas in complex fluids see Physics of Complex and Supermolecular Fluids, eds. S. A. Safran and N. A. Clark (Wiley, New York, 1987), Structure and Dynamics of Strongly Interacting Colloids and Supramolecular Aggregates in Solution, eds. S. Chen, J. S. Huang, and P. Tartaglia (Kluwer, Boston, 1992). 

Physics of Complex and Supermolecular Fluids, Safran, S. Clark, N. A., Eds. Wiley-Interscience, New York, New York, 1987 p. 65. 

Safran SA, Clark NA (eds) (1987) Physics of complex and supermolecular fluids. Wiley, New York... 

The introduction of large gas phase volumes into the polymer alters the physical characteristics of the material volume weight, permeability to fluids and gases, and physico-mechanical properties. Moreover, the properties of the polymer matrix itself are changed (owing to orientation effects, supermolecular structure of the polymer in the walls, ribs and tension bars of cells), which drives up the value of specific strength on impact, and results in anisotropy of elasticity. 

This situation changed dramatically in 1996 with the discovery of strong electro-optic (EO) activity in smectics composed of bent-core, bowshaped, or banana-shaped achiral molecules.4 Since then, the banana-phases exhibited by such compounds have been shown to possess a rich supermolecular stereochemistry, with examples of both macroscopic racemates and conglomerates represented. Indeed, the chiral banana phases formed from achiral or racemic compounds represent the first known bulk fluid conglomerates, identified 150 years after the discovery of their organic crystalline counterparts by Pasteur. A brief introduction to LCs as supermolecular self-assemblies, and in particular SmC ferroelectric and SmCA antiferroelectric LCs, followed by a snapshot of the rapidly evolving banana-phase stereochemistry story, is presented here. 

Collision-induced absorption is a well developed science. It is also ubiquitous, a common spectroscopy of neutral, dense matter. It is of a supermolecular nature. Near the low-density limit, molecular pairs determine the processes that lead to the collision-induced interactions of electromagnetic radiation with matter. Collision-induced absorption by non-polar fluids is particularly striking, but induced absorption is to be expected universally, regardless of the nature of the interacting atoms or molecules. With increasing density, ternary absorption components exist which are important especially at the higher temperatures. Emission and stimulated emission by binary and higher complexes have also... 

Specialists and advanced graduate students concerned with the basic principles or applications of the infrared spectroscopy of dense fluids, or with the fundamental interactions of supermolecular complexes with electromagnetic radiation, will find this a valuable text and general reference. 

The Influence of Temperature on the Viscoelastic Properties. The viscoelastic properties of the dilute surfactant systems depend on the temperature of the solutions strongly. Figure 8 shows the values for the storage modulus G as a function of the angular frequency at different temperatures for a 20 mM solution of CPySal. The elastic properties of the surfactant solutions decrease with increasing temperature. The solution equilibrated at 35 C shows only little elasticity in the frequency range below 1 Hz and at temperatures of 50 C the solutions behave as Newtonian fluids. The supermolecular structures which are present in these solutions and which are responsible for the viscoelastic properties seem to be completely destroyed under these experimental conditions. 

The analysis of the most important external factors involved in the fluid polymer processing, namely the temperature and the mechanical forces, reveals that the macromolecules can suffer thermal and mechanical stresses whose values can sometime exceed the limit of the fluid state existence. Irreversible transformations of the fluid molecular and supermolecular structures occur. When the mechanical factor prevails, the transformation is the mechanochemical nature. 

Rubber compounds tend to give a smooth extrudate without melt fracture. Also, the magnitude of the extrudate swell is smaller than that of the gum ruhher [5]. Compounds consist of supermolecular flow units, which form during compounding. No fracture occurs at the entrance of the capillary because it is a fluid material. Consequently, the memory of deformation at the entrance is smaller than that of gmn rubber, which is an elastic material. This explains the low extrudate swell. The supermolecular flow units are carbon black with adsorbed rubber and comminuted particles of the matrix rubber. There is some resemblance between the rheology of rubber compoimds and that of PVC both are in a particulate state during flow [5]. 

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