Range Domain Order

An as yet unresolved discrepancy between these two studies should be pointed out. Keller et al. (1970) observed cylinders for a material containing 25% polystyrene even after annealing on the other hand, McIntyre and Campos-Lopez observed spheres for a material containing a higher concentration of polystyrene, 38.5 %. In view of the work of Meier (1969) and others, spheres should have been obtained at the lower concentration, and cylinders at the higher. (See Section 4.7.) It is possible that the inversion of phase shape may be related to the fact that the specimens studied by Keller et al. (1970) were extruded rather than cast certainly the shear forces present in extrusion can themselves affect particle shape (VanOene, 1972) (see Section 9.6). 

---

This requirement, in conjunction with typical block molecular weights, means that the desired Q range falls within that wherein the Bragg peaks from the long range domain order are dominant, consequently subtraction of the undoped background has to be carried out with care. 

Grazing incidence excitation of a fluorescent probe in a phospholipid monolayer can also be used to indicate order. The collective tilt of the molecules in a domain inferred from such measurements is indicative of long-range orientational order [222]. 

When comparable amounts of oil and water are mixed with surfactant a bicontinuous, isotropic phase is formed [6]. This bicontinuous phase, called a microemulsion, can coexist with oil- and water-rich phases [7,1]. The range of order in microemulsions is comparable to the typical length of the structure (domain size). When the strength of the surfactant (a length of the hydrocarbon chain, or a size of the polar head) and/or its concentration are large enough, the microemulsion undergoes a transition to ordered phases. One of them is the lamellar phase with a periodic stack of internal surfaces parallel to each other. In binary water-surfactant mixtures, or in... 

The simulations yielded configurations, for which we have calculated the orientational correlation function G(r). This quantity enabled calculation of (a) the average coherence length and (b) the range of ordering. Within a volume which we refer to as a domain, the rod-like objects are... 

---