Flow-induced structuring

Nakatani AI, Dadmun MD (eds) (1995) Flow-induced Structure in Polymers, ACS Symp Ser 597, American Chemical Society... 

P. D Haene, J. Mewis, and G.G. Fuller, Scattering dichroism measurements of flow-induced structure of a shear thickening suspension, J. of Col. and Interf. Sci 156, 350 (1993). 

While rheological measurements are wonderfully quantitative, they are usually poor qualitative probes of fluid structure. This is because in rheological experiments, the structural changes responsible for the measured relaxation behavior remain hidden. Thus, rheometry is often most useful when supplemented by other experimental methods that characterize fluid structure and flow-induced structural changes. Some of the most useful methods are microscopy, light, x-ray, and neutron scattering, and polarimetry. 

Takahashi Y, Noda I (1995). In Flow Induced Structure in Polymers, Nakatani AI, Dadmun MD (eds), ACS Symposium Series 597, American Chemical Society, Washington, DC. Takahashi Y, Kurashima N, Noda I, Doi M (1994). J Rheol 38 699. 

Studies of the orientation phenomena in injection molding have shown that irrespective of the molding conditions and type of thermoplastic, molecular orientation is higher near the walls and decreases toward the interior. " " Low crystallinity and flow-induced structures have been observed near the walls for injection molded isotactic polypropylene parts. " High modulus materials have also been obtained with some injection molding techniques. " ... 

SH for CPNCs containing a small amount of clay to the presence of house-of-cards structures, resulting in the yield behavior. The flow-induced structures were different in shear and elongation. 

Appendix. Plastic-flow-induced structural alterations the relation between flow dilatations of free volume and liquid-like material... 

Wheeler EK, Eischer P, Puller GG (1998) Time-periodic flow induced structures and instabilities in a viscoelastic surfactant solution. J Non-Newt Fluid Mech 75(2-3) 193-208... 

A difference in the defect structure of PBLG in BA versus PBLG in m-cresol may prove to be the underlying cause of this alignment behavior. Regardless, the results exemplify the need for a broader choice of model liquid crystalline polymer solutions when examining the flow-induced structure in liquid crystalline polymer solutions. Moreover, a more complete understanding of the important parameters that affect the flow of LCP solutions is needed so that a more universal theory can be developed which can predict flow behavior of non-model LCP solutions. 

Burghardt, W. Bedford, B. Hongladarom, K. Mahoney, M. in Flow Induced Structures in Polymers Nakatani, A.I., Daidmun, M.D., Eds., ACS Symposium Series 597, American Chemical Society Washington, D.C., 1995. 

S0ndergaard, K., Lyngaae-Jprgensen, J. In Flow Induced Structure in Polymers Nakatani, A. I. Dadmun, M. D., Eds. ACS Symposium Series 597 American Chenucal Society Washington, DC, 1995 pp. 169-187. 

Equation 10.5.2 fits available data (see Figure 10.2.3 and de Kruif et al., 1985) within measurement accuracy. Higher order expansions do not seem to be usefiil because they are applicable over increasingly small concentration regions. Various approaches are being used to compute viscosities at higher concentrations. The hydrodynamics for multiple particle interactions become very involved. They have been studied mainly by simulation (e.g., Brady and Bossis, 1988 Phillips et al., 1988). Other workers have used an approach based on nonequilibrium thermodynamics (Russel and Cast, 1986). Finally, Woodcock (e.g., 1984) uses molecular dynamics simulations, ignoring the medium viscosity, to calculate the flow-induced structure and then the viscosity. 

Vermant J, Solomon MJ (2005) Flow—induced structure in colloidal suspensions. J Phys Condens Matter 17 187-216... 

The previous discussion relates to the initial state of the flow-induced structures, which form the fingerprint for the final structures enhanced point nucleation creates a more fine-grained structure than the equivalent quiescent structure, mild stretch will lead to internal orientation of the spherulites while higher stretch levels will create fibrils (shish) on which lamellae (kebabs) will grow. The initial nucleated structure is, therefore, of utmost importance for the evolving post-shearing structure. 

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