Particles and Colloidal Suspensions

A. Cuinier, La diffusion des rayons X sous les ties faibles angles appliqu a I etude de fines particules et de suspensions colloidales (The diffiision of X-rays under the extremely weak angles appUed to the study of fine particles and colloidal suspension). CR Hebd. Seance Acad. Sci. 206(19), 1374-1376 (1938)... 

The second factor to influence fine particle and colloidal suspension rheology is the interaction force between the particles. (The first factor being the volume fraction of particles.) The sense (attractive or repulsive), range and magnitude of the surface forces all influence the suspension rheological behaviour. 

Sintered metal fibers with filaments of uniform size (2-40 (tm), made of SS, Inconel, or Fecralloy , are fabricated in the form of panels. Gauzes based on thicker wires (100-250 tm) are made from SS, nickel, or copper. They have a low surface area of about 10 m g. Several procedures are used to increase the surface area, for example, leaching procedures, analogous to the production of Ra-Nickel, and electrophoretic deposition of particles or colloid suspensions. The porosity of structures formed from metal fibers range from 70 to 90%. The heat transfer coefficients are high, up to 2 times larger than for random packed beds [67]. 

Silicified microcrystalline cellulose is manufactured by codrying a suspension of microcrystalline cellulose particles and colloidal silicon dioxide so that the dried finished product contains 2% w/w colloidal silicon dioxide. 

The internal chemical coupling C-+C includes homogeneous reactions in a gaseous or aqueous phase, and transport processes driven by chemical forces, such as molecular or ionic diffusion, and those heterogeneous processes related to it that do not involve large-scale transport for example, certain types of surface reactions or interactions between particles in colloidal suspensions (O Melia, Chapter 16, this volume) that are driven primarily by electrochemical forces fall in the class of C->C interactions. 

E, M, Wong, J, E, Bonevich, and P. C. Searson. Growth kinetics of nanocrystaUine ZnO particles from colloidal suspensions. J. Phys. Chem. B, 102 7770-7775, 1998... 

In summary, the model systems discussed in this part were zero-shear suspensions of disk-shaped particles in Newtonian liquids, mica-filled polymeric composites, LCPs and colloidal suspensions. The TCP model offers a good understanding of the flow behavior of exfoliated CPNCs. In the case of intercalated systems similar behavior is expected but is complicated by stress-induced changes in the degree of the dispersion and aspect ratio, as well as other possible modifications, such as the thermal decomposition of intercalant. 

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