Mono-disperse colloidal particles suspensions

Reflux for 30 minutes. The color of the suspension will change from a dark blue to a red as the mono-disperse colloidal gold particles are formed. 

When a dilute suspension of sufficiently large, mono-disperse, spherical particles is irradiated with white light, vivid colors appear at various angles to the incident beam. The angular positions of the spectra depend on m and D, hence they may be used to determine particle size in colloidal suspensions. 

The structure of the consolidated colloid formed is actually more complex than the arrangements illustrated in Fig. 4.33. The microstructures of nearly mono-disperse Si02 particles shown in Fig. 4.34 indicate that the difference in structure formed from the stable suspension and the unstable suspension is not controlled by the way in which the individual particles arrange themselves in the sediment but rather the way they group themselves to form densely packed multiparticle units called domains (52). Figure 4.34c shows that the domains in a consolidated... 

In a practical colloidal suspension, the particle always has a size distribution, and cannot be considered as a mono-disperse system. In this case, a method for estimation of the maximum packing fraction on the basis of the particle size distribution information would be very useful. A mathematical expression, originally for binary mixtures, was proposed [30].to estimate the maximum packing fraction, for any particle system having a size distribution without significant particle interaction... 

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