Page 195 - Book Hosokawa Nanoparticle Technology Handbook

3.8 SIMULATION OF COLLOIDAL DISPERSION SYSTEM FUNDAMENTALS
Firstly desired would be a simulation method for problems for engineering/technological purposes,
nanoparticles in the broad sense, or those including and what point should be improved in the technique.
up to ca. 100 nm, which would provide various While the MD faithfully traces the thermal motion
functional materials by controlling the dispersed of the computational elements, or molecules, the
state or their array structure. The Brownian BD inevitably approximates the thermal motion of
Dynamics (BD) should be appropriate for this pur- nanoparticles for simulating them without sur-
pose because it expresses the thermal Brownian rounding fluid molecules. Thus the comparison of
motion, which become prevailing for particles the simulation results with corresponding experi-
smaller than submicron scale. The BD has been pro- mental ones must show its applicability before it
posed by Ermak [2], and followed by certain num- stands as a “predictive” method. In this sense the
ber of researches after 80s mainly in the field of authors have recently started a study with the BD
physics, but its application to engineering aspects, method applied to the adsorption and order forma-
especially for concentrated dispersion systems, is tion by colloidal nanoparticles adsorbing onto a
insufficient at present. As a result, one cannot know substrate with counter charge [3, 4]. Figure 3.8.2
to what extent the method is effective in solving illustrates some examples: Adsorption process and

Figure 3.8.2
Order formation of mesoscale particles by adsorption onto substrate.

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