*3.1.2. Celis model*

Guglielmi model triggered the development of other codeposition theories by Celis, and his co-workers. They predicted the co-deposited particles content in the matrix. According to the Celis model the inert particles approach towards the cathode in a specific sequence: (1) the adsorption of ionic cloud surrounding the particle surface, (2) the force of convection currents in electrolyte also supports the particles incorporation partly, (3) the diffusion kinetics of particles across the electric double layer, (4) the adsorption of the inert particles and the absorption of ionic cloud onto the cathode, and (5) the decrease in adsorbed ionic content and their embedment in the metal coating (Fig. 3).

**Figure 3.** Electric double layer around the ceramic particle showing the ionic concentration and generated potential difference as a function of the distance from the charged particle suspended in electrolyte.[51]

There are various other codeposition models such as for non-Brownian motion of particles in the bath.[52, 53] Although the various developed codeposition models are important tools in the nanocomposite fabrication yet. these models are not perfect for the understanding the influences of process parameters on the codeposition rate in the metal matrix without any experimental data.
