LAUSR

Fabrication of carbonaceous bulk bodies via colloidal aqueous routes has some problems. So it was intended to fabricate carbonaceous bodies through the gelcasting method. Effective parameters of this process (stability of graphite in water-based solutions studied in different solid loadings, pH values, and tween 80 additive) have been investigated. Also, other methods for modifying rheological behavior like surface oxidation and adding nano-silica particles have been considered. It has been seen that with the use of graphite as the carbon source in quantities equal to 45 and 50 wt%, proper suspension can be made and stability of the suspension improves with adding 2.5 wt% nano-silica particles and 6 wt% twin 80. For preparing these suspensions, the addition of nano-silica particles in the mentioned quantity is essential. Based on experiments, above-mentioned parameters cause higher mechanical strength in comparison with carbon lack bodies with identical parameters. Microscopically experiments show polymeric network constructed in raw bodies. Graphite suspensions fabricated in this research have proper rheological behavior and water molecules are remain on the surface of particles. But, because of the hydrophobic nature of graphite, it's wetting ability is weak. This property can be modified with adjusting pH value between 10 and 11, the addition of twin 80 (6 wt% based on solid loading) and the most important, nano-silica sol (2.5 wt%). Presence of acrylamide polymeric network is obvious in microscopic images. So, complete gelcasting process has been done successfully.