Insights into the flow behaviour of the AR24 mesophase pitch and nanoparticle-doped AR24 mesophase pitch during infiltration into particulate porous preforms

Abstract

Synthetic mesophase pitches, extensively used as graphite precursors, manifest particular fluid-dynamic properties given their liquid crystal nature. Their recent use in infiltration processes to manufacture graphite-based monolithic and porous materials demands the study of their physical properties, mainly viscosity and contact angle, under dynamic conditions. In this work a new infiltration device was conceived and constructed to measure the infiltration kinetics of the AR24 naphthalene-based mesophase pitch and TiC nanoparticle-doped AR24 mesophase pitch into preforms of packed NaCl particles. The experiments allowed activation energies for viscosity to be obtained, along with pseudo-equilibrium and advancing contact angles.

In situ Ti assisted graphitization approach for the preparation of graphite foam with light weight and high thermal conductivity

“…As the temperature continued to rise, the presence of Ti as the nucleation site could promote the evaporation of low-molecularweight units in the ARMP, which caused ARMP to condense into macromolecules, resulting in an increase in viscosity. 52 Variations in viscosity might contribute to differences in the behavior of stretching during the bubble formation and growth phases, and consequently affect the evolution of cell structures. 53,54 When the Ti content was low, the mixture showed poor elasticity and facilitated bubbles development, leading to enlarged open-cell sizes in the low viscosity.…”