Evolution of throttle-channel dual pores in YSZ ceramic monolith through in situ grown nano carbon wedges

Interconnectivity of the pore channels and their size distribution in a ceramic monolith influence the flow dynamics of permeating fluid. This work proposes an innovative pore-forming mechanism that begins with the growth of poly(p-phenylene terephthamide) (PPTA) in a ceramic green body of yttrium-doped zirconia (YSZ). The spatial confinement drove the formation of PPTA through an extrusion manner, resulting in submicron PPTA rods embedded in the matrix. Theses rods were carbonized under Ar between 800 and 1200 °C for 2 h before oxidizing atmosphere was introduced to facilitate their removal and sintering of YSZ. This dwelling temperature is crucial to the pore size distribution in the sintered ceramic due to the chemical and dimensional changes of the carbon wedges and YSZ grains. The sintered ceramic is characterized by interconnected throttle-to-channel pore structure, which manifested a marked improvement on fluid permeability and a capability of stretching viscous fluids passing through it.