Trace addition of cellulose nanofiber in gel-casting system for structurally controlled porous ceramics towards superior thermal-insulating property

Abstract

In present work, structurally controlled porous hydroxyapatite ceramics are fabricated via a novel and facile gel-casting process with trace addition of cellulose nanofiber (CNF). The pore structure with respects to pore size, shape and open/close porosity is selectively controlled by altering the addition amount of CNF and surfactant, as well as forming time. The origin of pore structure controlling is systemically investigated in the point view of chemical/physical interaction between ceramic powder, CNF as well as dispersant, assisted by detailed characterizations as X-ray computer tomography observation, viscosity analysis, and z-potential analysis. Fabricated porous ceramic bodies exhibit superior low thermal conductivity which opens a new avenue for the wide applications of hydroxyapatite ceramics.