Stabilization of oil-in-water emulsions via short-chain-amine-modified cordierite platelets: A route to high-strength porous ceramics

This study develops a new type of lightweight, high-strength porous cordierite ceramic with isolated spherical pore structures by using oil-in-water (O/W) emulsions stabilized by synthesized submicron cordierite platelets as precursors. The particle hydrophobicity required for oil-water interface stabilization originates from in-situ adsorption of short-chain amines on particle surfaces. The type of dispersed system formed via mechanical shearing depends on amine concentrations and alkyl chain lengths. While stable O/W emulsions are formed at higher amine concentrations, the threshold for complete emulsification decreases with increasing alkyl chain length. Increasing amine concentration improves emulsion viscosity and stability, ultimately reducing the average droplet size. The preferred orientations of cordierite platelets at the oil-water interface and in the continuous phase lead to strong multilayered pore walls and dense struts during sintering, endowing the 65%-porous ceramic bodies with a compressive strength tunable by pentylamine concentration and up to 69.2 MPa.