Supervariate Ceramics : Gelatinous and Monolithic Ceramics Fabricated under Ambient Conditions

Ceramics are normally fabricated by firing compacted raw powders at high temperatures. Herein, a general mechanism for directly fabricating ceramic objects at the centimeter scale from ceramic gels at room temperature and ambient pressure is disclosed—all by simply mixing precursor solutions of multiple metal salts/ionic compounds to afford a supervariate system. Upon drying, the supervariate ceramic gels convert into monolithic ceramic materials to deliver excellent mechanical properties, e.g., a hardness/reduced elastic modulus (H/E_r) of 1.2/26 GPa. Furthermore, the room temperature-dried ceramics are tolerant to high-temperature annealing at 1500 ºC, staying intact and achieving further enhanced H/E_r (e.g., 11.7/132 GPa). By utilizing the supervariate strategy, ceramics can be casted or molded like metals or polymers under mild conditions, offering great convenience to achieve desirable mechanical performances and functionalities.