Blowing Route towards Advanced Inorganic Foams
In this account, we review a blowing strategy for manufacturing cellular solid materials. Solid foams have been important engineering materials since the early 20th century, and are newly explored for versatile functionalities in recent decades. The blowing route is a practicable technique to yield foams, compatible with scalable industry. With rising 2D materials, the blowing protocol has been applied to synthesizing foams built of 2D materials or nanosheets for the past several years. It is worthy outlining the fundamentals of foaming processes, which include geometry, statics, kinetics, and dynamics in foaming, to study topological constraint, equilibrium configuration, nucleation-growth, and structural evolution, respectively. They are essential for controlling the production towards high-quality foams. Recent progress on foams derived via blowing methods is surveyed, covering traditional foams and newly developed inorganic foams. Advanced foams of boron-carbon-nitrogen systems, e.g. carbon foams, 3D graphene foams, carbon nitride foams, boron nitride foams, doped and hybrid foams, are highlighted and elaborated individually. The relationships between structure, property, and functionality in foam structures are additionally discussed, and the constructive applications of foams are investigated.