Gas-Solution Interface Technique as a simple method to produce inorganic microtubes with scroll morphology

Over the past decade, numerous studies have dealt with new properties of inorganic nanomaterials with improved characteristics due to a particular morphology, and new facile methods to produce such materials have been reported. Inorganic microtubes can be designed for multifunctional materials with highly specific surface area. These microtubes can act as individual on-chip components of miniature devices or off-chip micro-machines. The paper first discusses the main regularities of the reactions at the gas-solution interface and then goes on to present the basic principles of the Gas-Solution Interface Technique (GSIT), thus demonstrating a new way of facile synthesis of inorganic rolled-up microtubes. A distinctive feature of the technique is the formation of a gradient solid layer on the surface of the aqueous solution as a result of the gaseous and liquid reagents interaction. When dried in the air, this thin layer is capable of self-folding into microtubes with specific morphology. The paper considers the specific features of microtubes obtained by GSIT from numerous classes of inorganic compounds, including oxides, hydroxides, sulfides, fluorides. Further areas of possible practical applications of GSIT microtubes are discussed. The prospects of future development of the GSIT are outlined.