Hydrophobic or hydrophilic? Aero-gallium nitride is both

Physics World  February 6, 2019
Biological cell membranes are made up of phospholipid building blocks that both attract and repel water. An international team of researchers (Germany, Moldova, Australia, Italy, UK) developed a nanomaterial exhibiting hydrophobic and hydrophilic properties using nanoscopically thin membranes of gallium nitride shaped as hollow microtetrapods, called aerogalnite (AGaN). The material is extremely porous, mechanically flexible, stretchable, and exhibits hydrophilicity under tension and hydrophobicity when compressed against water. Self-assembling the AGaN tetrapods on water enabled them to develop self-healing waterproof rafts carrying liquid droplets 500-times as heavy as rafts, and to demonstrate self-propelled liquid marbles. Aerogalnite and its peculiar characteristics are promising for applications in sensorics, microfluidic devices and microrobotics…read more. VIDEO  Open Access TECHNICAL ARTICLE 

The dual hydrophobic–hydrophilic behaviour of the new material.