Structured superhydrophilic coatings made from aminomalononitrile

Abstract

The motivation for new versatile and biocompatible coatings incites researchers to try to copy solutions developed by living organisms like mussels able to adhere to all kinds of substrates in wet conditions. Another source of inspiration may be found in molecules containing reactive CN groups which have been formed in prebiotic conditions on the early formed Earth. Among such molecules, aminomalonitrile (AMN) has been shown to allow the formation of coatings on all kinds of known materials. In the present investigation, the deposition mechanism of AMN based coatings on silicon, quartz and glass is investigated. It is shown that the film deposition is preceded by a lag phase during which AMN undergoes already a transformation in solution. The obtained coatings undergo a morphological transition from islands to fibrillar structures with a concomitant change in composition and hydrophilicity. A putative structure based on X-ray photoelectron spectroscopy data is proposed for the AMN based films deposited at the solid-water interface.