Density functional theory study of azobenzene derivatives as potential materials for wettability switching

Abstract

In this study, density functional theory (DFT) is employed to analyze the properties of 16 azobenzene derivatives,
assessing their potential as wettability switching materials. Inspired by K. Ichimura’s 2001 report on
azobenzene-modified surface wettability, we explore the impact of photoisomerization-induced changes in
molecular dipole moments between cis and trans configurations of different azobenzene derivatives. In parent
azobenzene molecule this process transforms non-polar molecule into a more hydrophilic cis form. The control
of surface wettability holds immense potential across diverse domains, such as industry, medicine, microbiology,
electronics, and materials science. By harnessing this control, we can unlock the potential to create
innovative materials, elevate functionality, and boost efficiency. It enables to enhance product performance,
improve adhesion, and achieve precision in liquid handling. Our investigation delves into the structural,
electronic, and molecular aspects of all studied molecules utilizing the hybrid B3LYP functional with
DFT-D3 dispersion correction and a 6-31++G(d, p) basis set, presenting promising azo-type structures for
surface wettability manipulation. Two azobenzene derivatives emerge as potential candidates, exhibiting
transformations during cis-trans photoisomerization — one towards increased hydrophilicity and the other in
the opposite direction.