Article Cite This: Macromolecules XXXX, XXX, XXX−XXX
pubs.acs.org/Macromolecules
Water Impact Resistant and Antireflective Superhydrophobic Surfaces Fabricated by Spray Coating of Nanoparticles: Interface Engineering via End-Grafted Polymers Ilker Torun,† Nusret Celik,† Mehmet Hancer,‡ Fırat Es,§ Cansu Emir,∥ Raşit Turan,§ and M. Serdar Onses*,†,⊥ Macromolecules Downloaded from pubs.acs.org by CALIFORNIA STATE UNIV FRESNO on 11/30/18. For personal use only.
†
Department of Materials Science and Engineering, Nanotechnology Research Center (ERNAM) Erciyes University, Kayseri 38039, Turkey ‡ Department of Metallurgical and Materials Engineering, Muğla Sıtkı Koçman University, Muğla 48000, Turkey § Center for Solar Cell Research and Applications (GUNAM), Department of Physics, Middle East Technical University, 06800 Ankara, Turkey ∥ iTechSolar, Middle East Technical University Technopark, 06800 Ankara, Turkey ⊥ UNAM − Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara, Turkey S Supporting Information *
ABSTRACT: Fully transparent and water impact resistant superhydrophobic coatings are of great importance for a range of applications including photovoltaics, photonics, automotive windshields, and building windows. A widely utilized approach to fabricate such coatings involves solution-based deposition of hydrophobic nanoparticles. A central challenge is that these coatings do not simultaneously offer high levels of water repellency, perfect transparence, and water impact resistance. Here we demonstrate that end-grafted polymers present excellent interfaces for spray-coated hydrophobic nanoparticles and enable fabrication of water impact resistant and antireflective superhydrophobic coatings (SHPARCs). Depending on the backbone chemistry and thickness, end-grafted polymers uniquely interacted with the fluorinated nanoparticles, resulting in nanostructured films that provided reduction of reflective losses and protection from the impact of water droplets. Counterintuitively, substrates modified with end-grafted hydrophilic polymers exhibited high water impact resistance: the sliding angle of SHPARC on 12 nm thick end-grafted poly(ethylene glycol) layer was 170° and sliding angle
