Simple and Scalable Protocol for Producing Hydrophobic Polymer Brushes Beyond Wafer-Scale Dimensions toward Real-Life Applications

Wafer-scale fabrication of polymer brushes has recently attracted considerable attention because of their applicability in a wide variety of real-life applications. In this study, we have demonstrated a simple, facile, and scalable approach of grafting a wide variety of hydrophobic polymer brushes onto organic/inorganic substrates via surface-initiated atom transfer radical polymerization under air (named water-accelerated paint-on SI-ATRP). A mixture of ethanol and water was used as a solvent to demonstrate the water-accelerated SI-ATRP of 12 water-insoluble vinyl monomers having hydrophobic functional (alkyl, aromatic, and perfluoroalkyl) groups. Thanks to the addition of a small amount of water, uniform hydrophobic polymer brushes with sufficient thicknesses (more than 20 nm) could be easily grafted from organic/inorganic substrates covered with surface initiator layers (SILs) in a short reaction time of 5-30 min without any severe experimental conditions. The degree of hydrophobicity of the resulting polymer brush surfaces could be arbitrarily tuned from a relatively hydrophobic (water contact angle (CA): 79 degrees) to a highly hydrophobic (water CA: 119 degrees) state by selecting monomers. In addition, using an optimized water-accelerated paint-on SI-ATRP, we have successfully prepared perfluorinated polymer brushes having excellent liquid repellency, antismudge/self-cleaning, and anti-icing properties on glass slides above wafer-scale dimensions (e.g., about 21 cm x 30 cm, nearly letter size).

Automated summary

This study demonstrated a simple and scalable method of grafting various hydrophobic polymer brushes onto organic/inorganic substrates using water-accelerated paint-on SI-ATRP. Uniform hydrophobic polymer brushes with adjustable levels of hydrophobicity could be easily grafted from substrates in a short reaction time, showing potential for applications in liquid repellency, antismudge/self-cleaning, and anti-icing properties.