Spatially-Regulated Deposition of Quantum Dots on the Patterned Polymer Brush

Abstract

We have demonstrated direct patterning of surface initiator layer (SIL) for Atom Transfer Radical Polymerization (ATRP) using a sol-gel based "ink" containing (p-chloromethyl)phenyltrimethoxysilane and tetraethoxysilane for an inkjet printer. Mechanically/chemically robust and smooth micropatterns of SIL several tens of micrometer in width and 15 nm thickness were directly printed on silicon substrates under mild conditions (open to the atmosphere, at ~28 °C under >60% relative humidity). Subsequent surface-initiated ATRP of glycidyl methacrylate (GMA) under the air atmosphere gave area-selective/stepwise growth of homogeneous polyGMA brushes (pGMA) from the micropatterns of SIL. This area-selective growth of pGMA was also confirmed by a fluorescence microscopy. Because of chemical reactivity of epoxy groups on the grafted pGMA surfaces toward amino-functionalized nanomaterials, CdS/ZnS-alloyed quantum dots were spatially deposited only on the pGMA-covered regions with a complete area-selectivity.