Micro- and nano-scale polymer-on-polymer stamping of the polyelectrolytes SPS and PDAC

Abstract

Micro-contact printing has emerged as a promising new technique for patterning micron scale features with a wide variety of materials. Most of the materials examined have been small, reactive molecules patterned on surfaces they are chemically attracted to, like thiols on metals or silanes on glass and metal oxides. Our group has introduced a new approach to surface patterning by using polymers to pattern polymeric surfaces. To further expand the options of charged surfaces, we decided to study strong polyelectrolytes, and their optimal stamping conditions when printed onto polymer platforms, particularly multilayer surfaces. The size of the features that could be produced was also examined. The success of printing strong polyelectrolytes onto polymer layers depends on the properties of the ink solution as well as the properties of the polyelectrolyte used. SPS is best printed from a concentrated aqueous solution including a large amount of salt. PDAC can be stamped from either concentrated ethanol based inks or from a dilute aqueous one. The more concentrated ink produces prints faster and more reliably, but causes more damage to the stamps used. PDAC can also be used to print nano-scale features, using a concentrated aqueous ink.