Polyelectrolyte Brushes as Ink Nanoreservoirs for Microcontact Printing of Ionic Species with Poly(dimethyl siloxane) Stamps

In this work a new variation of microcontact printing is described, which is used to transfer chemical patterns onto different substrates. The approach is based on the use of conventional elastomeric stamps modified with polyelectrolyte brushes. It is demonstrated that, by using stamps modified with brushes acting as preconcentrating/sorbent nanolayers, it is possible to control the uptake of aqueous inks containing ionic species. This controlled uptake can be easily used for site‐selective delivery of the loaded species by means of soft lithography. The potential of this approach is demonstrated by creating patterned counterion domains in a flat polyelectrolyte brush and by promoting a site‐selective metallization through galvanic displacement reactions with reactive species. Polyelectrolyte‐brush‐coated stamps can be used in the controlled delivery of a range of ionic species. This phenomenon has been exploited to locally collapse polymer brushes and to generate metallic micropatterns via galvanic displacement reactions (see figure).