title: Reactive microCP on ultrathin block copolymer films: investigation of the microCP mechanism and application to sub-microm (bio)molecular patterning.
abstract: In this paper, the mechanism of the recently introduced soft lithographic patterning approach of reactive microcontact printing on thin substrate-supported polystyrene-block-poly(tert-butyl acrylate) (PS690-b-PtBA1210) films using trifluoroacetic acid (TFA)-inked elastomeric poly(dimethylsiloxane) (PDMS) stamps is investigated in detail. In this approach, solventless deprotection reactions are carried out with very high spatial definition using TFA as a volatile reagent that partitions into the PtBA skin layer. On the basis of a systematic investigation of the process, ink loading was identified as a crucial parameter for obtaining faithful pattern transfer. Using optimized conditions, submicrometer-sized patterns were successfully fabricated. In combination with subsequent wet chemical covalent coupling of various (bio)molecules, reactive microCP is established as an approach to afford positive, as well as negative, images of the features of the stamps used. In addition, the size of the patterned areas was manipulated by exploiting the controlled spreading of the ink; thus, stamps with identical features yield patterns with different sizes, yet identical periodicity, as shown for bovine serum albumin (BSA)-poly(ethylene glycol) patterns. The reactive microCP methodology affords new pathways for submicrometer-scale patterning of bioreactive surfaces.
authors.affiliation: University of Twente, MESA+ Institute for Nanotechnology and Faculty of Science and Technology, Department of Materials Science and Technology of Polymers, P.O. Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Chuan Liang
authors.initials: CL
authors.lastname: Feng
authors.forename: G Julius
authors.initials: GJ
authors.lastname: Vancso
authors.forename: Holger
authors.initials: H
authors.lastname: Schönherr
mesh_terms: D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D004129:Dimethylpolysiloxanes; D011137:Polystyrenes / Q000737:chemistry*; D012828:Silicones; D013499:Surface Properties; D014269:Trifluoroacetic Acid
chemical_list: D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D004129:Dimethylpolysiloxanes; D011137:Polystyrenes; D012828:Silicones; C013830:baysilon; D014269:Trifluoroacetic Acid