Surface-Grafted Rodlike Polymers: Adaptive Self-Assembled Monolayers and Rapid Photo-Patterning of Surfaces

다국어 초록 (Multilingual Abstract)

<P>We present a new concept of functionalizing solid surfaces using polymeric self-assembled monolayers (PSAM) that are obtained by grafting onto solid surfaces an asymmetric block copolymer composed of a long rodlike block and a short surface-reactive block. Poly(n-hexylisocyanate)-<I>b</I>-poly[3-(trimethoxysilyl)propyl methacrylate] (PHIC-<I>b</I>-PTMSM) is synthesized via a living anionic polymerization and an atom transfer radical polymerization. The new rod–coil block copolymer forms a polymeric self-assembled monolayer (PSAM) through covalent bonding of the sticky PTMSM block and planar adsorption of PHIC rodlike chains onto the substrate surface. The uniform PSAM with a thickness identical to the diameter of the rodlike chain is produced by the immersion coating method in a range of immersion solution concentrations and coating times. The PSAMs present unique properties thanks to the freedom of rotation of the end-grafted rodlike chains. The PSAMs exhibit nematic liquid crystalline ordering when the monolayer is fluidized by solvent vapor. A mixed SAM with a nanodot pattern is obtained by introducing a second coating agent of octadecyltrimethoxysilanes (ODTMS) onto the PSAM-coated substrate. The PSAM is micropatternable using photochemical cleavage of the anchoring blocks by brief exposure to UV. Use of the PSAMs as an additional dielectric layer in P3HT-based field effect transistors (FETs) is also demonstrated.</P><P>Rodlike polymers are covalently tethered to the surface to yield a polymeric self-assembled monolayer (PSAM). Thanks to noncovalent adsorption of planar rods, the PSAMs exhibit unique properties such as liquid crystalline order, the reactivity toward an additional surface-modifying agent to generate a mixed SAM, and the capability of photochemical patterning.</P><P><B>Graphic Abstract</B>
<IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cmatex/2011/cmatex.2011.23.issue-15/cm201138u/production/images/medium/cm-2011-01138u_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cm201138u'>ACS Electronic Supporting Info</A></P>