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

Abstract

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)-b-poly [3-(trimethoxysilyl) propyl methacrylate] (PHIC-b-PTMSM) is synthesized via a living anionic polymerization and an atom transfer radical polymerization. The new rodÀcoil 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.

Photovoltaic Efficiency Enhancement by the Generation of an Embedded Silica‐Like Passivation Layer along the P3HT/PCBM Interface Using an Asymmetric Block‐Copolymer Additive

“…The allyl‐P3HT homopolymer with a number‐average molecular weight ( M n ) of 13 600 g mol −1 and a polydispersity index of 1.09 was synthesized by Grignard reagent‐initiated metathesis polymerization and termination with allylmagnesium bromide 38, 39. The resulting polymer was then converted to the macroinitiator, P3HT‐Br,40 and subsequent atom‐transfer radical polymerization (ATRP) with TMSM using conditions reported previously41 yielded P3HT‐ b ‐PTMSM. The molecular weight ( M n ) of the P3HT‐ b ‐PTMSM was estimated to be 15 200 g mol −1 with the composition of the PTMSM block of 10% by comparing the integration of the 1 H‐NMR spectrum of the block copolymer and the gel‐permeation chromatography (GPC) molecular weight of allyl‐P3HT homopolymer (Supporting Information, Figure S1).…”

Hybrid Silicon‐Based Organic/Inorganic Block Copolymers with Sol–Gel Active Moieties: Synthetic Advances, Self‐Assembly and Applications in Biomedicine and Materials Science

“…[30] Poly(n-hexylisocyanate)-b-poly [3-(trimethoxysilyl)propyl methacrylate] (PHIC 125 -b-PTMSPMA 6,12 )w ere synthesized by Park et al by ac ombination of living anionic polymerization and ATRP. [32] As previously mentioned anionic polymerization of substituted isocyanates leads to rod-like organic block that can be combined with as ol-gelr eactive block. In this publication, HIC was polymerized with sodiumb isphenylamidei nT HF at À98 8Ca nd end-capped with 2-bromoisobutanoyl bromide.…”

“…The synthesis of polymers based on ethylene oxide motif is not only limited to linear structures:m acromolecular engineering has been used to produce miktoarm and H-shapedp olymers based on such motifs.I ndeed, Ngai et al used aP EO-(Br)b-PS macroinitiator to synthesize miktoarm m-PEO 45 -b-PS 25-86 -b-PIPSPMA [25][26][27][28][29][30][31][32][33][34][35] triblock copolymers by bpy/CuBr mediated ATRP of IPSPMA in anisole at 80 8C. The diblock copolymer macroinitiator,n amely PEO-(Br)-b-PS, was synthesized via the esterification of PEO-(OH)-b-PS with 2-bromoisobutyryl bromide in dichloromethanea nd the PEO-(OH)-b-PS diblock copolymers bearing hydroxyl group on the junction point had been previously synthesized by the click reaction between aP EO bearing an azide and hydroxyl group and an a-alkynyl-w-diethylaminopolystyrene.…”

“…The diblock copolymer macroinitiator,n amely PEO-(Br)-b-PS, was synthesized via the esterification of PEO-(OH)-b-PS with 2-bromoisobutyryl bromide in dichloromethanea nd the PEO-(OH)-b-PS diblock copolymers bearing hydroxyl group on the junction point had been previously synthesized by the click reaction between aP EO bearing an azide and hydroxyl group and an a-alkynyl-w-diethylaminopolystyrene. The miktoarm m-PEO 45 -b-PS 25-86 -b-PIPSPMA [25][26][27][28][29][30][31][32][33][34][35] triblock copolymers were obtained with relatively low dispersities of 1.22-1.27 and am olarm ass of up to 22.5 kDa. [46] Pan and co-workersp repared H-shaped PEO-b-PTMSPMA copolymers by using am ultifunctional Br 2 -PEO-Br 2 macroinitiator.…”

“…Concerning the first approach, Ngai and co-workers used silica nanoparticles (21 nm) coated with miktoarm m-PEO 45 -b-PS 25-86 -b-PIPSPMA [25][26][27][28][29][30][31][32][33][34][35] triblock copolymers as Pickering emulsifiers ( Figure 8a). [46] For the hairy nanoparticles grafted with m-PEO 45 -b-PS 25 -b-PIPSPMA 25 ,w hen they were initially dispersed in oil, W/O emulsions werea lwayso btained with particles having collapsed PEO chains but mobile PS chains, while by initially dispersing the particlesi nw ater,O /W emulsions resulted, where the hairy particles had collapsed PS chains and mobile PEO chains.…”