Versatile approach for grafting polymer brushes to « passivated » silicon substrates using click chemistry

International audienc

A 1,2,3-triazolate lithium salt with ionic liquid properties at room temperature

International audienc

Exchange Process in the Dielectric Loss of Molecular and Macromolecular Ionic Conductors in the Interfacial Layers Formed by Electrode Polarization Effects

International audienc

Versatile approach for grafting polymer brushes to « passivated » silicon substrates using click chemistry

International audienc

A 1,2,3-triazolate lithium salt with ionic liquid properties at room temperature

International audienc

Surface modification with cross-linked random copolymers: Minimum effective thickness

International audienceUltrathin films of benzocyclobutene (BCB)-functionalized random copolymer with styrene and methyl methacrylate, P(S-r-BCB-r-MMA), with thicknesses ranging from 0 to 10.5 nm, were thermally cross-linked on Si substrates. The penetration of deuterated PMMA (dPMMA) into the P(S-r-BCB-r-MMA) films and the microdomain orientation of PS-b-PMMA diblock copolymers on P(S-r-BCB-r-MMA) coated substrates were investigated by neutron reflectivity (NR) and scanning force microscopy (SFM), respectively. NR measurements on bilayers of dPMMA on cross-linked P(S-r-BCB-r-MMA) showed that the neutron scattering length density (SLD) at the substrate was equal to that of P(S-r-BCB-r-MMA) if the P(S-r-BCB-r-MMA) film was thicker than 5.5 nm. With decreasing thickness of the P(S-r-BCB-r-MMA) film, the SLD at the substrate increased, characteristic of an increasing penetration of the dPMMA. When thin films of PS-b-PMMA diblock copolymer having cylindrical microdomains are placed on surfaces modified with cross-linked films of P(S-r-BCB-r-MMA) thinner than 5.5 nm, the cylindrical microdomains orient parallel to the surface, whereas for thicker films, the microdomains orient normal to the surface. Both of these results indicate that interfacial interactions are screened when the P(S-r-BCB-r-MMA) film is thicker than 5.5 nm