@article{FilimonKopfSchmidtetal.2011,
  author    = {Filimon, Marlena and Kopf, Ilona and Schmidt, Dietrich A. and Bruendermann, Erik and R{\"u}he, J{\"u}rgen and Santer, Svetlana and Havenith, Martina},
  title     = {Local chemical composition of nanophase-separated polymer brushes},
  series = {Physical chemistry, chemical physics : a journal of European Chemical Societies},
  volume    = {13},
  journal   = {Physical chemistry, chemical physics : a journal of European Chemical Societies},
  number    = {24},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1463-9076},
  doi       = {10.1039/c0cp02756a},
  pages     = {11620 -- 11626},
  year      = {2011},
  abstract  = {Using scattering scanning nearfield infrared microscopy (s-SNIM), we have imaged the nanoscale phase separation of mixed polystyrene-poly(methyl methacrylate) (PS-PMMA) brushes and investigated changes in the top layer as a function of solvent exposure. We deduce that the top-layer of the mixed brushes is composed primarily of PMMA after exposure to acetone, while after exposure to toluene this changes to PS. Access to simultaneously measured topographic and chemical information allows direct correlation of the chemical morphology of the sample with topographic information. Our results demonstrate the potential of s-SNIM for chemical mapping based on distinct infrared absorption properties of polymers with a high spatial resolution of 80 nm x 80 nm.},
  language  = {en}
}
@article{SchuhLomadzeRueheetal.2011,
  author    = {Schuh, Christian and Lomadze, Nino and R{\"u}he, J{\"u}rgen and Kopyshev, Alexey and Santer, Svetlana},
  title     = {Photomechanical degrafting of Azo-functionalized Poly(methacrylic acid) (PMAA) brushes},
  series = {The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces \& biophysical chemistry},
  volume    = {115},
  journal   = {The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces \& biophysical chemistry},
  number    = {35},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1520-6106},
  doi       = {10.1021/jp2041229},
  pages     = {10431 -- 10438},
  year      = {2011},
  abstract  = {We report on the preparation and characterization of photosensitive polymer brushes. The brushes are synthesized through polymer analogous attachment of azobenzene groups to surface-attached poly(methacrylic acid) (PMAA) chains. The topography of the photosensitive brushes shows a strong reaction upon irradiation with UV light. While homogeneous illumination leaves the polymer topography unchanged, irradiation of the samples with interference patterns with periodically varying light intensity leads to the formation of surface relief gratings (SRG). The height of the stripes of the grating can be controlled by adjusting the irradiation time. The SRG pattern can be erased through solvent treatment when the periodicity of the stripe pattern is less than the length of the fully stretched polymer chains. In the opposite case, photomechanical scission of receding polymer chains is observed during SRG formation, and the inscribed patterns are permanent.},
  language  = {en}
}
@article{LomadzeKopyshevRueheetal.2011,
  author    = {Lomadze, Nino and Kopyshev, Alexey and R{\"u}he, J{\"u}rgen and Santer, Svetlana},
  title     = {Light-Induced chain scission in photosensitive polymer brushes},
  series = {Macromolecules : a publication of the American Chemical Society},
  volume    = {44},
  journal   = {Macromolecules : a publication of the American Chemical Society},
  number    = {18},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0024-9297},
  doi       = {10.1021/ma201016q},
  pages     = {7372 -- 7377},
  year      = {2011},
  abstract  = {We report on a process inducing photomechanical fracture of chemical bonds in photosensitive PMAA polymer brushes. The photosensitive PMAA polymer brushes were prepared by covalent attachment of azobenzene groups to poly(methylacrylic acid) (PMAA) chains generated by surface-initiated polymerization. While homogeneous irradiation leaves the polymer topography unchanged, the azo-PMAA brushes show a strong response upon irradiation with UV interference patterns. The photoisomerization process in the surface-attached polymer films results in the irreversible formation of surface relief gratings (SRG), which are strongly enhanced upon washing with a good solvent for the polymer. The photomechanical forces during mass transport induced by the irradiation lead to the scission of covalent bounds and accordingly to a degrafting of the polymer chains in areas where the polymer is receding from. It is observed that the number of ruptured chains depends strongly on the amount of azo side chains in the polymer.},
  language  = {en}
}
@article{FilimonKopfBalloutetal.2010,
  author    = {Filimon, Marlena and Kopf, Ilona and Ballout, Fuad and Schmidt, Dietrich A. and Bruendermann, Erik and R{\"u}he, J{\"u}rgen and Santer, Svetlana and Havenith, Martina},
  title     = {Smart polymer surfaces : mapping chemical landscapes on the nanometre scale},
  issn      = {1744-683X},
  doi       = {10.1039/C0sm00098a},
  year      = {2010},
  abstract  = {We show that Scattering Infrared Near-field Microscopy (SNIM) allows chemical mapping of polymer monolayers that can serve as designed nanostructured surfaces with specific surface chemistry properties on a nm scale. Using s- SNIM a minimum volume of 100 nm x 100 nm x 15 nm is sufficient for a recording of a "chemical'' IR signature which corresponds to an enhancement of at least four orders of magnitudes compared to conventional FT-IR microscopy. We could prove that even in cases where it is essentially difficult to distinguish between distinct polymer compositions based solely on topography, nanophase separated polymers can be clearly distinguished according to their characteristic near-field IR response.},
  language  = {en}
}
@article{SchlemmerBetzBerchtoldetal.2009,
  author    = {Schlemmer, Christian and Betz, Wolfgang and Berchtold, Bernd and R{\"u}he, J{\"u}rgen and Santer, Svetlana},
  title     = {The design of thin polymer membranes filled with magnetic particles on a microstructured silicon surface},
  issn      = {0957-4484},
  doi       = {10.1088/0957-4484/20/25/255301},
  year      = {2009},
  abstract  = {In this paper we present the fabrication and characterization of polymer nanomembranes filled with magnetic nanoparticles and attached covalently to a periodic array of free-standing silicon walls, forming an array of micro- channels with the membrane as a cover. The width of a micro-channel of about 1.4 mu m sets a characteristic lateral size and the thickness of the polymer membrane ranges between 100 and 300 nm. The membrane is made of cross-linked hydrophilic polymers possessing a Young's modulus of only a few MPa. The presence of the magnetic particles within the membrane makes the film responsive to external magnetic fields. The mechanical and magnetic properties of the membrane are characterized by bulge tests and with atomic force microscopy.},
  language  = {en}
}