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This paper presents a bilayer model to account for surface effects on the wrinkling of ultrathin polymer films. Assuming a surface layer of finite thickness, effects of surface properties on the critical strain, the equilibrium wavelength, and the wrinkle
Brian H. Clare, Kirill Effimenko, Daniel A. Fischer, Jan Genzer, Nicholas L. Abbott
We report the formation of continuous spatial gradients in the density of grafted semifluorinated chains on silicon oxide surfaces by vapor phase diffusion of semifluorinated silanes. We quantify the orientations of a nematic liquid crystal (LC) on these
L R. Pattison, A Hexemer, E. J. Kramer, Sitaraman Krishnan, P Petroff, Daniel A. Fischer
The temperature-dependent alignment of semiconducting liquid crystalline fluorene-thiophene copolymer (F8T2) thin film surfaces was investigated using the near-edge X-ray absorption fine structure (NEXAFS) technique. Partial electron yield spectra were
Christopher Stafford, J Y. Kim, D Kawaguchi, Gareth Royston, Martin Chiang
We are developing a measurement platform, based on the edge lift-off test geometry, geared towards combinatorial and high-throughput (C&HT) assessment of interfacial reliability in thermally cured epoxy materials. A critical parameter space to be explored
Kristen H. Brosnan, G L. Messing, Richard J. Meyer, Mark D. Vaudin
Textured (1-x)(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT) ceramics obtained by the templated grain growth (TGG) process a significant fraction of the piezoelectric properties of the Bridgman growth single crystals at a fraction of the cost. These materials could have
Elizabeth A. Wilder, Shu Guo, Sheng Lin-Gibson, Michael J. Fasolka, Christopher Stafford
We present a new method for measuring the modulus of soft polymer networks (E 10 MPa).This metrology utilizes compression-induced buckling of a sensor film applied to the surface of the specimen,where the periodic buckling wavelength, assessed rapidly by
The effects of co-monomer composition and irradiation time on material properties and cell response were determined using high-throughput and combinatorial methods. 2-Dimensional gradient samples varying in monomer composition and light exposure time were
A study is made of median crack evolution in brittle coatings subjected to sharp contacts. A model bilayer system consisting of a glass plate bonded to a polycarbonate base, with a Vickers pyramid as indenter, is used to demonstrate the evolution in situ
Forrest A. Landis, J S. Stephens, James A. Cooper, Sheng Lin-Gibson
Model tissue engineering scaffolds based on photocurable resin mixtures with sodium chloride have been prepared for optical imaging studies of cell attachment. A photo-activated ethoxylated bisphenol-A dimethacrylate was mixed with sieved sodium chloride
L A. Bailey, Matthew Becker, J S. Stephens, Nathan D. Gallant, Christine M. Mahoney, N Washburn, Aarti Rege, J Kohn, Eric J. Amis
Tyrosine-derived polycarbonates are extremely promising degradable materials for use in orthpedic applications and two-dimensional thin films consisting of homopolymer and discrete compositional blends of the ethyl (DTE) and octyl (DTO) ester polycarbonate
Christopher Stafford, Kristen Roskov, Thomas Epps, Michael J. Fasolka
Thickness is a governing factor in the behavior of films and coatings. To enable the high-throughputanalysis of this parameter in polymer systems, we detail the design and operation of a flow coater device for fabricating continuous libraries of polymer
Jaroslaw Grobelny, Pradeep N. Namboodiri, Doo-In Kim, Z C. Ying
Adhesion forces between a gold sphere and flat gold substrate are studied using atomic force microscopy in different environments. The pull-off force measured in vacuum is found to be a small fraction of that in ambient air or nitrogen atmosphere. In
M B. Smith, J Tong, Jan Genzer, Daniel A. Fischer, P K. Kilpatrick
Amphiphilic -helices were formed from designed synthetic peptides comprising alanine, phenylalanine, and lysine residues. The insertion of the - helical peptides into hybrid bilayers assembled on gold was studied by a variety of methods to assess the
Sitaraman Krishnan, R J. Ward, A Hexemer, K E. Sohn, K L. Lee, E R. Angert, Daniel A. Fischer, E J. Kramer, Christopher K. Ober
Polystyrene-block-poly(4-vinylpyridine) copolymers were quaternized with 1-bromohexane and 6-perfluorooctyl-1-bromohexane. Surfaces prepared from these polymers were characterized by contact angle measurements, near-edge X-ray absorption fine structure