Three-dimensional inorganic nanostructured thin films with slanted columnar morphologies are functionalized with organic polymer brushes to fabricate a nanohybrid functional material. Nanostructured thin films are fabricated by glancing angle deposition of silicon onto silicon or gold to produce slanted columnar thin films (SCTFs). Polymer brushes are regarded as very promising nanomaterials for surface coatings because these systems are capable of responding to external stimuli such as temperature or pH, generally by reversible swelling/deswelling behavior. The fabrication of the SCTF as well as the stepwise reactions of poly(acrylic acid) guiselin polymer brushes to the SCTF nanocolumns are characterized with generalized ellipsometry and scanning electron microscopy. This study demonstrates that SCTFs are capable of withstanding the polymer brush grafting-to process and that both ellipsometry and electron microscopy indicate polymer brush immobilization within the void spaces of the SCTF. Furthermore, in situ combinatorial ellipsometry and quartz crystal microbalance with dissipation both reveal that the brushes retain their ability to swell/deswell with changes in pH of buffer solution. These tunable nanohybrid functional materials with increased surface area, complex columnar geometries, and stimuliresponsive characteristics provide novel material surfaces for nanoelectronics, biotechnology, and a variety of other advanced material applications.

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Influence of deposition conditions on the thermal stability of ZnO:Al films grown by rf magnetron sputtering Iron films deposited by direct current magnetron sputtering onto glass substrates were converted into FeS 2 films by thermal sulfurization. Experiments were carried out to optimize the sulfurization process, and the formation of FeS 2 thin films was investigated under different annealing temperatures and times. High quality FeS 2 films were fabricated using this process, and single phase pyrite films were obtained after sulfurization in a sulfur and nitrogen atmosphere at 450°C for 1 h. Film crystallinity and phase identification were determined by using x-ray diffraction. The cubic phase pyrite films prepared were p-type, and scanning electron microscopy studies exhibited a homogeneous surface of pyrite. The authors have found that the best Ohmic contact for their pyrite thin films, using inexpensive metals, was Ni. The following were chosen for the study: Al, Mo, Fe, and Ni, and the one that led to the lowest resistance, 333 ⍀, was Ni.

Sculptured thin film (STF) substrates consist of nanocolumns with precise orientation, intercolumnar spacing, and optical anisotropy, which can be used as model biomaterial substrates to study the effect of homogenous nanotopogrophies on the three-dimensional distribution of adsorbed proteins. Generalized ellipsometry was used to discriminate between the distributions of adsorbed FN either on top of or within the intercolumnar void spaces of STFs, afforded by the optical properties of these precisely crafted substrates. Generalized ellipsometry indicated that STFs with vertical nanocolumns enhanced total FN adsorption two-fold relative to flat control substrates and the FN adsorption studies demonstrate different STF characteristics influence the degree of FN immobilization both on top and within intercolumnar spaces, with increasing spacing and surface area enhancing total protein adsorption. Mouse fibroblasts or mouse mesenchymal stem cells were subsequently cultured on STFs, to investigate the effect of highly ordered and defined nanotopographies on cell adhesion, spreading, and proliferation. All STF nanotopographies investigated in the absence of adsorbed FN were found to significantly enhance cell adhesion relative to flat substrates; and the addition of FN to STFs was found to have cell-dependent effects on enhancing cell-material interactions. Furthermore, the amount of FN adsorbed to the STFs did not correlate with comparative enhancements of cell-material interactions, suggesting that nanotopography predominantly contributes to the biocompatibility of homogenous nanocolumnar surfaces. This is the first study to correlate precisely defined nanostructured features with protein distribution and cell-nanomaterial interactions. STFs demonstrate immense potential as biomaterial surfaces for applications in tissue engineering, drug delivery, and biosensing.

Measuring the interactions between engineered nanoparticles and natural substrates (e.g. soils and sediments) has been very challenging due to highly heterogeneous and rough natural surfaces. In this study, three-dimensional nanostructured slanted columnar thin films (SCTFs), with well-defined roughness height and spacing, have been used to mimic surface roughness. Interactions between titanium dioxide nanoparticles (TiONP), the most extensively manufactured engineered nanomaterials, and SCTF coated surfaces were measured using a quartz crystal microbalance with dissipation monitoring (QCM-D). In parallel, in-situ generalized ellipsometry (GE) was coupled with QCM-D to simultaneously measure the amount of TiONP deposited on the surface of SCTF. While GE is insensitive to effects of mechanical water entrapment variations in roughness spaces, we found that the viscoelastic model, a typical QCM-D model analysis approach, overestimates the mass of deposited TiONP. This overestimation arises from overlaid frequency changes caused by particle deposition as well as additional water entrapment and partial water displacement upon nanoparticle adsorption. Here, we demonstrate a new approach to model QCM-D data, accounting for both viscoelastic effects and the effects of roughness-retained water. Finally, the porosity of attached TiONP layer was determined by coupling the areal mass density determined by QCM-D and independent GE measurements.