共查询到20条相似文献,搜索用时 15 毫秒
1.
《Spectrochimica Acta Part B: Atomic Spectroscopy》2004,59(10-11):1789-1797
Nanostructured polymer films of poly(styrene-block-paramethylstyrene) diblock copolymers P(Sd-b-pMS) on silicon substrates with a native oxide layer are investigated. Resulting from a storage under toluene vapor, a surface structure is installed. The early stages, characterized by the creation of a host structure out of an initially continuous film, are addressed. Grazing incidence small-angle X-ray scattering (GISAXS) experiments were performed as a function of exposure time. Results are compared to modelling of the scattering pattern and other experimental techniques, such as grazing incidence small-angle neutron scattering (GISANS) and atomic force microscopy (AFM) data. Possibilities and limits of the techniques are discussed. 相似文献
2.
Peter Müller‐Buschbaum Jochen S. Gutmann Manfred Stamm Robert Cubitt 《Macromolecular Symposia》2000,149(1):283-288
The surface structure of thin polymer blend films of deuterated polystyrene (dPS) and polyparamethylstyrene (PpMS) after annealing above the glass transition temperature was investigated. With scanning force microscopy (SFM) the surface topography originated by a dewetting process is detected. The sample surface is covered with small droplets consisting of several polymer molecules. Utilizing grazing incidence small angle neutron scattering (GISANS) the topographical information as well as the in‐plane composition is probed. For thin confined blend films a substructure of the droplets resulting from an additional phase separation process at different length scales is detected. 相似文献
3.
Förster S Timmann A Konrad M Schellbach C Meyer A Funari SS Mulvaney P Knott R 《The journal of physical chemistry. B》2005,109(4):1347-1360
Analytical expressions for the scattering functions of ordered mesoscopic materials are derived and compared to experimentally determined scattering curves. Ordered structures comprising spheres (fcc, bcc, hcp, sc), cylinders (hex, sq), and lamellar structures are considered. The expressions take into account particle size distributions and lattice point deviations, domain size, core/shell structures, as well as peak shapes varying analytically between Lorentzian and Gaussian functions. The expressions allow one to quantitatively describe high-resolution synchrotron small-angle X-ray (SAXS) and neutron scattering (SANS) curves from lipid and block copolymer lyotropic phases, core/shell nanoparticle superstructures, ordered nanocomposites, and ordered mesoporous materials. In addition, the diffuse out-of-plane scattering of grazing incidence GISAXS and GISANS experiments of laterally ordered thin films can be quantitatively analyzed. 相似文献
4.
Polystyrene film of about 50 nm in thickness on silicon wafer was obtained by spin-coating in tetrahydrofuran solution. The
film exhibits a rough surface as shown by atomic force microscopy images and ellipsometry data. Furthermore, such surface
roughness produced a characteristic lateral correlation peak in an “out-ofplane” scan in the synchrotron grazing incidence
ultra-small angle X-ray scattering pattern. The film was treated with liquids of solvent and non-solvent sequentially, resulting
in a process of swelling and precipitation of the polystyrene film. Such a solvent/non-solvent treatment completely changed
the original surface structure of the film. Aggregates of polystyrene of different sizes were observed both in atomic force
microscopy and synchrotron grazing incidence ultra-small angle X-ray scattering measurements. The results demonstrate that
synchrotron grazing incidence ultra-small angle X-ray scattering is a unique means to investigate large area micro-structural
features of thin films supported on smooth surfaces. 相似文献
5.
Müller-Buschbaum P Schulz L Metwalli E Moulin JF Cubitt R 《Langmuir : the ACS journal of surfaces and colloids》2008,24(15):7639-7644
The lateral structure of an ABA-type triblock copolymer polyparamethylstyrene- block-polystyrene- block-polyparamethylstyrene at the buried silicon substrate interface is studied as a function of different substrate surface treatments. With grazing incidence small-angle neutron scattering (GISANS), high interface sensitivity is reached. With GISANS, the orientation and degree of order of the morphology are probed. The powderlike oriented lamellar structure in the bulk orients along the surface normal in the vicinity of the substrate. A modification of the short-ranged interface potential of the substrate introduces a lateral stretching of this lamellar structure of up to 8% as compared to the bulk. The decay in stretching toward the volume structure is probed with depth profiling. It extends at least up to a distance of 51 nm from the solid surface. 相似文献
6.
Müller-Buschbaum P Schulz L Metwalli E Moulin JF Cubitt R 《Langmuir : the ACS journal of surfaces and colloids》2009,25(7):4235-4242
The morphology transition due to midblock swelling with low-molecular-weight homopolymer polystyrene of an ABA-type triblock copolymer polyparamethylstyrene-block-polystyrene-block-polyparamethylstyrene at the buried silicon substrate interface is studied as a function of different substrate surface treatments. With grazing incidence small-angle neutron scattering (GISANS), high interface sensitivity is reached. The powderlike oriented lamellar structure in the bulk becomes oriented along the surface normal in the vicinity of the substrate. A transition of the lamellar into a cylinder phase at the polymer-silicon interface is probed with GISANS. The transition is induced by the addition of the homopolymer, but the modification of the short-ranged interface potential of the substrate influences the amount of homopolymer that is necessary for this transition. Without and with 0.1 vol % added homopolymer, the lateral spacing is stretched at the interface as compared to the bulk whereas for a higher added amount of homopolymer no stretching occurs. 相似文献
7.
Müller-Buschbaum P 《Analytical and bioanalytical chemistry》2003,376(1):3-10
Hamburg workshop on the "application of synchrotron radiation in chemistry"With grazing incidence small-angle X-ray scattering (GISAXS) the limitations of conventional small-angle X-ray scattering with respect to extremely small sample volumes in the thin-film geometry are overcome. GISAXS turned out to be a powerful advanced scattering technique for the investigation of nanostructured polymer films. Similar to atomic force microscopy (AFM), a large interval of length between molecular and mesoscopic scales is detectable with a surface-sensitive scattering method. While with AFM only surface topographies are accessible, with GISAXS the buried structure is also probed. Because a larger surface area is probed, GISAXS also has a much larger statistical significance compared to AFM. Due to the high demand on collimation, GISAXS experiments are based on synchrotron radiation. Nanostructures parallel and perpendicular to the sample surface observable in thin poly(styrene- block-isoprene) diblock copolymer films are presented as an example of the possibilities of GISAXS. 相似文献
8.
P. Müller-Buschbaum J. S. Gutmann R. Cubitt M. Stamm 《Colloid and polymer science》1999,277(12):1193-1199
The surface morphologies of confined, dewetted polymer films were investigated with atomic force microscopy (AFM) and grazing-incidence
small-angle neutron scattering (GISANS). On examining homopolymer films of deuterated polystyrene (dPS) both techniques reveal
the resulting droplet structure which is described by one most prominent in-plane length. Due to the contrast resulting from
deuteration in the case of polymer blend films of dPS and poly(p-methyl styrene) GISANS is able to probe the in-plane composition of the dewetting structure. An additional phase separation
process at different length scales gives rise to a sub- and superstructure which is not detectable by AFM. In addition, the
influence of the wavelength used in the GISANS experiments on the structures observed is discussed.
Received: 13 April 1999 Accepted in revised form: 29 June 1999 相似文献
9.
Rebollar E Pérez S Hernández JJ Martín-Fabiani I Rueda DR Ezquerra TA Castillejo M 《Langmuir : the ACS journal of surfaces and colloids》2011,27(9):5596-5606
In this work we evaluate the potential of grazing incidence X-ray scattering techniques in the investigation of laser-induced periodic surface structures (LIPSSs) in a series of strongly absorbing model spin-coated polymer films which are amorphous, such as poly(ethylene terephthalate), poly(trimethylene terephthalate), and poly(carbonate bisphenol A), and in a weaker absorbing polymer, such as semicrystalline poly(vinylidene fluoride), over a narrow range of fluences. Irradiation was performed with pulses of 6 ns at 266 nm, and LIPSSs with period lengths similar to the laser wavelength and parallel to the laser polarization direction are formed by devitrification of the film surface at temperatures above the characteristic glass transition temperature of the polymers. No crystallization of the surface is induced by laser irradiation, and crystallinity of the material prevents LIPSS formation. The structural information obtained by both atomic force microscopy and grazing incidence small-angle X-ray scattering (GISAXS) correlates satisfactorily. Comparison of experimental and simulated GISAXS patterns suggests that LIPSSs can be well described considering a quasi-one-dimensional paracrystalline lattice and that irradiation parameters have an influence on the order of such a lattice. 相似文献
10.
Lavcević ML Dubcek P Orel ZC Turković A 《Journal of chemical information and modeling》2005,45(6):1553-1557
An examination of structural modifications, induced by mixing vanadium and cerium oxides and by the introduction of lithium in vanadium and mixed vanadium/cerium oxide films, was performed using synchrotron sourced grazing incidence small-angle X-ray scattering. Samples were sol-gel-derived films, deposited by a dip-coating technique. An analysis of the scattering data, acquired by a two-dimensional detection system, is based on the comparison of the surface and bulk characteristics of the film. The trend of estimated structural modifications is supported by the results of previous investigations on a different length scale, performed by atomic force microscopy. 相似文献
11.
Eric Verploegen Derrick Boone Jr. Paula T. Hammond 《Journal of polymer science. Part A, Polymer chemistry》2007,45(24):3263-3266
The self-assembly behavior of siloxane based side chain liquid crystalline block copolymer thin films are investigated via grazing incidence small angle X-ray scattering and atomic force microscopy. The as-spun films displayed polystyrene cylinders perpendicular to the substrate and the cylinders reoriented parallel to the surface after thermal annealing. The morphology observed in the as-spun films is resultant from the orientation of the smectic LC mesophase relative to the substrate. Annealing above both the polystyrene glass transition temperature and the smectic to isotropic transition temperature eliminates the influence of the LC phase, leading to a reorientation of the morphology that minimizes the interfacial energy of the system. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 3263–3266, 2007 相似文献
12.
Nikhila Mahadevapuram Joseph Strzalka Gila E. Stein 《Journal of polymer science. Part A, Polymer chemistry》2013,51(7):602-610
Thin films of lamellar and cylindrical block copolymers are popular systems for low-cost nanolithography. To be useful as nanoscale templates, the lamellae or cylinders must be oriented perpendicular to the substrate. Domain orientations are usually characterized by microscopy measurements of the film surface, but these techniques cannot detect tilted, bent, or tortuous domains in the film interior. We report a simple method to quantify out-of-plane disorder in thin films of block copolymers based on a variant of grazing-incidence small angle X-ray scattering (GI-SAXS). A typical GI-SAXS experiment illuminates the center of a substrate-supported film at a grazing angle of incidence (near the film/substrate critical angle), and the strong reflected signal is interpreted with the distorted-wave Born approximation. In a new approach, the beam footprint is moved to the far edge of the sample, allowing the acquisition of a transmission pattern. The grazing-incidence transmission data are interpreted with the simple Born approximation, and out-of-plane defects are quantified through analysis of crystal truncation rods and partial Debye-Scherrer rings. Significantly, this study demonstrates that grazing-incidence transmission small angle X-ray scattering can detect and quantify the buried defect structure in thin films of block copolymers. © 2013 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013 相似文献
13.
Dixon MC Daniel TA Hieda M Smilgies DM Chan MH Allara DL 《Langmuir : the ACS journal of surfaces and colloids》2007,23(5):2414-2422
Thin nanoporous gold (np-Au) films, ranging in thickness from approximately 40 to 1600 nm, have been prepared by selective chemical etching of Ag from Ag/Au alloy films supported on planar substrates. A combination of scanning electron microscopy (SEM) imaging, synchrotron grazing incidence small angle X-ray scattering, and N2 adsorption surface area measurements shows the films to exhibit a porous structure with intertwined gold fibrils exhibiting a spectrum of feature sizes and spacings ranging from several to hundreds of nanometers. Spectroscopic ellipsometry measurements (300-800 nm) reveal the onset of surface plasmon types of features with increase of film thicknesses into the approximately 200 nm film thickness range. Raman scattering measurements for films functionalized with a self-assembled monolayer formed from 4-fluorobenzenethiol show significant enhancements which vary sharply with film thickness and etching times. The maximum enhancement factors reach approximately 10(4) for 632.8 nm excitation, peak sharply in the approximately 200 nm thickness range for films prepared at optimum etching times, and show high spot to spot reproducibility with approximately 1 microm laser spot sizes, an indication that these films could be useful as durable, highly reproducible surface-enhanced Raman substrates. 相似文献
14.
《Spectrochimica Acta Part B: Atomic Spectroscopy》1999,54(1):41-82
Grazing incidence X-ray techniques are now widely used for surface and thin film analysis. The present article overviews the recent advancement since 1993 of the grazing incidence X-ray spectrometry and reflectometry in both theoretical and experimental aspects. Every current topic related to the total reflection X-ray fluorescence spectrometry (TXRF) is described in detail through the introduction of numerous published works on the application in the various fields of the science and industrial technologies. Recent rapid growth in diffuse scattering at grazing incidence as well as in specular reflection is another important scope. The combined measurements of different grazing incidence X-ray techniques might be a future trend for realizing further advanced analysis of the surface and interfaces of materials. 相似文献
15.
O. A. Shilova N. N. Gubanova A. G. Ivanova M. Yu. Arsent’ev V. A. Ukleev 《Russian Journal of Inorganic Chemistry》2017,62(5):645-653
Chemical processes that can occur during aging of sols based on water–alcohol solutions of tetraethoxysilane (TEOS) and hexachloroplatinic acid and during formation of films from these sols are analyzed by the results of visible and UV spectroscopy and X-ray powder diffraction. The sizes and compositions of the platinum particles that are formed in xerogels and in thin films on the nanometer and submicron levels are estimated based on X-ray crystallography, energy dispersive spectral analysis, high-resolution scanning and transmission electron microscopy, and grazing incidence small-angle X-ray scattering studies. 相似文献
16.
I. D. Leshchiner E. V. Agina N. I. Boiko R. Richardson V. P. Shibaev 《Russian Chemical Bulletin》2008,57(10):2101-2110
Amphiphilic carbosilane liquid-crystalline codendrimers with terminal mesogenic butoxybenzoate and phenolic groups have been synthesized for the first time. The structures and compositions of the synthesized codendrimers were characterized by NMR spectroscopy. The data from polarization optical microscopy, differential scanning calorimetry, and small-angle X-ray scattering demonstrated that all codendrimers possessed mesomorphic properties. They form thin (Langmuir) films at the water-air interface. The surface pressure-surface area isotherms were plotted. The Langmuir-Blodgett films of different thicknesses were obtained by the vertical dipping method on the solid substrate. The film structures were studied by grazing incidence X-ray diffraction analysis. 相似文献
17.
Synchrotron X-ray techniques for the investigation of structures and dynamics in interfacial systems
《Current Opinion in Colloid & Interface Science》2014,19(3):228-241
This review focuses on recent results obtained by synchrotron X-ray techniques applied to the characterization of interfacial systems, with main emphasis on flat interfaces and on colloidal systems. The techniques covered are, for structural determinations: X-ray reflectivity (XRR), grazing incidence X-ray diffraction (GIXRD) and grazing incidence X-ray excited fluorescence (GIXF), while dynamics are investigated by X-ray photon correlation spectroscopy (XPCS) mainly in the grazing-incidence geometry (GIXPCS).The systems reviewed are, in order of growing complexity, floating Langmuir monolayers, supported films of lipids and proteins, polymeric films, buried interfaces, colloidal systems and gels formed by colloids either in 3D or in the form of 2D interfacial layers. Recent results are critically discussed, and some interesting directions of development are outlined, having also in mind new technical developments such as X-ray free electron laser sources and micro-focused synchrotron beamlines. 相似文献
18.
Wang JY Chen W Sievert JD Russell TP 《Langmuir : the ACS journal of surfaces and colloids》2008,24(7):3545-3550
Lamellae orientation in lithium-complexed polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) copolymer films on natively oxidized silicon wafers is investigated as a function of film thickness and percentage of carbonyl groups coordinated with lithium ions using cross-sectional transmission electron microscopy and grazing incidence small-angle X-ray scattering. For films with a lower percentage of ionic complexes, the strong surface interaction of the PMMA blocks with the substrate is not changed significantly and the orientation of the lamellar microdomains depends on the film thickness and is dictated by a coupling of the interfacial interactions and the degree of microphase separation. For films with a higher percentage of ionic complexes, the surface interaction is mediated. Along with the enhanced immiscibility between the two blocks, which drives the self-assembly into a stronger microphase segregation, an orientation of the lamellar microdomains normal to the surface is seen, independent of film thickness. Thus, by tuning the amount of ionic complexes, the orientation of lamellar microdomain can be controlled from a random arrangement to being oriented parallel or perpendicular to the film surface without any surface modification or use of external fields, which opens a simple and general route for the fabrication of nanostructured materials. 相似文献
19.
Buffet A Abul Kashem MM Schlage K Couet S Röhlsberger R Rothkirch A Herzog G Metwalli E Meier R Kaune G Rawolle M Müller-Buschbaum P Gehrke R Roth SV 《Langmuir : the ACS journal of surfaces and colloids》2011,27(1):343-346
Cobalt (Co) sputter deposition onto a colloidal polymer template is investigated using grazing incidence small-angle X-ray scattering (GISAXS), scanning electron microscopy (SEM), and atomic force microscopy (AFM). SEM and AFM data picture the sample topography, GISAXS the surface and near-surface film structure. A two-phase model is proposed to describe the time evolution of the Co growth. The presence of the colloidal template results in the correlated deposition of an ultrathin Co film on the sample surface and thus in the creation of Co capped polystyrene (PS) colloids. Well below the percolation threshold, the radial growth is restricted and only height growth is observed. 相似文献
20.
The structural properties of Langmuir monolayers on aqueous substrates of a metal free phthalocyanine, 2,9,16,23-tetrakis(phenylthio)-29H,31H-phthalocyanine and an Aluminum centered phthalocyanine, Aluminum 2,9,16,23-tetrakis(phenylthio)-29H,31H-phthalocyanine chloride are reported here. Their structure is investigated under progressive lateral compression by grazing incidence diffuse X-ray scattering out of the specular plane to determine specular reflectivity-like information where the phase change of the molecules from "flat-lying" on the surface to "edge-standing" perpendicular to the surface was directly observed. Furthermore grazing incident X-ray diffraction is used to investigate the in-plane ordering of the system where it has been found that at high density states the systems can be considered as monolayers consisting of arrays of side-by-side cofacially aggregated cylindrical rodlike entities. 相似文献