Thin block copolymer films are promising candidates for a variety of applications, such as the preparation of nanoporous films, nanostructured templates, photonic crystals and biosensors [1]. Lateral structures are of special interest, e.g. for the structuring of inorganic substrates [2] and for the preparation of nanoporous membranes [3]. Solvent annealing offers a simple and flexible method with a potentially high degree of controllability through careful choice of solvent [4].

We have found very slow crystallization in thin films of cylinder-forming poly(isoprene-b-ethyleneoxide) (P(I-b -EO)) diblock copolymers with PEO being the minority block. The film was crystallized at room temperature after melting at 62 °C. Imaging methods were combined with X-ray reflectometry and grazing-incidence small-angle X-ray scattering and diffraction. Initially, hexagonally packed, amorphous PEO cylinders lie in the film plane. After 148 days, crystallized, finger-like terraces were observed over the entire film surface. The terrace height is 20% higher than the repeat distance in the as-prepared film. Thus, at the film surface, the cylinders have been destroyed by crystalline lamellae lying in the film plane. The PEO chain stems are perpendicular to the substrate surface and are once-folded and fully interdigitated. The substrate-near layers still consist of the hexagonally packed, amorphous PEO cylinders within the PI matrix.

Grazing-incidence small-angle x-ray scattering (GISAXS) is a standard tool for the analysis of surfaces and thin layers containing nanometer-sized structures. In order to obtain a two-dimensional map of their local morphology, we performed GISAXS microtomography on dried drops of colloidal suspensions. In particular, we investigated the self-organization of drying suspensions of TiO2 on polyethylene surfaces. Hierarchically structured titania films and their mesoporous structure on the nanoscale have a large variety of applications, e. g., in photovoltaics, photocatalysis, and gas sensing. They are prepared by combining sol-gel chemistry with an amphiphilic diblock copolymere as a structure-directing agent. The sample presented here is a dried drop of nanostructured titania (TiO2), consisting of a sponge-like structure with an expected pore size of 30 40 nm. Figure 1(a) shows an optical micrograph of this laterally inhomogeneous sample. Prior to depositing the drop, the Si substrate was spin coated with the same solution.

The ordered nanoparticle monolayers and multilayers over macroscopic areas were prepared by the modified Langmuir-Blodgett method. Using this approach, the nanoparticle monolayer is formed on the water surface by compression and subsequently it is transferred onto the substrate by a controlled removal of the water subphase. The ordering and homogeneity of the prepared mono- and multilayers was studied by scanning electron microscope (SEM), grazing-incidence small-angle X-ray scattering (GISAXS) and X-ray reflectivity (XRR) techniques. From the results it follows that an ordered nanoparticle monolayer was formed over a large area. For the multilayer, the layering and lateral ordering of each layer was confirmed by XRR and SEM performed after the deposition of each nanoparticle layer.

Real-time reassembly of an ordered nanoparticle monolayer due to UV-photolysis of the surfactant shell of nanoparticles was observed. The technique of grazing-incidence small-angle X-ray scattering provided the possibility to track in situ the nanoparticle pair correlation function of the sample processed in a UV-ozone reactor. The analysis revealed a total shift of approximately 1 nm of the nanoparticle nearest-neighbor distance. The temporal evolution of the interparticle distance proved to be the first-order process governed by the UV-photolysis and described by a single-exponential decay function. The nanoparticles tend to agglomerate into a labyrinth-like structure with a typical length scale of some 30 nm.

A high-performance W/B 4 C multilayer mirror with 80 periods of nominally 1.37 nm was measured by grazing-incidence small-angle X ray scattering (GISAXS) in order to analyse the lateral and vertical correlations of the interface roughness within the framework of a scaling concept of multilayer growth. A dynamic growth exponent z = 2.19 (7) was derived, which is close to the value predicted by the Edwards–Wilkinson growth model. The effective number of correlated periods indicates a partial replication of the low interface roughness frequencies. A simulation of the GISAXS pattern based on the Born approximation suggests a zero Hurst fractal parameter H and a logarithmic type of autocorrelation function. The as-deposited mirror layers are amorphous and exhibit excellent thermal stability up to 1248 K in a 120 s rapid thermal vacuum annealing process. At higher temperatures, the B 4 C layers decompose and poorly developed crystallites of a boron-rich W–B hexagonal phase are formed, and yet multilayer collapse is not complete even at 1273 K. Ozone treatment for 3000 s in a reactor with an ozone concentration of 150 mg m −3 results in the formation of an oxidized near-surface region of a thickness approaching ∼10% of the total multilayer thickness, with a tendency to saturation.

Modified periodically ordered mesoporous organosilica materials were prepared starting from a recently introduced type of sol-gel precursor, containing both organic moieties and hydrolyzable Si-OR groups. In order to thoroughly characterize the mesoporosity and its accessibility, different probe gases were used in conventional gas adsorption experiments. Furthermore, in situ small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS) were applied to study the mesoporosity and the sorption processes, taking advantage of scattering contrast matching conditions. Thereby, the materials were characterized not only by different probe molecules but also at different temperatures (nitrogen at 77 K, dibromomethane at 290 K and perfluoropentane at 276 K). The comparison between the standard and in situ SAXS/SANS adsorption experiments revealed valuable information about the porosity and microstructure of the materials. It is demonstrated that the organic moieties are homogeneously distributed; that is, they do not phase-separate from silica on the nanometer scale.

This work shows that phase separations in 2D polymer films can be tuned by employing entropically constraining grafting points. We present experimental results oil surface-grafted 2D polystyrene (PS)/polyvinylmethylether (PVME) blended Films using surface-anchored benzophenone derivates. In contrast with 2D films that have not been grafted, it was possible to raise the blended lower critical solution temperature (LCST) above room temperature by using low grafting point densities. Highly constrained films did not show polymer-polymer phase separation. In addition to the in situ structural analysis performed with surface probe microscopy (SPM), mu-beam-sized grazing incidence small-angle X-ray scattering (mu-GISAXS), and mu-X-ray reflectivity (mu-XRR), surface stress investigations performed using nano mechanical cantilever sensor (NCS) arrays gave detailed insight into the phase separation mechanism. Phase separations were shown to result in dominating attractive entropic spring mechanisms with opposing repulsive effects resulting from surface and interfacial energy changes.

In this article we discuss the applicability of global scattering functions for structure analysis of Grazing Incidence Small Angle X-ray Scattering (GISAXS) data. Contrary to rigorous analysis of the full 2-D detector image, which can be performed with complex simulation models, the global scattering functions described here will be used to model transverse detector scans in the q(parallel to) reciprocal scattering planes. In contrast to a full GISAXS analysis, this procedure cannot explain structural features perpendicular to the sample plane. The discussed method is useful for the analysis of weakly correlated films. These films are e. g. found in polymer inorganic composite materials based on commercially available nanoparticles. In hybrid material systems polydisperse structures, including particle aggregates without precisely defined shape are formed. The pictured approach, which models scattering in terms of structural levels, has been previously applied with success in conventional transmission SAXS geometry. It is based on conventional exponential and power laws. Hence, data analysis becomes less complex compared to simulation approaches. Here we examine if this unified fitting model can be used to model diffuse, non specular scattering resulting from GISAXS. In this context the applicability and limit of its application to diffuse scattering in the GISAXS geometry is discussed. Furthermore diffuse q(parallel to) scattering from different ideal particle types is simulated and compared with fitted results. To verify our approach, fit results from experimental GISAXS curves obtained for real samples are compared with results from Scanning Probe Microscopy and Scanning Electron Microscopy studies. The samples investigated range from evaporated Au films to hybrid TiO(2)/polymer films and demonstrate the usefulness in the structural analysis of complex films.

Thermo-sensitive polymeric hydrogels react strongly to temperature changes. When they are heated above the lower critical solution temperature (LCST), their volume decreases. Due to this thermosensitive behavior, they may be used as drug delivery systems or in micromechanics [1]. The kinetics of the volume change is of great importance for applications. So far, chemically crosslinked gels [2], microgels [3] and core-shell-particles [4] with a thermo-sensitive shell have been investigated. Triblock copolymers, consisting of a hydrophilic middle block and two hydrophobic end blocks, offer another way to form polymeric hydrogels [5-9]. In aqueous solution, these copolymers form core-shell micelles. At higher concentration, the end blocks act as physical crosslinks with the middle blocks bridging two micellar cores.

The morphology of buried interfaces plays a key role in high performing Mo/Si soft X-ray mirrors. We show that grazing-incidence small-angle X-ray scattering is a highly effective and non-destructive diagnostic technique for analysis of buried interfaces. The parameters of average interface autocorrelation function can be determined unambiguously. Additionally period thickness, roughness of interfaces and an effective number of vertically correlated periods can be extracted. The multilayer mirrors were prepared by e-beam evaporation on heated and unheated substrates, ion beam assisted e-beam evaporation, ion beam sputtering and RF magnetron sputtering. The latter three techniques produce multilayer mirrors with comparable interface roughness. The differences in lateral correlation length and Hurst parameter are found.

At BW4 at HASYLAB a beryllium compound refractive lens (Be-CRL) is used for the focusing in small-angle x-ray scattering experiments. Using it provides the advantages of higher long-term stability and a much easier alignment compared to a setup with focusing mirrors. In our investigations presented here, we show the advantages of using a Be-CRL in small-angle and also ultra small-angle x-ray scattering. We investigated the beam characteristics at the sample position with respect to spot size and photon flux. The spot size is comparable to that of a setup with focusing mirrors but with a gain in flux and better long-term stability. It is also shown that plane mirrors are still necessary to suppress higher order energies passing the monochromator.

We report on an incorporation of self-assembled templates of superparamagnetic Fe-O nanoparticles into tunnel magnetoresistance devices. We fabricated a multilayer stack composed of the following layer sequence: Cr/Au/Co/NP/Co/Cu on Si(100) substrate where NP stands for a self-assembled layer of nanoparticles deposited by the Langmuir-Blodgett technique. The X-ray reflectivity and grazing-incidence small angle X-ray scattering were employed to study the layers thicknesses and interface morphology in each preparation step. In particular, the gazing-incidence small angle X-ray scattering was measured before and after the nanoparticle incorporation as well as on the complete tunnel magnetoresistance stack. In this way, in-depth morphology profile during subsequent preparation steps was obtained. We demonstrate that X-ray analysis of the deposited tunnel magnetoresistance stack is essential for successful fabrication of novel hybrid devices consisting of self-assembled nanoparticles.

Tailoring of the titania morphology is achieved by the combination of a triblock copolymer, acting as structure-directing agent, and a sol-gel chemistry enabling the incorporation of the provided inorganic material (titania) into the selected phase of the triblock copolymer. Spin-coating of the solution on FTO-coated glass, followed by plasma etching and calcination of the thin film results in the formation of self-encapsulated crystalline titania nanostructures. The fabricated nanostructures are coated stepwise with dye, conductive polymers and gold forming a functional multilayer stack. An advanced small-angle scattering technique probing the sample with X-ray synchrotron radiation under grazing incidence (GISAXS) is employed for the characterization of the preparation route, as scattering allows accessing the structure inside the multilayers. The tailored titania morphology is preserved during the preparation route towards the functional multilayer stack of a photovoltaic demonstration cell. Two clearly distinguishable structures originate from the substrate and the titania templated by the triblock copolymer; hence the other layers induce no additional structures. Therefore, this investigation provides the evidence that the effort spent to tailor the morphology is justified by the preservation of the self-encapsulated titania morphology that is created by the structure-directing agent throughout the functional multilayer stack build-up.

The combination of physisorption experiments with simultaneous in situ small-angle X-ray and neutron scattering (SAXS/SANS) was used to elucidate the porosity in mesoporous silica with a trimodal pore structure. The material ("KLE-IL") contains spherical mesopores of 14 nm in diameter, worm-like mesopores (2-3 nm), and micropores, templated by a block copolymer and an ionic liquid surfactant, while the micropores originate from the hydrophilic block of the block copolymer. The main objective of the study was the quantification of the microporosity and the small mesopores and to find out if they are indeed located between the larger, spherical mesopores. Our in situ SAXS/SANS experiments took advantage of contrast matching of nitrogen (SANS, T = 77 K) and dibromomethane (SAXS, T = 290 K). By using the latter gas with a slightly larger kinetic diameter, it was possible to judge the accessibility of the pores under ambient conditions. The in situ experiments were supported by high-precision ex situ physisorption. Using suitable approaches for the SAXS/SANS analysis, it was possible to separate the content of the micropores and small mesopores.

We combine grazing-incidence small-angle X-ray scattering (GISAXS) with scanning X-ray microtomography to investigate the nanostructure in a dried gold/polystyrene nanocomposite drop. Local GISAXS structure factors are reconstructed at each position on the surface of this two-dimensionally heterogeneous sample with 30 microm pixel size. Evidence for four types of self-assembled colloidal crystalline structures is provided by the reconstructed data of the drop demonstrating the feasibility of the method.

The fabrication of titania nanostructures with hierarchical order of different structural levels is investigated. The nanostructures are prepared with a diblock-copolymer assisted sol-gel process. By iterative spin-coating of the solution onto silicon substrates a thin polymer-nanocomposite film is deposited and transformed to purely anatase titania nanostructures via calcination. In total, this procedure is repeated three times on top of the substrate. The approach is monitored with grazing incidence small angle X-ray scattering after each fiabrication step. With scanning electron microscopy the final hierarchical structure is imaged. From the characterization different structural levels are clearly identified. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

I Small-angle X-ray scattering (SAXS) has become a standard tool for the investigation of nano-structured materials with applications in many fields of science. Scanning tomography adds three-dimensional information to the method. We investigate the validity of the tomographic model in SAXS tomography. We identify the requirement of local rotational invariance of the SAXS cross section and discuss the role of coherence in the framework of SAXS tomography. A tomography experiment performed on nanoporous glass is described as a practical example of the method. SAXS tomography reveals the density and nanostructure on a virtual section through a piece of nanoporous sodium borosilicate glass. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim