From atoms to layers: in situ gold cluster growth kinetics during sputter deposition.

The adjustment of size-dependent catalytic, electrical and optical properties of gold cluster assemblies is a very significant issue in modern applied nanotechnology. We present a real-time investigation of the growth kinetics of gold nanostructures from small nuclei to a complete gold layer during magnetron sputter deposition with high time resolution by means of in situ microbeam grazing incidence small-angle X-ray scattering (μGISAXS). We specify the four-stage growth including their thresholds with sub-monolayer resolution and identify phase transitions monitored in Yoneda intensity as a material-specific characteristic.

P03, the microfocus and nanofocus X-ray scattering (MiNaXS) beamline of the PETRA III storage ring: the microfocus endstation.

The P03 beamline, also called the microfocus and nanofocus X-ray scattering (MiNaXS) beamline, exploits the excellent photon beam properties of the low-emittance source PETRA III to provide a microfocused/nanofocused beam with ultra-high intensity for time-resolved X-ray scattering experiments. The beamline has been designed to perform X-ray scattering in both transmission and reflection geometries. The microfocus endstation started user operation in May 2011.

Influence of nanoparticle surface functionalization on the thermal stability of colloidal polystyrene films.

The installation of large scale colloidal nanoparticle thin films is of great interest in sensor technology or data storage. Often, such devices are operated at elevated temperatures. In the present study, we investigate the effect of heat treatment on the structure of colloidal thin films of polystyrene (PS) nanoparticles in situ by using the combination of grazing incidence small-angle X-ray scattering (GISAXS) and optical ellipsometry.

Effect of solvent annealing on the tensile deformation mechanism of a colloidal crystalline polymeric latex film.

The influence of solvent annealing on microscopic deformational behavior of a styrene/n-butyl acrylate copolymer latex film subjected to uniaxial tensile deformation was studied by small-angle X-ray scattering. It was demonstrated that the microscopic deformation mechanism of the latex films transformed from a nonaffine deformation behavior to an affine deformation behavior after solvent annealing. This was attributed to the interdiffusion of polymeric chains between adjacent swollen latex particles in the film.

Time-resolved ultrathin cobalt film growth on a colloidal polymer template.

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.

Structural evolution of a colloidal crystal fiber during heating and annealing studied by in situ synchrotron small angle X-ray scattering.

The structural evolution of a colloidal crystal fiber during heating and annealing was followed by in situ synchrotron small-angle X-ray scattering. The polymer dispersion (with a particle size of 118 nm) from which the fibers were formed by directed drying contained emulsifier and salt. A cellular structure formed upon drying in which the percolating phase (the "membrane phase") is composed from these components; this membrane phase gives rise to the scattering contrast on which the present observations build.

Polymorphic transformation of isotactic poly(1-butene) in form III upon heating: in situ synchrotron small- and wide-angle X-ray scattering studies.

The phase transformation of form III isotactic poly(1-butene) was investigated as a function of temperature. The polymer was isothermally precipitated from a dilute solution in iso-amyl acetate and observed with real-time synchrotron small- and wide-angle X-ray scattering techniques. The results confirmed that the polymorphic transition of form III was strongly dependent on temperature.

Spatially resolved investigation of solution cast nanoparticle films by X-ray scattering and multidimensional data set classification.

A combinatorial high-throughput approach is used to investigate a solution cast gradient consisting of colloidal gold nanoparticles on top of a silicon substrate by means of a X-ray nanobeam. Classification algorithms are used to reveal and visualize structural transitions from a frozen colloidal solution to a well-defined nanostructure. Prominent length scales on the order of 100 nm are observed.

Combining imaging ellipsometry and grazing incidence small angle X-ray scattering for in situ characterization of polymer nanostructures.

A combination of microbeam grazing incidence small angle X-ray scattering (muGISAXS) and imaging ellipsometry is introduced as a new versatile tool for the characterization of nanostructures. muGISAXS provides a local lateral and depth-sensitive structural characterization, and imaging ellipsometry adds the position-sensitive determination of the three-dimensional morphology in terms of thickness, roughness, refractive index, and extinction coefficient. Together muGISAXS and imaging ellipsometry enable a complete characterization of structure and morphology.

Grazing incidence small-angle X-ray scattering microtomography demonstrated on a self-ordered dried drop of nanoparticles.

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.

Small angle x-ray scattering with a beryllium compound refractive lens as focusing optic.

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.

GIUSAXS and AFM studies on surface reconstruction of latex thin films during thermal treatment.

The structural evolution of a single-layer latex film during annealing was studied via grazing incidence ultrasmall-angle X-ray scattering (GIUSAXS) and atomic force microscopy (AFM). The latex particles were composed of a low-Tg (-54 degrees C) core (n-butylacrylate, 30 wt %) and a high-Tg (41 degrees C) shell (t-butylacrylate, 70 wt %) and had an overall diameter of about 500 nm. GIUSAXS data indicate that the q(y) scan at q(z) = 0.

A detailed analysis of biodegradable nanospheres by different techniques--a combined approach to detect particle sizes and size distributions.

Poly(d,l-lactide-co-glycolide) nanosupensions as intravenous nanosphere systems were produced by solvent deposition in aqueous Poloxamer 188 solutions. Light scattering techniques were applied to these colloidal systems to characterize particle sizes. Regularly shaped spherical particles were received as proved by freeze fracture replica and small-angle X-ray scattering (SAXS).

Facile preparation of macroscopic soft colloidal crystals with fiber symmetry.

A facile, efficient way to fabricate macroscopic soft colloidal crystals with fiber symmetry by drying a latex dispersion in a tube is presented. A transparent, stable colloidal crystal was obtained from a 25 wt % latex dispersion by complete water evaporation for 4 days. The centimeter-long sample was investigated by means of synchrotron small-angle X-ray diffraction (SAXD).

Non-affine structural evolution of soft colloidal crystalline latex films under stretching as observed via synchrotron X-ray scattering.

A polymer dispersion consisting of soft latex spheres with a diameter of 135 nm was used to produce a crystalline film with face-centered cubic (fcc) packing of the spheres. Different from conventional small-molecule and hard-sphere colloidal crystals, the crystalline latex film in the present case is soft (i.e.

Heterologous gene expression by infectious and replicon vectors derived from tick-borne encephalitis virus and direct comparison of this flavivirus system with an alphavirus replicon.

The flavivirus tick-borne encephaltis virus (TBEV) was established as a vector system for heterologous gene expression. The variable region of the genomic 3' non-coding region was replaced by an expression cassette consisting of the reporter gene enhanced green fluorescent protein (EGFP) under the translational control of an internal ribosomal entry site element, both in the context of an infectious virus genome and of a replicon lacking the genes of the surface proteins prM/M and E. The expression level and the stability of expression were measured by fluorescence-activated cell-sorting analysis and compared to an established alphavirus replicon vector derived from Venezuelan equine encephaltis virus (VEEV), expressing EGFP under the control of its natural subgenomic promoter.

Incorporation of tick-borne encephalitis virus replicons into virus-like particles by a packaging cell line.

RNA replicons derived from flavivirus genomes show considerable potential as gene transfer and immunization vectors. A convenient and efficient encapsidation system is an important prerequisite for the practical application of such vectors. In this work, tick-borne encephalitis (TBE) virus replicons and an appropriate packaging cell line were constructed and characterized.

Online SAXS investigations of polymeric hollow fibre membranes.

Polymeric membranes are used in industrial and analytical separation techniques. In this study small-angle X-ray scattering (SAXS) with synchrotron radiation has been applied for in-situ characterisation during formation of polymeric membranes. The spinning of a polyetherimide (PEI) hollow fibre membrane was chosen for investigation of dynamic aggregation processes during membrane formation, because it allows the measurement of the dynamic equilibrium at different distances from the spinning nozzle.

Characterisation of structure and aggregation processes of aquatic humic substances using small-angle scattering and X-ray microscopy.

Aquatic humic substances (HS), an important part of the dissolved organic carbon in freshwater systems, are polyfunctional natural compounds with polydisperse structure showing strong aggregation/coagulation behaviour at high HS concentrations and in the presence of metal ions. In this study, small-angle neutron scattering (SANS), small-angle X-ray scattering (SAXS) and X-ray microscopy (XRM) were applied to characterise the structure and aggregation processes of HS in solution. In SAXS and XRM the high brilliant synchrotron radiation was used as X-ray source.