In situ imaging using (scanning) transmission electron microscopy has proven to be an extremely important and powerful cross-disciplinary scientific technique. In particular nanotechnology and materials sciences have special interest in assembly and disintegration processes, in growth and shape-tuning of (nano)-particles, and, furthermore in mechanistic studies of chemical reactions underlying these processes. However, limitations for in liquid and in situ imaging using electron microscopy arise from the stringent experimental conditions required with respect to electron scattering.

Here, we present a nanofluidic sample cell allowing for controlled fluidic conditions which preserve the highest possible spatial resolution for in-liquid electron microscopy. The nanocell allows for liquid flow with a flow control mechanism operated external to the microscope column enabling on-the-fly sample exchange within the imaging area. A well-defined flow path allows us to direct the motion of gold nanorods through fluid flow. Further a particle’s Brownian motion becomes evident once the external flow is terminated. In addition to quantitatively showing the resolution capabilities of our nanofluidic design, we show preliminary results of in situ imaging of gold nanorods and unstained amyloid fibrils to emphasize the significance of this imaging modality for both material sciences and biology.

Triboemission comprises the emission of low energy electrons and photons, the eventual formation of micro-triboplasmas, and the possible charge-initiated tribochemical reactions on the surfaces under contact. Electron triboemission is often seen as a case of electron exoemission, but such low-energy output may be just a fraction of the total electronic excitation on the surface, the majority of which may proceed as internal currents. The dynamics of these related surface phenomena have been investigated by different techniques, which are discussed in this work; in particular, the authors have obtained extensive data indicating that electrons and photons are produced from mechanical surface work, particularly from surface oxides and semiconductors under contact sliding in vacuum. This paper also discusses the existing body of work on triboemission, and the possible use of the developed measurement techniques as novel probes for surface processes.

We demonstrate the potential of spectroscopic ellipsometry for the investigation of the chain segment density profile and layer thickness during the temperature-induced, reversible collapse−expansion transition of poly(N-isopropylacrylamide) (PNIPAM) grafted layers with variable grafting densities in aqueous systems. To obtain a quantitative description of the thickness of our swollen PNIPAM layers, various models were implemented to fit the ellipsometric data. From the ellipsometry results, the density and thickness variation accompanying the collapse transition across the lower critical solution temperature (LCST) was characterized. The collapse can be adequately explained by considering the PNIPAM film to consist of two layers: (i) a dense layer near the surface and (ii) a more diluted layer with a gradient density profile on the side of the film exposed to the solvent.

The sorption processes for hydrogen and carbon dioxide are of considerable, and growing interest, particularly due to their relevance to a society that seeks to replace fossil fuels with a more sustainable energy source. X-ray diffraction allows a unique perspective for studying structural modifications and reaction mechanisms that occur when gas and solid interact. The fundamental challenge associated with such a study is that experiments are conducted while the solid sample is held under a gas pressure. To date in-situ high gas pressure studies of this nature have typically been undertaken at large-scale facilities such as synchrotrons or on dedicated laboratory instruments. Here we report high-pressure XRD studies carried out on a multi-purpose diffractometer. To demonstrate the suitability of the equipment, two model studies were carried out, firstly the reversible hydrogen cycling over LaNi5, and secondly the structural change that occurs during the decomposition of ammonia borane that results in the generation of hydrogen gas in the reaction chamber. The results have been finally compared to the literature. The study has been made possible by the combination of rapid X-ray detectors with a reaction chamber capable of withstanding gas pressures up to 100 bar and temperatures up to 900 °C.

The application of magnetography as a novel method to determine the state of charge (SoC) of commercial Li-ion Batteries is reported. The method is non-invasive and nondestructive and suitable to be applied during normal operation. It is based on spatially resolved measurement of the magnetic field B, induced by the changing current flow during cycling. A standardized measurement setup and procedure for conventional AMR-sensors has been developed, offering high reproducibility (∼0.1%) and the chance to characterize the different spatial components of the magnetic field (Bx, By, Bz). The percentage deviation of the B-distributions for different SoCs for a given current load reveals significant differences. A change of B of up to 20% between SoCs of 90% and 10% is found. The influence of current density at different SoC reveals a constant magnetic susceptibility χ at low SoC and a field dependent χ at high SoC. Both effects are attributed to the change of the magnetic properties upon varying the amount of intercalated lithium in the transition metal (LixNi1/3Co1/3Mn1/3O2) based intercalation cathode. The method can be used to provide an additional parameter for SoCestimation to battery management systems.