Acid-functionalized PVA composite membranes for pervaporation-assisted esterification.

Composite flat-sheet membranes functionalized with imidazolium-based ionic liquids (ILs) grafted to poly(vinyl alcohol)/glutaraldehyde as a catalytic layer were developed to enhance the esterification between -butanol and acetic acid. The functionalized membranes were produced dip-coating commercial pervaporation membranes, and two distinct Brønsted-acidic ILs with an imidazolium-based cation and different (hydrogen sulfate [HSO] or bromide [Br]) anions were compared. Compact, 12 μm-thick, defect-free catalytic layers were observed on top of the pervaporation membrane supports, and the determined penetration depth of the ILs confirmed their presence in the upper part of the coating.

Improving Spatial Resolution by Reinterpreting Dosage for Laser-Induced Breakdown Spectroscopy Imaging: Conceptualization and Limitations.

Elemental imaging in laser-induced breakdown spectroscopy is usually performed by placing laser shots adjacent to each other on the sample surface without spatial overlap. Seeing that signal intensity is directly related to the amount of ablated material, this restricts either spatial resolution (for a given excitation efficiency) or sensitivity (when reducing the laser spot size). The experimental applicability of a concept involving the spatial overlapping of shots on the sample surface is investigated and compared to the conventional approach.

Polymerized ionic liquid Co-catalysts driving photocatalytic CO transformation.

Photocatalytic production of CO from CO has the potential for safe and atom-economic production of feedstock chemicals carbonylation chemistry. We developed novel ionic liquid-based polymeric materials through radical copolymerisation of 1-butyl-3-vinylimidazolium chloride and photocatalytically active Re- and Ru-complexes that serve as the CO reduction catalyst and photosensitiser, respectively. The crosslinked polymeric framework allows for the facile immobilisation of molecular organometallic complexes for use as heterogenised catalysts; moreover, the involved imidazolium core units co-catalyze the reduction of CO covalent interaction.

Assessing spatial distribution of bioindicator elements in various cutaneous tumors using correlative imaging with laser-ablation-based analytical methods.

Correlative imaging of cutaneous tumors provides additional information to the standard histopathologic examination. However, the joint progress in the establishment of analytical techniques, such as Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) in clinical practice is still limited. Their combination provides complementary information as it is also shown in our study in terms of major biotic (Ca, Mg, and P) and trace (Cu and Zn) elements.

Development of a defined medium for the heterotrophic cultivation of Metallosphaera sedula.

The heterotrophic cultivation of extremophilic archaea still heavily relies on complex media. However, complex media are associated with unknown composition, high batch-to-batch variability, potential inhibiting and interfering components, as well as regulatory challenges, hampering advancements of extremophilic archaea in genetic engineering and bioprocessing. For Metallosphaera sedula, a widely studied organism for biomining and bioremediation and a potential production host for archaeal ether lipids, efforts to find defined cultivation conditions have still been unsuccessful.

Towards a circular economy - Repurposing side streams from the potato processing industry by Chlorella vulgaris.

Common wastewater treatment strategies in the food industry do not include efficient remediation strategies for nitrogen, phosphorous and organic carbon. Incorporating microalgae in water treatment plants is rising in popularity because of their high nutrient and trace element uptake driven by light. In this study, four different side streams from an Austrian potato processing company have been screened for their applicability of microalgal cultivation.

LIBS as a novel tool for the determination of the imidization degree of polyimides.

Due to their outstanding chemical and physical properties, polyimides are widely used in industrial applications. The degree of imidization of polyimides significantly influences their properties, making it an important factor in tailoring the material for specific applications. Imidization refers to the process of converting a precursor poly(amic acid) by removing water, and it is essential to analyze this process in detail to tune the final structure and properties of the material.

Capabilities of simultaneous 193 nm - LIBS/LA-ICP-MS imaging for microplastics characterization.

Microplastics (MPs) are currently one of the major environmental challenges within our society. With the awareness of the impact of MPs on the environment increasing over the last years, the need for increased monitoring as well as comprehensive analysis to better understand the fate and impact of MPs has become more and more important. A major aspect of MP characterization is the assignment of the polymer type of individual particles.

Quantitative elemental mapping of biological tissues by laser-induced breakdown spectroscopy using matrix recognition.

The present study demonstrates the importance of converting signal intensity maps of organic tissues collected by laser-induced breakdown spectroscopy (LIBS) to elemental concentration maps and also proposes a methodology based on machine learning for its execution. The proposed methodology employs matrix-matched external calibration supported by a pixel-by-pixel automatic matrix (tissue type) recognition performed by linear discriminant analysis of the spatially resolved LIBS hyperspectral data set. On a swine (porcine) brain sample, we successfully performed this matrix recognition with an accuracy of 98% for the grey and white matter and we converted a LIBS intensity map of a tissue sample to a correct concentration map for the elements Na, K and Mg.

Laser ablation-inductively coupled plasma-mass spectrometry analysis reveals differences in chemotherapeutic drug distribution in surgically resected pleural mesothelioma.

Aims: Pleural mesothelioma (PM) is a highly aggressive thoracic tumour with poor prognosis. Although reduced tissue drug accumulation is one of the key features of platinum (Pt) resistance, little is known about Pt distribution in human PM.

Methods: We assessed Pt levels of blood samples and surgically resected specimens from 25 PM patients who had received neoadjuvant Pt-based chemotherapy (CHT).

A novel measurement strategy and a dedicated sampling cell for the parallel characterization of organic and inorganic constituents in polymer samples by concurrent laser ablation ICP-OES and EI-MS.

Polymeric composite materials are gaining importance due to their universal applicability and easy adaptability for their intended use. For the comprehensive characterization of these materials, the concurrent determination of the organic and the elemental constituents is necessary, which cannot be provided by classical analysis methods. In this work, we present a novel approach for advanced polymer analysis.

Surface Decorations on Mixed Ionic and Electronic Conductors: Effects on Surface Potential, Defects, and the Oxygen Exchange Kinetics.

The oxygen exchange kinetics of epitaxial PrCeO electrodes was modified by decoration with submonolayer amounts of different basic (SrO, CaO) and acidic (SnO, TiO) binary oxides. The oxygen exchange reaction (OER) rate and the total conductivity were measured by PLD impedance spectroscopy (-PLD), which allows to directly track changes of electrochemical properties after each deposited pulse of surface decoration. The surface chemistry of the electrodes was investigated by near-ambient pressure XPS measurements (NAP-XPS) at elevated temperatures and by low-energy ion scattering (LEIS).

A versatile approach for the preparation of matrix-matched standards for LA-ICP-MS analysis - Standard addition by the spraying of liquid standards.

In the last years, LA-ICP-MS has become an attractive technique for analyzing solid samples from various research fields. However, application in material science is often hampered by the limited availability of appropriate certified reference materials, which are a precondition for accurate quantification. Thus, frequently in-house prepared standards are used, which match the sample's composition and include all elements of interest at the required concentration levels.

Closed-Pore Formation in Oxygen Electrodes for Solid Oxide Electrolysis Cells Investigated by Impedance Spectroscopy.

Electrochemical impedance spectroscopy was used to investigate the chemical capacitance of LaSrCoO (LSC) thin-film electrodes under anodic polarization (i.e., in the electrolysis mode).

Li/H exchange of LiLaZrO single and polycrystals investigated by quantitative LIBS depth profiling.

LiLaZrO (LLZO) garnets are highly attractive to be used as solid electrolyte in solid-state Li batteries. However, LLZO suffers from chemical interaction with air and humidity, causing Li/H exchange with detrimental implication on its performance, processing and scalability. To better understand the kinetics of the detrimental Li/H exchange and its dependence on microstructural features, accelerated Li/H exchange experiments were performed on single crystalline and polycrystalline LLZO, exposed for 80 minutes to 80 °C hot water.

electrochemical observation of anisotropic lattice contraction of LaSrFeO electrodes during pulsed laser deposition.

LaSrFeO (LSF) electrodes were grown on different electrolyte substrates by pulsed laser deposition (PLD) and their oxygen exchange reaction (OER) resistance was tracked in real-time by PLD impedance spectroscopy (i-PLD) inside the PLD chamber. This enables measurements on pristine surfaces free from any contaminations and the direct observation of thickness dependent properties. As substrates, yttria-stabilized zirconia single crystals (YSZ) were used for polycrystalline LSF growth and LaSrGaMgO (LSGM) single crystals or YSZ single crystals with a 5 nm buffer-layer of GdCeO for epitaxial LSF film growth.

Laser-based techniques: Novel tools for the identification and characterization of aged microplastics with developed biofilm.

Microplastics found in the environment are often covered with a biofilm, which makes their analysis difficult. Therefore, the biofilm is usually removed before analysis, which may affect the microplastic particles or lead to their loss during the procedure. In this work, we used laser-based analytical techniques and evaluated their performance in detecting, characterizing, and classifying pristine and aged microplastics with a developed biofilm.

techniques reveal the true capabilities of SOFC cathode materials and their sudden degradation due to omnipresent sulfur trace impurities.

In this study, five different mixed conducting cathode materials were grown as dense thin films by pulsed laser deposition (PLD) and characterized impedance spectroscopy directly after growth inside the PLD chamber (i-PLD). This technique enables quantification of the oxygen reduction kinetics on pristine and contaminant-free mixed conducting surfaces. The measurements reveal excellent catalytic performance of all pristine materials with polarization resistances being up to two orders of magnitude lower than those previously reported in the literature.

Formation and Detection of High-Pressure Oxygen in Closed Pores of LaSrCoO Solid Oxide Electrolysis Anodes.

The chemical capacitance of LaSrCoO (LSC) thin film microelectrodes with different microstructures was investigated upon varying anodic DC voltages. Dense and porous electrodes (open porosity) were prepared by using different parameters during pulsed laser deposition (PLD). Furthermore, electrodes with closed porosity were fabricated by depositing a dense capping layer on a porous film.

Quantitative Depth Profiling Using Online-Laser Ablation of Solid Samples in Liquid (LASIL) to Investigate the Oxidation Behavior of Transition Metal Borides.

The increased demand for sustainability requires, among others, the development of new materials with enhanced corrosion resistance. Transition metal diborides are exceptional candidates, as they exhibit fascinating mechanical and thermal properties. However, at elevated temperatures and oxidizing atmospheres, their use is limited due to the fact of their inadequate oxidation resistance.

Performance modulation through selective, homogenous surface doping of lanthanum strontium ferrite electrodes revealed by PLD impedance measurements.

Accelerating the oxygen reduction kinetics of solid oxide fuel cell (SOFC) cathodes is crucial to improve their efficiency and thus to provide the basis for an economically feasible application of intermediate temperature SOFCs. In this work, minor amounts of Pt were doped into lanthanum strontium ferrite (LSF) thin film electrodes to modulate the material's oxygen exchange performance. Surprisingly, Pt was found to be incorporated on the B-site of the perovskite electrode as non metallic Pt.

Investigating oxygen reduction pathways on pristine SOFC cathode surfaces by PLD impedance spectroscopy.

The oxygen exchange reaction mechanism on truly pristine surfaces of SOFC cathode materials (LaSrCoO = LSC, LaSrFeO = LSF, (LaSr)PtFeO = Pt:LSF, SrTiFeO = STF, PrCeO = PCO and LaSrMnO = LSM) was investigated employing impedance spectroscopy during pulsed laser deposition (i-PLD) over a wide temperature and (O) range. Besides demonstrating the often astonishing catalytic capabilities of the materials, it is possible to discuss the oxygen exchange reaction mechanism based on experiments on clean surfaces unaltered by external degradation processes. All investigated materials with at least moderate ionic conductivity ( all except LSM) exhibit polarization resistances with very similar (O)- and -dependences, mostly differing only in absolute value.

Combining electrochemical and quantitative elemental analysis to investigate the sulfur poisoning process of ceria thin film fuel electrodes.

This work deals with the effect of sulfur incorporation into model-type GDC thin films on their in-plane ionic conductivity. By means of impedance measurements, a strongly deteriorating effect on the grain boundary conductivity was confirmed, which additionally depends on the applied electrochemical polarisation. To quantify the total amount of sulfur incorporated into GDC thin films, online-laser ablation of solids in liquid (online-LASIL) was used as a novel solid sampling strategy.

Elemental mapping of fluorine by means of molecular laser induced breakdown spectroscopy.

The growing importance of fluoropolymers in high-tech applications and green technologies results in the rising need for their characterization. In contrast to conventional methods used for this task, laser-induced breakdown spectroscopy (LIBS) provides the advantage of a spatially resolved analysis. Nevertheless, the high excitation energy of fluorine results in low sensitivity of the atomic F(I) lines, which limits the feasibility of its LIBS-based analysis.

Multisensor hyperspectral imaging approach for the microchemical analysis of ultramarine blue pigments.

This work presents a multisensor hyperspectral approach for the characterization of ultramarine blue, a valuable historical pigment, at the microscopic scale combining the information of four analytical techniques at the elemental and molecular levels. The hyperspectral images collected were combined in a single hypercube, where the pixels of the various spectral components are aligned on top of each other. Selected spectral descriptors have been defined to reduce data dimensionality before applying unsupervised chemometric data analysis approaches.