Not so biodegradable: Polylactic acid and cellulose/plastic blend textiles lack fast biodegradation in marine waters.

The resistance of plastic textiles to environmental degradation is of major concern as large portions of these materials reach the ocean. There, they persist for undefined amounts of time, possibly causing harm and toxicity to marine ecosystems. As a solution to this problem, many compostable and so-called biodegradable materials have been developed.

Degradation of synthetic and wood-based cellulose fabrics in the marine environment: Comparative assessment of field, aquarium, and bioreactor experiments.

As global production of textiles rapidly grows, there is urgency to understand the persistence of fabrics in the marine environment, particularly from the microfibers they shed during wearing and washing. Here, we show that fabrics containing polyester (one of the most common plastics) remained relatively intact (viz., with a limited biofilm) after >200 days in seawater off the Scripps Oceanography pier (La Jolla, CA), in contrast to wood-based cellulose fabrics that fell apart within 30 days.

LiCoTeO: synthesis, single-crystal structure and physical properties of a new tellurate compound with Co/Co mixed valence and orthogonally oriented Li-ion channels.

A tellurate compound with Co/Co mixed valence states and lithium ions within orthogonally oriented channels was realized in LiCoTeO. The single-crystal structure determination revealed two independent and interpenetrating Li/O and (Co,Te)/O substructures with octahedral oxygen coordination of the metal atoms. In contrast to other mixed oxides, a honeycomb-like ordering of CoO and TeO octahedra was not observed.

Surface chemistry and stability of metastable corundum-type InO.

To account for the explanation of an eventual sensing and catalytic behavior of rhombohedral InO (rh-InO) and the dependence of the metastability of the latter on gas atmospheres, in situ electrochemical impedance spectroscopic (EIS), Fourier-transform infrared spectroscopic (FT-IR), in situ X-ray diffraction and in situ thermogravimetric analyses in inert (helium) and reactive gases (hydrogen, carbon monoxide and carbon dioxide) have been conducted to link the gas-dependent electrical conductivity features and the surface chemical properties to its metastability towards cubic InO. In particular, for highly reducible oxides such as InO, for which not only the formation of oxygen vacancies, but deep reduction to the metallic state (i.e.

Surface chemistry of pure tetragonal ZrO and gas-phase dependence of the tetragonal-to-monoclinic ZrO transformation.

The surface chemical properties of undoped tetragonal ZrO and the gas-phase dependence of the tetragonal-to-monoclinic transformation are studied using a tetragonal ZrO polymorph synthesized via a sol-gel method from an alkoxide precursor. The obtained phase-pure tetragonal ZrO is defective and strongly hydroxylated with pronounced Lewis acidic and Brønsted basic surface sites. Combined in situ FT-infrared and electrochemical impedance measurements reveal effective blocking of coordinatively unsaturated sites by both CO and CO, as well as low conductivity.

Evidence for dissolved hydrogen in the mixed ionic-electronic conducting perovskites LaSrFeO and SrTiFeO.

Two mixed ionic-electronic conducting, Fe-containing perovskites were investigated regarding their reducibility in dry H, namely lanthanum strontium ferrite (LSF4, LaSrFeO) and strontium titanium ferrite (STF3, SrTiFeO). Upon treatment under comparable reduction conditions, LSF4 is by far more affected by reduction and is reduced more deeply than STF3. Thermal treatments of fully oxidized or slightly reduced LSF4/STF3 at decreased O partial pressure lead to spontaneous desorption of O.

Structural and Electrochemical Properties of Physisorbed and Chemisorbed Water Layers on the Ceramic Oxides Y2O3, YSZ, and ZrO2.

A combination of operando Fourier transform infrared spectroscopy, operando electrochemical-impedance spectroscopy, and moisture-sorption measurements has been exploited to study the adsorption and conduction behavior of H2O and D2O on the technologically important ceramic oxides YSZ (8 mol % Y2O3), ZrO2, and Y2O3. Because the characterization of the chemisorbed and physisorbed water layers is imperative to a full understanding of (electro-)catalytically active doped oxide surfaces and their application in technology, the presented data provide the specific reactivity of these oxides toward water over a pressure-and-temperature parameter range extending up to, e.g.

Structural and chemical degradation mechanisms of pure YSZ and its components ZrO2 and Y2O3 in carbon-rich fuel gases.

Structural and chemical degradation mechanisms of metal-free yttria stabilized zirconia (YSZ-8, 8 mol% Y2O3 in ZrO2) in comparison to its pure oxidic components ZrO2 and Y2O3 have been studied in carbon-rich fuel gases with respect to coking/graphitization and (oxy)carbide formation. By combining operando electrochemical impedance spectroscopy (EIS), operando Fourier-transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS), the removal and suppression of CH4- and CO-induced carbon deposits and of those generated in more realistic fuel gas mixtures (syngas, mixtures of CH4 or CO with CO2 and H2O) was examined under SOFC-relevant conditions up to 1273 K and ambient pressures. Surface-near carbidization is a major problem already on the "isolated" (i.

High-Temperature Carbon Deposition on Oxide Surfaces by CO Disproportionation.

Carbon deposition due to the inverse Boudouard reaction (2CO → CO + C) has been studied on yttria-stabilized zirconia (YSZ), YO, and ZrO in comparison to CH by a variety of different chemical, structural, and spectroscopic characterization techniques, including electrochemical impedance spectroscopy (EIS), Fourier-transform infrared (FT-IR) spectroscopy and imaging, Raman spectroscopy, and electron microscopy. Consentaneously, all experimental methods prove the formation of a more or less conducting carbon layer (depending on the used oxide) of disordered nanocrystalline graphite covering the individual grains of the respective pure oxides after treatment in flowing CO at temperatures above ∼1023 K. All measurements show that during carbon deposition, a more or less substantial surface reduction of the oxides takes place.

Enhanced kinetic stability of pure and Y-doped tetragonal ZrO2.

The kinetic stability of pure and yttrium-doped tetragonal zirconia (ZrO2) polymorphs prepared via a pathway involving decomposition of pure zirconium and zirconium + yttrium isopropoxide is reported. Following this preparation routine, high surface area, pure, and structurally stable polymorphic modifications of pure and Y-doped tetragonal zirconia are obtained in a fast and reproducible way. Combined analytical high-resolution in situ transmission electron microscopy, high-temperature X-ray diffraction, and chemical and thermogravimetric analyses reveals that the thermal stability of the pure tetragonal ZrO2 structure is very much dominated by kinetic effects.

A high-temperature, ambient-pressure ultra-dry operando reactor cell for Fourier-transform infrared spectroscopy.

The construction of a newly designed high-temperature, high-pressure FT-IR reaction cell for ultra-dry in situ and operando operation is reported. The reaction cell itself as well as the sample holder is fully made of quartz glass, with no hot metal or ceramic parts in the vicinity of the high-temperature zone. Special emphasis was put on chemically absolute water-free and inert experimental conditions, which includes reaction cell and gas-feeding lines.

Hydrogen Surface Reactions and Adsorption Studied on YO, YSZ, and ZrO.

The surface reactivity of YO, YSZ, and ZrO polycrystalline powder samples toward H has been comparatively studied by a pool of complementary experimental techniques, comprising volumetric methods (temperature-programmed volumetric adsorption/oxidation and thermal desorption spectrometry), spectroscopic techniques (in situ electric impedance and in situ Fourier-transform infrared spectroscopy), and eventually structural characterization methods (X-ray diffraction and scanning electron microscopy). Reduction has been observed on all three oxides to most likely follow a surface or near-surface-limited mechanism involving removal of surface OH-groups and associated formation of water without formation of a significant number of anionic oxygen vacancies. Partly reversible adsorption of H was proven on the basis of molecular H desorption.

Methane Decomposition and Carbon Growth on YO, Yttria-Stabilized Zirconia, and ZrO.

Carbon deposition following thermal methane decomposition under dry and steam reforming conditions has been studied on yttria-stabilized zirconia (YSZ), YO, and ZrO by a range of different chemical, structural, and spectroscopic characterization techniques, including aberration-corrected electron microscopy, Raman spectroscopy, electric impedance spectroscopy, and volumetric adsorption techniques. Concordantly, all experimental techniques reveal the formation of a conducting layer of disordered nanocrystalline graphite covering the individual grains of the respective pure oxides after treatment in dry methane at temperatures ≥ 1000 K. In addition, treatment under moist methane conditions causes additional formation of carbon-nanotube-like architectures by partial detachment of the graphite layers.

In Situ FT-IR Spectroscopic Study of CO and CO Adsorption on YO, ZrO, and Yttria-Stabilized ZrO.

In situ FT-IR spectroscopy was exploited to study the adsorption of CO and CO on commercially available yttria-stabilized ZrO (8 mol % Y, YSZ-8), YO, and ZrO. All three oxides were pretreated at high temperatures (1173 K) in air, which leads to effective dehydroxylation of pure ZrO. Both YO and YSZ-8 show a much higher reactivity toward CO and CO adsorption than ZrO because of more facile rehydroxylation of Y-containing phases.

Immunolocalization of BK channels in hippocampal pyramidal neurons.

Neurons are highly specialized cells in which the integration and processing of electrical signals critically depends on the precise localization of ion channels. For large-conductance Ca(2+)- activated K(+) (BK) channels, targeting to presynaptic membranes in hippocampal pyramidal cells was reported; however, functional evidence also suggests a somatodendritic localization. Therefore we re-examined the subcellular distribution of BK channels in mouse hippocampus using a panel of independent antibodies in a combined approach of conventional immunocytochemistry on cultured neurons, pre- and postembedding electron microscopy and immunoprecipitation.