Cover Picture: Lithography‐Free,Self‐Aligned Inkjet Printing with Sub‐Hundred‐Nanometer Resolution (Adv. Mater. 8/2005)

The inherently low resolution of inkjet printing on unpatterned surfaces can be overcome by selective surface modification of a first printed pattern, resulting in hydrophobic repulsion of subsequently deposited aqueous polymer dispersions. This technique, reported by Sirringhaus and co‐workers on p. 997, is capable of achieving sub‐100 nm resolution without any lithographic step. The cover shows an array of polymer transistors patterned with this method on three different length scales, as well as a schematic of the process.     

Large‐Area,Uniform, Aligned Arrays of Na3(VO)2(PO4)2F on Carbon Nanofiber for Quasi‐Solid‐State Sodium‐Ion Hybrid Capacitors

Sodium–vanadium fluorophosphate (Na₃V₂O_2x(PO₄)₂F_3?2x, NVPF, 0 ≤ x ≤ 1) is considered to be a promising Na‐storage cathode material due to its high operation potentials (3.6–4 V) and minor volume variation (1.8%) during Na⁺‐intercalation. Research about NVPF is mainly focused on powder‐type samples, while its ordered array architecture is rarely reported. In this work, large‐area and uniform Na₃(VO)₂(PO₄)₂F cuboid arrays are vertically grown on carbon nanofiber (CNF) substrates for the first time. Owing to faster electron/ion transport and larger electrolyte–electrode contact area, the as‐prepared NVPF array electrode exhibits much improved Na‐storage properties compared to its powder counterpart. Importantly, a quasi‐solid‐state sodium‐ion hybrid capacitor (SIHC) is constructed based on the NVPF array as an intercalative battery cathode and porous CNF as a capacitive supercapacitor anode together with the P(VDF‐HFP)‐based polymer electrolyte. This novel hybrid system delivers an attractive energy density of ≈227 W h kg^?1 (based on total mass of two electrodes), and still remains as high as 107 Wh kg^?1 at a high specific power of 4936 W kg^?1, which pushes the energy output of sodium hybrid capacitors toward a new limit. In addition, the growth mechanism of NVPF arrays is investigated in detail.     

The Barrier Effect of EVOH versus 1,4,7‐Triaxocyclotridecane‐8,13‐Dione,a Non‐intentionally Added Compound from Polyurethane Adhesives in Multilayer Food Packaging

The presence and migration of non‐intentionally added substances in food packaging materials are the big concerns nowadays in terms of food safety, and the identification and quantitation are an important analytical challenge. Among non‐intentionally added substances, 1,4,7‐trioxacyclotridecane‐8,13‐dione, a by‐product resulting from the interaction between ingredients in many polyurethane adhesives, has been identified and quantified. Migration tests were carried out with food simulant E (Tenax®) and 3% acetic acid (simulant B) stored at 40°C/10 days using different adhesives and with different film thickness in the presence and absence of EVOH layer. After the exposure, Tenax® was extracted and analysed by gas chromatography with mass spectrometry. For 3% acetic acid, the analyses were directly performed by the Acquity® ultra‐performance liquid chromatography system coupled to triple quadrupole mass spectrometer detector. A possible degradation of the lactone after migration tests with 3% acetic acid occurred, and total degradation after 8 days was confirmed. Two compounds were detected and identified, which were also found in the migration extracts. Partition experiments were carried out from laminates composed by polypropylene film, adhesive and non‐treated polyethylene film at 40°C for 10 days. After this, the polypropylene/adhesive and polyethylene layers were independently extracted and analysed by gas chromatography with mass spectrometry. Diffusion studies were carried out following the Moisan procedure. The results and conclusions are shown and discussed.     

Influence of the Al(Co,Ni) layer on the corrosion resistance of a cobalt based alloy (Mar‐M‐509®)

In the present work, the results of studies on the structure and corrosion resistance of Al(Co, Ni) layer are shown. The diffusion Al(Co, Ni) layer was created on the cobalt alloy Mar‐M‐509 substrate by chemical vapor deposition (CVD) method with aluminum trichloride (AlCl₃) under the hydrogen atmosphere. The scanning electron microscope (SEM) observations and microtomography measurements of layers were performed. Also an analysis of the chemical (energy‐dispersive X‐ray spectroscopy (EDS)) and phase (X‐ray diffraction (XRD)) composition was carried out. By the X‐ray diffraction method (sin² φ) also the residual stresses were calculated in the matrix of the material. The corrosion resistance was tested with impedance and potentiodynamic methods in 0.1 M Na₂SO₄, 0.1 M H₂SO₄ solutions and acidulous 0.1 M NaCl solution (pH = 4.2) at room temperature. The results indicate that the analyzed layer with a thickness of about 14 μm have a similar corrosion resistance compared to the base material – Mar‐M‐509^® cobalt alloy. Only in the strongly acidic environments, the corrosion resistance of the layer is remarkably decreased.