Liquid film deposition of chalcogenide thin films

Thin films of MoSx were prepared by liquid film deposition of MoS42- solutions in 1,2-diaminoethane (en) and 1,2-diaminopropane (pn) and subsequent thermolysis at temperatures up to 800°C under N2. As the coatings show a high carbon content of up to 30 at.% that influences the morphology and the physical properties, the precursor thermolysis and the solution properties were analysed in detail and correlated to the coating properties. A reduction of the intermediately formed MoS3 by organic residues at approx. 300°C was made out as the main cause of the carbon contamination during the thermolysis of the precursor salts (enH2)MoS4 and (pnH2)MoS4, leading to an immobilisation of the organic carbon. In the corresponding solutions cations of the form [RNH2...H...NH2R]+ could be detected, that result in an incorporation of additional diamine with 3-4 molecules per MoS42- ion in the wet films. This cross-linked structure on the one hand reduces the tendency of the precursor salts to crystallise and thus makes it easier to obtain amorphous precursor films, but on the other hand increases the content of organic residues before thermolysis

Wet chemical deposition of transparent conducting coatings in glass tubes

A modified dip coating process was developed to deposit transparent conducting sol-gel SnO2:Sb (ATO, antimony doped tin oxide) coatings inside tubes and cavities in optical quality. The necessity for this improvement arises from the fact that the conventional dip coating process applied to tubes results in coatings with poor and non-reproducible properties, showing large variations in the thickness, an increased roughness and an island-like morphology. The main reason for this is found in a delayed and restricted solvent evaporation, due to an impediment of a laminar flow and a progressive saturation of the atmosphere inside the tube. By means of an additional exhausting pipe, a forced laminar flow was, therefore, generated inside the tube, which guarantees a fast evaporation and hydrolysis of the sol-gel films by a continuous renewal of the atmosphere. In this way, ATO coatings with an excellent thickness uniformity and a low roughness of Ra ≈ nm could be deposited on borosilicate glass tubes of 300 mm length and inner diameters down to 11 mm. After a heat treatment at temperatures up to 550 °C, single layer coatings exhibit a high optical transmission (T>85%) and a resistance down to 10 kΩ over a length of 22 cm

Liquid film spray deposition of transparent conducting oxide coatings

A room temperature spraying technique was developed for the deposition of transparent conducting sol-gel ATO (antimony doped tin oxide, SnO2:Sb) coatings, based on an 0.2 M solution of SnCl2 in 1-propanol with 5 mol.% SbCl3 and a mixture of 2-isopropoxyethanol and 2-butoxyethanol as additives with a low evaporation rate. The selection of solvents and the adjustment of the evaporation rate are crucial to obtain uniform films and to avoid film defects like wetting problems or an orange peel effect. The ATO coatings were spray deposited manually on complex shaped substrates as well as on large area flat substrates with a size up to 21 x 30 cm2 by means of an industrial flat spray coater. The resulting ATO coatings are characterised by a thickness of up to 120 nm, a resistivity of approximately 2 x 10-2 Ω cm and a transmission T>85% in the visible, which is similar to the properties obtained for dip coated films

Transparent conducting sol-gel ATO coatings for display applications by an improved dip coating technique

Transparent conducting coatings of sol—gel ATO (antimony-doped tin oxide) were used to improve surface smoothness of commercial sputter-deposited ITO (indium tin oxide) coatings for application as display electrodes. In order to overcome the deteriorating evaporation-cooling during dip coating, the coating solution was heated moderately to 25 °C thus providing the substrate with the required heat. This way, the surface roughness of the ITO could be reduced with an only 45 nm thick ATO coating to Rpv = 3.8 nm (Ra = 0.4 nm) compared to 31 nm (3.8 nm) for the ITO substrate. Another benefit of such additional coating is the possibility to tailor surface properties of the electrodes in wide ranges. This was used to increase the work function of the ITO substrate from initially 4.3—4.6 eV to about 4.8—5.2 eV by the ATO coating

Strategies for novel transparent conducting sol-gel oxide coatings

Transparent conducting coatings of doped SnO2 and Zn2SnO4 have been deposited by the sol—gel technique on borosilicate and alumosilicate glass substrates, respectively. As films of SnO2 : Sb (ATO) show some intrinsic drawbacks, which are discussed in this report, alternative dopants for SnO2 such as Ta, Nb and W, were examined concerning the electrical and optical properties of the deposited coatings. In this way, coatings with resistivities on the order of

Multilayer SnO2:Sb transparent electronic conducting coatings made by the sol-gel process

Transparent conducting thin sol-gel SnO2:Sb multilayer coatings having the same total thickness, but different numbers of layers have been deposited on borosilicate glass by the dip-coating method using an ethanolic solution of SnCl2 (OAc)2 doped with 5mol% SbCl3. The densification of the multilayers was done by 3 different processes. In process I each layer was dried at 200°C and the coating process repeated to obtain a tick dry coating which was then sintered as a whole at 550°C. In process II every single layer was dried at 120°C and then directly sintered at 550°C before repeating the coating process. In process III every single layer was directly sintered at 550°C without drying step. The electrical properties and the morphologies of the coatings depend highly on the sintering and drying conditions. With process I all layers are homogenous and have a high resistivity (1.4x10 -² Omega cm) whatever their thickness. The multilayers produced by process II and III show a sandwich structure with alternated dense and porous layers. The resistivity of a 10 times dipped multilayers obtained by these processes is about 3,2X^0 -³ Omega cm. Moreover the electrical properties vary with the number of layers whereas in process I no such correlation can be found. A model was developed which allows to caclulate the electrical properties of the dense and porous layers. The chemical composition of the homogeneous coating and of the multilayers with the alternated structure is also reported

Jamming under tension in polymer crazes

Molecular dynamics simulations are used to study a unique expanded jammed state. Tension transforms many glassy polymers from a dense glass to a network of fibrils and voids called a craze. Entanglements between polymers and interchain friction jam the system after a fixed increase in volume. As in dense jammed systems, the distribution of forces is exponential, but they are tensile rather than compressive. The broad distribution of forces has important implications for fibril breakdown and the ultimate strength of crazes.Comment: 4 pages, 4 figure

Survival, functional outcome and satisfaction of first revision total knee arthroplasty at a mean eleven-year follow-up.

PURPOSE Providing long-term outcome data after rTKA and compare one- versus two-stage and septic versus aseptic revisions. METHODS This study represents a single-center retrospective study of first rTKAs performed for any reason with a final follow-up of a minimum of five years. Outcome parameters included stability assessment ROM, radiologic assessment, HSS score, KSS score, OKS score, EQ-5D-3L and VAS. 44 patients were included in the study. Subgroups analysis of one- versus two-stage revision and septic versus aseptic revision was performed. RESULTS The leading causes of rTKA in this mean 11 year follow-up study were aseptic loosening (36%) and periprosthetic joint infection (27%). At the final follow-up, there was a 89% survivorship of the implants. Patients showed a ROM of 114 ± 13°, HSS score of 78 ± 12, KKS objective score of 77 ± 16, KSS expectation and satisfaction score of 32 ± 11, KSS functional activity score of 50 ± 20, OKS of 30 ± 9, VAS of 53 ± 25 and EQ-5D index of 0.649. Functional outcome scores were not significantly altered in the analyzed subgroups. CONCLUSIONS In our 11 years follow-up, we obtained 89% implant survivorship. Measurements regarding functional outcome and pain showed results in the medium range of the respective scores, while patient satisfaction lay in the upper third. No significant differences in outcome scores between one- and two-stage revisions and septic versus aseptic revisions were observed. Level of Evidence Level III, retrospective cohort study