An Ammonium Argentothiosulphate Bromide

A sparingly-soluble ammonium argentothiosulphate bromide salt (called B-salt) has been prepared by the addition of excess silver bromide to an ammonium thiosulphate solution over the concentration range 0·5 M to 2·5 M. Its nearest “simple” empirical formula is (NH₄)₄(AgS₂O₃)₃Br. Chemical and physical properties of the salt are described. B-salt is formed in the practical fixing bath and in the photographic emulsion. The fixation of a bromo-iodide emulsion yields a B-salt containing a small quantity of iodide.     

Atmospheric-Pressure Plasma Amination of Polymer Surfaces

Using dielectric barrier discharges (DBDs) in suitable gas atmospheres, appreciable densities of amino groups can be generated on polymer surfaces. After the introduction and a few remarks on analytical methods for the determination of functional groups densities, this paper presents a short summary of recent studies on the mechanism of the polymer surface amination from nitrogen and nitrogen/hydrogen mixtures, and possible relevant precursor species. Combination of chemical derivatization with quantitative FT-IR spectroscopy was employed for the determination of primary amino groups densities introduced on polyolefin surfaces in DBD afterglows in N₂ and N₂ + H₂ mixtures. Owing to the possibility to generate atmospheric-pressure plasmas in sub-mm³ volumes, DBD plasmas can be used to modify polymer surfaces area selectively: a new process termed 'plasma printing' can be applied for the achievement of micropatterned surface modifications, such as hydrophilization/hydrophobization or chemical functionalization. Direct-patterning polymer surface modification processes are of interest for biochemical/biomedical applications as well as for polymer electronics. Two examples are presented in more detail: ? the area-selective plasma amination of carbon-filled polypropylene minidiscs to manufacture microarrays with peptide libraries utilizing parallel combinatorial chemical synthesis, and ?the continuous treatment of polymer foils by means of reel-to-reel patterned plasma amination for the subsequent electroless copper metallization, leading to a fast and highly efficient process for the manufacture of structured metallizations for flexible printed circuits or RFID antennas.     

New processes or old: complex shape processing of advanced ceramics

Abstract

Demand for advanced ceramics with more complex shapes continues to grow. This in combination with the need for more reliable components has forced manufacturers to look for improvements in their current processing techniques and to adopt new processes which may be better suited to fulfil market demand. New processing concepts have emerged over the past decade on two fronts, improved casting technologies, and rapid manufacturing routes that do not require moulds. In the present paper, examples of both routes are given. Possible advantages of combining conventional and emerging methods are discussed.     

Audio acoustic plant condition monitoring of spiral bevel gearbox

Abstract

Plant condition monitoring (PCM) is widely used by a variety of industries as part of a condition based maintenance programme. This replaces the previous ‘schedule’ based maintenance programme, in which individual components of a machine are replaced at specified intervals. With PCM the condition of the individual components is monitored, and they are only replaced when their performance is deemed unsatisfactory. PCM techniques are often capital and/or labour intensive, and their use limited to critical machines only. The objective of the present research is to develop a system comprised of microphones and accelerometers which is able to screen industrial environments, such as the hot rolling mill at Corus's Port Talbot plant, for machine faults. The system would use the minimum number of transducers to remotely screen the maximum number of machines, but is not required to provide detailed diagnostic information. To date, an omnidirectional microphone has been used successfully to detect badly damaged gear teeth. The method does not require the use of a soundproof enclosure to filter out background noise. A finite element analysis model of the test rig has been created to determine the eigenfrequencies and eigenmodes of the test rig and to improve the understanding of the vibration behaviour of the faults.     

The use of plasma pre-treatment for enhancing the performance of textile ink-jet printing

In this study the effect of low temperature plasma (LTP) treatment of cotton fabric for ink-jet printing was investigated. Owing to the specific printing and conductivity requirements for ink-jet printing, none of the conventional printing chemicals used for cotton fabric can be directly incorporated into the ink formulation. As a result, the cotton fabric requires treatment with the printing chemicals prior to the stage of ink-jet printing. The printing chemicals as a treatment to cotton fabric are applied by the coating method. The aim of this study was to investigate the possibility and effectiveness of applying LTP pre-treatment to enhance the performance of treatment paste containing sodium alginate, to improve the properties of the ink-jet printed cotton fabric. Experimental results revealed that the LTP pre-treatment in conjunction with the ink-jet printing technique could improve the final properties of printed cotton fabric.     

Double sided roll-to-roll manufacture of flexible display panels

A double sided roll-to-roll(R2R) system has been developed by the authors to automate the continuous manufacturing of flexible display panels.Here we report an overview of the system operation and the fabrication process.The system framework features a timer initiated slot-die coating followed by wet lamination to form a thin,active layer in between flexible conductive substrates.A rotary screen-printing unit is installed for adhesive deposition providing an edge seal for the panel.The system enables production of 15-cm~2 laminated panels.     

Synthesis of spherical lead zirconate titanate (PZT) nanoparticles by electrohydrodynamic atomisation

Abstract

This paper describes the production of spherical-shaped lead zirconate titanate (PZT) nanoparticles by the electrohydrodynamic atomisation (EHDA) process in order to make inks suitable for ink jet printing applications. PZT sols with different concentrations (0·1–0·6 M) were used as starting materials. Two different heating systems, gas heating and direct heating, were used in order to remove the solvent, reduce the particle size and stabilise the PZT particles. Several aspects have been considered, such as liquid flow rate, sol concentration and heat system temperature, and their influence on the particle dimension is determined. Using optimised processing parameters of direct heating at 520°C, 0·2 M precursor sol, flow rate of 0·2 mL h^?1 and field of 3 kV cm^?1, particles of 100–300 nm in diameter were synthesised. Following stabilisation at 300°C, the particles were suspended in a PZT sol to produce an ink suitable for ink jet printing.     

Textile-Based Sensors for Inspection of Composite Materials

The monitoring of mechanical deformation and damage of composite materials is normally performed by established analytical methods,such as strain gauges and opt...     

Characterization and adhesion testing of mixed silane-treated surfaces

Single silanes have been well studied as adhesion promoters, but there are areas of improvement that could use the properties of an additional silane. This research examines the combination of an adhesion promoter with a second silane of different chemical functionality in order, to increase the number of potential applications. Several techniques are investigated for producing mixed silane layers, including solution deposition, microcontact printing and vapor deposition. The second goal of this research is to determine the adhesion between polymers and heterogeneous micropatterned silanes. The two silanes used are n-octadecyltrichlorosilane (ODTS) and 3-aminopropyltriethoxysilane (APS). APS is an adhesion promoter between most polymers and oxide surfaces, while ODTS is very hydrophobic and has insignificant adhesion to polymers. Surfaces are characterized with an Atomic Force Microscope (AFM) with Pulsed Force Mode (PFM), allowing simultaneous topography, adhesion and stiffness measurements of the surface to be generated. In a 180°-peel test between poly(vinyl butyral) (PVB) and glass, the addition of ODTS results in the decrease of the surface energy and a dramatic decrease in adhesion. In a wedge test, the adhesion of APS is found to be proportional to the percent coverage.