The invention relates to an antimicrobial adhesive and coating substance that, as an antimicrobial constituent, contains metallic silver particles having a content of fewer than 5 ppm of silver ions, sodium ions and potassium ions.

Antimicrobial adhesive and coating substance and method for the production thereof

In antimicrobial material for implanting in bones or coating or producing an implant or implantable medical device, in which antimicrobial metal particles are finely dispersed in a material forming a matrix in the hardened state, the metal consists of aggregates of primary particles with an average particle size of 10-100 nm. Independent claims are also included for: (a) implants or implantable medical devices made from or (partly) coated with this material; and (b) the production of the material.

Antimicrobial powder and material

The spark plasma sintering behaviour of silver nanopowder prepared by the electro-explosion method was investigated. Consolidation was carried out from 50°C to 800°C for 5 mins at 34 MPa with differential scanning calorimetry indicating a sintering onset temperature as low as 160°C and an activation energy of 86±1 kJ/mol. Near full density resulted from treatment at 300°C, and at higher temperatures a normal Hall-Petch relation is obeyed. The enhancement of Vicker's hardness to 1000MPa for materials sintered at 300°C is three times greater than for silver annealed in a conventional way. While polysynthetic twinning contributes to superior hardness, the primary cause is the sub-micron grain size.

Spark plasma sintering of silver nanopowder

Disclosed is an absorbent sanitary article for absorbing body fluids which comprises a matrix containing metallic silver, wherein the silver is present bound to a fiber 24 exclusively on the surface thereof.

Absorbent sanitary article for absorbing body fluid

A preliminary, theoretical, analysis of the interfacial oxidization phenomena in a sprayed metal-carrier gas system was made to determine the initial conditions of the process which are compatible or not with surface saturation and the appearance of a separate oxide phase on the droplet surface. This discussion is based on previous theoretical and experimental works on single drop behavior. For the purpose of the discussion the liquid steady state, phase equilibrium and interfacial equilibrium conditions have been discussed; the material balance links of the phases and their coupling with the equilibrium equation have been examined; and the importance of the time variable and the various characteristic times has been underlined. Finally, by coupling the interface steady state conditions and oxygen material balance a set of sufficient conditions for obtaining a clean pure metallic phase has been derived.

Analysis of Oxygen-Condensate Interactions in Metal Powder Production : Sprayed Particles in a Carrier Gas Phase

Polymer found materials are made electrically conductive by compounding with a particulate conductive material. Carbon seat is used most often in anti-static applications and electromagnetic shielding. In this paper another type of filler material comprising highly porous metal powders (nanopowders) is evaluated that leads to improved thermonechanical properties of the composites at reaonably high electrical conductivity levels and et reduced metal contents. Such powders are produced by the inert gas condensation technique. The broad range of applications is exemplified with a cycloaliphatic epoxy matrix for use in electronic packaging. The mechanical properties of the cured polymer, nanopowder composites have been tested under shear loading and -40°C/150°C thermal cycling conditions. It is shown that these highly porous powders counterbalance the embrittling effect of a metal filler in polymer matrix composites. The underlying concept is not limited to conductive adhesives for chip-on-board bonding in the microelectronics industry.

B. H. Günther

Papers

Metal nanopowders for electrically conductive polymers