Air-to-air atmospheric pressure plasma treatment – perspective for composite manufacturing

Fibre-reinforced polymer composites are gaining increasing attention in various applications for constructing mechanical structures such as wind turbine blades. The interface between fibres and a polymer matrix should be optimally designed to promote the mechanical performance of the composites. Plasma treatment shows obvious advantages over conventional approaches, since it has the characteristic of environmental friendliness, low-cost, and easy operation. A plasma can be favourably generated at atmospheric pressure. One of the most commonly used atmospheric pressure plasmas is a dielectric barrier discharge (DBD). In the present work, an air-to-air DBD is introduced. The DBD was generated in a gas mixture of helium and fluorocarbon between a rod-shaped water-cooled powered electrode covered with alumina and a one-dimensionally movable ground aluminium plate. Polyethylene terephthalate films were used as model specimens, and attached on the aluminium plate for the surface modification. The results indicate that specimen surfaces can be oxidized or fluorinated, depending on the conditions, and that the gap between the electrodes and gas flowrates significantly affect the treatment effect.Included are the conference paper and the accompanying presentation

Nanoscale, zero valent iron particles for application as oxygen scavenger in food packaging

Oxygen scavengers which are based on oxidation of iron powder dispersed in a polymer matrix are established in the packaging industry. They protect foods from oxygen. The iron particles have a diameter of several micrometers, which is too high to allow thin layers in multilayer film structures. A promising alternative is a developed nanoscale oxygen scavenger which is subject of this study. The aim of this study was to evaluate the oxygen absorption rate and the oxygen absorption capacity of nanoscale iron at 100% relative humidity and at dry conditions. Nanoscale oxygen scavengers (zero valent iron particles) were synthesized. Their reactivity was tested. Furthermore, they were blended with a silicone matrix. The nanoscale oxygen scavenger absorbed oxygen in wet (100% relative humidity) and dry conditions. At 100% relative humidity the reaction rate of the powder was two to three times higher compared to non-nanoscale iron powder. The absorption rate of the nanoscale i ron dispersed in a silicon carrier was at least ten times higher at 100% relative humidity compared to a commercially available iron based oxygen scavenger in a polyethylene or polypropylene polymer matrix