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Compatibility in the sense of a tendency to molecular mixture and mutual solubility is rare for two solid polymeric components. Thus, not only mixtures but also graft and block copolymers constitute two phase systems. Possibilities for identification of separate phases are discussed, including optical methods and determination of freezing and melting temperatures of the individual phases. Problems of preparation of two phase mixtures and the phase distribution arising thereby, including identification of disperse and continuous phases are discussed. Examples are given of little known polymer mixtures for which complete or partial compatibility exists.

In this article, heat transfer in microstructure devices and its application in laboratory and industry will be described.

In this publication heat transfer in microstructure devices and its application in laboratory and industry will be described. Basic principles of microstructure heat exchangers made of metal, ceramics and polymers will be presented. A variety of laboratory prototype applications will be shown as well as some examples for industrial use of not only microstructure heat exchangers but also microstructure devices as chemical reactors. A brief outlook will describe possible future application fields.

The extremely high mixing quality reached by microstructured mixers in diffusion mixing under laminar flow conditions, as well as in mixing under turbulent flows is attributed to short mixing paths. The design of the micro devices and mixing volumes determine the flow condition to be achieved. In devices fabricated according to the multi-lamination principle, for instance, both laminar and turbulent mixing may take place due to the generally large mixing volumes. In microstructures, where the mixing volume is only a bit larger than the supply channels of the fluids, the mixing quality is dependent on diffusion or secondary flow, which may improve the mixing results. Commonly, the latter mixers can be scaled up by multiplying the mixing geometry (numbering up of the devices). As very rapid reactions between the mixed media frequently occur in the gas mixing range (e.g., combustion reactions) and turbulent flow is preferred, the present contribution primarily deals with mixers designed by the Institute for Micro Process Engineering (IMVT) on the basis of the multi-lamination principle. Among the key aspects covered are the manufacture of the pressure-resistant metal devices by the microstructurization of foil bands and the characterization of these devices by determining their mixing qualities in the gas phase. Studies carried out to assess the suitability of these mixers as flame arresters are also presented. Some model applications will be highlighted.

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