Process combination substrate mineralization

Probably no single causal mechanism functions in the calcification process of neointima-lined or smooth surface polyurethanes. Rather, surface calcification is most likely a result of the combination and interaction of mechanical and surface chemical effects at the blood-surface interface. Mechanical damage to or physical imperfections on the polymeric substrate in smooth surface devices or the neointima lining of textured bladders may be capable of inducing a deposition and mineralization process. Calcification of tissue valve leaflets has been proposed to result from the diffusion of blood elements into mechanically disrupted tissue (10), thus providing a site for mineralization to occur. Likewise, deposits of calcium-chelating proteins or lipids in defects in neointimal tissue or the polymer substrate may act as precursor binding sites for the observed mineralization. 

Templeton et al. (2002a) used a combination of Pb Lm-XAFS and pXANES spectroscopy and transmission electron microscopy to show that B. cepacia causes biomineralization of Pb(II) in the form of highly insoluble pyromorphite at ( ) concentrations well below supersaturation with respect to pyromorphite. The phosphate in these minimal medium experiments is though to be provided by B. cepacia, and the pyromorphite forms on the outer cell membrane of B. cepacia. These types of studies are beginning to provide unique information on how microbial biofilms affect metal sorption processes at mineral surfaces, which is essential for understanding the transport and bioavailability of toxic metal ions in natural systems where such biofilms exist. They are also allowing quantitative evaluation of the competition between NOM (or biofilms) and the mineral substrates they coat for metal ion binding. 

This highly hygroscopic molecule readily combines with water molecules to form an acid aerosol droplet. Other aerosols are formed by nucleation around mineral particles injected as a result of volcanic activity. Under very cold conditions, such as at the poles in winter, these aerosols freeze to form polar stratospheric ice clouds (PSCs), the surfaces of which provide a substrate for important heterogeneous catalytic processes. An example of this is the well-known ozone hole effect. This arises because the steady state concentration of O3 is sustained by the series of reactions (5.1) and (5.21)-(5.25). As already discussed, the sink mechanism (5.24) and (5.25) requires the presence of catalyst X, of which Cl atoms are nowadays the most important, and which are provided, such as reaction (5.26), mainly by the photolysis of CFCs present at trace levels in the upper atmosphere and much of the Cl is temporarily locked up into the reservoir species such as HCl and ClOx-... 

The Plasmadust process is suitable for a wide variety of materials, and this opens up tremendous potential. The prerequisites are that the material has to be available in powder form and it has to melt inside the temperature window of the Plasmadust process. Along with the mainstream metals (copper, aluminum, gold, tin, bismuth, tellurium) and polymers (PTFE, PE, ABS, PP), glass, ceramic materials, semiconductors such as GIGS (copper, indium, gallium, sulfur, selenium), and even minerals like salt can be deposited on substrates such as metal, plastic, glass, ceramic, paper, card, and textiles. Another advantage is that the process can also handle alloys and material combinations such as carbon and metal [42,139,140,179). 

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