Glass microfibre papers

Industrial glass microfibre papers are made from fibres that are longer and have a smaller diameter (from <0.5 pm to >4 pm) than cellulose fibres, and the paper mat requires strengthening by the inclusion of a binder. Typical binders are latex, acrylic polymers or polyvinyl alcohol. Typical mean pore sizes are between about 3 pm and 30 pm. 

Glass microfibre papers are made from 100% borosilicate glass or pure quartz. Their mechanical strength stems in part from very high surface areas of the sub-micron fibres, and from entanglement of very long fibres. They are particularly suitable for quantitative work, and may be used at temperatures as high as 500°C or at low temperatures without embrittlement. 

Physical methods involve adsorption of the photosynthetic material on a support or the inclusion in a natural or synthetic gel (Table 1). Various supports were used filter paper discs, alumina filter discs,glass microfibre filters, or a column containing diethylaminoethyl (DEAE)-cellulose. The immobilization was obtained by filtration on the support. After adsorption, the filter containing the biological material can be protected with a thin alginate layer that is hardened with CaCl2 or with another filter disc. The immobilization of photosynthetic material by adsorption on an inert or ion exchanger support is a simple, economic, soft technique that preserves the native activity of the material. However, the interaction forces which intervene are weak, hence desorption of the biocatalyst may be observed. 

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