Drying and Sintering of Particulate Coatings

Consolidation of the microstructure by neck-formation is the goal in the sintering step. Microstructural changes here are minor compared to the changes in pore size and porosity occurring in the wet-dry layer transition. 

6 — PREPARATION OF ASYMMETRIC CERAMIC MEMBRANE SUPPORTS BY DIP-COATING 

The drying and sintering of sol-gel films (mesoporous and microporous coatings) is discussed in Chapter 8. The drying of sol-gel films during dip-coating is discussed by Hurd and Brinker [43]. 

A defect in a porous layer on a porous support is a microstructural or textural feature which hampers application of a defect-free functional membrane layer. Defects are cracks or micro-cracks in the substrate layer, irregularities in surface roughness, pinholes or voids percolating the layer or large percolating pores as a result of the particle packing process. These last defects are not really defects because they are an unavoidable result of the particle size distribution in the dispersion and random packing. 

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