In situ growth of AlPO4-5 molecular sieve on stainless steel support

A continuous coating on stainless steel mesh with AFI-type molecular sieve was achieved by a simple one-step in situ synthesis. AlPO4-5 crystals have been grown directly on the surface of the substrate. Influences of composition of the staring reaction solution and crystallization temperature on the morphology and the orientation of crystals on the support were investigated. It was shown that the crystals in the coating grew along their one-dimensional channel perpendicular to the substrate when using the synthesis solution with the molar ratio of Al2O3:1.3P2O5:1.2TrEA:200H2O. Stainless steel slice was also used as the substrate to study the growth of molecular sieve AlPO4-5 film at similar synthesis conditions. A competitive growth model was implied to explain the formation of c-axis oriented film based on the observations. The supported coatings were characterized by scanning electron microscopy and X-ray diffractions.