| abstract |
In certain aspects, the invention features methods for forming crystalline membranes (20) (e.g., a membrane of a framework material, such as a zeolite) by inducing secondary growth in a layer of oriented seed crystals (32). The rate of growth of the seed crystals in the plane of the substrate (30) is controlled to be comparable to the rate of growth out of the plane. As a result, a crystalline membrane can form a substantially continuous layer including grains (35) of uniform crystallographic orientation that extend through the depth of the layer. |