Composite membranes and methods for making same
View Patent ↗Composite membranes that are adapted for separation, purification, filtration, analysis, reaction and sensing. The composite membranes can include a porous support structure having elongate pore channels extending through the support structure. The composite membrane also includes an active layer comprising an active layer material, where the active layer material is completely disposed within the pore channels between the surfaces of the support structure. The active layer is intimately integrated within the support structure, thus enabling great robustness, reliability, resistance to mechanical stress and thermal cycling, and high selectivity. Methods for the fabrication of composite membranes are also provided.
1. An asymmetric porous anodic aluminum oxide support structure, comprising:
a first major surface;
a mutually opposed second major surface; and
a plurality of substantially parallel elongate pore channels extending through the support structure from the first major surface to the second major surface, the pore channels comprising at least a first portion having a first average pore channel diameter, a second portion having a second average pore channel diameter, and a third portion disposed between the first and second portions, the third portion having a third average pore channel diameter, where the third average pore channel diameter is less than either of the first and the second average pore channel diameters.
2. A structure as recited in claim 1 , wherein said first and second average pore channel diameters are substantially the same.
3. A structure as recited in claim 1 , wherein said first average pore channel diameter is greater than said second average pore channel diameter.
4. A structure as recited in claim 1 , wherein any one of said first, second and third average pore channel diameters is at least about 1 nm and is not greater than about 1000 nm.
5. A structure as recited in claim 1 , further comprising an active layer disposed within said third portion.