Described herein is a membrane separation module and articles and methods thereof, wherein the membrane separation module has a series of repeating layers, each layer comprising (a) a selectively permeable membrane; and (b) at least one support layer, wherein the support layer comprises a plurality of flow channels and a plurality of rails extending from the support layer, wherein the sides of two adjacent rails form a flow channel, wherein the plurality of rails on the support layer comprise a thermoplastic polymer at the distal end of at least a portion of the plurality of rails, and wherein the distal end of the plurality of rails contacts the selectively permeable membrane to form a bonded stack.