Photocurable compositions and method of forming topographical features on a membrane surface using photocurable compositions

A method of forming topographical features on a membrane surface comprising:

• providing a membrane comprising a membrane surface and an opposed side of the membrane;
• providing a stencil or screen over the membrane surface, the stencil or screen having openings exposing the membrane surface for receiving a curable composition;
• depositing one or more layers of curable composition having a Thixotropic index (TI) (cp at 1 s−1/cp at 10 s−1) from about 2 to about 15 into the stencil openings or screen openings and onto the membrane surface to form the topographical features, the openings defining an approximate shape and size of the topographical features;
• exposing the opposed side of the membrane to a light source to partially cure the one or more layers of curable composition;
• removing the stencil or screen to leave in place the topographical features on the membrane surface;
• and
• fully curing the curable composition,
• wherein, after removal of the stencil or screen and prior to curing, the topographical features have an aspect ratio (height/width) from about 0.5 to about 2;
• wherein, after curing, the aspect ratio of the topographical features is substantially the same;
• and
• wherein the height of the topographical feature is from about 0.025 inches to about 0.04 inches.