A polyfluoroalkyl iodide is reacted with a (meth)acrylic acid metal salt to form a corresponding polyfluoroalkyl (meth)acrylate ester. The polyfluoroalkyl (meth)acrylate ester is separated from the reaction product through the evaporation, so that the ester is recovered. According to the present method, the polyfluoroalkyl iodide is reacted with the (meth)acrylic acid metal salt without introducing water, thus making it possible to prepare a polyfluoroalkyl (meth)acrylate ester. The resulting ester can also be used to copolymerize an ethylenically unsaturated compound capable of copolymerizing with the ester.

Coating compositions containing an alkyd, urethane or unsaturated polyester resin, and an ester of an unsaturated acid and a fluorinated alcohol wherein the cured coating has an advancing hexadecane contact angle of at least about 40 degrees and durable improved oil and water repellency is disclosed.

A layered sheet construction contains at least one gas permeable, liquid water impermeable layer, and a gas delivery layer formed of a corrugated sheet proximate the gas permeable, water impermeable layer. The corrugated sheet has corrugations that form flow channels through which gas can be conveyed to the gas permeable layer. One embodiment of the layered sheet construction includes a gas permeable, liquid water impermeable layer having a surface energy that is below 20 dynes per centimeter.

The invention features integrated membrane assemblies for selectively transferring a constituent to or from a fluid. The assemblies include two or more flat sheet membrane elements and at least one common manifold connected to the interior regions of the membrane elements.