Multilayer articles including coatings on microfiltration membrane substrates and methods of making same

Abstract

The present disclosure provides a multilayer article. The multilayer article includes a) a microfiltration membrane substrate; b) a first layer directly attached to the first major surface of the microfiltration membrane substrate; and c) a second layer directly attached to the first layer. The first layer includes a first polymeric binder and acid-sintered interconnected first silica nanoparticles arranged to form a continuous three-dimensional porous network. The second layer includes acid-sintered interconnected second silica nanoparticles arranged to form a continuous three-dimensional porous network. The present disclosure also provides a method for forming a multilayer article. The method includes (a) saturating a microfiltration membrane substrate with a liquid; (b) applying a first aqueous coating formulation to at least a portion of a first major surface of the microfiltration membrane substrate to form a coated substrate; (c) sintering the coated substrate, thereby forming a first layer; (d) applying a second aqueous coating formulation to the first major surface of the first layer to form a twice-coated substrate; and (e) sintering the twice-coated substrate.