US Patent 9315721 Self-suspending proppants for hydraulic fracturing

The present invention provides modified proppants, and methods for their manufacture. In embodiments, the modified proppant comprises a proppant particle and a hydrogel coating, wherein the hydrogel coating is applied to a surface of the proppant particle and localizes on the surface to produce the modified proppant. In embodiments, formulations are disclosed comprising the modified particles, and methods are disclosed for using the formulations.