Patent ID: 8158002

Claim:
A process for filtering seawater comprising: (a) providing a filter system comprising a substrate and a responsive gel, wherein responsive gel is hydroxypropylcellulose (HPC) or hydroxypropyl methyl cellulose (HPMC), the substrate having a predetermined permeability, and the responsive gel coating or impregnating the substrate, wherein the responsive gel is coated or impregnated such that shrinkage and expansion of the gel in response to a change in environmental condition alters the permeability of a fluid through the filter system; (b) causing the responsive gel to expand so as to decrease the permeability of a fluid through the filter system; (c) passing seawater through the filter system to entrap or filter particles from the seawater; (d) causing the responsive gel to shrink so as to increase the permeability of a fluid through the filter system; (e) removing or cleaning the entrapped particles from the filter system by passing water through the filter system; and (f) optionally repeating steps (b)-(e) one or more times.