Method of making a polymer matrix composite comprising a porous polymeric network structure; and a plurality of particles distributed within the polymeric network structure, the method comprising: combining a thermoplastic polymer, a solvent that the thermoplastic polymer is soluble in, and a plurality of particles to provide a slurry; forming the slurry in to an article; heating the article in an environment to retain at least 90 percent by weight of the solvent, based on the weight of the solvent in the slurry, and inducing phase separation of the thermoplastic polymer from the solvent to provide the polymer matrix composite.