Microcomposites comprising titanium dioxide (TiO2) nanoparticles embedded within cross-linked, thermally responsive microgels of poly(N-isopropylacrylamide) are disclosed. Interpenetrating linear chains of poly(acrylic acid) functionalize the nanoparticles for dispersal within the microgel framework. The microcomposites show rapid sedimentation, which is useful for gravity separation applications such as environmental remediation via photocatalytic degradation.The extent of loading of the TiO2 within the colloidal particles can be easily manipulated from 10% (weight) to a value as high as 75%. The microgel-titania composites showed rapid sedimentation, which is useful for gravity separation of these particles in photocatalytic applications. The settling of the microgel-titania composites occurred over minutes and was much faster than solid, impermeable spheres. As the content of TiO2 increased within the particles from 10% to 75%, the increased effective particle density led to significant decrease in the settling time from approximately 2200 seconds to approximately 100 seconds.