Patent ID: 8304454

Claim:
A method of maintaining the ability of a cleaning structure to be antimicrobial, the method consisting of: providing an anionically functionalized cellulose sponge, wherein the anionic functional groups are formed during the manufacture of the cellulose sponge; absorbing into the cellulose sponge an input solution consisting of water and biguanide having cationic functional groups; bonding the cationic functional groups of the biguanide to the anionic functional groups of the cellulose sponge; and packaging the cellulose sponge with biguanide bonded thereto in a sealed package; wherein the packaged cellulose sponge optionally includes a material selected from the group consisting of a dye, a perfume, a fragrance, a surfactant, and reinforcing fibers; wherein the packaged cellulose sponge does not include humectant; and wherein the cellulose sponge maintains at least 0.02 weight percent bonded biguanide, based on a dry weight of the cellulose sponge, following 100 cycles of rinsing and wringing with water to provide at least a three log reduction in microorganisms in the cellulose sponge.