Examples of suitable nanoparticles includes: Aerosil R202?? (14 nm), Aerosil R812?? (7 nm), Aerosil 200?? (12nm) and Aerosil R 974?? (12 nm). [00208] In an embodiment, the thickening agent is a polymer of the acrylic acid ester monomer component. [00209] In an e