Polyacrylate/graphene oxide (GO) nanocomposites were prepared by the copolymerisation of GO with acrylic acid and acrylamide. The effects of polyacrylate/GO nanocomposites on cement paste fluidity and the microstructure and mechanical strength of hardened cement paste were investigated. The results indicate that the GO nanocomposites have no effect on cement paste fluidity and can efficiently control cement hydration products and its microstructure compared with using GO sheets directly. The corresponding hardened cement paste has a high compressive strength and particularly high flexural strength. This research provides a basis for the use of GO in cement-based composites for reinforcing and toughening.

Graphite oxide nanosheets (GONs) and the copolymer of GONs with methacrylic acid (MAA) and sodium allyl sulfonate (SAS) (poly(GON-MAA-SAS)) were prepared. The GONs in poly(GON-MAA-SAS) are smaller and uniformly dispersed, allowing them to penetrate into collagen fibers of leather and produce better tanning effects than current nano-tanning agents. Tanning effects due to chemical bonding and nanoeffects are elucidated by measuring the shrinkage temperature (T s ) of wet and dry leather. The results indicate that poly(GON-MAA-SAS) could be used alone as a tanning agent to provide excellent mechanical properties, especially good elasticity and softness, although the T s is slightly lower than that of chrome-tanned leather. Poly(GON-MAA-SAS) in combination with a chrome tanning agent could allow the dosage of the latter to be halved. These results indicate the potential for new nano-tanning agents to reduce the pollution caused by tanning agents. ª 2015 Production and hosting by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).