Waterproof filter paper

In work aimed at developing superhydrophobic surfaces, polymer scientists in Sweden have shown that filter paper can be turned into a water-resistant, self-cleaning material (Chem. Commun. 2006, 3594). Water droplets roll off the paper's surface carrying dirt along with them. The creation of self-cleaning, cellulose-fiber-based materials could have applications in the textile industry, suggest Eva Malmström and coworkers at the Royal Institute of Technology, in Stockholm. The team employed a process known as atom transfer radical polymerization to graft the fiber surfaces with a superhydrophobic, fluorinated polymer layer that has a branched, brushlike architecture. The approach provides a facile route for transforming a highly hydrophilic substrate into one that is extremely hydrophobic, Malmström says. "To the best of our knowledge, it is the first example of a superhydrophobic cellulose substrate," she adds. The technique can be used for a variety of organic and inorganic substrates and could be employed to pattern thin papers or other biomass-based substrates for sensor applications.