Figure 8.

(Color online) (a) Image of filter and pump arrangement used to “flash dry” nanoparticles removed from aqueous solution for detailed. (b) Graph showing percent weight (moisture) loss as a function of drying time under −20 mm Hg vacuum (open circles). Without the vacuum assist, variable amounts of moisture often were retained in the collection of particles. As shown by the horizontal line, an additional 2 to 3% of moisture could be removed by storing the particles for 24 h in a desiccator filled with 50:50 anhydrous calcium sulfate and activated charcoal. Reprinted with the permission from Nurmi et al., J. Nanopart. Res. 13, 1937 (2010). Copyright 2010, Springer Science and Business Media.