Polymeric barrier coatings via initiated chemical vapor deposition

Initiated chemical vapor deposition (iCVD) enables micron sized particles to be coated with conformal polymeric films. Unlike wet chemistries, particle agglomeration is mitigated due to the vapor phase deposition. A custom built iCVD with a rotary evaporator was used to coat a variety of particles with poly(glycidyl methacrylate) (PGMA). Glass beads with average diameters of 355 mu m were coated with a similar to 1 mu m PGMA film. Thermo gravimetric analysis (TGA) was used to assess if the beads were coated with PGMA and to estimate the PGMA thickness. The TGA testing showed a 0.7% mass loss at similar to 275 degrees C, which corresponds to the decomposition temperature of PGMA and a PGMA thickness of -1 mu m. In addition sodium chloride (similar to 355 mu m) particles were coated in the iCVD system again with PGMA. The dissolution rate of these particles in an aqueous solution was found to be reduced by an order of magnitude (versus uncoated NaCl). Finally, NaCl particles with metallic coatings were coated with PGMA and showed a dissolution rate two orders of magnitude slower than the bare NaCl. (C) 2011 Elsevier B.V. All rights reserved.