Stephan A Letts

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A series of vapor-deposited poly(amic acid) (PAA) films were exposed to dimethyl sulfoxide (DMSO) vapors to investigate sorption kinetics and surface smoothing phenomena. Gravimetric sorption and secondary-ion mass spectrometry (SIMS) results are both consistent with frontal (case II) diffusion. These experiments suggest that the solvent front is defined by(More)
Porosity generally embrittles ceramics, and low-density nanoporous oxides typically exhibit very brittle behavior. In contrast to such expectations, we find that an effective fracture strain of nanoporous silica increases with increasing porosity. At ultralow relative densities of <0.5%,[1] nanoporous monoliths start exhibiting super-compressible(More)
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