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Effect of polymer coatings from CO 2 , on water‐vapor transport in porous media
Author(s) -
Hé Florence E.,
Carbonell Ruben G.,
Desimone Joseph M.
Publication year - 2002
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690480504
Subject(s) - polymer , porosity , penetration (warfare) , porous medium , supercritical fluid , water vapor , materials science , chemical engineering , gaseous diffusion , mineralogy , composite material , chemistry , organic chemistry , operations research , engineering , fuel cells
Abstract A variety of perfluorinated polyethers were coated onto surfaces of marble, sandstone and limestone samples from solutions in supercritical carbon dioxide. These polymers make ideal protectants for civil infrastructure by making stone surfaces hydrophobic and preventing penetration and deterioration of the stone by acid rain. The effective diffusivities of water vapor through coated and uncoated stones were measured as a function of polymer applied per unit area of sample. An analysis of the diffusive transport of water through the stones led to estimates of the penetration depths of the polymers and the percentages of blockage of the pores in the coated layers as a function of polymer surface coverage. Penetration depths were seen to strongly depend on the mean size and porosity of the stones. It is important for water‐vapor diffusion to occur through the samples to prevent water condensation inside polymer‐coated structural materials.