Water absorption and transport in bis-silane films

Abstract

Water (D2O) ingress in bis-amino silane and bis-sulfur silane films was studied by in situ neutron reflectivity. Bis-amino silane film absorbs substantially more D2O (33 vol%) than the bis-sulfur silane film (4.6 vol%) at equilibrium. The volume increase (swelling) of both films, however, is much smaller than the total volume of D2O absorbed in the films. The results suggest that the absorbed water exists in two populations: one is dissolved in the polymer matrix (Henry's mode) while the other occupies unrelaxed free volume existing in the polymer (Langmuir mode). The dominance of Langmuir mode accounts for the small film thickness change during the water absorption. Dual-mode sorption is also consistent with the observed two-stage swelling process whereby an initial rapid increase in film thickness is followed by a slower process extending over 11 h.

Tailoring amine functionalized hybrid ceramics to control CO2 adsorption

“…On the other hand swelling generally increases with the extent of interactions between the solvent (water) and the material [43,44]. As an example, the amount of remaining unhydrolyzed ethoxy groups was observed to decrease with increasing amounts of water until complete removal if reacted in the presence of an excess amount of water [46].…”

“…The degree of cross-linking is also important for the extent of swelling under humidity. Less swelling is expected for a more highly cross-linked network [43,44].…”

“…Humidity induced swelling might also be expected for BisA derived materials [43,44]. For spin coated films of acidified methanolic solutions of BisA on silicon wafers it was observed that water uptake was mainly due to the free space inside of the material and only to a small extent to swelling [44].…”

Neutron Reflectometry for Studying Corrosion and Corrosion Inhibition

“…The crosslink density and water migration can both be determined by NR. Although the evidence suggests that water is still able to migrate through these films reasonably quickly [121,125], transport of other species is inhibited, which can have a significant corrosion inhibition effect [126].…”

“…Silane barrier films are studied as models for a variety of applications including adhesion promotion, durability and corrosion resistance [55,[121][122][123][124][125][126][127]. There is a good summary of the field in [123].…”