A simple method for rheological measurements of air sensitive samples

Rheology of air- or moisture sensitive liquids, gels, and glasses requires expensive and complicated rheometer-in-glovebox laboratory setups. Here, we demonstrate the use of a heavy-than-air cover gas, sulfur hexafluoride, and the design of a cheap and simple cover gas container that can attach to the lower geometry plate of any rheometer in order to carry out rheology experiments on air-sensitive liquids and soft solids. Rheological measurements of titanium(IV) propoxide, a moisture-from-air reactive liquid, are shown to demonstrate the effectiveness of the cover-gas method on acquiring correct temperature dependent viscosity data of the sample in the absence of polymeric reaction products.