For technical applications of supported ionic liquids (ILs), the stability of the IL layers both with regard to thermal decomposition and to losses by evaporation is of great importance. An innovative radio frequency-based method is presented to determine the pore filling degree of supported ILs in situ and in a contactless way. As an example, the IL 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide, which was supported on the internal surface of porous silica, was selected. The complex permittivity of the porous solid coated with the IL increases linearly with the IL pore filling degree. Therefore, the evaporation rate of the IL in a fixed bed could be measured in situ in the reactor.
An active heatable cloud water collector for ground sampling is presented. The collector can be operated unattended for approximately one week, even in harsh winter conditions. The collection strands are Teflon tubes. A preset cycle of 15-min sampling followed by 250 s of mild heating using wires inserted into the tubes is used. The lower cutoff diameter for fog droplets is 7.3 μm, and its overall collection efficiency is 79% for the liquid water content of fogs at the experimental site in central Europe. It performed reliably during a 2-yr experiment. The collected fog water interacts exclusively with inert materials such as Teflon and Perspex so the collector is well suited for trace analyses of fog water. The collector can be upgraded with an interstitial aerosol collection unit, at the expense of unattended operation. The lower cutoff diameter of the fog water collection strands is 8.1 μm when the interstitial aerosol module is installed. The module efficiently collects particles with diameters <3.5 μm. For these particles, size-segregated samples in four size classes at diameters down to 0.06 μm are collected with a Berner-type impactor. The collector was successfully employed in a mountainous region of central Europe. Over 400 samples were collected within 2 yr. With the collection unit for interstitial aerosol added, 31 samples were collected in a 2-month period.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.