An aligned macro-porous carbon nanotube/waterborne polyurethane sensor for the detection of flowing organic vapors

We report a conductive multi-walled carbon nanotube (MWNT)/waterborne polyurethane (WPU) sensor with an ultra-regular aligned macro-porous structure obtained simply by a directional freeze-drying process. This novel polymer material can broaden the application area of polymer based gas sensors from static or quasi-static organic vapors to flowing organic vapors such as acetone, n-hexane, toluene and tetrahydrofuran, and is particularly suitable for monitoring the latter. Because of the unique micro-phase separation structure of WPU, the conductive MWNT/WPU sensor has a broad applicability to flowing organic vapors from nonpolar to polar.