Functionalized Sorbent Membranes for Use with Ion Mobility Spectrometry

Abstract

Ion mobility spectrometry (IMS) is a technique commonly used for trace detection of hazardous chemicals. The inlet of an IMS typically utilizes a membrane made of generic polymers such as polydimethylsiloxane or polyvinylidene fluoride. These membranes are designed to allow analytes through but protect the detector from dust and keep a controlled relative humidity and pressure. IMS signals can be enhanced using sorbent polymer membranes to concentrate vapors of interest. Specifically, in this work a strong hydrogen bond acid (HBA) sorbent polymer (HCSFA2) was synthesized to reversibly bind with hydrogen bond basic (HBB) analytes. HCSFA2 has suitable thermal stabilities but offers low viscosities above 50degC. To mitigate this problem HCSFA2 was combined with fillers to maintain the membrane's physical structure. The HCSFA2 composites were characterized using various techniques including thermogravimetric analysis, optical microscopy, inverse gas chromatography, FTIR, and differential scanning calorimetry. Additionally, data from a membrane interfaced with an ion mobility spectrometer (IMS) is described.