Synthesis of MFI zeolite films on optical fibers for detection of chemical vapors.

We report the development of a novel zeolite-incorporated optical fiber sensor and demonstrate its capability for in situ detection of chemical vapors. The sensor comprises a polycrystalline silicalite thin film grown upon the cleaved end face of a standard single-mode optical fiber. The sensor device operates by measuring the optical reflectivity of the zeolite crystals, which changes reversibly in response to the amount of chemical vapor adsorbed in its crystalline microporous structure. The sensor has been successfully demonstrated for measuring the concentration of isopropanol vapor in mixtures with nitrogen gas.