Abstract
A zeolite thin film-coated long period fiber grating (LPFG) sensor was developed and tested for direct measurement of trace organic vapors with straightforward operation. The sensor was fabricated by growing pure silica MFI-type zeolite (i.e. silicalite) thin film on the optical fiber grating by in situ hydrothermal crystallization. The sensor measures chemical vapor concentration by monitoring the molecular adsorption-induced shift of LPFG resonant wavelength (λR) in near infrared (IR) region. Upon loading analyte molecules, the zeolite's refractive index changes in the close vicinity of the fiber index where the λR responds with extremely high sensitivity. Because the silicalite is hydrophobic and preferentially adsorbs organic molecules, the zeolite-LPFG sensor is capable of quantifying organic vapor concentrations in lower ppm or ppb ranges without sample pre-concentration and rigorous control of operating conditions. The sensor had a much faster response speed for isopropanol than for toluene as the former has a smaller molecular kinetic size and greater diffusivity in the zeolite pores than the latter.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
