{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T08:31:13Z","timestamp":1777624273268,"version":"3.51.4"},"reference-count":29,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2018,4,4]],"date-time":"2018-04-04T00:00:00Z","timestamp":1522800000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Fiber optic interferometer (FOI) sensors have been fabricated by directly growing pure-silica MFI-type zeolite (i.e., silicalite) films on straight-cut endfaces of single-mode communication optical fibers. The FOI sensor has been demonstrated for determining molecular diffusivity in the zeolite by monitoring the temporal response of light interference from the zeolite film during the dynamic process of gas adsorption. The optical thickness of the zeolite film depends on the amount of gas adsorption that causes the light interference to shift upon loading molecules into the zeolitic channels. Thus, the time-dependence of the optical signal reflected from the coated zeolite film can represent the adsorption uptake curve, which allows computation of the diffusivity using models derived from the Fick\u2019s Law equations. In this study, the diffusivity of isobutane in silicalite has been determined by the new FOI sensing method, and the results are in good agreement with literature values obtained by various conventional macroscopic techniques. The FOI sensor platform, because of its robustness and small size, could be useful for studying molecular diffusion in zeolitic materials under conditions that are inaccessible to the existing techniques.<\/jats:p>","DOI":"10.3390\/s18041090","type":"journal-article","created":{"date-parts":[[2018,4,4]],"date-time":"2018-04-04T12:42:57Z","timestamp":1522845777000},"page":"1090","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["A Fiber Optic Interferometric Sensor Platform for Determining Gas Diffusivity in Zeolite Films"],"prefix":"10.3390","volume":"18","author":[{"given":"Ruidong","family":"Yang","sequence":"first","affiliation":[{"name":"Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhi","family":"Xu","sequence":"additional","affiliation":[{"name":"Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shixuan","family":"Zeng","sequence":"additional","affiliation":[{"name":"Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wenheng","family":"Jing","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, 5 Xinmofan Road, Nanjing 210009, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Adam","family":"Trontz","sequence":"additional","affiliation":[{"name":"Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Junhang","family":"Dong","sequence":"additional","affiliation":[{"name":"Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2018,4,4]]},"reference":[{"key":"ref_1","unstructured":"K\u00e4rger, J., and Ruthven, D.M. 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