A New Method for the Measurement of the Diffusion Coefficient of Adsorbed Vapors in Thin Zeolite Films, Based on Magnetoelastic Sensors

Abstract

In the current work an experimental method is used in order to calculate the diffusivity D (diffusion coefficient) of various vapors in thin zeolite films. The method is based on adsorption data from magnetoelastic sensors on top of which a zeolite layer was synthesized, and the diffusivity is extracted by fitting the data to Fick’s laws of diffusion. In particular, the method is demonstrated for two volatile organic compound (VOC) vapors on two different zeolites, the p-Xylene adsorption in Faujasite type zeolite with D = 1.89 × 10 − 13 m 2 / s at 120 ° C and the propene adsorption in Linde Type A type zeolite with D = 5.9 × 10 − 14 m 2 / s at 80 ° C , two diffusion coefficients which are extracted experimentally for first time. Our results are within the order of magnitude of other VOC/zeolite values reported in literature.

Contactless and Vibration-Based Damage Detection in Rectangular Cement Beams Using Magnetoelastic Ribbon Sensors

“…This exceptional characteristic makes Metglas materials highly suitable for sensing applications. Typically, Metglas materials consist of thin metallic amorphous ribbons, approximately 25 m in thickness, and have demonstrated their potential in various sensing applications [ 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 ]. They offer several advantages, including low cost, the absence of a need for sophisticated and expensive electronic systems for interrogation (operating at low frequencies in the kHz range), and a contactless nature that eliminates the requirement for electric connections, as their signal relies solely on magnetic properties.…”

Magnetoelastic Ribbons as Vibration Sensors for Real-Time Health Monitoring of Rotating Metal Beams

“…It is an iron-nickel alloy with high corrosion resistance that is typically formed into thin foils or ribbons. It is extremely flexible and strong due to its geometry and elasticity, and it has many applications in sensing research [33][34][35][36][37].…”

The Effect of the Thermal Annealing Process to the Sensing Performance of Magnetoelastic Ribbon Materials

“…Due to both their soft magnetic properties, which practically mean a linear relationship between the applied magnetic field and the resulting magnetization, and their amorphous nature, which means high resistivity and low eddy currents, they are excellent candidates for transformer applications, giving a linear input-output relationship with low losses (see transformer products by Metglas Inc. located in Conway, SC, USA). As sensing devices, they find great usage in a variety of applications such as vibration sensors [8][9][10][11][12] or as mass-load sensors [13,14] for bio-sensing [15][16][17][18][19] or gas-sensing [20][21][22] applications. Furthermore, Sustainability 2021, 13, 13947 2 of 10 these materials are the magnetic analogs of electric piezo-crystals, which, for example, are utilized to detect very weak magnetic fluctuations and where the magnetic response optimization is equally critical [23,24].…”