Superhydrophobic Polymerized n-Octadecylsilane Surface for BTEX Sensing and Stable Toluene/Water Selective Detection Based on QCM Sensor

Abstract

The present study reports a facile and low-cost route to produce a superhydrophobic polymerized n -octadecylsilane surface with micronano hierarchical structure on the surface of quartz crystal microbalance (QCM). The surface is used as a novel functional sensing material to detect benzene, toluene, ethylbenzene, and xylene (BTEX) vapor on the basis of QCM platform. The composites were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and contact angle measurements. The type of solvent used to dissolve N -octadecyltrichlorosilane has a big impact on the morphology, wettability, and sensing performance of the polymer material. Further systematic studies suggest that surface wettability (contact angle) and molecular polarity of the detected analytes are effective factors in selective detection toward BTEX using resonator-type gas sensors. Gas sensing results toward toluene in different relative humidities show that the new-style sensor has stable toluene/water selective detection performance and that the disturbance of water is negligible. Besides, the limit of detection toward toluene of the sensor is lower than the odor threshold value.

Polyvinyl Acetate Film-Based Quartz Crystal Microbalance for the Detection of Benzene, Toluene, and Xylene Vapors in Air

“…The sensitivity of xylene was higher than that previously reported [16,18], 0.026 and 0.071 Hz/ppm, respectively. Meanwhile, it was lower than that reported in [17], which is 0.15 Hz/ppm. The BTX sensing performance of the QCM n-octadecylsilane film [17] was better than the others, which could be due to the film's superhydrophobic properties, which is also structurally crystalline.…”

“…Meanwhile, it was lower than that reported in [17], which is 0.15 Hz/ppm. The BTX sensing performance of the QCM n-octadecylsilane film [17] was better than the others, which could be due to the film's superhydrophobic properties, which is also structurally crystalline. The wettability of the n-octadecylsilane film contributes to the sensing performance.…”

“…Reports on the development of the BTX sensing system using QCM are abounded [16][17][18][19]. The studied materials as active films were pentacene [16], n-octadecylsilane [17], poly(4-vinyl benzyl chloride) [18], and organosilicate [19]. The sensitivity of the QCM system modified with pentacene, n-octadecylsilane, poly (4-vinyl benzyl chloride), and organosilicate for toluene detection was found to be 0.008, 0.2, 0.02, and 0.08 Hz/ppm, respectively.…”

Quartz crystal microbalance coated with PEDOT–PSS/PVA nanofiber for a high-performance humidity sensor

“…Recently, various types of humidity sensors have been proposed (Lensch et al, 2019;Xu et al, 2019;Zhang et al, 2018). A humidity sensor with high sensitivity, rapid response time, low hysteresis, and long-term stability has become the main goal to pursue (Haidry et al, 2015;Yao et al, 2017).…”

“…A humidity sensor with high sensitivity, rapid response time, low hysteresis, and long-term stability has become the main goal to pursue (Haidry et al, 2015;Yao et al, 2017). To date, several sensing methods, including resistance, capacitance, optical fiber, and quartz crystal microbalance (QCM), have been used to develop a humidity sensor (Blank et al, 2016;Xu et al, 2019). A QCM is a kind of piezoelectric crystal resonator, of which the frequency resonance relies on the change of the loading mass.…”