HCl gas adsorption/desorption properties of poly(N-isopropylacrylamide) brushes grafted onto quartz resonator for gas-sensing applications

Recent advances in nanotechnology have revealed the superiority of nanocarbon species such as carbon nanotubes over other conventional materials for gas sensing applications. In this work, analytical modeling of the semiconducting zigzag carbon nanotube field-effect transistor (ZCNT-FET) based sensor for the detection of gas molecules is demonstrated. We propose new analytical models to strongly simulate and investigate the physical and electrical behavior of the ZCNT sensor in the presence of various gas molecules (CO2, H2O, and CH4). Therefore, we start with the modeling of the energy band structure by acquiring the new energy dispersion relation for the ZCNT and introducing the gas adsorption effects to the band structure model. Then, the electrical conductance of the ZCNT is modeled and formulated while the gas adsorption effect is considered in the conductance model. The band structure analysis indicates that, the semiconducting ZCNT experiences band gap variation after the adsorption of the gases. Furthermore, the bandgap variation influences the conductance of the ZCNT and the results exhibit increments of the ZCNT conductance in the presence of target gases while the minimum conductance shifted upward around the neutrality point. Besides, the I-V characteristics of the sensor are extracted from the conductance model and its variations after adsorption of different gas molecules are monitored and investigated. To verify the accuracy of the proposed models, the conductance model is compared with previous experimental and modeling data and a good consensus is observed. It can be concluded that the proposed analytical models can successfully be applied to predict sensor behavior against different gas molecules.

Download Full-text

Evaluation of Indium Tin Oxide for Gas Sensing Applications: Adsorption/Desorption and Electrical Conductivity Studies on Powders and Thick Films

Sensors ◽

10.3390/s21020497 ◽

2021 ◽

Vol 21 (2) ◽

pp. 497

Author(s):

Stefan Dietrich ◽

Mihails Kusnezoff ◽

Uwe Petasch ◽

Alexander Michaelis

Keyword(s):

Electrical Conductivity ◽

Carbon Monoxide ◽

Tin Oxide ◽

Indium Tin Oxide ◽

Detrimental Effect ◽

Gas Sensing ◽

Oxygen Adsorption ◽

Sensing Applications ◽

Oxygen Coverage ◽

Adsorption Desorption

By combining results of adsorption/desorption measurements on powders and electrical conductivity studies on thick and thin films, the interaction of indium tin oxide with various ambient gas species and carbon monoxide as potential target gas was studied between room temperature and 700 °C. The results show that the indium tin oxide surfaces exhibit a significant coverage of water-related and carbonaceous adsorbates even at temperatures as high as 600 °C. Specifically carbonaceous species, which are also produced under carbon monoxide exposure, show a detrimental effect on oxygen adsorption and may impair the film’s sensitivity to a variety of target gases if the material is used in gas sensing applications. Consequently, the operating temperature of an ITO based chemoresistive carbon monoxide sensor should be selected within a range where the decomposition and desorption of these species proceeds rapidly, while the surface oxygen coverage is still high enough to provide ample species for target gas interaction.

Download Full-text

A Study of HCl Gas Adsorption/Desorption Properties of PNIPAM Brushes

Macromolecular Theory and Simulations ◽

10.1002/mats.201500027 ◽

2015 ◽

Vol 24 (5) ◽

pp. 460-467

Author(s):

Xin Jun Zhao ◽

Zhi Fu Gao ◽

Zhong Ying Jiang

Keyword(s):

Gas Adsorption ◽

Hcl Gas ◽

Adsorption Desorption

Download Full-text

QCM-Based HCl Gas Sensors Using Spin-Coated Aminated Polystyrene Colloids

Polymers ◽

10.3390/polym12071591 ◽

2020 ◽

Vol 12 (7) ◽

pp. 1591 ◽

Cited By ~ 1

Author(s):

Young-Jae Jin ◽

Jinyoung Park

Keyword(s):

Gas Adsorption ◽

Gas Sensing ◽

Limit Of Detection ◽

Binding Capacity ◽

Sensitivity Coefficient ◽

Frequency Change ◽

Simple Strategy ◽

Sensing Platform ◽

Sensing Platforms ◽

Hcl Gas

Hydrogen chloride (HCl) gas is highly toxic to the human body. Therefore, HCl gas detection sensors should be installed at workplaces where trace HCl gas is continuously generated. Even though various polymer-based HCl-gas-sensing films have been developed, simpler and novel sensing platforms should be developed to ensure the cost effectiveness and reusability of the sensing platforms. Therefore, we present a simple strategy to fabricate reusable HCl-gas-sensing platforms using aminated polystyrene (a-PS) colloids and investigate their sensitivity, reusability, and selectivity using a quartz crystal microbalance (QCM). The reusable a-PS(1.0) colloidal sensor with a high degree of amination (DA) exhibited the highest binding capacity (102 μg/mg) based on the frequency change (Δf) during the HCl gas adsorption process. Further, its sensitivity and limit of detection (LOD) were 3.88 Hz/ppm and 5.002 ppm, respectively, at a low HCl gas concentration (<10 ppm). In addition, the sensitivity coefficient (k*) of the a-PS(1.0) colloid sensor with respect to HCHO was higher than that in the case of HF because of the lower binding affinity of the former with the a-PS(1.0) colloids. Based on these results, highly sensitive and reproducible a-PS colloids could be reused as an HCl-gas-sensing platform and used as an HCl sorbent in a gas column filter.

Download Full-text

Polymer-Templated Durable and Hydrophobic Nanostructures for Hydrogen Gas Sensing Applications

Polymers ◽

10.3390/polym13244470 ◽

2021 ◽

Vol 13 (24) ◽

pp. 4470

Author(s):

Mohammad Kamal Hossain ◽

Qasem Ahmed Drmosh

Keyword(s):

Contact Angle ◽

Surface Area ◽

Gas Adsorption ◽

Sessile Drop ◽

Gas Sensing ◽

Hydrogen Gas ◽

Adsorption Sites ◽

Wetting Contact Angle ◽

Sensing Applications ◽

Surface Nanostructures

A simple and hands-on one-step process has been implemented to fabricate polymer-templated hydrophobic nanostructures as hydrogen gas sensing platforms. Topographic measurements have confirmed irregular hills and dips of various dimensions that are responsible for creating air bubble pockets that satisfy the Cassie–Baxter state of hydrophobicity. High-resolution field-emission scanning electron microscopy (FESEM) has revealed double-layer structures consisting of fine microscopic flower-like structures of nanoscale petals on the top of base nanostructures. Wetting contact angle (WCA) measurements further revealed the contact angle to be ~142.0° ± 10.0°. Such hydrophobic nanostructures were expected to provide a platform for gas-sensing materials of a higher surface area. From this direction, a very thin layer of palladium, ca. 100 nm of thickness, was sputtered. Thereafter, further topographic and WCA measurements were carried out. FESEM micrographs revealed that microscopic flower-like structures of nanoscale petals remained intact. A sessile drop test reconfirmed a WCA of as high as ~130.0° ± 10.0°. Due to the inherent features of hydrophobic nanostructures, a wider surface area was expected that can be useful for higher target gas adsorption sites. In this context, a customized sensing facility was set up, and H2 gas sensing performance was carried out. The surface nanostructures were found to be very stable and durable over the course of a year and beyond. A polymer-based hydrophobic gas-sensing platform as investigated in this study will play a dual role in hydrophobicity as well as superior gas-sensing characteristics.

Download Full-text

Gas Adsorption Investigation on SiGe Monolayer: A First-Principle Calculation

Sensors ◽

10.3390/s20102879 ◽

2020 ◽

Vol 20 (10) ◽

pp. 2879

Author(s):

Xiang Sun ◽

Yuzheng Guo ◽

Yan Zhao ◽

Sheng Liu ◽

Hui Li

Keyword(s):

Gas Adsorption ◽

Gas Sensing ◽

First Principles Calculation ◽

First Principle Calculation ◽

Adsorption Sites ◽

Sensing Applications ◽

Adsorption Behaviors ◽

Sensing Material ◽

Nh3 Adsorption ◽

No2 Adsorption

The gas adsorption behaviors of CO, CO2, SO2, NO2, NO, NH3, H2, H2O, and O2 on SiGe monolayer are studied using the first-principles calculation method. Three special adsorption sites and different gas molecule orientations are considered. Based on adsorption energy, band gap, charge transfer, and the electron localization function, the appropriate physical adsorptions of SO2, NO, NH3, and O2 are confirmed. These gases possess excellent adsorption properties that demonstrate the obvious sensitiveness of SiGe monolayer to these gases. Moreover, SiGe may be used as a sensing material for some of them. NO2 adsorption in different adsorption sites can be identified as chemical adsorption. Besides, the external electric field can effectively modify the adsorption strength. The range of 0 ~ − 2 V/nm can create a desorption effect when NH3 adsorbs at the Ge site. The NH3 adsorption models on Ge site are chosen to investigate the properties of the I-V curve. Our theoretical results indicate that SiGe monolayer is a promising candidate for gas sensing applications.

Download Full-text

A reversible chromogenic covalent organic polymer for gas sensing applications

Dalton Transactions ◽

10.1039/c9dt04788c ◽

2020 ◽

Vol 49 (4) ◽

pp. 1007-1010 ◽

Cited By ~ 17

Author(s):

Subodh Subodh ◽

Kunal Prakash ◽

Dhanraj T. Masram

Keyword(s):

Gas Sensing ◽

Organic Polymer ◽

Sensing Applications ◽

Hcl Gas

A triazine-based covalent organic polymer (COP) was designed, synthesized and utilized as a quick, portable and reversible chromogenic sensor for noxious HCl gas.

Download Full-text

A statistical thermodynamics model for monolayer gas adsorption on graphene-based materials: implications for gas sensing applications

RSC Advances ◽

10.1039/c4ra08124b ◽

2014 ◽

Vol 4 (88) ◽

pp. 47481-47487 ◽

Cited By ~ 24

Author(s):

H. H. Pu ◽

S. H. Rhim ◽

M. Gajdardziksa-Josifovska ◽

C. J. Hirschmugl ◽

M. Weinert ◽

...

Keyword(s):

Gas Adsorption ◽

Gas Sensing ◽

Statistical Thermodynamics ◽

Sensing Applications

Download Full-text

Nitrogen-Containing Gas Sensing Properties of 2-D Ti2N and Its Derivative Nanosheets: Electronic Structures Insight

Nanomaterials ◽

10.3390/nano11092459 ◽

2021 ◽

Vol 11 (9) ◽

pp. 2459

Author(s):

Hongni Zhang ◽

Wenzheng Du ◽

Jianjun Zhang ◽

Rajeev Ahuja and Zhao Qian

Keyword(s):

Density Functional ◽

Gas Adsorption ◽

Gas Sensing ◽

Density Functional Theory Calculations ◽

Fast Response ◽

Two Dimensional ◽

Sensing Applications ◽

Sensing Material ◽

Physical Insight ◽

The Stability

In this work, the potentials of two-dimensional Ti2N and its derivative nanosheets Ti2NT2(T=O, F, OH) for some harmful nitrogen-containing gas (NCG) adsorption and sensing applications have been unveiled based on the quantum-mechanical Density Functional Theory calculations. It is found that the interactions between pure Ti2N and NCGs (including NO, NO2, and NH3 in this study) are very strong, in which NO and NO2 can even be dissociated, and this would poison the substrate of Ti2N monolayer and affect the stability of the sensing material. For the monolayer of Ti2NT2(T=O, F, OH) that is terminated by functional groups on surface, the adsorption energies of NCGs are greatly reduced, and a large amount of charges are transferred to the functional group, which is beneficial to the reversibility of the sensing material. The significant changes in work function imply the good sensitivity of the above mentioned materials. In addition, the fast response time further consolidates the prospect of two-dimensional Ti2NT2 as efficient NCGs’ sensing materials. This theoretical study would supply physical insight into the NCGs’ sensing mechanism of Ti2N based nanosheets and help experimentalists to design better 2-D materials for gas adsorption or sensing applications.

Download Full-text