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1.
A novel system for the detection of ammonia was developed by monitoring the conductance of inkjet printed or screen printed polyaniline films with a radio frequency detector. The system has the advantage of non-contact detection of ammonia within sealed packages. Since the sensor is a passive printed film that is externally interrogated, it does not require an internal power source or associated circuitry, and therefore may be a low-cost device suitable for smart packaging applications. When printed on a suitable substrate, the sensor can be cycled several times using heat or a volatile acid to regenerate the polyaniline surface. 相似文献
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Saúl E. Bustamante Fonseca Bernabé L. Rivas José M. García Pérez Saúl Vallejos Calzada Félix García 《应用聚合物科学杂志》2018,135(19)
A dense membrane (MS) based on vinyl polymers and containing a pyrylium salt [2,6‐diphenyl‐4(p‐methacryloyloxy)phenylpyryliumtetrafluoroborate] was prepared. The MS has hydrophilic and sensory properties that make it a good material for the selective colorimetric detection of trimethylamine (TMA) vapors, a biogenic amine of great importance in food safety. The polymeric sensor changes from yellow to an intense pink color with increasing concentrations of TMA. The material could be reused in the presence of HCl vapors for at least 10 times. The detection and quantification limits were determined by ultraviolet–visible absorption spectroscopy (4.42 and 13.40 ppm, respectively) and by the RGB parameters of digital color (3.37 and10.22 ppm, respectively). © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46185. 相似文献
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Jéssyka Carolina Bittencourt Bruno Henrique de Santana Gois Vinicius Jessé Rodrigues de Oliveira Deuber Lincon da Silva Agostini Clarissa de Almeida Olivati 《应用聚合物科学杂志》2019,136(13):47288
In this article, the results of the process and fabrication of ammonia gas sensors are obtained through the production of poly(vinyl alcohol) and polyaniline (PVA/PANI) nanofibers in different concentrations deposited on interdigitated electrodes (IDEs) The results showed good interaction between PVA and PANI, as well as the solvents involved, with good adhesion of the nanofibers in substrate, shown for morphological analysis by scanning electron microscopy (SEM). The good performance of the gas sensor was carried out by direct current measurements. It has been proven that the high surface density, dimensions, and quality of nanofibers are essential parameters for a good response of the ammonia gas sensor. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47288. 相似文献
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Izyan Najwa Mohd Norsham Siti Nor Atika Baharin Muggundha Raoov Syed Shahabuddin Jaroon Jakmunee Kavirajaa Pandian Sambasevam 《Polymer Engineering and Science》2020,60(12):3170-3182
A simple, cost-effective, and novel chemical sensor for ammonia (NH3) gas detection was developed from polyaniline (PANI)/quail eggshell (QES) composites. QES is a natural waste enriched in calcium carbonate. In this work, pure PANI was synthesized from chemical oxidation method and PANI/QES composites were prepared from physical mixing of QES with the synthesized PANI at different mass ratio. A series of complementary techniques including Fourier transform infrared and ultraviolet-visible spectrometers, scanning electron microscope with energy dispersive detection coupled with mapping, thermogravimetric analysis, and X-ray diffractometer were used to characterize the physicochemical and textural properties of the biocomposites. From the results, PANI/QES composite with a mass ratio of 1 exhibited the lowest NH3 detection limit of 5.24 ppm with a linear correlation coefficient (R2) of close to unity (0.9932) between the signal and NH3 gas concentration. As a whole, the PANI/QES biocomposites synthesized from this work exhibited excellent selectivity toward NH3 gas even in the presence of other gas impurities, such as acetone, ethanol, and hexane. For the sensor reusability, the PANI/QES biocomposites can be reused in the application of NH3 gas detection for at least 4 cycles. 相似文献
5.
C.S. Huang B.R. Huang Y.H. Jang M.S. Tsai C.Y. Yeh 《Diamond and Related Materials》2005,14(11-12):1872
A novel three-terminal gas sensor was fulfilled by utilizing the vertically aligned carbon nanotubes (CNTs) mat. Carbon nanotubes were synthesized by thermal chemical vapor deposition (thermal CVD) at 700 °C under C2H2 gas flow rate of 30 sccm. Upon exposure to a with and without N2 environment at the room temperature of 25 °C, the electrical resistance of as-made devices was found to increase and to return back, respectively. Compared to a low bias one, the sensitivity increased when applying a high source drain bias voltage. Furthermore, the device became more sensitive for N2 detection by applying a negative gate voltage. It was concluded that the alteration of free holes concentration in the CNTs mat played the major mechanism for the N2 gas detection. 相似文献
6.
《Ceramics International》2023,49(6):9122-9129
The inhaling rate of toxic gases in daily life is increasing alarmingly; in turn, human health is in question. To resolve this dilemma, the possible remedy is the early detection and adequate regulation of VOCs in the atmosphere via sensors. Therefore, the investigation focused on developing a gas sensor for sensing several VOCs and flourished with a highly selective C3H8O2 gas sensor at room temperature. In-depth structural, elemental, and morphological analysis followed by the sensing test affirmed the enhanced C3H8O2 detection performance of Ag–NiO over pure NiO. The nanosized sphere formation was confirmed via XRD and TEM characterizations alongside the effect of sintered temperature on the shape and crystallite size. Moreover, the XPS examined the combined effect of sintering temperature and doping on the synthesized nanostructures and optimized the exact temperature as 500 °C because of the improved hole concentration. The Ag–NiO(500 °C) exhibited appealing sensing characteristics, specifically, a high response of 6491.57 for 100 ppm C3H8O2 at room temperature. The sensor displayed a quick response and recovery (10 s,10 s) C3H8O2 alongside long-term repeatability and stability; it showed practical implementation in real-time scenarios. 相似文献
7.
描述了利用熔化极混合气体保护焊技术焊接薄板的工艺开发方法,并以具体实例数据为依据作了有关展开介绍及分析。对于熔化极混合气体保护焊技术在金属加工中的推广应用有一定的参考价值。 相似文献
8.
《Ceramics International》2017,43(14):11123-11131
Development of efficient room temperature ammonia (NH3) gas sensor from one pot synthesized zinc oxide (ZnO) – polyaniline (PANI) nanocomposite is reported in the present article. Prior to gas sensing study, the material is characterized to understand the structural, morphological, compositional, optical and thermal properties. Structural and morphological studies indicate good incorporation of ZnO particles in PANI matrix. The gas sensing efficiency of ZnO-PANI nanocomposite is examined at room temperature for ethanol (C2H5OH), methanol (CH3OH) and NH3 gas. The results confirm that ZnO-PANI nanocomposite to be highly selective for NH3 with fast response time and better stability. The response and recovery times are observed to be significantly dependent on NH3 concentration and the lowest detectivity limit of the sensor for NH3 is found 10 ppm. ZnO-PANI nanocomposite shows better gas sensing efficiency as compared to the sensors developed from single phase PANI film. 相似文献
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A deodorant was prepared by drying charcoal particles after dipping in aqueous H3PO4 solutions. The deodorization performances of the samples against NH3 and (CH3)3N odor gases were examined by a detection test tube method and compared with those of a conventional coconut shell-derived active carbon loaded with H3PO4 in the same manner. The charcoal particles with H3PO4 exhibited higher performances than those of the other against both the odor gases. Ammonia gas was caught on the sample surface through reaction with the loaded H3PO4 to form NH4H2PO4 and further (NH4)2HPO4 but the deodorization mechanism for (CH3)3N could not be decided. The high performances of the charcoal particles loaded with H3PO4 were due to its characteristic porous structure consisting of large pores, i.e., such pores were suited for loading a large amount of H3PO4 and were not apt to be blocked by the loaded H3PO4. Also large pores were not blocked by expansion of H3PO4 on the pore surface through the deodorization reactions. The active carbon being composed of a large number of micropores did not exhibit these advantages. 相似文献
11.
《Ceramics International》2021,47(23):32828-32836
This study successfully developed a semiconductor metal oxide-based ammonia gas sensor that was powered by an Ultraviolet–Visible-near-IR optical light source. However, optical fibre gas sensors using single metal oxide nanomaterial are limited. To address this situation, a h-MoO3 nanorod was grown on a tapered region of optical fibre glass using a simple chemical bath deposition to form a unique sensing element. An additional annealing treatment was then performed to modify the oxidation state of h-MoO3. The property changes of the samples were characterised using different techniques, such as FESEM, TEM, XRD, XPS, TGA and UV–Vis. Overall, the annealing treatment improved the sensitivity performance, response and recovery time of the sensor towards NH3. h-MoO3 that was annealed at 150 °C in air showed stable room temperature absorbance responses of 0.05, 0.18, 0.22, 0.28 and 0.35, a fast response time of 210 s towards 500 ppm of NH3 and strong stability and repeatability. The optical NH3 gas-sensing behaviour was significantly correlated with the non-stoichiometric Mo5+ content. The chemisorbed oxygen species and physiosorbed NH3 altered the refractive index and its absorption coefficient on the nanorod, which manipulated the optical signal and acts as a sensing mechanism. These results verify that a chemical bath deposition growth of the h-MoO3 nanorod exhibits a promising optical sensing characteristic, which paves a path for emerging gas-sensing technology. 相似文献
12.
Kyohei Ogata Takaaki Tsuda Shingo Amano Shunsuke Hashimoto Takeshi Sugahara Kazunari Ohgaki 《Chemical engineering science》2010,65(5):1616-1620
The thermodynamic stability and hydrogen occupancy for the hydrogen+trimethylamine mixed semi-clathrate hydrate system were investigated by means of phase equilibrium (pressure–temperature) measurements and Raman spectroscopic analyses. The hydrogen molecule gradually advanced to occupy the empty small cage of trimethylamine hydrate in proportion to pressure increase. Almost all small cages were filled up with the hydrogen molecules at about 80 MPa. Isothermal Raman spectroscopic analysis showed that the absorption-rate of hydrogen to the pre-treated trimethylamine hydrate was comparable to those of tetrahydrofuran hydrate. Only one hydrogen molecule was enclosed with one small cage at the equilibrium state in pre-treated trimethylamine hydrate. 相似文献
13.
《Ceramics International》2022,48(7):9269-9276
In this paper, a mixed potential gas sensor based on YSZ solid electrolyte and LaNiTiO3 sensing electrode was produced. The perovskite-type oxide LaNiTiO3 was synthesized by the sol-gel method as a sensitive electrode, which was intended to detect the low-level concentration of SO2 in the environment. After the aging process and continuous testing, it was found that the LaNiTiO3-SE sensor had the best response value of ?27.5 mV to 5 ppm SO2 at 510 °C, at this temperature, as low as 50 ppb SO2 still had a response of -1mV. Meanwhile, when the sensor was tested at 510 °C, it was found that the response value of the sensor showed a piecewise linear relationship with the logarithm of SO2 concentration, with a sensitivity of -4 mV/decade for 0.05–1 ppm SO2 and -40mV/decade for 1–100 ppm SO2. In addition, the sensor also showed good selectivity, and the response to interference gases could be ignored such as NO2, CO, CH4, NH3, H2, ethanol, and formaldehyde. At the same time, the sensor also shows good repeatability and stability, being still relatively stable after two weeks of continuous operation at high-temperature. 相似文献
14.
Buse Comert Sertel Nihan Akin Sonmez Meltem Donmez Kaya Suleyman Ozcelik 《Ceramics International》2019,45(3):2917-2921
In this study, structural, morphological and optical properties, and gas sensor performance of magnesium oxide (MgO) doped titanium dioxide (TiO2) thin films were investigated in detail. Gas sensor metallic patterns were fabricated on Si substrate using traditional photolithographic technique. MgO doped TiO2 thin films were deposited on formed Pt electrode surface by confocal sputtering (co-sputtering) system as the active layer. Thin film characterizations were realized by using secondary ion mass spectroscopy (SIMS), atomic force microscope (AFM) and UV–Vis Spectrometer (UV–Vis). Gas sensing measurements were performed by gas sensing test system against methane gas at working temperature of 300?°C. To evaluate deposition and thermal annealing effects on the sensing performance, sensors were tested under gas. The sensitivity and response/recovery time of gas sensors were measured in 1000?ppm. MgO doped TiO2 based sensor at substrate temperature of 100?°C has high sensitivity and short response/recovery time. 相似文献
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Abdolkarim Abbaspour Leila Baramakeh S. Masoud Nabavizadeh 《Electrochimica acta》2007,52(14):4798-4803
The electrocatalytic oxidation of guanine and DNA is demonstrated on a sol-gel coated carbon screen printed electrode modified with {MeReO(edt)}2 using cyclic and differential pulse voltammetric techniques. An oxidation peak at 370 mV was found, but no corresponding reduction peaks could be detected in the negative scan, which indicates that the oxidation of guanine is completely irreversible process. The oxidation peak potentials are shifted to more negative values with increasing pH. The utility of applying the sensor for determination of guanine and ss-DNA were investigated. The linear ranges were 0.19-10.8 and 0.45-7.8 μg ml−1 for guanine and DNA, respectively. Detection limits of 0.1 and 0.32 μg ml−1 were obtained for guanine and ss-DNA, respectively. 相似文献
17.
将凝聚式过滤机理应用于合成氨工业领域,采用不锈钢丝毡折叠滤芯与微米级超细玻璃纤维复合滤芯两级过滤,研制了除油效率高达001μm、残余含油量仅为01mg/m3的氮氢工艺气专用超高效除油过滤器。着重从其原理、结构、技术性能及经济效益分析等方面进行了讨论。 相似文献
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Min Hu Weimin Kang Zongjie Li Shi Jie Yixia Zhao Lei Li Bowen Cheng 《Journal of Porous Materials》2016,23(4):911-917
A functional zinc(II)porphyrin-poly(lactic acid) nanoporous fiber membrane (Zn(II)TPP-PLA NFM) for ammonia (NH3) gas detection was developed via the one-step electrospinning method. With the porous structure, Zn(II)TPP-PLA NFM overcomes the limited gas absorption and diffusion of the sensing materials and thus is beneficial to NH3 gas detection. FE-SEM and FT-IR were employed to characterize the morphology and structure of the Zn(II)TPP-PLA NFM. NH3 gas sensing properties of the Zn(II)TPP-PLA NFM were studied by UV–visible spectroscopic techniques. Results showed the Zn(II)TPP-PLA NFM with the volume ratio of dichloromethane/tetrahydrofuran (DCM/THF) 4/1 has a relatively higher porosity of 38 % and the Zn(II)TPP-PLA NFM with 2.0 mg mL?1 Zn(II)TPP content exhibits an excellent response/recovery performance toward sub-ppm levels of NH3 gas. The detection limit was found to be 0.264 ppm toward NH3 at room temperature. In addition, the performance of this sensor was highly stable after five cycles of tracing NH3 gas and recovery. 相似文献
20.
K. Li G. Lian H.H. Jiang X. Zhao H.P. Jing D.L. Cui X.T. Tao Q.L. Wang 《Diamond and Related Materials》2008,17(6):989-992
The previous results have proved that the phase-selective synthesis route is an effective method for preparing cubic boron nitride (cBN) from hydrothermal solutions. However, the experimental parameters are still required to be optimized in order to synthesize pure cBN at high yield. Here we report the results of investigating the effects of adding trimethylamine (N(CH3)3) and ammonia (NH3·H2O) (denoted as secondary nitrogen source) into the reacting solutions. It was found that the content of cBN could be increased by adding appropriate amount of N(CH3)3 and decreased with excess amount of it. On the contrary, hexagonal boron nitride (hBN) was always promoted by adding NH3·H2O into the reacting solutions. The samples were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectrum (FTIR) and high resolution transmission electron microscopy (HRTEM). The experimental results were briefly discussed based on a reported model. 相似文献