基于信息融合技术的呼气丙酮分析

通过人体呼气中丙酮含量的分析是快速诊断糖尿病的一种新方法.针对目前没有专门直接检测丙酮的传感器,提出了通过间接检测丙酮转化的一氧化碳确定丙酮含量的方法,并将电场用于提高丙酮的转化效率.为了克服病人呼气中少量氢气和甲烷对检测信号的影响,采用了神经网络技术对传感器信号进行智能处理,通过对混合气体样本的训练,确定丙酮气体的分析算法.实验证明,这种检测和信号处理方法可以较好地实现丙酮的分析,这项研究成果对糖尿病的早期检查和快速诊断具有重要的应用前景.     

丙酮气敏传感材料的研究进展

丙酮是一种有毒有害的有机气体,广泛存在于工业生产及家居生活中,同时也是糖尿病的诊断物之一,因此准确实时的丙酮检测手段是安全生产和人体健康所迫切需要的。金属氧化物半导体气体传感器具有灵敏度高、成本低、可靠性高等优点,在有毒有害气体检测领域应用广泛。本文综述了近年来丙酮气敏传感材料的研究进展,对气敏材料的结构与形貌、气敏机理与改性手段等方面进行了介绍,分析了其研究现状以及未来的发展趋势。     

ZnFe2O4纳米球的制备及其对丙酮的气敏性能研究

丙酮被广泛应用于工业和实验室,对丙酮浓度的检测十分重要。ZnFe₂O₄是一种尖晶石型三元金属氧化物,气敏性能优良,可广泛应用于气体传感器。本文采用简单的一步水热法制备了球状的ZnFe₂O₄气敏材料。通过XRD、XPS、SEM、TEM、N2吸附-解析仪对材料的形貌结构、化学组成、比表面积等进行分析,并以丙酮为目标气体对其气敏性能进行了综合研究。结果表明,ZnFe₂O₄纳米球是由纳米粒子自组装而成,有较大的比表面积;该ZnFe₂O₄基气体传感器在最佳工作温度150℃下对丙酮的灵敏度为65.74,并具有出色的选择性、稳定性、重复性,但随着湿度的增加其气敏性能逐渐降低。     

用于挥发性有机化合物探测的微悬臂梁传感器

在研制成功的用于化学气体探测的热驱动微悬臂梁谐振器的基础上,提出了基于这种微悬臂梁谐振器,并以聚合物涂层作为挥发性有机化合物吸附敏感层的谐振式气体传感器.利用3种聚合物材料：聚氧化乙烯（PEO）、聚乙烯醇（PVA）和聚乙二醇乙醚醋酸酯（PEVA）,在微悬臂梁谐振器上制备气体敏感层,探测6种挥发性有机化合物：甲苯、苯、乙醇、丙酮、己烷和辛烷.通过有限元分析估计了聚合物涂层的工作温度.用喷射法制备了PVA和PE-VA涂层,用点滴法制备了PEO涂层.测试了传感器的开环幅频特性,实验检测了气体传感器的谐振频率变化与分析物蒸气浓度的关系以及传感器对相对湿度的响应,分析了传感器的灵敏度和线性度.实验结果表明,这种涂覆聚合物敏感层的热驱动微悬臂梁谐振器为探测挥发性有机化合物提供了良好的平台.根据实验结果,可开发几种基于不同聚合物敏感层的高灵敏度微型气体传感器.     

微波辅助制备Pt/WO_3用于生物标志物丙酮的检测

通过微波辅助溶剂热法一锅制备了贵金属Pt修饰的WO_3(Pt/WO_3),并将该材料应用于呼吸生物标志物丙酮的检测。实验结果表明,相比于纯相WO_3,贵金属Pt修饰的WO_3明显提高了材料对于丙酮气体的响应的灵敏度,并且当反应溶液中加入0.25 mL 0.1 mol/L的氯铂酸乙醇溶液时得到的材料(Pt/WO_3-2)对丙酮的气敏性能提高最为明显,提高了23倍。Pt/WO_3-2对丙酮检测的下限低至250 ppb。Pt/WO_3-2表现出对丙酮气体的良好的选择性和长期稳定性。本实验采用的微波辅助溶剂热法一锅制备贵金属修饰的氧化物的方法,为后续构筑高性能传感器提供了一种新的思路。     

基于六氟丙酮的功能材料

在介绍六氟丙酮理化性能的基础上,对于以六氟丙酮作为最初始原料合成的功能性材料的起始物进行了介绍,并对由此起始物出发所形成的双酚AF类、6F-双酸(酐)类、一元或多元氟醇类、环氧聚合物类等各类功能材料的制备及主要性能进行了介绍和评述,最后对基于六氟丙酮的功能材料发展进行了展望.     

丙酮气敏传感器研究进展

近年来,丙酮对人们生活的影响越来越明显,所以对特定空气环境中丙酮含量检测装置的研究也势在必行。在各种检测装置中,氧化物半导体气敏传感器以灵敏度高、简便快捷、成本低廉而备受关注。综述了丙酮敏感氧化物半导体气敏传感器的研究进展,介绍了其敏感机理,并对现阶段研究中需要注意的问题以及一些新的研究方向进行了概述。     

酸处理对MWCNTs石英晶振微天平VOCs传感器灵敏度的影响(英文)

为分析酸处理过程对石英晶振型碳纳米管(CNTs)有机(VOCs)气体传感器灵敏度的影响,制作了一种多壁碳纳米管(MWCNTs)石英晶振式VOCs传感器.发现酸处理可以明显提高传感器灵敏度,利用毛细凝聚原理与开尔文公式对上述实验现象进行了分析.另外,比较了传感器对不同有机气体(甲苯、乙醇和丙酮)的灵敏度,研究结果表明传感器灵敏度与气体饱和蒸汽压有关,同样,该实验现象可利用毛细凝聚原理与开尔文公式来解释.     

TiO2基有机气体敏感元件的制备及性能研究

将多种金属氧化物掺入TiO2中,通过传统的陶瓷气敏传感器制备技术,制作了旁热式烧结型传感器,研究了这些传感器对有机挥发性气体(VOCs)的敏感特性。在不同浓度的甲醛、苯、丙酮和乙醇气氛中,测试了传感器的气敏特性。测试结果表明,添加In2O3、Cr2O3或SnO2能提高传感器对苯的灵敏度,添加In2O3或Cr2O3能提高传感器对丙酮的灵敏度,添加Cr2O3或SnO2的元件对甲醛气体较灵敏。此外,本文还研究了传感器陶瓷的烧结温度对传感器气敏特性的影响。     

静电纺丝法制备CuO/SnO2复合材料及其气敏特性研究

为研究p型材料和n型材料复合时气敏特性的变化,采用静电纺丝法分别制备了CuO、SnO_2以及3种比例混合的CuO/SnO_2复合纳米纤维材料,并通过XRD及SEM对其形貌、微观结构等进行表征.测试了该5种材料对丙酮、甲醛、甲醇、乙醇、甲苯等VOC气体的敏感特性.研究表明,CuO/SnO_2=2∶1的复合材料对丙酮、甲苯和乙醇的的响应值有一定提高;CuO/SnO_2=1∶1的复合材料对丙酮具有很高响应的同时,对乙醇和甲苯的响应产生了一定的抑制作用,从而大大提高了材料的选择性.其机理是:半导体材料复合后,在复合材料的表面会有更多的氧吸附,导致更多的VOC气体在半导体材料表面发生反应,使材料的电阻值变化更加明显,提高了材料的响应值.     

Highly enhanced acetone sensing performances of porous and single crystalline ZnO nanosheets: high percentage of exposed (100) facets working together with surface modification with Pd nanoparticles

Porous and single crystalline ZnO nanosheets, which were synthesized by annealing hydrozincite Zn(5)(CO(3))(2)(OH)(6) nanoplates produced with a water/ethylene glycol solvothermal method, are used as building blocks to construct functional Pd-ZnO nanoarchitectures together with Pd nanoparticles based on a self-assembly approach. Chemical sensing performances of the ZnO nanosheets were investigated carefully before and after their surface modification with Pd nanoparticles. It was found that the chemical sensors made with porous ZnO nanosheets exhibit high selectivity and quick response for detecting acetone, because of the 2D ZnO nanocrystals exposed in (100) facets at high percentage. The performances of the acetone sensors can be further improved dramatically, after the surfaces of ZnO nanosheets are modified with Pd nanoparticles. Novel acetone sensors with enhanced response, selectivity and stability have been fabricated successfully by using nanoarchitectures consisting of ZnO nanosheets and Pd nanoparticles.     

Al_2O_3掺杂ZnO微米花对丙酮超高灵敏度和优异选择性

利用水热合成技术,成功制备具有孔道的纯ZnO微米花和Al_2O_3掺杂的ZnO(Al_2O_3-ZnO)微米花。通过X射线衍射(XRD)、扫描电镜(SEM)、电子能谱(EDS)对样品的形貌和结构进行表征。利用所得的纯ZnO和Al_2O_3-ZnO样品制备气敏元件,并对其气敏特性进行研究。结果表明:在工作温度为260℃时,基于Al_2O_3-ZnO的气敏元件对100×10~(-6)的丙酮气体的灵敏度约为82.8,约为同条件下基于纯ZnO的气敏元件对丙酮气体灵敏度(18.0)的4.6倍,其响应时间和恢复时间分别为3s和8s,是同条件下干扰气体中灵敏度最高的乙醇气体的灵敏度(26.2)的3.16倍,该元件具有优异的选择性,能成功区分具有相似性质的丙酮和乙醇。此外,Al_2O_3-ZnO器件可检测到0.25×10-6的丙酮气体,其灵敏度约为3.1。     

Tuning temperature-dependent microstructural properties of tungsten oxide thin films for acetone sensor

Journal of Materials Science: Materials in Electronics - In this paper, the physical properties of thermally evaporated tungsten oxide thin films and their performance towards acetone sensors are...     

ZIF-8衍生La掺杂ZnO纳米颗粒的制备及其气敏性能

以ZIF-8及La掺杂ZIF-8为前驱体,经高温煅烧制备ZnO及La掺杂ZnO纳米颗粒.研究了La掺杂对ZnO纳米颗粒的形貌、晶体结构及气敏性能的影响.利用X射线衍射仪、扫描电子显微镜对材料的微结构进行表征,结果表明:La掺杂有利于获得更小粒径的类球形纳米结构,但La掺杂未改变ZIF-8及衍生ZnO纳米结构的晶体结构....     

Semiconductor metal oxide compounds based gas sensors: A literature review

This paper gives a statistical view about important contributions and advances on semiconductor metal oxide (SMO) compounds based gas sensors developed to detect the air pollutants such as liquefied petroleum gas (LPG), H₂S, NH₃, CO₂, acetone, ethanol, other volatile compounds and hazardous gases. Moreover, it is revealed that the alloy/composite made up of SMO gas sensors show better gas response than their counterpart single component gas sensors, i.e., they are found to enhance the 4S characteristics namely speed, sensitivity, selectivity and stability. Improvement of such types of sensors used for detection of various air pollutants, which are reported in last two decades, is highlighted herein.     

Indium Tin Oxide Thin-Film Sensor for Detection of Volatile Organic Compounds (VOCs)

Indium tin oxide (ITO) (In₂O₃ + 17% SnO₂) thin films were grown on glass substrate by direct evaporation method. Two thick gold pads were deposited to take out contacts. The response of these films at different operating temperatures, when exposed to various volatile organic compounds (VOCs) such as methanol, ethanol, butanol, and acetone in the concentration range 200-2500 ppm was evaluated. Additionally, the effect of film thickness on the response charateristics of methanol and acetone was studied. The linearity and sensitivity of the sensors were measured. The ITO thin-film sensors showed a sensitivity of 0.256 ohms/ppm to acetone vapors, which was almost linear in the range 200-2500 ppm. In order to improve sensitivity and selectivity, a thin layer of various metal and metal oxides such as Cu and PbO was deposited on the sensor surface to work as catalytic layer and the effect on the performance of the sensor was studied. The response and recovery times of the sensor were determined for acetone vapors and were found to be 155 sec and 110 sec, respectively.     

Atmosphere analyzer based on an array of resistor gas sensors

The possibilities of an array made from 24 sensors are studied in order to determine a selection of vapors from organic reagents: ethyl, methyl, isopropyl alcohols, acetone, benzene, ether, gasoline, etc. It is shown that in spite of the absence of special selection of sensors and their working temperatures it is possible to distinguish reagents with sufficient confidence. __________ Translated from Izmeritel’naya Tekhnika, No. 2, pp. 59–61, February, 2006.     

Optical fiber gas sensors based on hydrophobic alumina thin films formed by the electrostatic self-assembly monolayer process

Optical fiber gas sensors have been fabricated by deposition of Al/sub 2/O/sub 3/ and polymer ultra-thin films on the ends of optical fibers using the electrostatic self assembly monolayer process. These sensors are designed to operate at the standard transmission wavelengths with no cross sensitivity to temperature from at least 10 to 70/spl deg/C. Experimental results of the response of these sensors to organic volatile compounds such as acetone, dichloromethane, or ethanol, are presented. In addition, a thermal curing process is proposed for achieving a humidity cross sensitivity of less than 1.4% from 11% to 85% of relative humidity, this cross sensitivity was still negligible after one year of the thermal curing process.     

Optimization of gas-sensitive polymer arrays using combinations of heterogeneous and homogeneous subarrays

Results for optimizing an array of conducting polymer gas sensors for sensing one of five analytes in the presence of up to four interferents are presented. The optimized array consists of subarrays of homogeneous (like) sensors contributing to a larger heterogeneous array of up to ten points (unlike sensors) in multidimensional sensor space. The optimization techniques presented here are linear, since the polymer sensors in their useful (low concentration) operating range exhibit linear and additive response characteristics. The optimization of these arrays produces maximum separability between analytes, demonstrating the trade-off between the addition of both information and variability induced by increasing the size of the heterogeneous array. Optimization results for sensing acetone, hexane, THF, toluene, and ethanol in the presence of interferents result in array sizes that are significantly less than the maximum available number of sensors (ten in the heterogeneous partition of the array). This result adds fuel to the argument that fewer sensors are better; the argument for more sensors, however, is also made in the context of the electronic nose systems where significant chemical diversity is required. Homogeneous subarrays of up to four elements each improve the separability of analytes in these optimized heterogeneous arrays by over 10% and also effectively flag broken or unhealthy sensors in a manner that is independent of analyte and concentration.