Ionic Liquid Gas Sensors for Detection of Flammable Gases In Workplace

描述(由申请人提供)：可燃气体检测传感器对于防止气体设施和地下采矿中的火灾或爆炸的职业健康和安全是必不可少的。支持起火或爆炸需要三样东西：燃料源(例如可燃气体或蒸汽)、空气(氧气)和引燃源(例如火花、明火或高温表面)。因此，用于可燃气体检测的传感器需要在较宽的温度范围内工作。室温离子液体(ILS)是检测可燃气体的潜在新材料。它们在常压下的蒸汽压可以忽略不计，在空气中具有很高的热稳定性。离子液体的非挥发性和非凡的热稳定性使其非常适合用作检测易燃气体的涂层，因为它们降低了与闪点和易燃性相关的危险。离子液体也特别有希望，因为它们有可能非常稳定，而许多聚合物或有机涂层材料最终会恶化，导致它们失去活性。ILS的合成灵活性使其能够适应广泛的化学多样性。一个离子可以用来提供一种功能，而第二个离子可以提供不同的、完全独立的功能。此外，许多离子液体由于其较大的本征电导率和较宽的电化学电势窗口而被证明是优良的非水电解质。文献研究表明，气体(CH4、C2H4、C2H6、CO2、O2)在离子液体中的溶解度差别很大。报道了离子液体中NH3和SO2的电化学氧化和O2和CO2的电化学还原。因此，我们建议将ILS独特的溶剂化和电化学性质与正交电化学和石英晶体微天平(QCM)传感器的实时、便携、低成本特性相结合，开发一种集成的可燃气体检测器，广泛应用于天然气设施或地下采矿中的独立/手持气体检测器。这项建议在很大程度上基于以往的成果，概述了一项研究计划，以了解、设计和控制电极表面离子液体的分子特性，以便将其应用于可燃气体的检测。甲烷将是最初的目标分析物。几项创新将通过以下项目目标实现。首先，开发、表征和优化离子液体化学界面固定化，以形成坚固耐用的薄膜；其次，评估和验证用于甲烷检测的IL QCM传感器阵列；第三，开发用于甲烷检测的IL电化学传感器，最后改进电化学IL传感器以及QCM IL传感器阵列，以增加稳定性、提高灵敏度和选择性，以满足实际应用。我们的整个研究计划是一项综合努力，如果成功，将对职业安全和健康传感器技术产生重大的科学和实际影响，使天然气设施和矿山的人员能够防止爆炸或火灾，拯救生命，避免受伤，并保护价值数十亿美元的资产。气体传感器因其在环境空气监测、职业健康和安全、生物医学诊断、工业过程控制以及军事和民用反恐方面的潜在应用而受到越来越多的关注。近年来发生的煤矿爆炸造成人员伤亡的悲剧，加强了认识地下煤矿开采潜在危险的重要性，以及系统安全和健康警戒的必要性。在这项提案中，我们旨在开发新技术，探索离子液体作为传感材料和非水电解液在工作场所检测易燃气体的应用，以防止爆炸或火灾，拯救生命，避免伤害，并保护价值数十亿美元的资产。

DESCRIPTION (provided by applicant): Sensors for flammable gas detection are essential in occupational health and safety to prevent fire or explosion in gas facilities and underground mining. Three things are needed to support a fire or explosion: a source of fuel (e.g. flammable gas or vapor), air (oxygen) and a source of ignition (e.g. spark, open flame, or high temperature surface). As a result, a sensor for flammable gas detection requires it functioning over a broad temperature range. Room-temperature Ionic Liquids (ILs) represent potential new materials for use in the detection of flammable gases. They have negligible vapor pressure at ambient pressure and possess high thermal stability in air. The nonvolatile nature of ionic liquids and their remarkable thermal stability make them well suited for use as coatings for the detection of flammable gases since they reduce hazards, associated with flash points and flammability. Ionic liquids are also particularly promising because they have the potential to be incredibly stable whereas many polymer or organic coating materials eventually deteriorate leading to their loss of activity. The synthetic flexibility of ILs allows them to be tailored with broad chemical diversity. One ion can be used to provide one function and the second ion can provide a different, completely independent function. Additionally, many ILs are proven to be excellent non-aqueous electrolytes due to their large intrinsic conductivity and wide electrochemical potential windows. Literature study shows that gases (i.e.CH4, C2H4, C2H6, CO2, O2) have widely varying gas solubility in ILs. Electrochemical oxidation of NH3 and SO2 and electrochemical reduction of O2 and CO2 in ILs have been reported. Therefore, we propose to integrate ILs unique solvation and electrochemical properties with real-time, portable, low cost characters of orthogonal Electrochemical and Quartz Crystal Microbalance (QCM) transducers to develop an integrated flammable gas detector widely applicable as a standalone/hand-held gas detector at gas facilities or underground mining. Based substantially on prior achievements, this proposal outlines a research plan to understand, design and control molecular character of ionic liquids on electrode surfaces for their applications in detection of flammable gases. Methane will be the initial target analyte. Several innovations would be realized through the following project Aims. First, develop, characterize and optimize ionic liquid chemical interface immobilization in order to form robust, thin rigid films; Second, evaluate and validate the IL QCM sensor array for methane detection; Third, develop IL electrochemical sensors for methane detection and finally refine the electrochemical IL sensors as well as the QCM IL sensor array to Increase stability, heighten sensitivity and selectivity for real world applications. Our entire research plan is an integrated effort which if successful will have substantial scientific and practical impact in sensor technology for occupational safety and health that could enable personnel in gas facilities and mines to prevent explosions or fires, save lives, avoid injuries, and protect billions of dollars worth of assets. Gas sensors are of increasing interest due to their potential applications in ambient air monitoring, occupational health and safety, biomedical diagnostics, industrial process control, and military and civilian counter-terrorism. The tragedies of human loss in mine explosions in recent years reinforce the importance of recognizing the potential hazards in underground coal mining, and the need for systematic safety and health vigilance. In this proposal, we aim to develop new technology that explore ionic liquids' application as sensing materials and non-aqueous electrolytes for detection of flammable gases at workplace to prevent explosions or fires, save lives, avoid injuries, and protect billions of dollars worth of assets.