共查询到18条相似文献,搜索用时 78 毫秒
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新型碳纳米管气敏传感器的研究进展 总被引:1,自引:0,他引:1
该文综述了新型的单壁碳纳米管SWNT、多壁碳纳米管MWNT、多壁碳纳米管阵列气敏传感器的制备、结构特点、气敏性能和未来的发展方向。 相似文献
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中药在我国卫生体系中占有非常重要的地位,其质量好坏对人们的健康至关重要.提出了应用伏安型电子舌对不同品种的中药材进行分类鉴别研究.采用差分脉冲伏安法和方波伏安法,分别以玻碳电极和金电极作为工作电极来检测被识别样品,并利用主成分分析法对其检测后的数据进行分析.结果显示:同种实验方法下应用双电极体系检测的识别结果要优于单电极体系检测的识别结果,不同实验方法下基于差分脉冲伏安法检测的识别结果要优于基于方波伏安法检测的识别结果.应用伏安型电子舌对中药材进行检测能够很好地区分不同品种的中药材,为伏安型电子舌系统在中药材领域的研究提供了一定的基础. 相似文献
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采用酸氧化法对多壁碳纳米管(MWCNTs)进行表面修饰,并研究了基于MWCNTs/羟乙基纤维素(HEC)复合体系的结露传感特性。通过红外光谱和热失重分析对MWCNTs进行了结构表征。氧化处理有效提高了MWCNTs的分散性。基于改性MWCNTs的结露元件与本征MWCNTs的器件相比表现出更好的开关特性。结露元件在相对湿度(RH)为75 %RH以前伴随湿度变化,电阻变化非常小,而在85 %RH以后呈现电阻的非线性增大。MWCNTs在复合膜中的最佳质量分数约为22 wt%,在100 %RH下灵敏度达到31。 相似文献
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在玻碳电极表面形成碳纳米管/壳聚糖膜/空壳纳米钯均匀致密稳定的修饰层,制备了用于测定葡萄糖的新型无酶传感器。该传感器可以快速地实现电极与葡萄糖之间的直接电子转移,有良好的稳定性。在最佳实验条件下,用差分脉冲伏安法(DPV)测定葡萄糖,其响应电流与葡萄糖的浓度在2.5×10-7~1.5×10-6mol/L范围内有很好的线性关系,线性回归方程为I(μA)=2.169c(μmol/L)+8.399×10-6,相关系数r=0.9872。 相似文献
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基于气体电晕放电原理,利用纳米碳管独特的物理结构和尖端发射效应,提出了一种新型的纳米碳管离子型气体传感器.采用阳极氧化铝模板法生长的定向纳米碳管阵列所构成的传感器,纳米碳管和电极是一体的,简化了器件结构和工艺.在外加直流电压激励下,纳米碳管顶部形成很强的非均匀电场,在电压相对低的情况下能很容易地电离气体,根据气体的击穿电压和放电电流来实现对单一气体和确定性混合气体的检测.为了提高检测混合气体的灵敏度,创新地在检测回路中引入随机共振发生装置,有效地提高了混合气体浓度检测的范围.实验中还分析了温度、湿度对传感器的影响,对该传感器的性能也作了评价.实验结果表明该传感器具有选择性好、体积小、响应时间快、灵敏度高、稳定性好,室温操作等优点,而且实现方便,操作简单,有较大的实用价值. 相似文献
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研究了氨氯地平(Amlodipine besylate,Aml)在离子液体(1-Benzyl-3-Methylimidazole,[BnMIM]PF6)修饰碳糊电极([BnMIM]PF6/CPE)上的电化学行为和电化学动力学性质,并用循环伏安法(CV)及计时电流法(CA)测得Aml在[BnMIM]PF6/CPE上的电极反应动力学参数。实验结果表明,Aml在[BnMIM]PF6/CPE上发生了受吸附控制的不可逆电化学氧化过程。用方波伏安法(SWV)考察了Aml氧化峰电流与其浓度在1.2×10-6~1.0×10-3mol/L范围内呈良好的线性关系,检出限(3S/N)3.3×10-7 mol/L,RSD1.3%~3.4%之间,加样回收率98.2%~103%。 相似文献
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《Sensors and actuators. A, Physical》2007,133(2):431-438
This paper reports the development of a micro thermal shear stress sensor that utilizes multiwalled carbon nanotubes as the sensing element. The sensor was fabricated by laterally aligning randomly distributed nanotubes into a 360 μm long and 90 μm wide conductive trace between two triangular shaped micro electrodes through the use of a high frequency AC electric field. During operation, the aligned nanotubes are electrically heated to an elevated temperature and surface shear stress is measured indirectly by the amount of convective heat transfer from the heated nanotubes to the surrounding fluid flow.The nanotube alignment process was primarily controlled by three different phenomena: dielectrophoresis, joule heating, and Brownian motion. Numerical simulations, together with experimental verifications, indicated that a successful alignment could only be realized if: (1) the dielectrophoretic force was positive, (2) the electro-thermal force was also positive, and (3) the dielectrophoretic force was high enough to overcome Brownian motion. The aligned nanotube trace has a room-temperature resistance of 580 Ω, which corresponds to a conductivity of 2.7 × 104 S/m. The absolute temperature coefficient of resistivity ranges from 0.01 to 0.04% °C−1. This is about one order of magnitude smaller than the highly doped polysilicon sensing material used in the MEMS micro shear stress sensor. The shear stress sensitivity of the nanotube trace operated at a 3% overheat ratio is found to follow the theoretical sensor power ∝ (shear stress)1/3 relationship, provided the shear stress level is higher than 0.34 mPa. This result confirms the feasibility of using aligned multi-walled carbon nanotubes as a thermal shear stress sensing material. 相似文献
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基于碳纳米管修饰石墨电极测定槲皮素 总被引:1,自引:0,他引:1
该文首次利用化学气相沉积法在石墨基体上直接生长出碳纳米管.制备了对槲皮素具有电催化氧化的碳纳米管修饰石墨电极(CNTs/C),槲皮素在该修饰电极上发生可逆的氧化还原反应.在B-R缓冲溶液(pH1.81)中,氧化峰电流与槲皮素的浓度在1.0×10-7~5.0×10-4mol/L范围内呈线性关系,相关系数为0.9980,检测限为1.5×10-8mol/L,当槲皮素的浓度为1.0×10-5mol/L时,测得槲皮素的RSD(n=5)为2.3%,回收率在95.1%~100.7%之间. 相似文献
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《Sensors and actuators. A, Physical》2007,133(2):467-471
A novel, high efficiency detector for humidity is described, in which the multiwall nanotubes grown on the silicon substrates serve as anode and ITO film glass plate as cathode are separated and insulated by a glass insulator. Application of a positive bias to the multiwall nanotubes generates high electric field sufficient to field-ionize passing gas-phase atoms especially for water vapor. By monitoring the prebreakdown current, relative humidity can be determined. The sensitivity factor (I75.8%/I12%) is about 229.4. The recovery time from 53.4 to 6.8% RH for the humidity sensor is about 10 s. 相似文献