无铅铜基钙钛矿Cs2CuBr4的湿度传感性能

铅卤钙钛矿因其优异的光电性能引起了人们的极大关注,但由于其内在的不稳定性以及铅的毒性问题,限制了其实际应用。本文制得一种性能较稳定的无铅铜基钙钛矿Cs₂CuBr₄,利用其对湿度较为敏感的特性,创制了基于Cs₂CuBr₄敏感膜的石英晶体微天平（quartz crystal microbalance, QCM）湿度传感器。结果表明,当钙钛矿溶液的浓度小于0.4μg/μL时,敏感膜在11%~84%相对湿度下具有良好的湿度传感性能。其中最优浓度为0.3μg/μL（QCM-3）、薄膜质量398.95ng时,传感器具有高灵敏度（37.65Hz/% RH）,优异的对数线性关系（R²=0.9948）和快速的响应/恢复时间（5s/1s）。由此可见,无铅铜基钙钛矿Cs₂CuBr₄在湿度传感领域具有良好的应用前景。     

基于氯化钴改性的纤维素纸比色湿度传感器

为了获得兼具良好湿敏响应和颜色可视性的湿度传感器,以纤维素滤纸（FP）和氯化钴（CoCl₂）为原料,滤纸为传感器的基底材料,氯化钴为感湿材料和颜色指示剂,通过简单的浸泡-干燥的方法制得CoCl₂/FP复合膜。采用扫描电子显微镜（SEM）、傅里叶红外光谱仪（FTIR）、X射线衍射仪（XRD）对复合膜进行一系列物理化学性能测试。结果表明,CoCl₂/FP复合膜上均匀地分布着氯（Cl）元素和钴（Co）元素,且滤纸和氯化钴之间主要发生的是物理变化。采用电化学工作站和电脑配色仪对CoCl₂/FP比色湿度传感器进行电流响应测试和可见光光谱测试。结果表明,在相对湿度（RH）为11%~98%的范围内,CoCl₂/FP比色湿度传感器具有明显的电流响应,电流变化超过1000倍。另外,从低湿度到高湿度,CoCl₂/FP比色湿度传感器呈现出由蓝色到红色的颜色变化,且这种颜色变化是可逆的。     

基于纳米探针的压电重金属离子检测

文章通过在QCM（Quartz Crystal Microbalance,石英晶体微天平）表面形成纳米复合物引起质量变化来检测溶液中的痕量重金属离子。先让金属离子在羧基修饰的QCM表面进行络合吸附,然后加入羧基修饰的金纳米粒子,使之与QCM表面吸附的重金属离子结合,在QCM表面形成一层三明治结构的纳米复合物,引起QCM谐振频率明显下降。该方法大大提高了QCM检测重金属离子的灵敏度,且具有重现性好、传感器易再生等特点。     

壳聚糖接枝聚丙烯酸/凹凸棒石复合材料对毒死蜱的吸附行为

以壳聚糖（chitosan,CTS）、丙烯酸（acrylic acid,AA）和凹凸棒石（attapulgite,ATP）为原料,利用分散聚合法制备壳聚糖接枝聚丙烯酸/凹凸棒石（CTS-g-PAA/ATP）复合吸附剂,以毒死蜱（chlorpyrifos,CPF）为模型农药,研究了复合吸附剂CTS-g-PAA/ATP在不同温度、时间和不同毒死蜱浓度下对毒死蜱的吸附性能,并对实验结果进行吸附热力学与动力学拟合分析。结果表明,CTS-g-PAA/ATP和HATP（酸化凹凸棒石）在24h和30℃下对毒死蜱的吸附量分别为7.42mg/g和18.95mg/g,复合材料的吸附能力提高了180%;拟合结果分析表明,吸附过程遵循Langmuir单分子层等温吸附（R²≥0.97）,在30℃、35℃、40℃下理论上最大吸附量分别为57.8mg/g、54.3mg/g、51.2mg/g;并与准二级动力学模型精准拟合（R²≥0.97）,化学吸附是吸附过程的主要控制因素。     

细菌纤维素基水凝胶的制备及传感器应用进展

概述了细菌纤维素和水凝胶两种材料的优势,综述了功能性细菌纤维素水凝胶的制备及其功能化方法,介绍了原位合成法、异位合成法中的浸渍法、溶解再生法的原理、优缺点及相关研究进展。基于细菌纤维素水凝胶具有优异的机械性能、生物相容性、可降解性和可修饰性等诸多特性,总结了细菌纤维素基水凝胶在传感器领域的最新进展,包括应变传感器、pH传感器和热传感器、电响应传感器、湿度传感器。最后对细菌纤维素基水凝胶的发展前景进行了展望。     

TOCNF与磁性羧甲基壳聚糖纳米粒子复合物的制备及吸附Pb2+的特性

水体中铅污染对环境及人的健康安全造成了极大的危害。本文将四甲基呱啶（TEMPO）氧化的纤维素纳米纤维（TEMPO-oxidized cellulose nanofibers,TOCNF）与磁性羧甲基壳聚糖纳米粒子（magnetic carboxymethyl chitosan nanoparticles,MCCN）交联复合制备一种经济高效且对环境无毒害的Pb²⁺吸附剂,对复合前后的材料进行结构表征。通过单因素实验研究pH、Pb²⁺初始浓度、吸附时间及温度对Pb²⁺吸附效率的影响,确定最优吸附条件后比较TOCNF/MCCN及TOCNF对Pb²⁺的吸附效果,研究复合材料对Pb²⁺的吸附特性。研究结果表明,Fe₃O₄成功被羧甲基壳聚糖纳米粒子包裹并与TOCNF交联复合,在最优吸附条件（pH=5,Pb²⁺初始浓度为100mg/L,吸附时间为240min,常温下进行实验）下,TOCNF/MCCN吸附Pb²⁺的饱和容量为193.5mg/g,比TOCNF高了近一倍。复合吸附剂吸附Pb²⁺的过程更符合准二级动力学方程,说明决定吸附速率的主要是化学吸附。等温吸附方程的相关系数R²表明,Langmuir方程能更好地拟合吸附过程,说明复合吸附剂对Pb²⁺的吸附主要是表面基团的单分子层吸附。通过线性方程的斜率计算得到的理论饱和吸附量为201.1mg/g,与实际值差3.8%,经过5次解吸再吸附的过程,吸附剂的吸附效率仅下降了13%,表明该吸附剂有良好的可再生性,具有很好的应用前景。     

KBrO3-Fe（Ⅱ）-双吡啶阻抑光度法测定饮用水中微量溴酸盐

在pH=2.7的条件下,BrO₃^2-对Fe（Ⅱ）-双吡啶（2,2′-bipyridine,BPY）显色体系有明显的阻抑作用,据此建立了一种测定饮用水中微量BrO₃^2-的新方法。实验考察了pH、超声时间、显色剂用量和显色时间对溴酸盐测定的影响。在选定条件下,该方法的线性范围为0.2~1.0 mg/L（R²=0.999 3）,检出限为0.002 6 mg/L。该法用于饮用水中BrO₃^2-含量的测定,其RSD均小于5%（n=3）,加标回收率为92.8%~101.5%,能满足饮用水中微量BrO₃^2-的测定要求。     

Au/UiO-66(Hf)纳米复合材料修饰电极电化学检测Cr（Ⅵ）的性能研究

采用溶剂热法和化学还原法制备出Au/UiO-66(Hf)纳米复合材料,再将该纳米复合材料修饰到玻碳电极上,运用线性扫描伏安法（LSV）实现了废水中Cr（Ⅵ）的有效检测。Au/UiO-66(Hf)/GCE传感器对质量浓度范围为100～1 000μg/L的Cr（Ⅵ）具有优异的线性响应,检测灵敏度为0.002 34μA·L/μg,最低检测限为18.76μg/L。同时,该传感器具有良好的稳定性与抗干扰性能,对实际电镀废水中Cr（Ⅵ）的检测回收率达105.03%。     

微波超声波联用萃取白藜芦醇及其苷的HPLC测定

建立了花生芽和葡萄籽微波超声波联用提取白黎芦醇及其苷的HPLC测定方法。采用高效液相色谱进行测定,色谱柱为迪马C₁₈, 流动相为乙腈-水溶液，梯度洗脱，流速1.0 ml/min，柱温为30℃，检测波长为306 nm，进样量为20 μl。白黎芦醇在0.343～15.15×10³ μg/ml范围内呈良好的线性关系，相关系数R² = 0.9967；白藜芦醇苷在110.712～1774.23×10³ μg /ml范围内线性关系良好，相关系数R² = 0.9993。该方法检测快速、简便、重现性好，适用于花生芽和葡萄籽中白藜芦醇及其苷的定量分析。     

油菜秸秆高温水解液中单糖组分的高效液相色谱测定

建立了高温水中CO₂催化油菜秸秆水解体系中单糖的高效液相色谱（HPLC）分析的方法。其分析采用Prevail^TM ES糖柱,蒸发光散射检测器（ELSD）,流动相为乙腈/水（体积比80∶20）,等度洗脱,流速0.8 mL/min,柱温35 ℃,漂移管温度95 ℃,干燥空气作为载气,流速为3.0 L/min。20 min内阿拉伯糖、木糖、果糖、甘露糖、半乳糖和葡萄糖6种单糖得到了较好的分离,各物质线性回归方程的相关系数R²为0.999 1~0.999 7,其平均回收率为95.3 %~108.0 %,相对标准偏差（RSD）均小于3 %。     

氧化石墨烯/钒钛酸复合材料的制备及湿敏性能研究

通过Hummers法制备氧化石墨后进行超声分散,得到分散均匀的氧化石墨烯(GO)分散液,物理复合滴涂制备氧化石墨烯/钒钛酸薄膜并对其感湿性能进行了研究,并通过交流与直流方法对其感湿机理进行了深入探究。结果表明:氧化石墨烯/钒钛酸复合膜的湿敏性能优于氧化石墨烯和钒钛酸单层膜,该湿敏薄膜的湿滞为8.3%RH,灵敏度变化2个数量级,响应时间为8 s,还原时间为10 s,曲线线性度良好。材料在低湿阶段主要表现为电子导电,中高湿阶段为电子导电和离子导电同时存在,高湿阶段主要表现为离子导电。     

基于电纺NiI2/TPU纳米纤维膜的湿敏变色传感器的制备及性能

以热塑性聚氨酯(TPU)母粒、碘化镍为原料,通过静电纺丝法制备了基于碘化镍/热塑性聚氨酯(NiI2/TPU)纳米纤维膜,将NiI2/TPU纳米纤维膜贴合在聚酰亚胺(PI)基叉指电极上制得湿度传感器.对纳米纤维膜的表面形貌及微观结构进行了表征分析,并研究了该传感器基于颜色变化和电阻电容响应的湿度敏感特性.结果表明,由于碘化镍的颜色变化特性,随相对湿度(RH)从0增加到97％,NiI2/TPU纳米纤维膜显示了从橘红色到黄绿色的颜色转变.此外,该湿度传感器表现出快速的响应/回复时间(0.9 s/9.9 s)、较宽的湿度监测区间(0～97％RH)、较小的洄滞度(0.4％RH)以及优异的稳定性能(>30 d).     

A Novel Highly Sensitive Humidity Sensor Based on ZnO/SBA‐15 Hybrid Nanocomposite

This work deals with the study of hydrothermally synthesized zinc oxide (ZnO) loaded mesoporous SBA‐15 hybrid nanocomposite for relative humidity sensing (RH) at room temperature. The sensor exhibits an excellent ~5 orders impedance change along with excellent linearity, quick response time (17 s), rapid recovery time (18 s), negligible hysteresis (1.2%), good repeatability, and stability (1.8%) in 11%–98% RH range. In addition, complex impedance spectra of the sensor at different RHs were analyzed to understand the humidity sensing mechanism. Our study can open a new way for realizing ZnO/SBA‐15 hybrid nanocomposite for fabrication of high‐performance RH sensors.     

Functionalized multi‐wall carbon nanotubes/silicone rubber composite as capacitive humidity sensor

Functionalized multi‐wall carbon nanotubes (MWCNTs) treated by mixed acids have been used to develop a capacitive humidity sensor based on MWCNTs/silicone rubber (SR) composite film. The MWCNTs/SR composites were prepared through conventional solution processed method. The micrographs of MWCNTs/SR composites were observed by transmission electron microscopy (TEM) and scanning electron microscope. The FT‐IR spectra demonstrated the successfully grafting of ? OH groups on the treated MWCNTs. The sensing properties of the composite at different relative humidity (RH) and frequency were characterized and linear sensing responses of the MWCNTs/SR composites to RH were observed. The treated MWCNTs/SR composite film (Tr‐film) had higher sensitivity than that of the untreated MWCNTs/SR composite film (Un‐film). Experimental data indicate that the Tr‐film exhibits an excellent long‐term stability, small hysteresis, and fine reproducibility. The response and recovery time of the Tr‐film were 30 and 27 s, respectively. Thereby, such Tr‐film had potential applications as humidity sensors. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40342.     

Mn‐Loaded Mesoporous Silica Nanocomposite: A Highly Efficient Humidity Sensor

We report a relative humidity sensor based on manganese‐nanoparticle‐loaded mesoporous silica SBA‐15 using a facile hydrothermal route. The as‐developed nanocomposite material (Mn/SBA‐15) possesses a high surface area and a high pore volume. The obtained samples were characterized by using low‐angle X‐ray Diffraction (XRD), Fourier‐transform infrared spectroscopy (FTIR), N₂ adsorption–desorption, high‐resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), and energy‐dispersive X‐ray (EDX) spectroscopy techniques. The Mn/SBA‐15 exhibited, improved humidity response and recovery time as compared to pure SBA‐15 in the 11%–92% RH range. Optimal results were obtained for the 5 wt% Mn‐loaded SBA‐15 sample, which displayed excellent linearity, low hysteresis, and high humidity response. A change in ~5 orders of magnitude in resistance was observed over 11%–92% RH range. The investigation of humidity sensing properties of Mn/SBA‐15 nanocomposite shows that this material has good prospects as humidity sensor.     

Humidity sensing properties of ZnO colloid crystals coated on quartz crystal microbalance by the self-assembly method

ZnO colloid crystals were coated on quartz crystal microbalance (QCM) by the self-assembly method. Field emission scanning electron microscopy and X-ray diffraction were used to analyze the morphology and crystal structure of ZnO colloid crystals. The sensing behavior was examined by measuring the resonance frequency shifts of QCM. The device exhibits excellent humidity sensing properties in the whole humidity range from 11% to 95%, such as good linearity, fast response time and recovery time, excellent reliability, and long-term stability. We also discussed the adsorption and desorption of water molecules on ZnO colloid crystals at different humidity conditions.     

Synthesis and humidity sensitive properties of pyrrole‐based polyelectrolytes

Pyrrole (Py)‐based polyelectrolytes (Py‐PE): P(Py‐COOLi), P(Py‐COONa), and P(Py‐COOK) was synthesized, characterized, and used to prepare thin film resistive humidity sensors. Their humidity sensitive properties have been investigated, and sensing mechanism was presented. The Py‐PE contains PPy as backbone and the side chain bearing carboxylic salt group, which made its sensor exhibited a very wide humidity sensing range of 0–97% relative humidity (RH), high conductivity even at very low humidity, and both ionic and electronic conduction contributed to its conductivity. Among all the Py‐PE, P(Py‐COOK) showed high sensitivity, with the impedance changing of about three orders of magnitude (10³–10⁶ Ω) from 97 to 0% RH, whereas P(Py‐COONa) showed quick response for both absorption (12.5 s) and desorption (15.2 s). Py‐PE prepared is promising for preparation of thin film resistive humidity sensors capable of detecting low humidity. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Dielectric and AC conductivity studies of novel porous armalcolite nanocomposite‐based humidity sensor

Armalcolite, a current motivated rare earth ceramic usually available in the moon, had been used for the first time, as dielectric‐type humidity sensors. The armalcolite nanocomposite was prepared using multistep solid‐state sintering under high pressure and a high‐sensitive dielectric sensor was developed for humidity controlling applications. Different concerning phases developed by the proper sintering were analyzed precisely by X‐ray diffraction (XRD) as well as scanning electron microscopy (SEM). At 100 Hz frequency, the obtained dielectric constant was 24 times greater at 95% relative humidity (RH) as compared to 33% RH. The armalcolite‐based sensor showed lower hysteresis (<3.5%), good stability, and faster response (~18 seconds) and recovery (~35 seconds) times compared to conventional humidity sensors. The sensing mechanism of the nanocomposite was categorically determined by the analyzed characteristics parameters such as dielectric constants, normalized loss tangent, and alternating current conductivity properties. This study also confirmed that the whole conduction mechanism was accomplished by electrons or ions and dipoles in the entire RH range. Therefore, the present armalcolite‐based porous nanocomposite would be a potential sensing material for novel humidity sensors.     

电容式湿度传感器电容式湿度传感器——交联的聚甲基丙烯酸甲酯的感湿性能

运用本体聚合法合成了聚甲基丙烯酸甲酯（ＰＭＭＡ）和分别用三种交联剂交联的ＰＭＭＡ。以ＰＭＭＡ和交联的ＰＭＭＡ为感湿膜制成电容式湿度传感器，在１０％～９０％ＲＨ范围内，这些传感器的电容随相对湿度呈线性规律变化。交联的ＰＭＭＡ传感器具有正的温度系数，但与乙酸丁酸纤维素（ＣＡＢ）传感器相比，ＰＭＭＡ的温度依赖性更小。交联的ＰＭＭＡ传感器能耐有机蒸气，在饱和丙酮蒸气中放置３０ｍｉｎ后，３次测试循环后在９０％ＲＨ下传感器电容的变化约为１％。在高温、高湿、油烟气等各种苛刻环境中放置预定时间后，传感器的漂移一般在±２％ＲＨ范围内。