高聚物湿度传感器的研究

本文介绍采用辐射引发聚合的方法制备高聚物/晶振型湿度传感器。通过对高聚物膜的感湿性能测试与评价,确定聚合物膜中各单体组分含量,并优化辐射聚合工艺。该高聚物/晶振型湿度传感器的技术特点是:湿度测量范围宽10％～100％RH;湿滞回差小,测量误差小于±2％RH。尤其适于在易燃易爆环境下应用。     

矿浆中金属离子对硅线石与石英浮选分离的影响

系统研究了Fe^3 和Al^3 等金属离子对硅线石和石英可浮性的影响，结果表明：采用油酸钠为捕收剂，Fe^3 和Al^3 在中性或弱碱性介质中对石英浮选有很强活化作用，从而使硅线石和石英浮选分离困难，柠檬酸对金属离子活化石英有很强抑制作用，而对硅线石抑制作用较弱，是浮选分离硅线石和石英较好的的选择性抑制剂，Auger电子能谱仪测试表明：柠檬酸在硅线石表面作用前后Al峰的化学位移为-0.1eV，化学作用很弱，而在Fe^3 和Al^3 离子活化的石英表面，加入柠檬酸前有明显Al Auger电子能峰，加入后，石英表面Al Auger电子能峰消失，表明柠檬酸加入促使吸附在石英表面Al^3 离子溶解，使石英表面阴离子捕收剂吸附活性点降低。     

石英晶体微天平的研究进展综述

石英晶体微天平(QCM)能够感知到纳克级的质量变化,在分析化学、电化学、有机化学、生物医学等方面得到了广泛的应用。根据与QCM电极表面相接触的研究介质即应用对象的不同,分别阐述了刚性薄层、牛顿流体、粘弹性膜层的基础方程、分析方法及应用,并探讨了其存在的问题与发展趋势。     

Electrodeposition and dissolution of yttrium-hexacyanoferrate layers

The electrodeposition and dissolution of yttrium-hexacyanoferrate [YHCNFe(II)] were investigated by electrochemical quartz crystal microbalance technique (EQCM). The electrodeposition was carried out by potential cycling or stepping from solutions of Y(NO₃)₃ and K₃[Fe^III(CN)₆] of different concentrations. The ratio of the reactants was also varied. No deposition was found in dilute solutions (c < 10⁻³ mol dm⁻³). The increase of concentrations led to an intense deposition of YHCNFe(II) in the course of reduction of [Fe^III(CN)₆]³⁻. At high concentrations of the reactants a coagulation deposition of YHCNFe(III) at open-circuit has also been detected. During the reduction the first phase is the nucleation which requires saturation or oversaturation in respect to the reacting species near the gold surface. The growth phase is much faster than the formation of nuclei, and its rate depends on the concentration and the concentration ratio of the species. The composition of the deposits has been determined by total reflection X-ray fluorescence (TXRF) spectrometry. From the molar ratio of atomic constituents (K, Y and Fe) of the slightly soluble deposit (solubility: 5 × 10⁻⁵ mol dm⁻³) formed after reduction of Fe(III) a formula K_0.46Y_1.18[Fe^II(CN)₆] can be derived. This value is in good accordance with the molar mass calculated from the results of EQCM experiments which also revealed that the deposit contains ca. 2 mol H₂O/mol YHCNFe(II). The solubility of YHCNFe(III) is substantially higher (s = 2 × 10⁻³ mol dm⁻³), and according to the results of TXRF measurements, its composition is Y[Fe^III(CN)₆]. The reoxidation of YHCNFe(II) takes place in two steps. The first one is a partial oxidation which is accompanied by the desorption of K⁺ ions from the layer. During further oxidation a fast dissolution occurs due to the high solubility of YHCNFe(III).     

环氧地坪涂料在酸碱环境中的应用

用低黏度环氧树脂、活性稀释剂、固化剂、流平剂、消泡剂、不同目数的硅微粉等配制的地坪涂料,经实际使用,效果良好。环氧地坪涂料固化物经43%硫酸溶液60℃/120 h及5.3%次氯酸钠溶液常温/200 h浸泡,质量变化率均小于1.2%。     

Carbon molecular sieve films produced by dc sputtering

This paper reports adsorption measurements that show molecular sieve effects in amorphous hydrogenated carbon (a-C : H) films deposited by d.c. magnetron discharge decomposition of acetylene. Adsorption of organic gases on the films is studied by using a quartz crystal microbalance technique. The sieve effect in this material depends on both deposition and annealing conditions. Films having significant molecular sieve effects are found to be typically microporous and to have a very small characteristic micropore dimension. It is suggested that the d.c. sputtered a-C : H film may be useful as a molecular sieve material in selective adsorption and gas permeation studies.     

石英晶体最大双折射率色散特性的椭偏测量

为了测量石英晶体最大双折射率的色散特性,在椭偏光谱仪的水平透射测量模式下,通过对确定厚度的石英波片相位延迟量的精确测量,计算出了石英晶体的最大双折射率值,并进行了误差分析。结果表明:这种方法光路简单、操作方便,屏蔽了光源的不稳定性;双折射率测量精度达到了10-6,比连续偏光干涉法的测量精度提高了1个数量级;实现了对石英晶体的最大双折射率色散特性的连续光谱测量;此方法对其它双折射晶体材料的双折射率色散特性的研究也同样适用。     

Alkaline treatment kinetics of calcium phosphate by piezoelectric quartz crystal impedance

Calcium phosphate film was prepared by electrochemical deposition technology. Subsequently, the alkaline treatment process of calcium phosphate film in 0.1 mol/L NaOH solution was monitored on real time by the piezoelectric quartz crystal impedance (PQCI) technique. The variations of morphology and composition for the alkaline treatment products were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) and X-ray diffraction (XRD), respectively. The dynamic variations of calcium phosphate can be characterized by the change of equivalent circuit parameters. The results show that the forming process of hydroxyapatite (HA) is composed of three stages: (1) acidic calcium phosphate dissolution; (2) phase transformation; and (3) HA formation. Furthermore, the correlative kinetic equations and parameters are obtained by fitting the static capacitance (C _s)—time curves. Foundation item: Project(2005CB623901) supported by the Major State Basic Research and Development Program of China     

19.6μm微管内部阻力特征

分别以蒸馏水、四氯化碳为工质,流过内径19.6 μm光滑石英管,分别采用"单管法"和"双管法"测量微管进出口压力、温度和流量,实验得到了雷诺数(Re数)在9.6～530之间的微管内部流动阻力,并与经典理论值进行了对比.实验研究结果表明,粘性耗散效应降低了摩擦系数,降低了约13.7%;进出口压力降、入口效应与双电层效应(electrical double layer,EDL效应)则增加微管内部摩擦系数,在Re数相同时,其中,进出口压力降与入口效应大约增加了16.12%摩擦系数,EDL效应增加了约6.84%摩擦系数.忽略3种微尺度效应,19.6 μm管流动摩擦系数与Hagen Poiseuille理论值几乎一致.     

改性石英砂的润湿性能研究

对经过改性处理之后的普通石英砂的润湿性能进行了研究。实验采用滴水穿透时间法（WDPT）、酒精溶液入渗法（MED）、接触角测定法三种方法。通过这三种方法来定性和定量地描述其润湿性能。实验结果表明：直接经过酸化处理的石英砂与经过硅烷化处理的石英砂的润湿性能有着明显的改变,前者较普通石英砂表现更为亲水,而后者表现出斥水性。此研究为用石英砂模拟不同润湿性能土壤提供了表面改性方法以及前期的理论准备。