Humidity Sensitive Properties of a Silicone-containing Polyelectrolyte Material

Resistive-type film humidity sensors were prepared with a silicone-containing polyelectrolyte （Si-PE） and their humidity sensitive properties have been investigated. The sensors so obtained show high sensitivity to humidity variation over a wide range of RH （20-96%）. In addition, they exhibit high reversibility, quick response and well long-term stability.

Preparation and Gas Sensitive Properties of Nanometer-Sized SnO_(2)

Nanometer sized SnO 2 particles were prepared by a sol gel method using inorganic salt as a precursor material. Its crystallization was investigated by means of TG DTA,IR absorption spectra, X ray diffractometry and TEM as well as its resistivity change and the gas sensitivity varied with temperature were measured in various reducing gas. The results indicate that well crystallized nano sized SnO 2 with size around 15nm can be obtained at annealing temperature 600℃. The activation energy for the growth of nano SnO 2 was calculated to be 26.55kJ.mol 1 when the annealing temperature was higher than 500℃. The measurements also show that there is a peculiar resistance change varied with temperature for nano SnO 2.It has relevance to the increase in surface adsorbed oxygen. The selective detectivities to C 4H 10 and petrol can be increased when ruthenium ion was doped in nano SnO 2 as a catalyst and so do the gas sensitivity to CO,CH 4,H 2 etc. when rhodium ion was doped in.The detection to the several reducing gas can be realized when the temperature ranged from 260℃ to 400℃.

Humidity Sensitive Properties of a Coplymer of Quaternary Ammonium Salt with Polyether-salt Complex

1 Results Humidity sensors have been widely used in meteorology, process controlling, agriculture and manufacturing. In recent year, more attention has been paid to resistive-type polymeric humidity sensors. Polyelectrolytes are the most usually used materials for their advantages of high sensitivity, fast response, easy preparation, low cost, etc[1,2]. In this paper quaternized and salt-doped copolymer of 2-(dimethylamino) ethylmethacrylate (DMAEMA) with poly(ethylene glycol) methyl ether methacrylate ...

Properties of Sensitive Materials Mainly Composed of ZnO

Sensitive materials mainly composed of ZnO and their multi-functional properties were investigated. The temperature extent of linear resistance, non-linear deviation and endurance ability of surge energy were further discussed. The effect of Mg^2+, AI^3+ and Si^4+, which could be solid solutioned in ZnO grain and the function of Y^3+ ion segregated out in grain boundary were studied as well. The function of Ti was analyzed emphatically.

Sensitive properties of In-based compound semiconductor oxide to Cl_2 gas

Aiming at detecting Cl2 gas, this study was made on how to make In-based compound semiconductor oxide gas sensor. The micro-property and sensitivity of In-based gas sensing material were analyzed and its gas sensitive mechanism was also discussed. Adopting constant temperature chemical coprecipitation, the compound oxides such as In-Nb, In-Cd and In-Mg were synthesized, respectively. The products were sintered at 600 ℃ and characterized by the Scanning Electron Microscope （SEM）, showing the grain size almost about 50-60 nm. The test results show that the sensitivities of In-Nb, In-Cd and In-Mg materials under the concentration of 50 × 10^-6 in Cl2 gas are above 100 times, 4 times and 10 times, respectively. The response time of In-Nb, In-Cd and In-Mg materials is about 30, 60 and 30 s, and the recovery time less than 2, 10 and 2 min, respectively. Among them, the In-Nb material was found to have a relatively high conductivity and ideal sensitivity to Cl2 gas, which showed rather good selectivity and stability, and could detect the minimum concentration of 0.5 × 10^-6 with the sensitivity of 2.2, and the upper limit concentration of 500 × 10^-6. The power loss of the device is around 220 mW under the heating voltage of 3 V.

Two Novel Nitrogen-rich Energetic Coordination Compounds M_2(DAT)_5(H_2O)_3(TNR)_2(M = Zn and Co):Synthesis,Characterization,Thermal Properties and Sensitivity

Two novel energetic coordination compounds Zn2（DAT）5（H2O）3（TNR）2 and Co2（DAT）5（H2O）3（TNR）2 were synthesized and their structures were characterized by elemental analysis and FT-IR spectroscopy.The crystal structures were determined by single-crystal X-ray diffraction.The results reveal that the compounds have similar molecular structures and the crystals belong to the triclinic system,space group P with a = 11.491（3）,b = 13.564（3）,c = 15.496（3） ,V = 2180.4（8） 3,C17H28 Zn2N36O19,Mr = 1203.02 g·mol-1,Dc = 1.832 g·cm-3,μ（MoKα） = 1.221 mm-1,F（000） = 1223,Z = 2,R = 0.0596 and wR = 0.1514 for 11289 observed reflections（I 〉 2σ（I）） for Zn2（DAT）5（H2O）3（TNR）2 and a = 11.5291（13）,b = 13.4894（15）,c = 15.4852（17） ,V = 2164.8（4） 3,C17H28Co2N36O19,Mr = 1190.14 g·mol-1,Dc = 1.826 g·cm-3,μ（MoKα） = 0.888 mm-1,F（000） = 1211,Z = 2,R = 0.0576 and wR = 0.1431 for 11218 observed reflections（I 〉 2σ（I）） for Co2（DAT）5（H2O）3（TNR）2,respectively.The thermal decomposition characteristics of the com-pounds were investigated using differential scanning calorimetry and thermal gravimetry-diffediffer-rential thermal gravimetry.The results of thermal decomposition processes were similar for the two compounds.Both undergo four-step decomposition after the loss of coordinated H2O molecules.The final solid residues for the two DAT complexes were the corresponding metal oxides.The kinetic parameter of the first exothermic process of the compounds was studied by applying the Kissinger and Ozawa-Doyle methods.The thermodynamic parameters of the activation could be calculated.Sensitivity tests revealed that Co2（DAT）5（H2O）3（TNR）2 was more sensitive than Zn2（DAT）5（H2O）3（TNR）2.

Sensitization Properties of Propolis and Balsam of Peru in Guinea Pig Maximization Test(GPMT)

Introduction: Propolis is used in Poland as an active ingredient of some drugs administered externally, dietary supplements and cosmetics. According to the literature, propolis is a non-toxic and safe substance, although it may cause allergic contact dermatitis. Aim: The aim of this study was to assess the allergenic properties of propolis and Balsam of Peru. Material and methods: The study was conducted according to the OECD Guideline for testing of chemicals-Skin sensitization with use of Guinea pig maximization test (GPMT). Guinea pigs have similar sensitivity to allergens as human body. Sensitization properties of propolis were tested in comparison with sensitization properties of Balsam of Peru because of the possibility of cross-reaction between those two substances. Results: The skin of guinea pigs in the propolis group showed no visible change compared to the control group during the first (48 h) and second observation (72 h). The skin of guinea pigs from Balsam of Peru group showed discrete erythema in only one case at the first observation (8.33% of the animals). During the second observation, no visible changes were observed compared to the control group. Conclusions: Guinea pig maximization test showed no sensitizing properties of propolis and weak sensitizing properties of Balsam of Peru in concentration of 5%.

Novel High-nitrogen Energetic Compound Based on Semicarbazide-substituted Tetrazine

A novel energetic compound 3-（3,5-dimethylpyrazol-1-yl）-6-semicarbazide-1,2,4,5-tetrazine（DSTZ） was prepared and characterized by elemental analysis and Fourier transform infrared（FTIR） spectroscopy.The crystal structure was determined by X-ray single crystal diffraction technology.The crystal belongs to the monoclinic system with a P2 1 /c space group,a=0.9942（7） nm,b=0.5067（3） nm,c=1.1830（8） nm,β=109.616°,Z=2 and D c =1.475 g/cm 3.With extensive hydrogen bonds,the molecules were linked together to form a three-dimensional herringbone-like pattern.Thermal analysis of the compound was carried out via differential scanning calorimetry（DSC） and thermogravimetric-derivative thermogravimetry（TG-DTG）.Under a nitrogen atmosphere at a heating rate of 10 K/min,DSTZ decomposed directly in a range of 493―513 K.Only one intense exothermic process was observed and the decomposition products were all gaseous products.Conventional sensitivity properties were determined,showing that the title complex was insensitive to friction,impact and flame.

Microstructure and Mechanical Performance of Cu-SnO_2-rGO based Composites Prepared by Plasma Activated Sintering

A novel chemical technique combined with unique plasma activated sintering（PAS） was utilized to prepare consolidated copper matrix composites（CMCs） by adding Cu-SnO2-rGO layered micro powders as reinforced fillers into Cu matrix. The repeating Cu-SnO2-rGO structure was composed of inner dispersed reduced graphene oxide（r GO）, SnO2 as intermedia and outer Cu coating. SnO2 was introduced to the surface of rGO sheets in order to prevent the graphene aggregation with SnO2 serving as spacer and to provide enough active sites for subsequent Cu deposition. This process can guarantee rGO sheets to suffi ciently disperse and Cu nanoparticles to tightly and uniformly anchor on each layer of rGO by means of the SnO2 active sites as well as strictly control the reduction speed of Cu^2＋. The complete cover of Cu nanoparticles on rGO sheets thoroughly avoids direct contact among rGO layers. Hence, the repeating structure can simultaneously solve the wettability problem between rGO and Cu matrix as well as improve the bonding strength between rGO and Cu matrix at the well-bonded Cu-SnO2-rGO interface. The isolated rGO can effectively hinder the glide of dislocation at Cu-rGO interface and support the applied loads. Finally, the compressive strength of CMCs was enhanced when the strengthening effi ciency reached up to 41.

Strain-rate Sensitivity of Aluminum 2024-T6/TiB_2 Composites and Aluminum 2024-T6

Strain-rate sensitivities of 55vol%-65vol% aluminum 2024-T6/TiB2 composites and the corresponding aluminum 2024-T6 matrix were investigated using split Hopkinson pressure bar method. The experimental results showed that 55vol%-65vol% aluminum 2024-T6/TiB2 composites exhibited significant strain-rate sensitivities, which were three times higher than the strain-rate sensitivity of the aluminum 2024-T6 matrix. The strain-rate sensitivity of the aluminum 2024-T6 matrix composites rose obviously with increasing reinforcement content（up to 60%）, which agreed with that from the previous researches. But it decreased as the ceramic reinforcement content reached 65%. After high strain rates compression, a large number of dislocations and micro-cracks were found inside the matrix and the Ti B2 particles, respectively. These micro-cracks can accelerate the brittle fracture of the composites. The aluminum 2024-T6/Ti B2 composites showed various fracture characteristics and shear instability was the predominant failure mechanism under dynamic loading.

Synthesis and Characterization of Y-Doped SnO_2 as Sensor Materials

Yttrium-doped SnO2 powders were successfully synthesized by solution co-precipitation method and characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The sensitivity of sensors based on Y-doped SnO2 and SnO2 nanocrystals were investigated comparatively. The results indicated that Y-doped SnO2 was with the result of enhancement of sensitivity and selectivity to ethanol and reduction of sensitivity to other gas components. The enhancements of selectivity and sensitivity could be contributed to for two reasons. The first is that rare metal yttrium has a high alkalescence and good catalysis, and the second is that the nanosized crystallite and large specific surface area of Y-doped SnO2 is advantageous for gas-diffusion control as well as an increase in active sites for gas detection.

Electrical Conductivity and Sensitive Characteristics of Ag-Added BaTiO_3-CuO Mixed Oxide for CO_2 Gas Sensing

Carbon dioxide gas sensors based on BaTiO3-CuO composite with different concentrations of Ag addition（1,1.5 and 2 wt%） have been prepared by stander ceramic method and sintered at 500 and 700℃ for 5 h.Electrical conductivity and gas sensing properties of the prepared samples were investigated.Electrical conductivity measurement was used to characterize the obtained sintered sensor pellets.It was found that electrical conductivity and the sensitivity to CO2 were improved with Ag addition and sintering.The correlation between Ag content at different sintering temperature and sensing characteristics towards CO2 is discussed.

Crystal Structure, Thermal Decomposition Behaviors and Sensitivity Properties of a Novel Energetic Compound [Co（DAT）6] （CIO4）2

A novel energetic coordination compound [Co（DAT）6]（CIO4）2 has been synthesized by using 1,5-diaminotetrazole （DAT） as a ligand and its structure has been characterized using X-ray single crystal diffraction, elemental analysis and FT-IR spectroscopy. The central cobalt（II） cation is coordinated by six N atoms from six DAT molecules to form a six-coordinated and distorted octahedral structure. Di-dimension layer structure was formed by the extensive intermolecular hydrogen bonds between DAT ligands and CIO4 anions along a-axis and b-axis. Thermal decomposition mechanism of [Co（DAT）6]（CIO4）2 was investigated based on differential scanning calorimetry （DSC）, thermogravimetric analysis （TGA） and Fourier transform infrared （FF-IR） spectra. The kinetic parameters of the first exothermic process were studied by applying the Kissinger＇s and Ozawa-Doyle＇s methods. Additionally, the sensitivities of this complex were tested. The results of all the studies show that [Co（DAT）6]（CIO4）2 has an extreme potential application as an energetic material.

Optical Properties of High Sensitivity Fiber Bragg Grating on Temperature Sensor

In this paper, the spectrum shift properties of the center reflection wavelength detected to be based on the FBG sensor with ambient temperature change. The basic theoretical methods and numerical simulation for the spectral properties of uniform Bragg grating is analyzed by using coupling mode theory which is optical properties of high sensitivity fiber Bragg grating on temperature sensor in accordance with experiment.

Dye-sensitized solar cells based on functionalized truxene structure

Three new metal-free organic dyes （TX1, TX2 and TX3） based on truxene core structure, with triphenylamine as the electron donor, thiophene as the n spacers, and cyanoacetic acid or rhodanine-3- acetic acid as the electron acceptor are designed and synthesized. Their UV-vis absorption spectra, electrochemical and photovoltaic properties were investigated. The cyanoacrylic acid is verified to be a better acceptor unit （meanwhile the anchoring group） compared to the rhodanine-3-acetic acid. And also, two anchoring groups in TX2 could provide stronger adsorption ability on the TiO2 surface. In addition, the EIS results indicate a slower charge recombination processes for TX2. As a result, dye TX2 bearing two cyanoacetic acid outperforms the other two dyes, exhibiting the photo-conversion efficiency of 2.64%, with Jsc = 5.09 mAcm^-2, Voc = 729 mV, FF = 71.1.

Effect of temperature on phase transition behavior of antiferroelectric (Pb_(0.97)La_(0.02) )(Zr_(0.75)Sn_(0.25-x)Ti_x)O_3 ceramics

Pb0：97La0：02（Zr0：75Sn0：25x Ti x/O3（x D0.10, 0.105, 0.11）（PLZST） antiferroelectric ceramics with highly preferred-（110） orientation were successfully fabricated via the conventional solid-state reaction method.The antiferroelectric nature of PLZST ceramics induced by electric field was demonstrated by the dielectric constant-temperature（D-T） and the polarization-electric field（P-E） measurement. Typical phase transition from ferroelectric（FE） to antiferroelectric（AFE）, and then to paraelectric（PE） is obtained. The results indicate that the phase transition behavior is suppressed with increasing of x, and T c is remarkably shifted to higher temperature of168 ℃, 170 ℃ and 174 ℃, respectively. Besides, high phase transition current（110 6A, 810 7A and 610 7A, respectively） is obtained with temperature induced. Consequently, the excellent electric properties and the restraint between temperature and electric field would provide basis on the application of PLZST antiferroelectric ceramics in microelectronic integrated systems and sophisticated weapons systems.