Soluble phthalocyanines as optical gas sensing materials

A novel soluble phthalocyanine compound, i.e zinc phthalocyanine (sulfonamide) has been synthesized by chemical substitution of zinc phthalocyanine and used to produce thin solid films by means of the spin coating technique. The chemical structure of the spin coated films has been investigated by FT-IR analysis. Atomic Force Microscopy (AFM) has been used to characterize the film morphology and to measure the film thickness. The spin coated films have been tested as optical sensing materials of volatile organic compounds such as methanol, ethanol and 2-propanol. The change of optical reflectance of the films upon exposure to alcohol-vapour-containing atmospheres has been measured versus alcohol concentration and exposure time. The films exhibit a fast and reproducible response, with a complete and fast recovery in methanol and ethanol-containing atmospheres, while diffusion-driven effects appear during exposure to 2-propanol. The response and sensitivity of the films to ethanol vapour is higher than to methanol and 2-propanol

液晶性アゾ色素を側鎖に有するポリウレタン薄膜における光誘起表面レリーフグレーティングの形成

The formation of the photoinduced surface relief grating (SRG) on the film of polyurethane containing liquid-crystalline azobenzene in the side chain has been studied. The peak of absorbance of the azo-polymer used in this study is around 360 nm, which is shorter than that of other azo-polymer, such as Disperse Red based, which has been mainly studied so far, and fabrication of SRG with short pitch can be performed using UV light source. Thermal stability of the formed SRG was investigated and discussed on the basis of the glass transition temperature.液晶性を示すアゾ色素を側鎖に有するポリウレタン薄膜に、UVレーザーの二光束を干渉させ照射することにより、表面レリーフグレーティングを作製した。他に多くの報告例があるディスパースレッドを側鎖に有するアゾ高分子に比べ、吸収のピークが360run付近と短波長であり、光源に短波長なUVレーザーを使用できる分、周期の細かいグレーティングが作製可能となる。また、作製された表面レリーフグレーティングの熱的安定性についても評価し、高分子のガラス転移点に基づく議論も行った

Current Fluctuation Measurements of Amperometric Gas Sensors Constructed with Three Different Technology Procedures

Electrochemical amperometric gas sensors represent a well-established and versatile type of devices with unique features: good sensitivity and stability, short response/recovery times, and low power consumption. These sensors operate at room temperature, and therefore have been applied in monitoring air pollutants and detection of toxic and hazardous gases in a number of areas. Some drawbacks of classical electrochemical sensors are overcome by the solid polymer electrolyte (SPE) based on ionic liquids. This work presents evaluation of an SPE-based amperometric sensor from the point of view of current fluctuations. The sensor is based on a novel three-electrode sensor platform with solid polymer electrolytes containing ionic liquid for detection of nitrogen dioxide − a highly toxic gas that is harmful to the environment and presenting a possible threat to human health even at low concentrations. The paper focuses on using noise measurement (electric current fluctuation measurement) for evaluation of electrochemical sensors which were constructed by different fabrication processes: (i) lift-off and drop-casting technology, (ii) screen printing technology on a ceramic substrate and (iii) screen printing on a flexible substrate