Humidity sensors materials metal oxides

Nd202C03 (a metal oxide carbonate) has also been reported as a strong candidate for a CO2 sensor (Djerdj et al, 2009) and gives an impressive response of 7.5 to 3000 ppm CO2 at an operating temperature of 350°C in 50% relative humidity air. The material also displays an impressive dynamic with sub-100 ppm concentrations of CO2 being readily detectable. However, the authors do not comment on the long-term stability of the material although it is well-known that oxides of the lanthanide metals are the most thermodynamically stable. 

Besides the utilization of PANI/Sn02 as a humidity sensor device, many scientific works emphasized that nanocomposites developed from polyaniline (PANI) and metal oxides—especially Sn02—are good candidates as gas sensor deviees. Taking into account all these observations, the literature supports fabrication of PANI/Sn02 hybrid materials with different amounts of Sn02 content prepared by in situ chemical oxidative polymerization method, with the sensitivity of materials toward toluene... 

One type of humidity sensor utilizes porous perovskite-type ceramic materials. Perovskite-type metal oxides are good candidates because their surfaces can be easily modified in order to obtain water adsorptive properties by choosing an appropriate cation in the oxides. In addition, the perovskite-type oxides do not require thermal treatment. Also, no influence is expected in sample gases from coexisting CO2. As the metals in perovskite... 

Copper, zinc, and titanium nanostractures are promising materials to be used in food safety and technology. The antimicrobial properties of above metals at the nanoscale provide affordable and safe innovative antimicrobial strategies (Table 2). Copper has been shown to be an efficient sensor for humidity, while titanium oxide has resistance to abrasion and UV-blocking performance. The migration of cations from the polymer matrices is the key point to determine their antimicrobial effectiveness, however, this migration of cations may affect the legal status of the polymer as a food contact material. 

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