Novel and Cost-efficient Sensors for the Concentration Measurement of Ammonia and Ammonium Nitrate Particles

In the presence of high concentrations of ammonia and nitric acid gas, the formation of ammonium nitrate particles (NH4NO3) is well established at low temperatures. As a result, high concentrations of ammonium nitrate particles are usually observed during the spring and winter period. Due to its semi-volatile nature, the measurement of ammonium nitrate with classical methods based on filter sampling (sampling time ³ 24 h) introduce severe artifacts. Thus, the main objective of this study is to develop new low-cost sensors able to measure simultaneously and selectively the concentration of ammonium nitrate particles and its gaseous precursor ammonia. Sensors combine two surfaces which are sensitive to ammonia and based on polyaniline nano-composites materials. The mass concentration of ammonium nitrate is determined by measuring the concentration of the ammonia released by heating one of the sensitive surfaces. Sensors show a response to gaseous ammonia at concentrations less than 20 ppb with sensitivity around 0.3 %.ppb-1, and the limit of detection of sensors to ammonium nitrate particles is around 270 µg.m-3 with a sensitivity of 0.0014 %.µg- 1.m3

Effets de prelocalisation et de localisation dans InP de type n

SIGLET 55004 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

<italic>X</italic>-Band Microwave Absorbing Properties of Epoxy Resin Composites Containing Magnetized PANI-Coated Magnetite

International audienc

Hydrogen Sulfide Detection by Sensors Based on Conductive Polymers: A Review

International audienc

METHOD FOR PREPARING A MONOLITHIC NANOPOROUS SILICATE SOL-GEL MATERIAL

A method for preparing a monolithic nanoporous silicate sol-gel material for modulating the pore size distribution for one single starting composition without the addition of a structuring agent. The method includes the following steps: a) synthesising a gel from at least one organosilylated precursor, the synthesis being carried out in an aqueous medium, optionally including an organic solvent and without a structuring agent, and b) drying the gel obtained in step a) at a temperature between 10° C. and 70° C., preferably between 15° C. and 55° C. and more preferably between 20° C. and 40° C., in a gas flow in a drying chamber to obtain a monolithic nanoporous silicate sol-gel material and a residual relative humidity in the drying chamber of between 0.1 and 20%, preferably between 0.5 and 10% and more preferably about 5%

Acid-dopant effects in the formation and properties of polycarbonate-polyaniline composites

International audienc

Dispositif de prélèvement des gaz expirés par un patient

Date de dépôt : 11/06/2021N° de dépôt : PCT/EP2021/06584

PROCÉDÉ DE PRÉPARATION DE MATÉRIAU SOL-GEL SILICATÉ NANOPOREUX MONOLITHIQUE

The invention relates to a method for preparing a monolithic nanoporous silicate sol-gel material for modulating the pore size distribution for one single starting composition without the addition of a structuring agent, said method comprising the following steps: • a) synthesising a gel from at least one organosilylated precursor, the synthesis being carried out in an aqueous medium, optionally comprising an organic solvent and without a structuring agent, and • b) drying the gel obtained in step a) at a temperature between 10°C and 70°C, preferably between 15°C and 55°C and more preferably between 20°C and 40°C, in a gas flow in a drying chamber to obtain a monolithic nanoporous silicate sol-gel material and a residual relative humidity in the drying chamber of between 0.1 and 20%, preferably between 0.5 and 10% and more preferably about 5%

An Analysis of the Effect of Multiple Layers in the Multi-Objective Design of Conducting Polymer Composites

International audienceIn the design of materials for the shielding of electric devices, there is a recent trend to use multilayer compounds due to some restrictions in the making process of the materials but also since they are supposed to have a higher potential to offer “better” characteristics than the related monolayered materials. In this work, we investigate the possible impact of the number of layers in a compound critically. It will turn out that—at least for the general objectives we study here and for conducting polymer composites—multilayered materials are suitable to only a limited extent. To be more precise, when “just” aiming for a high shielding efficiency the task can be accomplished with merely one layer. If in addition the cost of the material comes into play, however, a second layer may be helpful, but further layers do not seem to have a significant impact on the performance of a material. Here we extend an existing multiobjective design problem for the design of shielding materials for our purpose, and attack the resulting multiobjective optimization problem with evolutionary strategies, and finally analyze the results in the viewpoint of the required number of layers within a shielding material

A Multi-objective Approach to the Design of Conducting Polymer Composites for Electromagnetic Shielding

This work deals with the design of new shielding materials for the protection of electrical devices. Since there are many different requirements for modern materials, we have chosen a multi-objective approach to this problem. As material under consideration we chose conducting polymer composites due to their excellent electromagnetic properties in the microwave band and their high potential for the optimization process. In this paper, we start this process with the formulation of a novel model, deal further with the approximation of these solution sets, and finally consider the decision support related to this problem