Humidity effect on the response to ammonia of conductimetric sensors made of molecular materials
type: Dataset
description: Many ammonia sensors are available but the consideration of the humidity effect is scarcely insured even by manufacturers. The aim of this thesis is to propose a conductimetric transducer capable tomeasure ammonia selectively, with enough accuracy for air quality control, in a variable humidity environment. To reach this goal, we used thin film resistors made of cobalt phthalocyanines as semiconductor. This study deals with thin films processing made by vacuum evaporation, solventcast and electrodeposition. Automated workbenches were developed to perform electrical measurements under argon and to study the response of sensors to dry or humid ammonia by meansof 1 min / 4 min-long exposure / recovery cycles. From those cycles, relative responses are calculated to obtain values proportional to ammonia concentrations. The humidity and ozone effects are also studied independently as well. Ammonia / humidity cross sensitivity tests are made with four different resistors exposed to ammonia concentration in a 25-90 ppm range and in a 0-80%relative humidity range, under ambient temperature. Two of them, a cobalt phthalocyanine (CoPc)resistor and a hybrid resistor made of sulfonated cobalt phthalocyanine / polypyrrole (s-CoPc/PPy)gave interesting results.CoPc allows to discriminate 25, 45 and 90 ppm ammonia concentrations under 20-60% RH range,with a relative response of 40% at 45 ppm. Moreover, even if the RRs at 80% RH shift slightly, it isstill possible to discriminate the different concentrations.s-CoPc / PPy is less sensitive to ammonia but its study allowed to show that adding phthalocyaninein a PPy matrix enhances the sensitivity of this material and gives a RR of 3.3% at 45 ppm.However, the covered humidity range is larger, from 20 to 80% RH. Thus, this study allows to compare molecular materials and estimate their potential for air quality control applications with different humidity levels
landing page: https://theses.hal.science/tel-00783853
identifier: NNT: 2012DIJOS009
keyword: air-quality
keyword: ammonia
keyword: ammoniac
keyword: capteur-chimique
keyword: chemical-sensor
keyword: conductimetric-sensor
keyword: electronique-organique
keyword: humidite
keyword: humidity
keyword: infoeu-reposemanticsdoctoralthesis
keyword: materiau-moleculaire
keyword: molecular-material
keyword: phtalocyanine
keyword: phthalocyanine
keyword: physcondcm-genphysics-physicscondensed-matter-cond-matother-cond-matother
keyword: plastic-electronic
keyword: qualite-de-lair
keyword: spiotherengineering-sciences-physicsother
keyword: theses
keyword: transduction-conductimetrique
issued: 2026-05-14T18:19:45.982180
modified: 2026-05-14T18:19:45.982186
language: fr
contact point: Organization
  fn: CCSD

test_moissonnage_selune
type: Agent

Humidity effect on the response to ammonia of conductimetric sensors made of molecular materials
type: Distribution
format: HTML
access URL: https://theses.hal.science/tel-00783853
issued: 2026-05-14T18:19:46.038540
modified: 2026-05-14T18:19:45.936650