The system for methane detection, under development by our group, consists of gas sensor and pervaporation membrane. The gas sensor was designed and fabricated using ‘nano-on-micro’ approach. The membrane covers the sensor and preferentially transport detected component. Two kinds of hydrophobic membranes were investigated: titania membranes modified by grafting process and polimeric membranes made from polidimethoxysilane (PDMS). Hydrophobic properties of the ceramic membranes were obtained by surface modification with fluorinated silanes (C6F13C2H4Si(OEt)3 and C12F25C2H4Si(OEt)3). Modified ceramic membranes properties were estimated using contact angle measurements. The highest contact angle value (148º) was obtained for membrane modified C12, whereas for membrane modified C6 the highest value was 135º. PDMS membranes of different thickness (in range 75-195 μm) were formed. PDMS permeability properties were examined by water pervaporation. The permeability coefficient of water through PDMS membrane was equal 7,34•10-15 mol/m Pa s. It was proved that water transport is inversly proportional to membrane thickness. Results for PDMS membranes were compared with results obtained for commertial membrane. Moreover, selective commercial membrane properties were tested by pervaporation in water-ethanol sytsem (1-10wt.% of ethanol). The membrane transported selectively ethanol (enrichment factor was in range 4-15).
MONITORING SYSTEMS FOR UNDERWATER PIPELINES
Guarnieri, Vittorio;Lorenzelli, Leandro;
2012-01-01
Abstract
The system for methane detection, under development by our group, consists of gas sensor and pervaporation membrane. The gas sensor was designed and fabricated using ‘nano-on-micro’ approach. The membrane covers the sensor and preferentially transport detected component. Two kinds of hydrophobic membranes were investigated: titania membranes modified by grafting process and polimeric membranes made from polidimethoxysilane (PDMS). Hydrophobic properties of the ceramic membranes were obtained by surface modification with fluorinated silanes (C6F13C2H4Si(OEt)3 and C12F25C2H4Si(OEt)3). Modified ceramic membranes properties were estimated using contact angle measurements. The highest contact angle value (148º) was obtained for membrane modified C12, whereas for membrane modified C6 the highest value was 135º. PDMS membranes of different thickness (in range 75-195 μm) were formed. PDMS permeability properties were examined by water pervaporation. The permeability coefficient of water through PDMS membrane was equal 7,34•10-15 mol/m Pa s. It was proved that water transport is inversly proportional to membrane thickness. Results for PDMS membranes were compared with results obtained for commertial membrane. Moreover, selective commercial membrane properties were tested by pervaporation in water-ethanol sytsem (1-10wt.% of ethanol). The membrane transported selectively ethanol (enrichment factor was in range 4-15).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
