Combustion formed carbonaceous particles may have features similar to carbon compounds used in new technologies like optoelectronic and energy storage and conversion. Such species can roughly be distinguished into two classes: organic particles with diameter D=2-10 nm, which have molecular-like spectroscopic properties, and soot which is constituted by amorphous carbon in form of chainlike clusters of primary particles with D~50nm. Their physical-chemical properties of both classes can be tailored by changing the flame parameters, like temperature, fuel/air ratio etc. A detailed knowledge of the composition and properties of produced compounds is required to evaluate their potentialities as a low cost new nano-structured material. In this work, soot nanoparticles were produced in a laminar premixed rich ethylene-air flame. We used scanning spreading resistance microscopy (SSRM) for the electrical characterization of soot particles collected via thermophoresis on mica substrates rapidly inserted into the flame. The I-V characteristic of layers of carbonaceous soot particles have been measured and compared in terms of number of insertions in the flame, i.e. amount of soot particles. The results obtained in the present works show that SSRM is a very interesting and promising diagnostic tool for soot characterization. Furthermore, such results may lead to the development of soot sensors based on their electrical properties.
SCANNING SPREADING RESISTANCE MICROSCOPY FOR ELECTRICAL CHARACTERIZATION OF FLAME GENERATED PARTICLES
G De Falco;M Commodo;P Minutolo;
2012
Abstract
Combustion formed carbonaceous particles may have features similar to carbon compounds used in new technologies like optoelectronic and energy storage and conversion. Such species can roughly be distinguished into two classes: organic particles with diameter D=2-10 nm, which have molecular-like spectroscopic properties, and soot which is constituted by amorphous carbon in form of chainlike clusters of primary particles with D~50nm. Their physical-chemical properties of both classes can be tailored by changing the flame parameters, like temperature, fuel/air ratio etc. A detailed knowledge of the composition and properties of produced compounds is required to evaluate their potentialities as a low cost new nano-structured material. In this work, soot nanoparticles were produced in a laminar premixed rich ethylene-air flame. We used scanning spreading resistance microscopy (SSRM) for the electrical characterization of soot particles collected via thermophoresis on mica substrates rapidly inserted into the flame. The I-V characteristic of layers of carbonaceous soot particles have been measured and compared in terms of number of insertions in the flame, i.e. amount of soot particles. The results obtained in the present works show that SSRM is a very interesting and promising diagnostic tool for soot characterization. Furthermore, such results may lead to the development of soot sensors based on their electrical properties.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
