Insights on non-exhaust emissions: An approach for the chemical characterization of debris generated during braking

• DOI: 10.1016/j.heliyon.2023.e20672
• Publication Date: 2023-10-05T06:24:32Z
• Authors: C. Russo; G. Gautier di Con...; G. Magnacca; M.G. Faga; B. Apicella
• Keywords: Thermogravimetric analysis; Fraction (chemistry)

Up to 50 % of total PM2.5 emissions are due particles derived from the automotive sector, and both exhaust non-exhaust contribute pollution urban areas. Fuel incomplete combustion, or lubricant degradation high temperatures during combustion process, responsible for emissions. The ones concern brakes, tires road surface-wear resuspension contribution. present study aims provide a methodological approach detailed chemical characterization wear friction products by means large array techniques including spectroscopic tools, thermogravimetric analysis (TGA), chromatography, morphological elemental analysis. dust sample brake pad material was collected after Noise & Vibration Harshness (NVH) test under loads similar Worldwide Light vehicle Test Procedure (WLTP) braking cycle. TGA shows that only small fraction is burned in an oxidizing environment, testifying consists mostly metals (more than 90 %). Fe exhibits highest concentrations (50-80 %, even form oxides). Also other kinds metals, such as Zn, Al, Mg, Si, S, Sn, Mn, occur quantities (about 1-2% each). This finding confirmed X-ray diffraction (XRD) organic debris, investigated Raman spectroscopy, has evident aromatic character, probably oxidative phenomena occurring cycle test. Noteworthy, extraction with solvents, revealed first time presence ultrafine (UFPs), range few nanometers (nanoparticles), polycyclic hydrocarbons (PAHs), recognized highly toxic compounds. simultaneous carbon makes mandatory deep insight on their structure composition.