Characterization of gasoline soot and comparison to diesel soot: Morphology, chemistry, and wear

Comparative nanostructure analysis of gasoline turbocharged direct injection and diesel soot-in-oil with carbon black

“…A higher degree of disorder in the GTDI soot leaves more reactive sites on its surface, thus allowing for more interactions with the lubricating oil compared to diesel soot. In contrast, Uy et al [18] observed similarities in the morphology between diesel and GTDI soot samples. However, the latter exhibited higher concentrations of wear metals and oil additives, as well as some regions with a sludge-like structure.…”

“…TEM has been used to characterise soot from both the exhaust gas [18e21,24] and lubricating oil [7,17,18,24] of internal combustion engines, as well as soot from diffusion flames [23,30,31]. Depending on the soot origin the methods of sample collection differ significantly.…”

“…Despite altering the observed size distribution of the agglomerates, this procedure enabled observation of the primary particle nanostructure. A similar procedure was employed by Uy et al [18] using hexane as the solvent. Soot generated from diffusion flames, also known as carbon black, can be collected directly from the flame by thermophoresis on TEM grids, as done by Bhowmick et al [30] and Schenk et al [31].…”

“…However, this strategy is not necessarily applicable across all studies as the 'D' band is dispersive in nature, with its position and intensity sensitive to the wavelength of the excitation laser [43]. For example, Uy et al [18] observed that spectra acquired using a 244 nm ultraviolet laser exhibited no defective 'D' peaks and therefore important information could not be extracted. Moreover, it is now widely recognised that the observed bands in the D/G region more likely represent a superposition of up to five different vibrational modes, deconvolution of which permits quantification of the extent of ordered graphitic ('G' mode), disordered graphitic ('D1', 'D2' and 'D4' mode), and amorphous domains ('D3' mode) within the primary particles [43].…”

Wykorzystanie techniki dynamicznego rozpraszania światła laserowego (DLS) do wyznaczania krytycznego stężenia micelizacji dodatków detergentowych w paliwie wysokoetanolowym

“…Głównym zadaniem dodatków detergentowo-dyspergujących jest zapobieganie tworzeniu się osadów na elementach silnika, takich jak: układy wtrysku, zawory dolotowe, zawory wylotowe, komory spalania. Mechanizm działania dodatków detergentowo-dyspergujących jest bardzo złożo-ny, jedna z teorii głosi, że związki powierzchniowo czynne obecne w paliwie przywierają do metalowych powierzchni silnika, zapobiegając w ten sposób przywieraniu osadów, natomiast według innej ich rola polega na dyspergowaniu osadów i zanieczyszczeń [13].W ostatnich latach obserwowany jest wzrost udziału etanolu w benzynach silnikowych. Wynika on z dążenia do zwięk-szenia w ogólnym bilansie paliw udziału surowców odnawialnych.…”