Acetylene black is a special type of carbon black, obtained from the thermal decomposition of acetylene. Acetylene flames enable the investigation of the soot optical properties. A reliable knowledge of the optical properties of acetylene soot is necessary for interpreting the optical measurements in flames and the development of acetylene black applications in industry. However, a wide variation in the optical properties of soot is observed in different formation conditions. The main factors affecting soot formation in flames are fuel composition, equivalence ratio, and reaction time connected with the height above a burner. In this study, we measured the absolute value of the refractive index function of acetylene soot E(m,1064) at a wavelength of 1064 nm, as well as the ratio of the refractive index functions E(m,1064)/E(m,532) at laser wavelengths of 532 nm and 1064 nm in a premixed acetylene/air flame using laser-induced incandescence. The soot structure was studied using high-resolution electron microscopy. The obtained results showed that E(m,1064) increased from 0.19 to 0.53 and that the ratio of E(m,1064)/E(m,532) increased from 1.12 to 1.55 according to the height above a burner. These changes in the optical properties are attributed to differences in soot structure, such as different distances between graphene planes inside soot crystallites, which decreased from 0.43 to 0.36 nm as the height above the burner increased from 5 to 20 mm. It was concluded that the optical properties and structure of acetylene soot differ from those formed in other hydrocarbon flames.

乙炔黑是从乙炔的热分解中获得的一种特殊类型的炭黑。乙炔火焰可以研究烟灰的光学性质。对乙炔烟灰光学特性的可靠了解对于解释火焰中的光学测量结果和工业中乙炔黑应用的发展十分必要。然而，在不同的形成条件下观察到烟灰的光学性质有很大的变化。影响火焰中烟灰形成的主要因素是燃料成分，当量比以及与燃烧器上方高度相关的反应时间。在这项研究中，我们测量了乙炔烟灰E（m，1064）的折射率函数的绝对值激光诱导的乙炔/空气预混火焰中，在波长为1064 nm的乙炔/空气火焰中，在532 nm和1064 nm的激光波长下的折射率函数E（m，1064） / E（m，532）的比值白炽。使用高分辨率电子显微镜研究了烟灰结构。获得的结果表明E（m，1064）从0.19增加到0.53，并且E（m，1064） / E（m，532）之比根据燃烧器上方的高度从1.12增加到1.55。光学特性的这些变化归因于烟尘结构的差异，例如烟尘微晶内部石墨烯平面之间的距离不同，随着燃烧器上方高度从5毫米增加到20毫米，石墨烯平面之间的距离从0.43降低至0.36 nm。结论是乙炔烟灰的光学性质和结构与在其他烃火焰中形成的那些不同。