Determination of the Critical Supersaturation Ratio in Heterogeneous Nucleation of Benzene Vapor on a Cold Substrate

[摘要] References(11)Cited-By(6)The heterogeneous nucleation of benzene from the vapor phase to the solid phase on a foreign substrate contacted with vapor phase was studied experimentally at reduced pressures by cooling the copper substrate. The critical substrate temperature corresponding to the onset of nucleation was determined at a given vapor pressure by observing both the rapid decrease in vapor pressure that occurred as the substrate was cooled past the critical point and the subsequent appearance of benzene crystals on the substrate. The experimental critical supersaturation ratios determined from observed critical substrate temperatures were found to increase as the cooling rate of the substrate increased. The dependences of critical supersaturation ratios on substrate temperatures could be explained qualitatively by a theoretical expression derived from the classical heterogeneous nucleation theory.

[关键词] Heterogeneous Nucleation;Benzene. Crystal Growth;Sublimation;Supersaturation