The laminar flow tube reactor as a quantitative tool for nucleation studies: Experimental results and theoretical analysis of homogeneous nucleation of dibutylphthalate

A laminar flow tube reactor was designed and constructed to provide an accu rate, quantitative measurement of a nucleation rate as a function of supers aturation and temperature. Measurements of nucleation of a supersaturated v apor of dibutylphthalate have been made for the temperature range from -30. 3 to +19.1 degrees C. A thorough analysis of the possible sources of experi mental uncertainties (such as defining the correct value of the initial vap or concentration, temperature boundary conditions on the reactor walls, acc uracy of the calculations of the thermodynamic parameters of the nucleation zone, and particle concentration measurement) is given. Both isothermal an d the isobaric nucleation rates were measured. The experimental data obtain ed were compared with the measurements of other experimental groups and wit h theoretical predictions made on the basis of the self-consistency correct ion nucleation theory. Theoretical analysis, based on the first and the sec ond nucleation theorems, is also presented. The critical cluster size and t he excess of internal energy of the critical cluster are obtained. (C) 2000 American Institute of Physics. [S0021-9606(00)51133-7].