NON-ISOTHERMAL ANALYSIS OF NUCLEATION OF KBrO3 BY DIFFERENTIAL SCANNING CALORIMETRY

[摘要] References(5)Cited-By(2)The homogeneous nucleation of KBrO3 in quiescent aqueous solution was measured by a differential scanning calorimeter at constant cooling rate, and was analyzed theoretically by a nonisothermal technique for nucleation. As the result, it was found that differential scanning calorimetry with the constant cooling rate method is more useful in the study of the nucleation, where the parameters are given in the higher region of supersaturation ratio, compared with the constant-temperature method. Through the theoretical analysis of nucleation, a semi-empirical relation, Eq. (1), was found to hold between the width of maximum allowable supercooling temperature, that is, the metastable zone width, ΔTm, and the cooling rate, b. In (b/V)=In (k2/Nobs)-In B-MTTO/ΔTm2where,MT=16πδ3νm2/3k(ΔHsol)2 Equations (1) and (2) make the analysis of nucleation much simpler. The same nucleation data also satisfied Nývlt''s relation. However, Eqs. (1) and (2) may be more useful than Nývlt''s for the analysis of the nucleation process.