Dimensionless Entropy of Fusion as a Simple Criterion To Predict Agglomeration in the Supercritical Antisolvent Process

Abstract

The aim of this work was to understand the agglomeration phenomenon and to predict the agglomeration behavior of materials in the supercritical antisolvent (SAS) process. Carbon dioxide-induced melting point depression is believed to be one of the major causes of the formation of agglomerates during the SAS process. Here, we attempted to observe the CO 2 -induced melting behaviors of nine target materials and to recrystallize them in the SAS process. On the basis of the multicomponent Clapeyron equation, which describes the interaction between solute and carbon dioxide, the thermodynamic properties of 32 materials were investigated to correlate melting point depression with the agglomeration phenomenon. In this analysis, the dimensionless entropy of fusion was utilized as a simple criterion to predict agglomeration behavior. The extent of melting point depression was assumed to be inversely proportional to the entropy of fusion of the solute. This assumption enables us to predict the agglomeration behavior of recrystallized pharmaceuticals with dimensionless entropy of fusion during the SAS process. Furthermore, a correlation between the tendency of agglomeration and whether the recrystallized particles have either faceted or nonfaceted form was observed.

Enhanced Second Harmonic Generation from an Organic Self-Assembled Eutectic Binary Mixture: A Case Study with 3-Nitrobenzoic and 3,5-Dinitrobenzoic Acids

“…For most organic materials, the molecules are free to rotate in the liquid state, but they have a specific orientation in the crystal. Melting entropies for many of these materials are relatively high, e.g., α values around 6, ,, except in rare cases . Unfortunately, the α values for DNBA LT and 3-NBA MET cannot been determined due to their conversion toward their high-temperature polymorphs.…”

A Dissolution Kinetic Study of Disperse Dye in Supercritical Carbon Dioxide to Design an Efficient Supercritical Dyeing Process

“…According to the results, an increase in the initial mass of the dye corresponds to a decrease in the dissolution mass transfer coefficient of the dye. In general, the melting point of DR60 is known to be 185 • C. However, according to the study results that melting-point depression may occur in a high-pressure CO 2 environment, dye particles can be aggregated even under this experimental condition [33]. This is interpreted as the increase in the initial mass of the dye causes the aggregation of the dye particles to increase, which gradually reduces the surface area of the particles that can participate in dissolution.…”

Primary dendrite growth of Co3Sn2 intermetallic compound in rapidly solidified ternary Co35Cu35Sn30 alloy

“…(Co) phase with small volume fraction grows in the interdendritic region of primary Co 3 Sn 2 intermetallic compound, and the Cu 41 Sn 11 phase is not obvious in such small droplet. Most intermetallic compounds usually grow in a faceted way, and the Jackson factor [22,23] is a criterion to predict the growth forms of intermetallic compounds. Values of it are less than 2 and can result in non-faceted crystal growth.…”