Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 39, 2016
Previous Article Next Article

The influence of solution environment on the nucleation kinetics and crystallisability of para-aminobenzoic acid

Author affiliations

Abstract

The influence of solvent type on the solution thermodynamics, nucleation-kinetics and crystal growth of alpha para-aminobenzoic acid (PABA) crystallising from supersaturated ethanol, acetonitrile and water solutions, is examined using poly-thermal analysis of the metastable zone width. Application of a recently proposed model for analysis of crystallisation kinetics (J. Cryst. Growth, 2010, 312, 698–704) indicates a solvent and concentration dependence of the nucleation mechanism and key nucleation parameters for the alpha form of PABA. The mechanism of nucleation is found to change from instantaneous to progressive with decreasing concentration and also when changing the solvent from ethanol to acetonitrile to water. The dependence of the nucleation mechanism is correlated to the kinetic component of the nucleation rate through calculated values of instantaneously nucleated crystallites, which increase from 1.40 × 109 m−3 in ethanol to 1.08 × 1010 m−3 in acetonitrile to 2.58 × 1010 m−3 in water. This in combination with low calculated number concentrations of interfacial tension between 1.13 and 2.71 mJ m−2, supports the conclusion that the kinetic component of the nucleation rate is more limiting when crystallising PABA from ethanol solutions in comparison to water solutions. This finding is further supported by molecular dynamics simulations of the solvation free energy of PABA, which is found to be greatest in water, −42.4 kJ mol−1 and lowest in ethanol, −58.5 kJ mol−1.

Graphical abstract: The influence of solution environment on the nucleation kinetics and crystallisability of para-aminobenzoic acid

Back to tab navigation

Supplementary files

Article information


Submitted
20 Jun 2016
Accepted
09 Sep 2016
First published
23 Sep 2016

Phys. Chem. Chem. Phys., 2016,18, 27507-27520
Article type
Paper

The influence of solution environment on the nucleation kinetics and crystallisability of para-aminobenzoic acid

T. D. Turner, D. M. C. Corzo, D. Toroz, A. Curtis, M. M. Dos Santos, R. B. Hammond, X. Lai and K. J. Roberts, Phys. Chem. Chem. Phys., 2016, 18, 27507
DOI: 10.1039/C6CP04320H

Social activity

Search articles by author

Spotlight

Advertisements