Nonclassical Crystallization of Dipicolinic Acid in Microemulsions

Chen, C.; Nicholson, C.E.; Ramsey, H.E.; Cooper, S.J.

Abstract

Dipicolinic acid (DPA) was crystallized in microemulsions to investigate the effect of three-dimensional nanoconfinement on the crystallization process. The microemulsions were acidified with 2 M HCl to prevent the formation of DPA metal salts, which occurs because of a pH shift toward neutrality arising from the nanoconfinement. Transmission electron microscopy (TEM) analysis showed that 30–100 nm square-plate nanoaggregates crystallized from these acidified microemulsions. Higher-resolution TEM images revealed that the nanoaggregates consisted of smaller 3–10 nm nanocrystals. The fast-Fourier transforms of images obtained from these nanocrystals were similar to the diffraction pattern arising from the whole nanoaggregate, confirming that the nanocrystals exhibited ordered packing and resembled mesocrystals. The crystallization of the nanoaggregates is aided by the suppression of Ostwald ripening of the nanocrystals in the nanometer-sized microemulsion droplets and adsorption of the surfactant onto the nanocrystals.

Citation

Chen, C., Nicholson, C., Ramsey, H., & Cooper, S. (2015). Nonclassical Crystallization of Dipicolinic Acid in Microemulsions. Crystal Growth and Design, 15(3), 1060-1066. https://doi.org/10.1021/cg501147j

• Journal Article Type: Article
• Acceptance Date: Dec 21, 2014
• Online Publication Date: Jan 19, 2015
• Publication Date: Mar 4, 2015
• Deposit Date: May 5, 2015
• Publicly Available Date: May 11, 2015
• Journal: Crystal Growth and Design
• Print ISSN: 1528-7483
• Electronic ISSN: 1528-7505
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 15
• Issue: 3
• Pages: 1060-1066
• DOI: https://doi.org/10.1021/cg501147j
• Public URL: https://durham-repository.worktribe.com/output/1439037