Effects of solvents and temperature on spherulites of self-assembled phloroglucinol tristearate

Abstract

Herein, phloroglucinol tristearate (PhgTS) was used to study the crystallization process due to its unique symmetric structure containing a benzene ring and three aliphatic chains. Spherulites of crystallized PhgTS from four solvents under diverse conditions were analyzed in detail and their formation process was studied. Maltese cross is shown by PhgTS spherulites obtained from aprotic solvents via polarized optical microscopy. In comparison, no Maltese cross can be observed from branch-like crystals formed from protic solvents. Independent on the microscaled morphology, lamellae were found to be the basic blocks constructing both PhgTS spherulites and branch-like crystals, which were formed predominantly by stacked PhgTS molecules. Although differential characters of the solvents did not affect the formation of lamellas, the solvents played a crucial role in the formation of self-assembled microscaled morphologies. In particular, the morphologies of spherulites were strongly affected by the concentration of PhgTS solutions, surrounding temperature and evaporation rate of solvents. Generally, a higher concentration of PhgTS led to more homogeneous spherulites, a lower evaporation rate resulted in more compact spherulites, and a higher surrounding temperature generated preferentially more ring-banded spherulites of PhgTS.

Key words： phloroglucinol; tristearate; aprotic and protic solvent; self-assembly; spherulites

Acknowledgements

Y.Y. thanks the China Scholarship Council (CSC) for financial support. K.Z. thanks Georg-August-University of Goettingen for the Anschubfinanzierung (Funding for the Promotion of Young Academics of University of Goettingen) and Fonds der Chemischen Industrie (FCI) for the financial support. The authors declare no conflicts of interest.

Electronic Supplementary Material

Supplementary material is available in the online version of this article at https://doi.org/10.1007/s11705-019-1911-3 and is accessible for authorized users.

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