Preparation and Characterization of a Novel Terbium Complex Coordinated with 10-Undecenoic Acid for UV-Cured Coatings

Chenjie Jiao,Yanfang Zhou,Hongfei Zhang,Rong Zhong

doi:10.1155/2020/2175259

Chenjie Jiao, Yanfang Zhou + Show 2 more

Open Access

https://doi.org/10.1155/2020/2175259

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Abstract

A UV-cured composite containing a rare earth complex was prepared for this study. First, the photoluminescent terbium complex was synthesized with a long-chain unsaturated fatty acid (10-Undecenoic acid) by a solution precipitation method, resulting in the 10-UA-Tb(III) complex. Its structure was proven by FTIR, elemental analysis, XRD, and TGA. The results indicated that the organic acid ligand successfully coordinated with the Tb3+ ion and that the complex had a chelate bidentate structure. The emission spectrum of the 10-UA-Tb(III) complex indicated that the complex can emit a bright green light with the unique luminescence of the Tb3+ ion. Furthermore, the luminescence properties of complexes with different ratios of Tb3+ and ligand were studied, and the ratio of Tb3+ and the ligand had an obvious impact on the luminescence intensity of the 10-UA-Tb(III) complex. Subsequently, the prepared rare earth complex was doped into a UV-cured coating in different proportions to obtain a UV-cured composite. The morphology of the rare earth UV-cured composite was observed by SEM. The images showed that the rare earth complex was dispersed uniformly in the polymer matrix. Moreover, the composites could emit fluorescence. Additionally, it has good thermal stability and compatibility with the resin. Therefore, these composites should have potential applications in UV curable materials, such as luminescence coatings.

Highlights

Lanthanide elements have excellent features that are unique to 4f electronic structures, such as abundant energy level transitions, large atomic magnetic moments, and strong spin coupling [1]
The coordination ability between rare earth ions and organic carboxylic acids is strong because rare earth ions are hard acids, and oxygen atoms in carboxylic acids are hard bases whose coordination is in accordance with the affinity principle of acids and bases [12]
The coordinated structure and molecular component of the 10-Undecenoic acid (10-UA)-Tb(III) complex were studied by a series of characterization methods that indicated that the 10-UA-Tb(III) complex was a chelate bidentate complex, and its molecular formula was Tb(C11H19O2)3·H2O

Summary

Introduction

Lanthanide elements have excellent features that are unique to 4f electronic structures, such as abundant energy level transitions, large atomic magnetic moments, and strong spin coupling [1]. The ability of organic ligands to sensitize rare earth ions is called the “antenna effect” [7]. The coordination between carboxylate oxygen ions and lanthanide ions can be of various forms, such as a chelated bidentate, bridged bidentate, and monodentate; as a result, rare earth carboxylic acid complexes have numerous special structures, such as lamellar, catenulate, and reticular, which are relatively stable [13]. Most rare earth complexes select aromatic cyclic carboxylic acids as ligands because they contain conjugate double bonds and rigid plane structures that have good absorption in the ultraviolet region [28,29,30,31]. The morphology of rare earth complexes and rare earth UVcured composite was observed by SEM Their luminescence properties and thermal stability were tested by a fluorescence spectrometer and TGA, respectively. The mechanical properties of the composite films were tested, including pencil hardness, adhesion, and flexibility

Experimental Section

Measurement and Characterization

Results and Discussion

Conclusions