Modelling of MOF-76(Nd) crystal growth and crystal habit modifications

Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang, Jl. Semarang No. 5, Malang 65145, Indonesia

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Abstract

MOF-76(Nd) is composed of neodymium(III) ions linked by 1,3,5-benzenetricarboxylate (BTC) ligands to form a 3D polymer framework. MOF-76(Nd) has applications as an adsorbent for Cs(I) and Sr(II) ions in radioactive waste, as well as gas storage and drug nanocarriers. The adsorption capacity of a material depends on its crystal habits. Therefore, modification of MOF-76(Nd) crystal habits by studying and understanding crystal growth is necessary to control its adsorption capacity. However, MOF-76(Nd) crystal growth has not been studied experimentally or theoretically. For that reason, it is crucial to study crystal growth and modify the crystal habits of MOF-76(Nd), which is the purpose of this research, with the limitation of the scope to a theoretical study using CrystalGrower. The research focuses on the effects of variations in supersaturation and screw dislocation. Theoretical modification using this software provides an efficient preliminary step before experimental implementation. The simulation results show that supersaturation plays an important role in determining crystal morphology and size. Crystals with an elongated needle-like morphology can be produced under low supersaturation conditions. Meanwhile, crystals with a shorter needle-like morphology can be produced under high supersaturation conditions. In addition, screw dislocation can change the layer-by-layer growth mechanism into a spiral growth mechanism and modify the crystal tips to be blunter. This study provides useful insights into the fundamental aspects of crystal growth and offers a preliminary framework that can guide experimental approaches for achieving desired crystal habits in practical applications.