Probing the Interaction Mechanism between Benzohydroxamic Acid and Mineral Surface in the Presence of Pb2+ Ions by AFM Force Measurements and First-Principles Calculations
发布时间：2020-07-21
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所属单位：central south university; University of Alberta
发表刊物：langmuir
摘要：Probing the interaction mechanism between organic molecules and material surfaces in the presence of metal ions is of great importance in many fields, such as mineral flotation. The collectability of benzohydroxamic acid (BHA) to a spodumene (LiAl(SiO3)(2)) mineral surface during mineral flotation could be enhanced with the addition of metal ion activators-Pb2+ ions. Pb2+ ions could be added as either Pb-BHA complex formed by premixing Pb2+ ions and BHA molecules at a given ratio or sequential addition of Pb2+ ions and BHA molecules. However, the complete understanding of the interaction mechanisms (e.g., adhesion) between BHA and the spodumene mineral surface in the presence of Pb2+ ions remains very limited. In this study, atomic force microscopy (AFM) was used to measure the intermolecular forces between BHA and the spodumene mineral surface in aqueous solutions. A BHA model molecule, that is, N-hydroxy-4-mercaptobenzamide (MBHA), was synthesized to prepare a BHA-functionalized AFM probe for force measurements. Two model systems (i.e., a Pb-BHA complex interacting with the spodumene mineral surface (model I) and BHA with a Pb2+-activated spodumene surface (model II)) were investigated for comparing the role of Pb2+ in BHA-mineral adhesion. The adhesion measured for model I (23.7 mN/m) is much higher than that of model II (12.5 mN/m), as further supported by the adsorption energies obtained from density functional theory (DFT) calculations. The calculation results showed a higher adsorption energy for model I (similar to 188.5 8 kJ/mol) than model II (similar to 128.16 kJ/mop, which is due to the better spodumene flotation recovery for the Pb-BHA complex as a collector than the sequential addition of Pb2+ and BHA. This work provides useful information on the intermolecular interactions between chemical additives and mineral surfaces in complex mineral flotation processes, and the methodology can be readily extended to other related interfacial processes such as membrane technology, water treatment, oil production, and bioengineering processes.
备注：田孟杰副教授是文章的共同第一作者；文章为Langmuir期刊的封面文章
第一作者：田孟杰
论文类型：期刊论文
卷号：36
期号：28
页面范围：8199-8208
是否译文：否
发表时间：2020-07-21
收录刊物：SCI
发布期刊链接：http://libdb.csu.edu.cn/rwt/SCI/https/PB4XE63PMFSYGLUQPJUB/doi/10.1021/acs.langmuir.0c01307