Amide group enhanced self‐assembly and adsorption of thioether‐containing hydroxamic acid on cassiterite surface

Abstract

Modified surfactants can regulate their adsorption at the target surface and are essential for various separation applications such as froth flotation. Thioether‐containing hydroxamic acid (BTHA) is an excellent oxidized‐ore collector with poor dispersibility. Herein, acylamino, which possesses the ability to improve the surfactants' self‐assembly and dispersion, was introduced to synthesize N‐[6‐(hydroxyamino)‐6‐oxohexyl] benzylthioacetamide (BTAHA); thus, applying it to cassiterite flotation. Surface tension, adsorption capacity, in situ AFM, and surface energy results reveal BTAHA displays strong bubble stability and readily adsorbs onto the mineral's surface, promoting hydrophobic flotation. BTAHA is an effective cassiterite collector and has good separation effects on cassiterite against calcite. It can form Van der Waals forces and five‐membered hydroxamate‐(O,O)‐Sn rings with Sn atoms on cassiterite surfaces via thioether and hydroxamate groups. Meanwhile, the presence of intermolecular hydrogen bond between the amide groups facilitates the self‐assembly of the collectors on the cassiterite surface, and has broad industrial application prospects in various separation processes.

A Novel Bipolar Surfactant, BETX, for Selective Flotation of Chalcopyrite: Folding-Synergistic Mechanism Based on Intramolecular Weak Interactions

“…21 Prior research efforts have predominantly focused on intermolecular interactions, with limited attention directed toward the intrinsic synergies emerging within single molecules through interactions among their constituent functional groups. 17,21,22 This skewed focus is primarily attributed to the inherent challenges associated with fully elucidating molecular conformations via conventional research methodologies. 23,24 Notably, functional groups within the same molecule exhibit a greater propensity for interaction due to their closer proximity compared to those between molecules.…”

“…Recently, collectors with multiple polar groups have emerged as a promising avenue for next-generation flotation agents. − Huang et al have conducted a series of work on Gemini collectors, characterized by two polar groups, and made full use of the advantages of lower critical micelle concentration and higher surface activity resulting from intermolecular interactions to realize the flotation enrichment of Chlorella, magnetite, and potassium salts. − Guo’s research demonstrates that amide lauric acid can enhance flotation recovery through intermolecular synergism via hydrogen bond interaction between amide groups …”

“…Prior research efforts have predominantly focused on intermolecular interactions, with limited attention directed toward the intrinsic synergies emerging within single molecules through interactions among their constituent functional groups. ,, This skewed focus is primarily attributed to the inherent challenges associated with fully elucidating molecular conformations via conventional research methodologies. , Notably, functional groups within the same molecule exhibit a greater propensity for interaction due to their closer proximity compared to those between molecules. , Such proximity can stabilize conformations through sp 3 bond rotation and intergroup interactions, leading to dominant conformations. − These conformations can subsequently interact with active centers to produce properties distinct from the independent functional groups, as shown by cryptands or metal proteins. − Our previous work has successfully examined the conformation of thionocarbamate compounds through a combination of molecular dynamics (MD) simulations and density functional theory (DFT) calculations, shedding light on the molecular structure of thionocarbamate compounds . This research paradigm promises to advance our understanding of the molecular structure and mechanisms of multipolar surfactants.…”