Efficient, robust surface functionalization and stabilization of gold nanorods with quaternary ammonium-containing ionomers as multidentate macromolecular ligands

Abstract

Surface functionalization of gold nanorods (GNRs) is critical to their applications in various fields. While there are several existing strategies, we report in this article a new general strategy for the surface functionalization of GNRs with quaternary ammonium-containing ionomers as a novel class of multidentate macromolecular surface ligands. A range of tetralkylammoniumcontaining hyperbranched polyethylene-and linear poly(n-butyl acrylate)-based ionomers has been specifically designed and employed in the strategy. Acting as multidentate macromolecular analogues of cetyltrimethylammonium bromide (CTAB), the ionomers have been demonstrated to bind onto the GNR surface by displacing the surface-bound CTAB species via ligand exchange to render CTAB-free ionomer-modified GNRs. By properly designing the enabling ionomers, we have shown that the modified GNRs can be endowed with some desired properties, such as excellent dispersibility in various organic solvents, robust stability under multiple rounds (up to 12 investigated) of high-speed centrifugation in organic solvents, amphiphilicity with dispersibility in both aqueous and organic media, fluorescence, and capability in carrying hydrophobic guest species. This strategy thus provides potential new ways for the construction of novel multifunctional GNR nanocomposites.3

1T‐2H Mixed‐Phase MoS2 Stabilized with a Hyperbranched Polyethylene Ionomer for Mg2+/Li+ Co‐Intercalation Toward High‐Capacity Dual‐Salt Batteries

“…[ 22 ] It contains a quaternary ammonium content of 1.03 mol%. Hyperbranched polyethylene ionomers have been previously used for the modification of nanomaterials of negatively‐surface‐charged including cellulose nanocrystals [ 21 ] and gold nanorods [ 23 ] to render their stable dispersions in nonpolar or low‐polarity organic solvents.…”

Modification of Ti3C2Tx MXene with hyperbranched polyethylene ionomers: stable dispersions in nonpolar/low-polarity organic solvents, oxidation protection, and potential application in supercapacitors

“…In view of the highly negatively charged surface of Ti 3 C 2 T x MXene nanosheets, 5,16,40 we reason that the ionomers should strongly bind onto the surface of MXene sheets through the strong ionic interactions between the quaternary ammonium cations and the negatively charged surface. 43,44 This is expected to facilitate the intercalation of the ionomers between the MXene sheets and the subsequent delamination of the MXene sheets by overcoming their interlayer interactions, providing exfoliated ionomer-modied MXene (I-MXene) multi-/few-layer sheets (see Scheme 1(b)). With the surface-bound nonpolar hydrophobic hyperbranched polyethylene chain segments, I-MXenes are expected to have good dispersibility in nonpolar/ low-polarity solvents that hyperbranched polyethylenes are known to have good affinity to.…”