Nano-gold with in situ-grown surface-charge layer in organic framework, superlattice-chiral structures, and tailored...

Nano-gold made up of chiral and superlattice structures is a model system whose exotic properties can be finely tailored for optical devices, energy harvesters, biosensors, and many other applications. In view of this, we explore the formalism of how it can bond to ˙CF₂ dipoles (of opposite polarity) in a polymer, such as poly(vinylidene fluoride) (PVDF), in such a way as to produce order in such high-energy structures in the polymer. With various media in hydrothermal reactions, it is described how a gold salt, HAuCl₄·3H₂O, dispersed with PVDF in a polar liquid slowly releases Au atoms, which bond in situ to ˙CF₂ heads in the PVDF chains in the form of Au-PVDF nanofluids. The PVDF dose is varied from 1 to 100 g L^-1 (with fixed 0.5 wt% Au) to explore how it modulates the Au³⁺ → Au-3e^- reaction and bonds over the nascent Au-atoms (as a template) to order them on the Au-anchored PVDF chains. The metal-ligand bonds create a charged Au⁺-PVDF layer that boosts the tailored properties. The Au⁺ ions of ¹D₂ ↔ ³D_J (J = 1 → 3) interband transitions (Au⁺-5d¹⁰ → 5d⁹6s¹) markedly trigger UV-visible-NIR light absorption/emission of coupled excitons of C-sp² electrons (PVDF), Au-5d¹⁰6s¹ electrons, and Au-LSPs (localized surface plasmons) cross-linked in the network channels. Thus, the ³D₃ states are superior light emitters to the Au-LSPs. The premier results are described with respect to microscopic images, XRD patterns, XPS bands, and phonons of the Au-PVDF nanofluids and films. An optimized charge layer is a game changer in terms of advancing exotic properties for the application.