Filamentous supramolecular structures with polyelectrolyte and cadmium sulfide

Abstract

In this study, a new type of filamentous structures consisting of a generation 9 poly(amido amine) dendrimer (G9) and CdS is reported. The linearity of the interconnected dendrimers is a result of the electrostatic repulsion between the multiply charged dendrimer macroions. Structures have been investigated by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The internal structure of the CdS-fibers reveals information on the mechanism of the fiber formation. In contrast to previous systems with smaller generation poly(propylene imine)-dendrimers, Cd 2+ is here found to be responsible for the interconnection of G9. Furthermore, more complex supramolecular structures were built by associating the CdS-dendrimer hybrid fibers with different ionic dyes, displaying the versatility of this system for future nanotechnology applications such as optoelectronics or energy conversion.

Photoresponsive Photoacid-Macroion Nano-Assemblies

“…A fundamental understanding regarding the interplaying interaction forces was developed [ 41 , 42 , 43 , 44 ]. Further, switchable structures based on electrostatic self-assembly were studied [ 45 ], in particular, the combination of a polyelectrolyte with a light-switchable molecule, such as azobenzenes [ 46 ] or spiropyrane [ 47 ], and—in one first concept study—a photoacid [ 37 ].…”

Functional Nano-Objects by Electrostatic Self-Assembly: Structure, Switching, and Photocatalysis

“… CdS and Au nanoparticles in supramolecular dendrimer−dye assemblies: (A) Electrostatic nanotemlating-electrostatic self-assembly approach; (B) TEM of a 100 nm god-dendrimer-dye assembly containing 3 nm gold particles prepared according to (A) ; (C) overview of the electrostatic nanotemplating routes for CdS in dendrimer–dye assemblies; (D–I) CdS fibers with dendrimer G9: (D,E) TEM of single-fibers; (F,G) TEM of double-fibers, (H,I) proposed orientation of CdS (yellow) and dendrimer (blue) ( Düring et al, 2013 ; Düring et al, 2015 ; Düring and Gröhn, 2016 ). Reprinted with permission.…”

“…Recently, the formation of CdS mono- and double-nanowires with G9 PAMAM dendrimers was presented ( Figure 15 bottom). An interplay involving Hamaker attraction, coordination, steric and dipole effects in addition to electrostatics was discussed to understand the structure formation ( Düring and Gröhn, 2016 ). Finally, an even larger structural variety becomes available when first building an organic supramolecular structure by electrostatic self-assembly and secondly use remaining charges for an electrostatic nanotemplating within this suprastructure ( Düring et al, 2015 ; Düring et al, 2017a ).…”

“…Finally, an even larger structural variety becomes available when first building an organic supramolecular structure by electrostatic self-assembly and secondly use remaining charges for an electrostatic nanotemplating within this suprastructure ( Düring et al, 2015 ; Düring et al, 2017a ). When using a light-responsive dye, it is also possible to switch the size and compactness of organic-inorganic hybrid structure such as the CdS–dendrimer fibers via light irradiation ( Düring and Gröhn, 2016 ). Thus, the combination of electrostatic self-assembly and electrostatic nanotemplating opens an important field for the design of targeted functional and triggerable hybrid structures via a tool-box principle.…”

Hierarchical electrostatic nanotemplating and self-assembly of electron-transferring hybrid nanostructures: CdS–polymer–porphyrin particles

“…Here, polyelectrolytes can play a key role, serving as an electrostatic nanotemplate. 29,30 Electrostatic nanotem-plating has been established over the past few years, [31][32][33][34] including the preparation of dye-CdS-dendrimer fibre-like morphologies, 34 but concepts towards more sophisticated and targeted functional structures, are yet to be exploited.…”