Hybrid Nanoalloy: Nanofibers Fabricated by Self‐Assembling Dendrimers Mediate In Situ CdSe Quantum Dots and Their Metallization with Discrete Gold Nanoparticles

Abstract

A simple one‐step procedure for 1D structures: Directed self‐assembly of hybrid materials based on a poly(propyleneimine) dendrimer template and CdSe nanoparticles in situ is an effective nanofabrication tool to form well‐defined semiconducting hybrid nanofibers coated with discrete Au nanoparticles (nanoalloy). Such functional nanofibers will offer great potential in various applications, such as biological markers and nanoprobes among others.

Filamentous supramolecular structures with polyelectrolyte and cadmium sulfide

“…22,23 As the G9 dendrimer with 13 nm is quite large compared to the visible CdS particles (2-3 nm), it is impossible, due to steric reasons, that only one CdS particle is attached to one dendrimer in the chain. Fahmi et al 12 gave an interpretation of a conformational change towards a more anisotropic dendrimer structure in a system with generation 4 PPI dendrimer. This, however, is not possible in the system investigated herein: due to the size and the strong branching of a ninth generation dendrimer, the G9 is not as flexible and therefore, unlike smaller generation dendrimers, retains its spherical shape 24,25 where it is impossible to locate all primary amino groups on the poles of the dendrimer.…”

“…11 In terms of self-assembly, recently the possibility of dendrimeric macromolecules to assemble into fibrous structures under certain reaction conditions has been shown. The process of fiber-formation with poly(propylene imine) (PPI) dendrimer of the fourth generation (G4) and cadmium acetate was discussed by Fahmi et al and Garzoni et al 12,13 On the one hand, a mechanism was proposed which is based on the flexibility of the G4 dendrimer becoming interconnected by Cd 2+ , yielding fibers that can subsequently be turned into chains of CdSe nanoparticles connected by dendrimer macromolecules. 12 On the other hand, Garzoni suggests that the reason for fiber formation lies in the hydrophobic effect of the acetate counterion, which induces anisotropy within the dendrimer.…”

“…The process of fiber-formation with poly(propylene imine) (PPI) dendrimer of the fourth generation (G4) and cadmium acetate was discussed by Fahmi et al and Garzoni et al 12,13 On the one hand, a mechanism was proposed which is based on the flexibility of the G4 dendrimer becoming interconnected by Cd 2+ , yielding fibers that can subsequently be turned into chains of CdSe nanoparticles connected by dendrimer macromolecules. 12 On the other hand, Garzoni suggests that the reason for fiber formation lies in the hydrophobic effect of the acetate counterion, which induces anisotropy within the dendrimer. 13 In the present study a system of a poly(amido amine) (PAMAM) dendrimer of the ninth generation (G9) in combination with cadmium nitrate and sodium sulfide was investigated, yielding fibrous structures.…”

Preparation of Unconventional Dendrimers that Contain Rigid NHTriazine Linkages and Peripheral tert‐Butyl Moieties for CO2‐Selective Adsorption

“…They have unusual properties, such as multiple functionalities and monomolecular weight, and can be prepared by convergent, divergent, and combination methods. [1] Recently, dendrimers have been the subject of much study owing to their potential use as catalysts, [2] molecular micelles, [3] light-harvesting molecules, [4] nanoparticle stabilizers, [5] and sensors. [6] In particular, dendrimers have been shown to possess internal cavities [7] and act as drug-transporting agents for the treatment of cancers.…”

“…[15c-h] Although dendrimers have been shown to contain cavities and to be capable of encapsulating medicinal ingredients for anti-tumor treatment after processing in solution, [7,8] the selective adsorption of CO 2 by dendrimers in the solid state has not been reported. [1][2][3][4][5][6][7][8][9][10][11] To date, only flexible amine-containing dendrimers in a mesoporous silicate, SBA-15, have shown potential in this area. [16] Most dendrimers consist of flexible spacer groups, as indicated in various literature reports.…”