Synthesis of silver nanocubes with controlled size using water-soluble poly(amic acid) salt as the intermediate via a novel ion-exchange self-assembly technique

Strategies to synthesize various nanostructures of silver and their applications - a review

Due to their various beneficial application-based properties, such as behavior, structure, and size, the synthesis of silver nanoparticles (Ag-NPs) with different structures has become an interesting yet common task for researchers to produce nanostructures for applications in various fields. This is because silver nanoparticles have interesting and unique properties, such as optical and catalytic, resulting from their different structures and sizes. These properties extend the use of nanostructures in various fields of research, especially in medicine, pharmacy, electronics, etc. Also, variations in their parameters affect the structures and sizes of Ag-NPs. This review provides an overview/brief presentation of various methodologies used to synthesize different application-based silver nanoparticles and lists areas where these nanoparticles are suitable for use according to their specific structures and sizes.

Preparation of Palladium/Silver-Coated Polyimide Nanotubes: Flexible, Electrically Conductive Fibers

A simple and practical method for coating palladium/silver nanoparticles on polyimide (PI) nanotubes is developed. The key steps involved in the process are silver ion exchange/reduction and displacement reactions between silver and palladium ions. With the addition of silver, the conductivity of the PI nanotubes is greatly enhanced. Further, the polyimide nanotubes with a dense, homogeneous coating of palladium nanoparticles remain flexible after heat treatment and show the possibility for use as highly efficient catalysts. The approach developed here is applicable for coating various noble metals on a wide range of polymer matrices, and can be used for obtaining polyimide nanotubes with metal loaded on both the inner and outer surface.

Preparation and characterization of a copper@polyimide core–shell structure via an in situ induction/imidization route

Based on the combination of an in situ induction and imidization method for improving the interface bonding of an inorganic material and a polymer, copper@polyimide (Cu@PI) core–shell composite particles have been successfully prepared from poly(amic acid) ammonium salts (PAAS) and a Cu complex via a simple solvothermal process. The structures and the morphologies of the samples were characterized by X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy (TEM), respectively. It was found that PAAS formed PI via a thermal imidization and subsequently precipitated in the solvent. Through crystallization induction, it then successfully coated on the surface of the formed Cu particles. Based on thermo gravimetric analyses curves and due to no Cu oxidation reactions taking place in the core coated with high-temperature-resistant PI, the weight increase was determined to be 106.4%, instead of up to 124.0% in samples consisting of pure Cu.

Syzygium aromaticum extract mediated, rapid and facile biogenic synthesis of shape-controlled (3D) silver nanocubes

The synthesis of metal nano materials with controllable geometry has received extensive attention of researchers from the past decade. In this study, we report an unexplored new route for rapid and facile biogenic synthesis of silver nanocubes (AgNCs) by systematic reduction of silver ions with crude clove (Syzygium aromaticum) extract at room temperature. The formation and plasmonic properties of AgNCs were observed and the UV-vis spectra show characteristic absorption peak of AgNCs with broaden region at 430 nm along with the intense (124), (686), (454) and (235) peak in X-ray diffraction pattern confirmed the formation and crystallinity of AgNCs. The average size of AgNC cubes were found to be in the range of ~80 to 150 nm and it was confirmed by particles size distribution, scanning and transmission electron microscopy with elemental detection by EDAX. Further FTIR spectra provide the various functional groups present in the S. aromaticum extract which are supposed to be responsible and participating in the reaction for the synthesis of AgNCs. The AgNCs casted over glass substrate show an electrical conductivity of ~0.55 × 10(6) S/m demonstrating AgNCs to be a potential next generation conducting material due to its high conductivity. This work provides a novel and effective approach to control the shape of silver nanomaterial for impending applications. The current synthesis mode is eco-friendly, low cost and promises different potential applications such as biosensing, nanoelectronics, etc.

Poly(amic acid) salt-stabilized silver nanoparticles as efficient and recyclable quasi-homogeneous catalysts for the aqueous hydration of nitriles to amides

The reversible pH-response of the Ag–PAAS catalyst allows it to catalyze the selective hydration of various nitriles quasi-homogeneously in water and to be easily recovered by simply adjusting the pH value of the solution.

Silver nanocube-mediated sensitive immunoassay based on surface-enhanced Raman scattering assisted by etched silicon nanowire arrays

An immunoassay based on surface enhanced Raman scattering (SERS) has been developed using immuno-silver nanocubes (NCs) and silicon nanowires with high sensitivity. The features of the samples were characterized by XRD profiles, absorption spectra, SEM, TEM, and AFM images, EDS analyses, and SERS spectra. It was found that the obtained silver NCs maintained higher SERS activity than silver nanospheres. After the silver NCs were modified by an antibody and employed in immunoassay with silicon nanowire arrays as the substrate, the antigen concentration-dependent SERS spectra and dose-response calibration curves were obtained. The detection limit of a prostate-specific antigen in this immunosystem was as low as 2 × 10(-14) g ml(-1), attributing to the significant electromagnetic coupling effect generated between the densely packed silver NCs and the SERS-active silicon nanowire arrays. It can be inferred that this proposed strategy will show great advantages in sensitive immunoassay and other biochemical examinations.

One-pot green synthesis of Ag/AgCl nanocube/reduced graphene oxide and its application to the simultaneous determination of hydroquinone and catechol

Uniformly dispersed Ag/AgCl nanocubes (AgNC) were successfully obtained on reduced graphene oxide (rGO) through the simultaneous reduction of Ag⁺and graphene oxide (GO) by chitosan in the presence of a little HCl.