Core-shell metal/polymer nanoparticles

A new class of metal-loaded nanoparticles was developed by Reynolds et al. (95). These materials have a core-shell morphology, where the core is a functionalized polymer with a high affinity to the Gd(III) ions. The core polymer contained monomers with carboxylate pendant arms, such as ethylacrylate, methacrylate, butylacrylate or allylmethacrylate. The shell consisted of a... 

An alcohol reduction method has been applied to the synthesis of polymer-stabilized bimetallic nanoparticles. They have been prepared by simultaneous reduction of the two corresponding metal ions with refluxing alcohol. For example, colloidal dispersions of Pd/Pt bimetallic nanoparticles can be prepared by refluxing the alcohol-water (1 1 v/v) mixed solution of palladium(II) chloride and hexachloro-platinic(IV) acid in the presence of poly(/V-vinyl-2-pyrrolidone) (PVP) at about 90-95°C for 1 h (Scheme 9.1.5) (25). The resulting brownish colloidal dispersions are stable and neither precipitate nor flocculate over a period of several years. Pd/ Pt bimetallic nanoparticles thus obtained have a so-called core/shell structure, which is proved by an EXAFS technique (described in Section 9.1.3.3). 

Several other examples of conducting-polymer/metal oxide nanocomposite materials also exist for chemical sensing of a range of analytes, including humidity [58,59], NO2, [60,61], CO and H2 [60], and H2O2 [62]. This latter example employed the use of Prussian blue, which is an iron complex with excellent catalytic properties, particularly towards O2 and H2O2. Miao et al. [62] stabilized nanoparticles of Prussian blue with polymerization of a PANI shell to form a Prussian blue/PANI core-shell composite. 

Synthesizing nanoparticle with core/shell structure is a way to combine multiple functionalities on nanocomposites. Core/shell nanomaterials are generally composed of the core in the center and the coated shell outside, which are structured by a variety of materials, including polymers, inorganics, and metals [1]. Most of the synthesis strategies are based on... 

A nanoparticle is generally defined as a particle whose diameter is between 1 and 100 nm. No distinction is made according to the material nanoparticles can be metals, metal compounds, organic compounds, and polymers. A composite nanoparticle is a nanoparticle which has a composite stmcmre, including core-shell structure, onion-like structure, or gladiate composition. 

There are a variety of different types of particle that can be synthesized using microfluidics and the exact fluidic format used defines the flow characteristics of the synthesis environment which needs to be carefully matched to the synthetic requirements of each particle type. Broadly speaking, the main particle types of interest include monodisperse microgels, metal nanoparticles and nanocrystals, core-shell particles, microemulsions, and microcapsules. Typically these particles should be homogeneous in size and are composed either of an organic polymer matrix or a metal or metal mixture at the micron or nanometer scale. In addition to these simple particle architectures, we may also consider more complex particles composed of multiple layers or components such as core-shell particles or using a central cavity to encapsulate small molecules, proteins, or other particles, and these are called microcapsules. 

Nanoparticles can be composed of any substance, including metals [21, 22], semiconductors [23, 24], core-shell composite architectures [25—27], and organic polymers [28], These particles often display properties intermediate between quantum and bulk materials because of their intermediate size [29] and large surface area to volume ratio [30], Nanoparticle of different sizes and shapes exhibit different absorbance and fluorescence features and reveal polymerization effects [31], Some of the characteristics of metallic nanoparticles are shown in Table 1. 

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