Although gold is the subject of one of the most ancient themes of investigation in science, its renaissance now leads to an exponentially increasing number of publications, especially in the context of emerging nanoscience and nanotechnology with nanoparticles and self-assembled monolayers (SAMs). We will limit the present review to gold nanoparticles (AuNPs), also called gold colloids. AuNPs are the most stable metal nanoparticles, and they present fascinating aspects such as their assembly of multiple types involving materials science, the behavior of the individual particles, size-related electronic, magnetic and optical properties (quantum size effect), and their applications to catalysis and biology. Their promises are in these fields as well as in the bottom-up approach of nanotechnology, and they will be key materials and building block in the 21st century. Whereas the extraction of gold started in the 5th millennium B.C. near Varna (Bulgaria) and reached 10 tons per year in Egypt around 1200-1300 B.C. when the marvelous statue of Touthankamon was constructed, it is probable that “soluble” gold appeared around the 5th or 4th century B.C. in Egypt and China. In antiquity, materials were used in an ecological sense for both aesthetic and curative purposes. Colloidal gold was used to make ruby glass 293 Chem. Rev. 2004, 104, 293−346

Gold nanoparticles: assembly, supramolecular chemistry, quantum-size-related properties, and applications toward biology, catalysis, and nanotechnology.

Polydopamine and Its Derivative Materials: Synthesis and Promising Applications in Energy, Environmental, and Biomedical Fields

Approaches, Derivatives and Applications Vasilios Georgakilas,† Michal Otyepka,‡ Athanasios B. Bourlinos,‡ Vimlesh Chandra, Namdong Kim, K. Christian Kemp, Pavel Hobza,‡,§,⊥ Radek Zboril,*,‡ and Kwang S. Kim* †Institute of Materials Science, NCSR “Demokritos”, Ag. Paraskevi Attikis, 15310 Athens, Greece ‡Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo naḿ. 2, 166 10 Prague 6, Czech Republic

Functionalization of Graphene: Covalent and Non-Covalent Approaches, Derivatives and Applications

Graphene has attracted tremendous research interest in recent years, owing to its exceptional properties. The scaled-up and reliable production of graphene derivatives, such as graphene oxide (GO) and reduced graphene oxide (rGO), offers a wide range of possibilities to synthesize graphene-based functional materials for various applications. This critical review presents and discusses the current development of graphene-based composites. After introduction of the synthesis methods for graphene and its derivatives as well as their properties, we focus on the description of various methods to synthesize graphene-based composites, especially those with functional polymers and inorganic nanostructures. Particular emphasis is placed on strategies for the optimization of composite properties. Lastly, the advantages of graphene-based composites in applications such as the Li-ion batteries, supercapacitors, fuel cells, photovoltaic devices, photocatalysis, as well as Raman enhancement are described (279 references).

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Graphene-based composites

We review the present state of polymer nanocomposites research in which the fillers are single-wall or multiwall carbon nanotubes. By way of background we provide a brief synopsis about carbon nanotube materials and their suspensions. We summarize and critique various nanotube/polymer composite fabrication methods including solution mixing, melt mixing, and in situ polymerization with a particular emphasis on evaluating the dispersion state of the nanotubes. We discuss mechanical, electrical, rheological, thermal, and flammability properties separately and how these physical properties depend on the size, aspect ratio, loading, dispersion state, and alignment of nanotubes within polymer nanocomposites. Finally, we summarize the current challenges to and opportunities for efficiently translating the extraordinary properties of carbon nanotubes to polymer matrices in hopes of facilitating progress in this emerging area.

Polymer Nanocomposites Containing Carbon Nanotubes

A surface modification technique was employed to functionalize electrically conductive polypyrrole (PPY) films with hyaluronic acid (HA). The PPY film was first graft copolymerized with 2-hydroxyet...

Surface Functionalization of Electrically Conductive Polypyrrole Film with Hyaluronic Acid

Chemical modification of Ar plasma-pretreated poly(tetrafluoroethylene) (PTFE) film by UV-induced graft copolymerization with glycidyl methacrylate (GMA), followed by reactive coupling of 3-aminopropyltriethoxysilane (APS), or reactive immobilization of polyaniline (PANI) chains had been carried out to improve the adhesion of the electrolessly deposited copper and nickel to PTFE film. The surface compositions and microstructures of the modified PTFE films were characterized by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), respectively. The PANI-modified PTFE surface was susceptible to the electroless deposition of copper and nickel in the absence of sensitization by SnCl 2 . The adhesion strength of the PANI-modified or silane-modified PTFE film with the electrolessly deposited metal was affected by the graft concentration of the GMA polymer, the Ar plasma post-treatment, the graft-modified PTFE surface, and the extent of thermal post-treatment after metallization, The optimum T-peel adhesion strength of the electrolessly deposited metal on the graft-copolymerized and APS-coupled PTFE film could reach about 13 N/cm. This adhesion strength represented a more than tenfold increase over that obtained when the PTFE film was modified by Ar plasma treatment alone, The mechanisms of the adhesion strength enhancement, thermal stability enhancement, and cohesive failure of the metal-PTFE interface were also investigated.

Electroless Plating of Copper and Nickel on Surface-Modified Poly(tetrafluoroethylene) Films

Important issues in the design of superparamagnetic iron oxide nanoparticles (SPIONs) for cancer diagnosis include stability under physiological conditions and specificity in targeting the cancer cells. In the present study, atom transfer radical polymerization (ATRP) was used to graft SPIONs with poly(glycidyl methacrylate-co-poly(ethylene glycol) methyl ether methacrylate) (SPIONs-P(GMA-co-PEGMA)). The PEGMA in the copolymer chain confers high stability to the nanoparticles in aqueous medium, and prevents recognition by macrophages with the aim of prolonging their in vivo circulation time. The GMA groups were used for conjugating the cancer targeting ligand, folic acid (FA), via ‘click’ chemistry. Using this method, the amount of FA conjugated to the nanoparticles (SPIONs-P(GMA-co-PEGMA)-FA) can be readily controlled. The specificity of cellular uptake of the nanoparticles by three different cell lines was investigated. The cellular iron uptake by KB cells (human epidermoid carcinoma) after 24 h of incu...

Combined ATRP and 'click' chemistry for designing stable tumor-targeting superparamagnetic iron oxide nanoparticles.

Controlled Micropatterning of a Si(100) Surface by Combined Nitroxide-Mediated and Atom Transfer Radical Polymerizations

Surface modification of poly(tetrafluoroethylene) (PTFE) films by Ar+ ion-beam irradiation with varying ion energy and ion dose was carried out. The changes in surface composition of the irradiated PTFE films were characterized, both in situ and after exposure to air, by X-ray photoelectron spectroscopy (XPS). The possible mechanisms of chemical reaction induced by the incident ion beam on the surface of PTFE film included defluorination, chain scission and cross-linking, as indicated by the presence of the characteristic peak components associated with the CF3,CF, and C(CF2)4 species in the C 1s core-level spectra, the decrease in surface [F]/[C] ratio, and the increase in surface micro-hardness of the Ar+ ion-beam-treated PTFE films. Furthermore, the free radicals generated by the ion-beam could react with oxygen in the air to give rise to oxidized carbon species, such as the peroxides, on the PTFE surface. Thus, after exposure to air, the Ar+ ion-beam-pretreated PTFE films were susceptible to further surface modification by UV-induced graft copolymerization with a vinyl monomer, such as acrylamide (AAm). The graft concentrations were deduced from the XPS-derived surface stoichiometries. The Ar+ ion energy and the ion dose affected not only the surface composition of the treated films but also the graft copolymerization efficiency of the corresponding pretreated films.

En-Tang Kang

Papers

Surface Functionalization of Electrically Conductive Polypyrrole Film with Hyaluronic Acid

Electroless Plating of Copper and Nickel on Surface-Modified Poly(tetrafluoroethylene) Films

Combined ATRP and 'click' chemistry for designing stable tumor-targeting superparamagnetic iron oxide nanoparticles.

Controlled Micropatterning of a Si(100) Surface by Combined Nitroxide-Mediated and Atom Transfer Radical Polymerizations

Surface modification of poly(tetrafluoroethylene) films by low energy Ar+ ion-beam activation and UV-induced graft copolymerization