There is intense interest in graphene in fields such as physics, chemistry, and materials science, among others. Interest in graphene's exceptional physical properties, chemical tunability, and potential for applications has generated thousands of publications and an accelerating pace of research, making review of such research timely. Here is an overview of the synthesis, properties, and applications of graphene and related materials (primarily, graphite oxide and its colloidal suspensions and materials made from them), from a materials science perspective.

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Graphene and Graphene Oxide: Synthesis, Properties, and Applications

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 based materials: Past, present and future

Recent advances in graphene based polymer composites

Graphene has emerged as a subject of enormous scientific interest due to its exceptional electron transport, mechanical properties, and high surface area. When incorporated appropriately, these atomically thin carbon sheets can significantly improve physical properties of host polymers at extremely small loading. We first review production routes to exfoliated graphite with an emphasis on top-down strategies starting from graphite oxide, including advantages and disadvantages of each method. Then solvent- and melt-based strategies to disperse chemically or thermally reduced graphene oxide in polymers are discussed. Analytical techniques for characterizing particle dimensions, surface characteristics, and dispersion in matrix polymers are also introduced. We summarize electrical, thermal, mechanical, and gas barrier properties of the graphene/polymer nanocomposites. We conclude this review listing current challenges associated with processing and scalability of graphene composites and future perspectives f...

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Graphene/Polymer Nanocomposites

Serving as both a reference and a textbook on rheology and rheological phenomena, this text enables students to retrieve worked examples, experienced rheologists to find references to the rheological techniques currently available, and readers who are primarily interested in using rheology to help solve a specific and immediate problem find a chapter of interest in the section on applications of rheology. This text tackles the tensor in such a way as to make the problems accessible and understandable - by simplifying notation and making the three-dimensional approach to rheology practical. Some exercises are included, with solutions at the end of the book. The text is suitable for students, engineers in the polymer industry and mechanical engineers.

Rheology: Principles, Measurements, and Applications

Recently developed strategies for isolating single-layer carbon sheets from graphite have enabled production of electrically conductive, mechanically robust polymer nanocomposites with enhanced gas barrier performance at extremely low loading. In this article, we present processing, morphology, and properties of thermoplastic polyurethane (TPU) reinforced with exfoliated graphite. For the first time, we compare carbon sheets exfoliated from graphite oxide (GO) via two different processes: chemical modification (isocyanate treated GO, iGO) and thermal exfoliation (thermally reduced GO, TRG), and three different methods of dispersion: solvent blending, in situ polymerization, and melt compounding. Incorporation of as low as 0.5 wt % of TRG produced electrically conductive TPU. Up to a 10-fold increase in tensile stiffness and 90% decrease in nitrogen permeation of TPU were observed with only 3 wt % iGO, implying a high aspect ratio of exfoliated platelets. Real- and reciprocal-space morphological characteri...

Graphene/Polyurethane Nanocomposites for Improved Gas Barrier and Electrical Conductivity

Two-dimensional carbon-based nanomaterials, including graphene oxide and graphene, are potential candidates for biomedical applications such as sensors, cell labeling, bacterial inhibition, and drug delivery. Herein, we explore the biocompatibility of graphene-related materials with controlled physical and chemical properties. The size and extent of exfoliation of graphene oxide sheets was varied by sonication intensity and time. Graphene sheets were obtained from graphene oxide by a simple (hydrazine-free) hydrothermal route. The particle size, morphology, exfoliation extent, oxygen content, and surface charge of graphene oxide and graphene were characterized by wide-angle powder X-ray diffraction, atomic force microscopy, X-ray photoelectron spectroscopy, dynamic light scattering, and zeta-potential. One method of toxicity assessment was based on measurement of the efflux of hemoglobin from suspended red blood cells. At the smallest size, graphene oxide showed the greatest hemolytic activity, whereas ag...

Cytotoxicity of graphene oxide and graphene in human erythrocytes and skin fibroblasts.

This study shows that a limiting dispersed phase particle size exists at very low concentrations for polymer blends mixed in an internal batch mixer and two types of twin-screw extruders. The Taylor limit for breakup of a single drop in a matrix underpredicts the limiting particle size; this discrepancy is attributed to viscoelastic effects. For uncompatibilized blends, the final particle size increases with the dispersed phase concentration due to increased coalescence. The particle size distribution also broadens at higher concentrations. Using in-situ reaction during blending or adding premade diblock copolymers suppresses coalescence resulting in smaller particle size and narrower particle size distribution. Using premade block copolymers is not as efficient in stabilizing morphology as using reactive polymers. It is shown that the main advantage of using compatibilizers in polymer blends is the suppression of coalescence achieved through stabilizing the interface, not a reduction in the interfacial tension. There is a critical shear rate in polymer systems where a minimum particle size is achieved. A qualitative explanation of why this occurs is given based on droplet elasticity

Christopher W. Macosko

Papers

Graphene/Polymer Nanocomposites

Rheology: Principles, Measurements, and Applications

Graphene/Polyurethane Nanocomposites for Improved Gas Barrier and Electrical Conductivity

Cytotoxicity of graphene oxide and graphene in human erythrocytes and skin fibroblasts.

Drop Breakup and Coalescence in Polymer Blends - The Effects of Concentration and Compatibilization