Thermal Conductivity of Polymer-Based Composites: Fundamentals and Applications

Polymers are widely used in industry and in our daily life because of their diverse functionality, light weight, low cost and excellent chemical stability. However, on some applications such as heat exchangers and electronic packaging, the low thermal conductivity of polymers is one of the major technological barriers. Enhancing the thermal conductivity of polymers is important for these applications and has become a very active research topic over the past two decades. In this review article, we aim to: 1). systematically summarize the molecular level understanding on the thermal transport mechanisms in polymers in terms of polymer morphology, chain structure and inter-chain coupling; 2). highlight the rationales in the recent efforts in enhancing the thermal conductivity of nanostructured polymers and polymer nanocomposites. Finally, we outline the main advances, challenges and outlooks for highly thermal-conductive polymer and polymer nanocomposites.

Thermal conductivity of polymers and polymer nanocomposites

Because of their excellent properties and extensive applications, ceria nanomaterials have attracted much attention in recent years. This perspective provides a comprehensive review of current research activities that focus on the shape-controlled synthesis methods of ceria nanostructures. We elaborate on the synthesis strategies in the following four sections: (i) oriented growth directed by the crystallographic structure of cerium-based materials; (ii) oriented growth directed by the use of an appropriate capping reagent; (iii) growth confined or dictated by various templates; (iv) other potential methods for generating CeO(2) nanomaterials. In this perspective, we also discuss the catalytic applications of ceria nanostructures. They are often used as active components or supports in many catalytic reactions and their catalytic activities show morphology dependence. We review the morphology dependence of their catalytic performances in carbon monoxide oxidation, water-gas shift, nitric oxide reduction, and reforming reactions. At the end of this review, we give a personal perspective on the probable challenges and developments of the controllable synthesis of CeO(2) nanomaterials and their catalytic applications.

Shape-controlled synthesis and catalytic application of ceria nanomaterials

CuFe2O4 magnetic nanoparticles: A simple and efficient catalyst for the reduction of nitrophenol

Nanoparticles of varying composition, size, shape, and architecture have been explored for use as photothermal agents in the field of cancer nanomedicine. Among them, gold nanoparticles provide a simple platform for thermal ablation owing to its biocompatibility in vivo. However, the synthesis of such gold nanoparticles exhibiting suitable properties for photothermal activity involves cumbersome routes using toxic chemicals as capping agents, which can cause concerns in vivo. Herein, gold nanoparticles, synthesized using green chemistry routes possessing near-infrared (NIR) absorbance facilitating photothermal therapy, would be a viable alternative. In this study, anisotropic gold nanoparticles were synthesized using an aqueous route with cocoa extract which served both as a reducing and stabilizing agent. The as-prepared gold nanoparticles were subjected to density gradient centrifugation to maximize its NIR absorption in the wavelength range of 800–1000 nm. The particles also showed good biocompatibilit...

Green Synthesis of Anisotropic Gold Nanoparticles for Photothermal Therapy of Cancer

Pt-Ru catalysts based on functional polymer-grafted MWNT (Pt-Ru@FP-MWNT) were prepared by radiolytic deposition of Pt-Ru nanoparticles on functional polymer-grafted multiwalled carbon nanotube (FP-MWNT). Three different types of functional polymers, poly(acrylic acid) (PAAc), poly(methacrylic acid) (PMAc), and poly(vinylphenyl boronic acid) (PVPBAc), were grafted on the MWNT surface by radiation-induced graft polymerization (RIGP). Then, Pt-Ru nanoparticles were deposited onto the FPMWNTsupports by the reduction of metal ions using γ-irradiation to obtain Pt-Ru@FP-MWNT catalysts. The Pt-Ru@FP-MWNT catalysts were then characterized by XRD, XPS, TEM, and elemental analysis. The catalytic efficiency of Pt-Ru@FP-MWNT catalyst was examined for CO stripping and MeOH oxidation for use in a direct methanol fuel cell (DMFC). The Pt-Ru@PVPBAc-MWNT catalyst shows enhanced activity for electro-oxidation of CO and MeOH oxidation over that of the commercial E-TEK catalyst.

/pdf/radiolytic-synthesis-of-pt-ru-catalysts-based-on-functional-4s2jouwj6l.pdf

Radiolytic synthesis of Pt-Ru catalysts based on functional polymer-grafted MWNT and their catalytic efficiency for CO and MeOH

One-step preparation of Pt–M@FP-MWNT catalysts (M = Ru, Ni, Co, Sn, and Au) by γ-ray irradiation and their catalytic efficiency for CO and MeOH

Synthesis of Pt–Ru@PThB catalyst by γ-irradiation and NaBH4 as reducing agent

This paper describes the electrocatalytic activity for CO, MeOH, and EtOH oxidation on the surface of Pt-Ru nanoparticles supported by metal oxide (Nb-TiO2-H) prepared for use in a fuel cell. To prepare Nb-TiO2-supported Pt-Ru nanoparticles, first, the Nb-TiO2 supports were prepared by sol-gel reaction of titanium tetraisopropoxide with a small amount of the niobium ethoxide in polystyrene (PS) colloids. Second, Pt-Ru nanoparticles were then deposited by chemical reduction of the Pt4+ and Ru3+ ions onto Nb-TiO2 supports ([email protected]2-CS). Nb element was used to reduce electrical resistance to facilitate electron transport during the electrochemical reactions on a fuel cell electrode. Finally, the [email protected]2-H catalysts were formed by the removal of core-polystyrene ball from [email protected]2-CS at 500°C. The successfully prepared Pt-Ru electrocatalysts were confirmed via TEM, XPS, and ICP analysis. The electrocatalytic efficiency of Pt-Ru nanoparticles was evaluated via CO, MeOH, and EtOH oxidation for use in a directmethanol fuel cell (DMFC). As a result, the [email protected]2-H electrodes showed high electrocatalytic activity for the electrooxidation of CO, MeOH, and EtOH.

https://downloads.hindawi.com/journals/jnm/2011/614983.pdf

Electrocatalytic activity for CO, MeOH, and EtOH oxidation on the surface of Pt-Ru nanoparticles supported by metal oxide

Radiolytic Preparation of MWNT-Supported Electrocatalysts with Monometallic (Pt), Bimetallic (Pt-Ru), Trimetallic (Pt-Ru-Sn and Pt-Ru-Mo), and Tetrametallic (Pt-Ru-Mo-Sn) Nanoparticles for Direct Methanol Fuel Cells

Kwang-Sik Sim

Papers

Radiolytic synthesis of Pt-Ru catalysts based on functional polymer-grafted MWNT and their catalytic efficiency for CO and MeOH

One-step preparation of Pt–M@FP-MWNT catalysts (M = Ru, Ni, Co, Sn, and Au) by γ-ray irradiation and their catalytic efficiency for CO and MeOH

Synthesis of Pt–Ru@PThB catalyst by γ-irradiation and NaBH4 as reducing agent

Electrocatalytic activity for CO, MeOH, and EtOH oxidation on the surface of Pt-Ru nanoparticles supported by metal oxide

Radiolytic Preparation of MWNT-Supported Electrocatalysts with Monometallic (Pt), Bimetallic (Pt-Ru), Trimetallic (Pt-Ru-Sn and Pt-Ru-Mo), and Tetrametallic (Pt-Ru-Mo-Sn) Nanoparticles for Direct Methanol Fuel Cells