Journal of Materials Chemistry Blog

Thermal halogenation of a wide range of metal carbides provides a simple route to a class of so-called carbide-derived carbon (CDC) materials. The porosity of the CDCs, which is mainly in the microporous regime, may be modulated by the choice of metal carbide precursor and synthesis process, the maximum surface area achieved is only up to 2500 m²g⁻¹, which limits their use in gas storage or in electrochemical capacitor applications that require larger surface areas.

This Highlight article is focused on what has and can be done to enhance the textural properties of CDCs via further post-synthesis treatments and the ramifications of such modifications on their gas/energy storage capacity. The main developments in physical and chemical activation of CDCs and consequences on gas and energy storage are summarised by the authors from the University of Nottingham, UK, and Instituto Nacional del Carbón, Spain.

Interested in knowing more?  Read for free until January 14th.

Activation of carbide-derived carbons: a route to materials with enhanced gas and energy storage properties 
M. Sevilla and R. Mokaya
J. Mater. Chem., 2011, Advance Article
DOI: 10.1039/C0JM03347B, Highlight

The second issue of Journal of Materials Chemistry in 2011 is now online.  The front cover features a communication from Lifang Jiao and co-workers based at Nankai University in China.  The paper, entitled ‘Novel flower-like CoS hierarchitectures: one-pot synthesis and electrochemical properties’ describes the synthesis, by a facile solvothermal method, of novel 3D flower-like CoS hierarchitectures and CoS microspheres which display good electrochemical properties.

Thinking of submitting to Journal of Materials Chemistry in 2011?  Sumbit online here.

In this ‘Hot’ paper, Mark Green and co-workers from Kings College, London report the synthesis of small luminescent conjugated polymer nanoparticles and the role of poly(ethylene glycol) in the nanoparticle structure.  This is the first time that semiconducting polymer nanospheres (SPNs) on the scale of quantum dots have been made using miniemulsion methods.

SPNs have been made using miniemulsion methods previously but the resulting materials have been significantly larger than quantum dots.  Quantum dots are desirable as these are the nanomaterial of choice for cell imaging.  The SPNs were characterized by TEM, absorption and emission spectroscopy, they were found to be stable in solution for months and bright and are expected to be effective in various fluorescence applications.

Interested in knowing more? Read for free until 13th January 2011.

Luminescent quantum-dot-sized conjugated polymer nanoparticles—nanoparticle formation in a miniemulsion system
Zeina Hashim, Philip Howes and Mark Green
J. Mater. Chem., 2011, Advance Article
DOI: 10.1039/C0JM02935A, Paper

Surface-enhanced Raman scattering (SERS)-active silver hierarchical assemblies are synthesized in solution by the assistance of small acid molecules without using any polymer surfactant or capping agent. In this ‘Hot’ paper a team from China and the USA demonstrate the acid-directed self-assembly of metal nanoparticles (MNPs) into large systems with complex structures. They verify that small acid molecules (citric acid, mandelic acid, etc.) incorporated into conventional solution chemistry can direct the assembly of MNPs into well-defined hierarchical structures. The constructed assembled structures with highly roughened surfaces can be highly sensitive SERS platforms, and the fabricated core–shell Ag wires show especially high SERS sensitivity toward the analyte melamine.

Interested in knowing more? Read for free until January 11th 2011.

Acid-directed synthesis of SERS-active hierarchical assemblies of silver nanostructures
Bin Zhang, Ping Xu, Xinmiao Xie, Hong Wei, Zhipeng Li, Nathan H. Mack, Xijiang Han, Hongxing Xu and Hsing-Lin Wang
J. Mater. Chem., 2011, Advance Article
DOI: 10.1039/C0JM02837A, Paper

This report by Chuan-Jian Zhong and co-workers at the State University of New York at Binghamton highlights recent insights into the nanoscale phase properties of gold-platinum (AuPt) nanoparticles.  The alloying and phase-segregation of supported AuPt nanoparticles depend on a combination of size, composition, and preparation parameters.  This system serves as an example to shine a light on the importance of changes in physical and chemical properties in which nanoscale multimetallic materials may differ from their bulk counterparts.

Interested in knowing more? Read for free until 7th January 2011.

Gold-platinum nanoparticles: alloying and phase segregation
Bridgid Nekesa Wanjala, Jin Luo, Bin Fang, Derrick Mott and Chuan-Jian Zhong
J. Mater. Chem., 2011, Advance Article
DOI: 10.1039/C0JM02682D, Highlight

The number of different nano- and micro-scale structures produced from the chemical oxidation of aniline into “polyaniline” is rivalled by few other organic materials.  Small and subtle changes in reaction parameters during aniline oxidation result in nanoscale structures such as tubes, flowers and even those resembling anatomical organs and sea animals!  A nanomaterial’s properties are highly dependent on its morphology so understanding polyaniline’s propensity for forming these structures is crucial towards tailoring the material for different applications as well as improving its synthetic reproducibility.

This ‘Hot’ Feature Article by Henry D. Tran from Fibron Technologies Inc. and Richard B. Kaner and co-workers from the University of California Los Angeles examines these different structures and the small and subtle changes in reaction parameters that result in their formation.  They discuss some of the highly debated aspects of these processes and give their perspective on where things are headed in the years to come.

Interested in knowing more?  Read for free until 6^th January 2011.

The oxidation of aniline to produce “polyaniline”: a process yielding many different nanoscale structures
Henry D. Tran, Julio M. D’Arcy, Yue Wang, Peter J. Beltramo, Veronica A. Strong and Richard B. Kaner
J. Mater. Chem., 2011, Advance Article
DOI: 10.1039/C0JM02699A, Feature Article

Three new hydroxy double salt (HDS) nanocomposites containing medicinal and agrochemical anions were prepared Dermot O’Hare and co-workers and their potential as sustained release matrices demonstrated in this Hot Article from the team based at Oxford University.

HDSs consist of layers of comprise positively charged layers, requiring charge balancing anions to be located between the layers to ensure electroneutrality. These anions can be easily replaced through an anion exchange process.  HDS have received far less attention than the related Layered double hydroxides (LDHs) which have been widely explored as hosts for the storage and controlled release of a broad spectrum of functional anions.

In this study two drug anions were chosen for investigation (ibuprofen and diclofenac, commonly used non-steroidal anti-inflammatory drugs) and an examplar agrochemical 2,4,5-trichlorophenoxyacetic acid, a widely used herbicide. The functional anion intercalates were thoroughly characterised, and the release of the functional anion studied in vitro in representative conditions. Mathematical models were applied to the release kinetics, and post-synthesis modification undertaken to optimise release times for industrial application.

Interested in knowing more?  Read for free until January 4th 2011

Hydroxy double salts as versatile storage and delivery matrices
Richard M. R. Bull, Charles Markland, Gareth R. Williams and Dermot O’Hare
J. Mater. Chem., 2011, Advance Article
DOI: 10.1039/C0JM03020A, Paper

In order to broaden the application fields of poly (vinylidene fluoride) (PVDF), a promising approach is introducing nanofillers into the polymer. In this paper from Wei-Hong Zhong and co-workers a facile method for surface modification of nanofillers has been developed in order to improve interfacial interaction and dispersion within PVDF matrix.

Rather than using the more conventional toxic fluorine gas method of treating nanofillers, the team from Beihang University and Washington State University developed a new method of depositing a fluorination coating from decomposition of polytetrafluoroethylene (PTFE) on a carbon nanofiber (CNF) surface. This study confirms that the new surface coating method provides a simpler way for practical modification of nanofillers, i.e. through decompositions of polymers.

Interested in knowing more? Read for free until January 4th 2011.

Fluorination deposition on carbon nanofibers by PTFE decomposition as a facile method to enhance dispersion and interaction in PVDF composites
Li-Li Sun, Zuo-Guang Zhang and Wei-Hong Zhong
J. Mater. Chem., 2011, Advance Article
DOI: 10.1039/C0JM03260C, Paper

The design of new materials for gaseous NOx (NO and NO2) removal at ambient temperature using organic active sites is reported in this paper from a team from the University of California at Berkeley. The materials consist of unfunctionalised silica and silica modified by immobilized aminoxyls and function via cascade reactions consisting of NO oxidation to NO2 and NO2 adsorption.The application of cascade reactions is an emerging research area that spans synthetic and biological catalysts, and has the potential to integrate the unique properties of both types of catalysts within a single process.

Interested in knowing more?  Read for free until January 4^th 2011.

Silica-supported aminoxyls as reactive materials for NO_x removal 
Tatiana Luts, Enrique Iglesia and Alexander Katz
J. Mater. Chem., 2011, Advance Article
DOI: 10.1039/C0JM02826F, Paper

In this Feature Article, Hongtao Liu, Yunqi Liu and Daoben Zhu present a summary of chemical doping of graphene aimed at tuning the electronic properties.  The authors, from the Chinese Academy of Sciences, focus on p-type and n-type doping of graphene and band gap tuning in graphene.

Recently, a lot of effort has been focused on improving the performance and exploring the electric properties of graphene with the aim of designing high performance electronic devices based on chemically doped graphene.

Interested in knowing more? Read for free until 4th January 2011

Chemical doping of graphene
Hongtao Liu, Yunqi Liu and Daoben Zhu
J. Mater. Chem., 2011, Advance Article
DOI: 10.1039/C0JM02922J, Feature Article