Journal of Materials Chemistry Blog

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