Journal of Materials Chemistry Blog

Researchers in Germany have achieved metal ion release from a silicone matrix by an electrochemistry-controlled method.

Synergistic metal ion release from a silicone matrix filled with silver and copper as well as silver and gold nanoparticles (NPs) was investigated. It was found that silver NPs enhanced the release of copper ions, whereas gold NPs did not enhance the release of silver ions. The mechanism of the release of the less noble metal nanoparticles is based on ion-mediated electrochemistry and not contact corrosion of both elements. This work shows potential in the design of time- and rate-controlled bioactive nanocomposites.

Interested to know more? Why not read the full article for free: A. Hahn, S. Günther, P. Wagener and S. Barcikowski, J. Mater. Chem., 2011, DOI: 10.1039/c0jm04480f (Advance Article)

Ti4+/Mn2+-activated Mg2SnO4 phosphors were prepared using a solid state reaction by a team of Chinese scientists. The blue colour purity and emission intensity of Mg2SnO4:Ti4+ is enhanced compared to pure Mg2SnO4, and the Mg2SnO4:Mn2+ shows a much higher green colour purity than that of ZnO:Zn. Wide cyan-emitting cathodoluminescence can be achieved simply by adjusting the relative doping concentration of Ti4+ and Mn2+ in the Mg2SnO4 host. The team behind the research say that the wide cyan light emissions are outside of the typical colour gamut for FED phosphors and theses phosphors could increase the display quality of full-color FEDs. 

Interested to know more? Read the full article for free until 2nd May:

Cyan-emitting Ti4+- and Mn2+-coactivated Mg2SnO4 as a potential phosphor to enlarge the color gamut for field emission display, Guogang Li, Xiao Zhang, Chong Peng, Mengmeng Shang, Dongling Geng, Ziyong Cheng and Jun Lin, J. Mater. Chem., 2011, DOI: 10.1039/C1JM00057H (Advance Article)

Gold nanocluster-based light-controlled fluorescence molecular switch. A light-controlled fluorescence molecular switch has been created by a team of Chinese scientists. The molecular switch is made from Au nanoclusters and thiolated spiropyran dyes. The fluorescence can be reversibly modulated using UV/Visible light due to fluorescence resonance energy transfer from the Au nanoclusters to the open-ring state merocyanine of the spiropyran molecules. The team say the switch could potentially be used for biological imaging and labeling, as well as in other fields such as reversible data storage and erasing. J. Mater. Chem., 2011, DOI:10.1039/C0JM04146G (Advance Article)

Ferroelectric, electrical, and structural properties of Dy and Sc co-doped BaTiO3. Ferroelectric barium titanate is a perovskite used in many electronic devices, including high permittivity multilayer ceramic capacitors. In an effort to improve the properties of this material, scientists at the University of Sheffield investigated the influence of Dy and Sc co-doping on the ferroelectric, electrical and structural properties of BaTiO3. The team prepared Ba1−xDyxTi1−xScxO3 ceramics with 0 ≤ x ≤ 0.075 and investigated the effect on phase transitions and ferroelectric properties. J. Mater. Chem., 2011, DOI:10.1039/C0JM04429F (Advance Article)

Visual optical discrimination and detection of microbial pathogens based on diverse interactions of conjugated polyelectrolytes with cells. A method to rapidly identify fungi and bacteria using a blend of two cationic conjugated polymers has been developed by Qiong Yang, Shu Wang and coworkers at the Institute of Chemistry, Chinese Academy of Sciences, Beijing, China. The team say that their approach could eventually have applications in medical, forensic, and environmental sciences. J. Mater. Chem., 2011, Advance Article DOI:10.1039/C0JM04424E

Collaborative research from Japan and Canada has shed light on the type and mechanism of conductance of individual WO₃ nanowire FETs.

Individual WO₃ nanowire photodetectors were shown to hold great potential as UV-A light sensors. By fabricating these sensors on carbon paper, significantly enhanced stability and shortened response and decay times were obtained. The WO₃ nanowires were also subjected to field-emission measurements and the results showed that these nanostructures are promising candidates for incorporation into novel electronic and optoelectronic devices.

Interested to know more? Why not read the full article for free: L. Li, Y. Zhang, X. Fang, T. Zhai, M. Liao, X. Sun, Y. Koide, Y. Bando and D. Golberg, J. Mater. Chem., 2011, DOI: 10.1039/c0jm04557h (Advance Article)

A new method to rationally design and fabricate silica ridge optical waveguides in a simple, cost-effective manner has been developed by researchers from the Republic of Korea and USA.

This new method is based on the controlled evaporative self-assembly of a polymer solution constrained in a cylinder-on-flat geometry with subsequent wet and dry etching of the sacrificial Ni–Cr film, polymer template and silica layer. Waveguides made in such a way may find potential applications as optical sensors.

Interested to know more? Why not read the full article for free:  S. W. Kwon, M. Byun, D. H. Yoon, J.-H. Park, W.-K. Kim, Z. Lin and W. S. Yang, J. Mater. Chem., 2011, DOI: 10.1039/C0JM04514D (Advance Article)

In this hot article Shuyan Gao, Kai Jiang and co-workers create flower-like Ag/CuO micro/nanostructures with superhydrophilicity and sunlight self-cleaning properties. The “flowers” were synthesized through a facile biomimetic hydrothermal method. The team claim that this research could pave the way for designing useful nanoscale building blocks for photocatalytic applications, especially as self-cleaning photovoltaic coatings.

Read the article for free until 14th April.

Biomolecule-assisted in situ route toward 3D superhydrophilic Ag/CuO micro/nanostructures with excellent artificial sunlight self-cleaning performance. Shuyan Gao, Zhengdao Li, Kai Jiang, Haibo Zeng, Liang Li, Xiaosheng Fang, Xiaoxia Jia and Yanli Chen, J. Mater. Chem., 2011, DOI:10.1039/C0JM04533K (Advance Article)

Researchers from Ben-Gurion University of the Negev and University of Maryland Baltimore County have shown that mixed metal substrates made from aluminium and silver nanodeposits can enhance luminescence.

This enables enhanced luminescence from UV protein residues, solvents and traditional visible fluorophores. The wavelength enhancement range is much broader than silver alone and other metal enhanced fluorescence (MEF) substrates reported thus far. These results indicate that mixed metal surfaces are a better choice for MEF applications than the customary single metal surfaces. Films made in such a way could prove to be very useful for various biomedical assays that utilise fluorescence.

Interested to know more? Why not read the full article for free: K. Golberg, A. Elbaz, Y. Zhang, A. I. Dragan, R. Marks and C. D. Geddes, J. Mater. Chem., 2011, DOI: 10.1039/C0JM04311G (Advance Article)

Researchers from University of Virginia have investigated the effects of aromatic substituents in boron diketones.

All of the dyes studied except BF₂mbm (i.e. those with aromatic rather than aliphatic substitution) showed emission changes upon mechanical perturbation. Aromatics with increased π conjugation led to more dramatic, red-shifted fluorescence. Their recovery is also significantly affected by the aromatic substituents.

Interested to know more? Why not read the full article for free:  T. Liu, A. D. Chien, J. Lu, G. Zhang and C. L. Fraser, J. Mater. Chem., 2011, DOI: 10.1039/c0jm04326e (Advance Article)

Researchers at Nanyang Technological University have synthesised organic single crystals with thicknesses ranging from a few monolayers to micrometres by an “Organic Crystal Cleavage” method.

Ultrathin F₁₆CuPc and pentacene single crystal field-effect transistors were subsequently fabricated and the corresponding thickness dependence of mobility was investigated. The charges induced in the metal–semiconductor interface reduced the contact barrier. This, in turn, allowed measurement of the values of mobility that precisely reflected the real transport properties of organic semiconductors.

Interested to know more? Why not read the full article for free: H. Jiang, K. Jie Tan, K. K. Zhang, X. Chen and C. Kloc, J. Mater. Chem., 2011, DOI: 10.1039/c0jm04383d (Advance Article)