Journal of Materials Chemistry Blog

Enhancing photocatalytic activity of titania materials by using porous structures and the addition of gold nanoparticles
Xingdong Wang and Rachel A. Caruso
J. Mater. Chem., 2011, Advance Article
DOI: 10.1039/C0JM02620D, Highlight

 The strategy to enhance the photocatalytic activity of TiO₂ materials by introducing both porous structure to improve the mass transportation and gold nanoparticles to enhance the charge separation is reviewed in this highlight article from Xingdon Wang and Rachel Caruso from Australia.

Interested in knowing more?  Read the full article for free until the 3^rd December!

Growth and reductive transformation of a gold shell around pyramidal cadmium selenide nanocrystals
Michaela Meyns, Neus G. Bastus, Yuxue Cai, Andreas Kornowski, Beatriz H. Juárez, Horst Weller and Christian Klinke
J. Mater. Chem., 2010, Advance Article
DOI: 10.1039/C0JM03004J, Communication

Cadmium selenide nanocrystals were coated with a gold shell which could be transformed to small clusters by additional reducing agents reports Christian Klinke and co-workers from Germany and Spain in this Communication.  By varying the conditions of gold deposition they were able to tune the gold domain size and gain important information on the role of surface chemistry in heteronanoparticle synthesis and seed reactivity, both of which are crucial points regarding the chemical design of new materials for photocatalysis and optoelectronic applications.

Interested in knowing more?  Read the full article for free until the 3^rd December!

Size-dependent light-scattering effects of nanoporous TiO2 spheres in dye-sensitized solar cells
In Gyoung Yu, Yong Joo Kim, Hark Jin Kim, Chongmu Lee and Wan In Lee
J. Mater. Chem., 2010, Advance Article
DOI: 10.1039/C0JM02606A, Paper

In this paper a team from Inha University in South Korea report the successful application of submicron-sized monodispersed TiO₂ spheres (SPs) with high porosity as the light scattering layer of dye-sensitized solar cells.  This resulted in an increase of the photovoltaic conversion efficiency from 6.92 to 9.04% when using the SP which gave the highest light scattering efficiency.

Interested in knowing more?  Read the full article for free ntil the 3^rd December!

Carbon nanotubes from short hydrocarbon templates. Energy analysis of the Diels–Alder cycloaddition/rearomatization growth strategy
Eric H. Fort and Lawrence T. Scott
J. Mater. Chem., 2011, Advance Article
DOI: 10.1039/C0JM02517H, Paper

In this paper by Eric Fort and Lawrence Scott, aromatic hydrocarbon belts and hemispherical end-caps of varying length and diameter are evaluated computationally as possible templates from which carbon nanotubes might be grown by the Diels-Alder cycloaddition/rearomatization strategy.  The team from Boston College in the USA found that the Diels–Alder reactivity of nanotube template rims was relatively unaffected by the presence or absence of a cap on the other end.

Interested in knowing more? Read for free until November 30^th!

Ultra-narrow WS₂ nanoribbons encapsulated in carbon nanotubes
Zhiyong Wang, Keke Zhao, Hong Li, Zheng Liu, Zujin Shi, Jing Lu, Kazu Suenaga, Soon-Kil Joung, Toshiya Okazaki, Zhaoxia Jin, Zhennan Gu, Zhengxiang Gao and Sumio Iijima
J. Mater. Chem., 2011, Advance Article
DOI: 10.1039/C0JM02821E, Paper

A team from China and Japan report the synthesis via chemical reaction in the interior space of carbon nanotubes of zigzag-edged WS₂ nanoribbons with widths down to 1–3 nm and layer numbers of one to three. Layered WS₂ nanostructures are of both fundamental and technological interest. The widths of currently synthesized WS₂ ribbons are in the microscale but by using single-walled carbon nanotubes and double-walled carbon nanotubes as templates this team demonstrate that ribbons in the nanoscale are possible. 

Interested in knowing more? Read for free until November 30^th!

Fabrication of covalently crosslinked and amine-reactive microcapsules by reactive layer-by-layer assembly of azlactone-containing polymer multilayers on sacrificial microparticle templates
Eric M. Saurer, Ryan M. Flessner, Maren E. Buck and David M. Lynn
J. Mater. Chem., 2010, Advance Article
DOI: 10.1039/C0JM02633F, Paper

David Lynn and colleagues from the University of Wisconsin demonstrate an approach to the fabrication of covalently crosslinked and amine-reactive microcapsules by the ‘reactive’ layer-by-layer fabrication of azlactone-functionalized polymer multilayers on the surfaces of sacrificial microparticle templates.  These microcapsules have potential use in a wide range of fields, including catalysis, drug and gene delivery, imaging, and biomedical research.

Interested in knowing more? Read for free until November 30^th!

This ‘Hot Article’ by Liang Li, Yoshio Bando, Dmitri Golberg and colleagues, reviews recent developments in the synthetic strategies and unique applications of one-dimensional (1D) nanostructure arrays based on polystyrene (PS) spheres.

Polystyrene sphere-assisted one-dimensional nanostructure arrays: synthesis and applications
Liang Li, Tianyou Zhai, Haibo Zeng, Xiaosheng Fang, Yoshio Bando and Dmitri Golberg
J. Mater. Chem., 2011, Advance Article
DOI: 10.1039/C0JM02230F, Feature Article

PS spheres can self-assemble into colloidal crystal monolayers that are currently employed as templates for the synthesis of 1D nanostructure arrays.  Compared to other classes of templates these monolayers can be easily formed and adjusted on substrates and further manipulated using subsequent growth methods.  Reported applications of PS-sphere mediated nanoarrays include field-emitters, antireflection, light-emitting diodes (LEDs), photonic crystals, surface wetting, and photocatalysis.

In this feature article, the team from the National Institute for Materials Science in Japan highlight recent developments in synthetic strategies, review emerging applications and analyse future challenges.

Read the full text here.  Free until November 24th!

A team from Oklahoma report the fabrication of non-leaching antibacterial surfaces using a single-step vapour crosslinking method.

Single-step fabrication of non-leaching antibacterial surfaces using vapor crosslinking
Yumin Ye, Qing Song and Yu Mao
J. Mater. Chem., 2010, Advance Article
DOI: 10.1039/C0JM02578J, Paper

Bactericidal surfaces are highly desirable to prevent bacteria-associated infections in hospital and health care facilities. Current surfaces are based on the release of antibacterial agents, however, leaching of antibiotics can contribute to the escalation of bacteria resistance. An alternative strategy is to create non-leaching antibacterial surfaces. The non-leaching surfaces kill bacteria on contact, which has been reported to reduce the probability of developing bacteria resistance.

Yu Mao and colleagues copolymerised vapours of dimethylaminomethylstyrene (DMAMS) and ethylene glycol diacrylate (EGDA) to produce crosslinked polymer coatings.  The tertiary amine groups in DMAMS units become partially protonated at neutral pH conditions, resulting in crosslinked coatings which have cationic charges distributed across the polymer network and kill bacteria through disruption of the bacteria membrane upon surface contact. Killing efficacy of more than 99.99% against both B. subtilis and E. coli was achieved and leaching tests indicated that the crosslinked coatings did not leach from the surface to kill bacteria and were stable after the durability tests.

Interested in knowing more?  Read the full article here.  Free until November 22nd!

Erin Murphy from the University of California reports the use of birefringence to assess damage and extent of repair in healable polymers based on the thermally reversible Diels–Alder reaction, in this ‘Hot Article’.

The return of photoelastic stress measurements: utilizing birefringence to monitor damage and repair in healable materials
Erin B. Murphy
J. Mater. Chem., 2011, Advance Article
DOI: 10.1039/C0JM02308F, Paper

Examining a transparent polymer under polarized light reveals the stress distribution throughout the sample due to the birefringence in the material arising from anisotropy, clearly indicating areas of high stress; by applying a photoelastic coating to metal and opaque composite structures, it is also possible to identify areas of stress in non-transparent materials and parts.

Herein, Erin Murphy demonstrates the application of birefringence and the principles of photoelastic stress measurements to monitor a healable polymer. By systematically monitoring the birefringence of the material under a controlled applied stress, her group have developed their own calibration curve for the analysis of isochromatic fringes in the polymers.

The birefringent property of these polymers affords the ability to analyze residual stress in a fabricated sample, in order to assess the sites most likely to fracture and to then re-design the specimen geometry and processing parameters to avoid such areas within the material.

Interested in knowing more?  Read the full article here.  Free until November 22nd!

Processable donor–acceptor type electrochromes switching between multicolored and highly transmissive states towards single component RGB-based display devices 
Abidin Balan, Derya Baran and Levent Toppare
J. Mater. Chem., 2010, Advance Article
DOI: 10.1039/C0JM01815E, Paper

Levant Toppare and his team reported last year in ChemComm on the synthesis of a polymer (PTBT) with the capability to switch between all RGB colours, black and transmissive states.  In this Journal of Materials Chemistry ‘Hot Article’ donor acceptor type PTBTs (PTBT-DAs) with alternating alkyl chain substitution were synthesized and characterized in terms of their electrochemical and optical properties.

The electrochemical and spectral results demonstrate that in the context of low cost flexible display device technology, requirements for polymers showing multicoloured and transmissive states can be fulfilled by PTBT-DAs.

Interested in reading more?  Read for free here until November 19th.

Anomalous Eu layer doping in Eu, Si co-doped aluminium nitride based phosphor and its direct observation
Takashi Takeda, Naoto Hirosaki, Rong-Jun Xie, Koji Kimoto and Mitsuhiro Saito
J. Mater. Chem., 2010, Advance Article
DOI: 10.1039/C0JM02096F, Paper

Takeshi Takeda and colleagues in Japan have provided insight into the luminescent properties of Eu, Si co-doped AlN.  This material shows blue luminescence by UV and electron excitation. However, it is not clear how Eu is located in the wurtzite AlN lattice as there is not enough space for a large Eu cation.  In the present study, the team from The National Institute of Materials Science and Tohoku University set out to elucidate the luminescent Eu centre’s location and the role of co-dopant Si.

Their findings show that Si co-doping is essential for Eu incorporation into AlN and that Eu forms a single layer structure with the Si condensation between the AlN wurtzite blocks.  Their work indicates that layer type doping can be used to design new phosphors.

Interested in reading more?  Read for free here until November 19th.