Journal of Materials Chemistry Blog

Vapor-based synthesis of ultrathin hydrogel coatings for thermo-responsive nanovalves: Thermo-responsive nanovalves were fabricated by depositing ultrathin hydrogel coatings inside nanoporous track-etched polycarbonate membranes. The hydrogel coatings swell in response to changes in temperature, controlling the flow through a channel and creating a nanovalve. (J. Mater. Chem., 2011, DOI: 10.1039/C1JM10713E, Advance Article)

Efficient quantum cutting in hexagonal NaGdF4:Eu3+ nanorods: single phase, oxygen free, hexagonal NaGdF4:Eu3+ (2 mol%) nanorods with a visible quantum efficiency of 187% were prepared using an ionic liquid assisted solvothermal method. The team behind this research was led by Anja-Verena Mudring from Ruhr-Universität Bochum, Germany. (J. Mater. Chem., 2011, DOI:10.1039/C1JM10728C Advance Article)

Synthesis of magnetic hollow nanotubes based on the kirkendall effect for MR contrast agent and colorimetric hydrogen peroxide sensor: A simple solvothermal approach to synthesize hollow Mn ferrite nanostructures was developed by scientists in Taiwan. The team say that these high magnetic Mn ferrite nanotubes significantly enhance the magnetic resonance imaging contrast signal. (J. Mater. Chem., 2011, DOI:10.1039/C1JM10429B, Advance Article)

Read all the articles for free until 14^th June

Engineering structured MOF at nano and macroscales for catalysis and separation: In this Hot Article, Sonia Aguado, Jerome Canivet and David Farrusseng from the Université Lyon 1, France, present for the first time the combination of the postfunctionalization of a MOF with its shaping as structured bodies. The team demonstrate that it is possible to achieve multiscale engineering of a MOF for catalytic and separation applications, which they claim could help create MOFs for use in industry. (J. Mater. Chem., 2011, DOI:10.1039/C1JM10787A, Advance Article)

Nanoheterostructures on TiO2 nanobelts achieved by acid hydrothermal method with enhanced photocatalytic and gas sensitive performance: Double heterostructure TiO2 nanobelts exhibit a much higher photocatalytic activity than normal TiO2 nanobelts and single heterostructure TiO2 nanobelts say scientists at Shandong University, China and Bowling Green State University, US. Optimising the nanobelt surface nanoheterostructure provides a broad approach to modify the physical properties and should have wide applications in photocatalysts, solar cells, chemical/bio sensors, and other techniques they claim. (J. Mater. Chem., 2011, DOI:10.1039/C1JM10588D, Advance Article)

Pt nanocrystal evolution in the presence of Au(III)-salts at room temperature: spontaneous formation of AuPt heterodimers: A straightforward synthesis of AuPt heterodimers performed at room temperature using oleylamine as the reducer and Pt seeds has been developed by Spanish scientists. The presence of Pt nanocrystals markedly accelerates the nucleation rate of Au, which suggest it acts as both nucleation platforms and initial catalytic reducers. (J. Mater. Chem., 2011, DOI:10.1039/C1JM10313J, Advance Article)

Read the articles for free until 10^th June

Fabrication and characterization of well-aligned, high density ZnO nanowire arrays and their realizations in Schottky device applications using a two-step approach: A two-step approach for preparing a large area array of high density and horizontally well-aligned of zinc oxide nanowires, has been developed by German and Chinese scientists. The team claim that these arrays are suitable for preparing Schottky diodes on inexpensive and flexible polymer substrates. (J. Mater. Chem., 2011, 21, 7090-7097)

TAT-conjugated nanodiamond for the enhanced delivery of doxorubicin: The anticancer drug doxorubicin and cell penetrating peptide TAT were conjugated to the surface of nanodiamonds. The conjugate is designed to avoid premature release and enhance the intracellular delivery of the drug. The team says that conjugation of TAT to nanodiamond–doxorubicin increases the cytotoxicity of doxorubicin compared to the free drug. (J. Mater. Chem., 2011, DOI: 10.1039/C1JM10653H, Advance Article)

Flower-like hydroxyapatite modified carbon paste electrodes applicable for highly sensitive detection of heavy metal ions: A team of scientists based in China and the UK have created a highly sensitive sensor for the detection of Pb2+ and Cd2+ ions. The sensor uses flower-like hydroxyapatite crystals fabricated on egg-shell membranes as modifiers for a chemically modified carbon paste electrode. (J. Mater. Chem., 2011, DOI: 10.1039/C1JM10949A, Advance Article)

Read all the articles for free until 7^th June

Synthesis of magnetic hollow periodic mesoporous organosilica with enhanced cellulose tissue penetration behaviour: A team of scientists based in Australia have created nanoparticles designed to penetrate plant cell walls. The hybrid particles show excellent cellulose tissue penetrating performance, with relatively high magnetic response and high enzyme loading capacity. The team claim that the enhanced penetration of cellulose tissue could potentially be used for targeted delivery into plant cells. (J. Mater. Chem., 2011, DOI:10.1039/C1JM10615E, Advance Article)

The structural evolution and diffusion during the chemical transformation from cobalt to cobalt phosphide nanoparticles: Knowledge about the structural rearrangements occurring during the chemical transformation of nanoparticles could help tailor the synthesis and composition of the nanoparticles to improve their properties. In this Hot Article a team at Cornell University, USA, report the atomic and morphological structure of Cobalt nanoparticles as they are transformed into cobalt phosphide using X-ray absorption spectroscopy, XRD, TEM, and DFT calculations. (J. Mater. Chem., 2011, DOI:10.1039/C1JM10337G Advance Article)

Polymer-stabilized optically isotropic liquid crystals for next-generation display and photonics applications: In this Hot Feature Article Shin-Tson Wu and the team explain why polymer-stabilized optically isotropic liquid crystals, including blue phases, are emerging as a strong contender for next-generation display technology. (J. Mater. Chem., 2011, DOI:10.1039/C1JM10711A, Advance Article)

Interested to know more? Read all the articles for free until the 3^rd June.

High-temperature redox chemistry of La1.5+xSr0.5−xCo0.5Ni0.5O4+δ (x = 0.0, 0.2) studied in situ by neutron diffraction. A team from France and the UK has found first structural evidence of the coexistence of both anion vacancies and interstitial anions in a type of materials that could be used for solid oxide fuels. The team used neutron powder diffraction to study the redox behaviour of two n = 1 Ruddlesden–Popper oxides in real time as the sample was heated and exposed to H2. (J. Mater. Chem., 2011, DOI: 10.1039/C1JM10445D, Advance Article)

What can we learn about battery materials from their magnetic properties? In this Hot Article M. Stanley Whittingham and co-workers discuss how the connection between the magnetic properties and the electronic and atomic structure in Li-ion battery materials can been used to reveal details about the electrochemical performance of the battery materials. (J. Mater. Chem., 2011, DOI: 10.1039/C1JM00024A, Advance Article)

Switchable photoconductivity of quantum dot films using cross-linking ligands with light-sensitive structures. Using a light sensitive ligand to cross-link films of CdSe quantum dots can be used to create electrical junctions with photoswitchable conductivity say a team of US scientists. The team from Northwestern University led by Emily Weiss achieved an enhancement in the current density by an average factor of 6.5 times upon switching from visible excitation to UV excitation, which induces the ligand to switch from an open, non-conductive form to a closed, conductive form. (J. Mater. Chem., 2011, Advance Article DOI:10.1039/C0JM04397D)

Interested to know more? Read the full articles for free until 26th May

Materials for central nervous system regeneration: bioactive cues. In this review Christiane Gumera, Britta Rauck and Yadong Wang report on how materials-based approaches offer a way to combine synthetic and biological components to help neural regeneration. The authors outline various biomaterials that are promising for central nerve applications and they discuss the array of bioactive cues that are valuable in promoting nerve repair. (J. Mater. Chem., 2011, DOI: 10.1039/C0JM04335D, Advance Article)

Organic–inorganic hybrid polysilsesquioxane nanospheres as UVA/UVB absorber and fragrance carrier. A material designed to protect you from the sun could also contain a scent say a team of scientists based in Thailand. The material is based on hybrid organic–silica particles with UVA/UVB absorptive chromophores. In addition to encapsulating fragrant molecules, these materials avoid the photocatalysis property of inorganic UV absorbers, such as TiO₂ and ZnO nanoparticles, retain the minimal transdermal penetration and non-sticky nature of particulate silica particles, whilst at the same time harnessing the UV absorption characteristics of organic chromophores. (J. Mater. Chem., 2011, DOI: 10.1039/C0JM04271D, Advance Article)

Graphene oxide coated core–shell structured polystyrene microspheres and their electrorheological characteristics under applied electric field. In this Hot Article a team of Korean scientists fabricate and study core–shell structured polystyrene–graphene oxide microspheres. These particles were synthesized by adsorbing graphene oxide sheets onto a polystyrene surface through a strong π–π stacking interaction. Monodispersed polystyrene microspheres were prepared as the core material using a dispersion polymerization, while the shell part of grapheme oxide was synthesized by a modified Hummers method. (J. Mater. Chem., 2011, DOI: 10.1039/C1JM10323G, Advance Article)

Read these articles for free until 18^th May

A perfluorinated anion exchange membrane with a 1,4-dimethylpiperazinium cation demonstrated enhanced hydroxide ion conductivity.

The membrane also exhibited a better water uptake than a typical hydrocarbon anion exchange membrane with the same cation. When tested, the membrane showed a remarkable stability of over 30 days in 2 M KOH at 60 °C and good fuel cell performance. Work is ongoing to investigate the attachment of more basic cations to further enhance the hydroxide ion conductivity, fuel cell performance and long term stability.

Interested to know more? Why not read the full article for free: M.-s. J. Jung, C. G. Arges and V. Ramani, J. Mater. Chem., 2011, DOI: 10.1039/c1jm10320b

Researchers from Bar-Ilan University have developed novel hybrid silica nanoparticles (NPs) with highly photoreactive sites on their surface by incorporation of phenyl azide (PA) or benzophenone (BPh) functionality.

It is found that, in contrast to what is stated in the literature, SiO₂@PA NPs are much more reactive than SiO₂@PFPA ones in solid state photochemical reactions. Additionally, this is the first report of covalent immobilization of NPs into biocompatible parylene C films to form hydrophilic and functional composite films. Amine functionality has also been introduced onto the silica NPs by reaction with APTES. This approach could open up new possibilities for simple and solvent-free functionalization of materials by light.

Interested to know more? Why not read the full article for free: A. Peled, M. Naddaka and J.-P. Lellouche, J. Mater. Chem., 2011, DOI: 10.1039/c1jm00055a

ZnO single butterfly wing scales: synthesis and spatial optical anisotropy. The team from Shanghai Jiao Tong University created ZnO replicas of butterfly wing scales by using the natural scales as templates. The team says this work should help researchers to understand the mechanism behind the optical properties of functional butterfly wing scale replicas. (J. Mater. Chem., 2011, DOI:10.1039/C1JM10678C, Advance Article)

Synthesis and modelling of gold nanostars with tunable morphology and extinction spectrum. Italian scientists have created stable gold nanostars with tunable extinction properties from the visible up to 1800 nm. These nanostars could lead to the improvement of IR diagnostics or chemical sensing the team say. (J. Mater. Chem., 2011, DOI:10.1039/C0JM04519E, Advance Article) 

Electrospinning fabrication, structural and mechanical characterization of rod-like virus-based composite nanofibers. A biodegradable fibrous mat that mimics the extracellular matrix has been created by a team from China and the US. The mat is formed by electrospinning tobacco mosaic virus with polyvinyl alcohol into continuous TMV–PVA composite nanofibers. (J. Mater. Chem., 2011, DOI:10.1039/C1JM00078K, Advance Article)

Read the full articles for free until the 9th May

Highly ordered π-extended discotic liquid-crystalline triindoles. In this Hot Paper a team of Spanish chemists create discotic liquid crystals based on a heptacyclic triindole arrangement. The team claim that attaching groups to the indole rings offers a great opportunity to tune the properties of these liquid crystals making them suitable for incorporation into devices. (J. Mater. Chem., 2011, DOI: 10.1039/C0JM04395H Advance Article)

Solid-state photochemical and photomechanical properties of molecular crystal nanorods composed of anthracene ester derivatives. A series of photoresponsive molecular crystal nanorods have been created by a team from USA, Saudi Arabia, and Lebanon. The photomechanical response of the nanorods is determined by a metastable crystalline intermediate that slowly converts into the low energy solution grown dimer crystal structure over a course of weeks. The team says that the photomechanical response of these structures arises from nonequilibrium crystal forms and cannot be predicted from the equilibrium reactant and product crystals. (J. Mater. Chem., 2011, DOI:10.1039/C1JM10228A Advance Article)

FRET-based probe for fluoride based on a phosphorescent iridium(III) complex containing triarylboron groups. A FRET-based F− probe based on carbazole-fluorene-carbazole as the fluorescent donor and a dimesitylboryl group-functionalized cationic Ir(III) complex as the phosphorescent acceptor has been designed by Chinese scientists. The introduction of dimesitylboryl groups to the Ir(III) complex unit leads to red-shifted and more intense absorption and phosphorescence emission. In addition, the FRET efficiency from the fluorescent donor to the phosphorescent acceptor is enhanced significantly. (J. Mater. Chem., 2011, DOI:10.1039/C1JM00071C Advance Article)

Read all of these Hot Articles for free until 5th May