Author Archive

Rare-earth fluoride upconversion nanoparticles and their applications in bioimaging

Posted on behalf of Josh Campbell, web writer for CrystEngComm

Rare earth metals and their compounds are some of the most important elements in modern economies and science. They can be found in superconductors, catalytic converters and lasers. Most rare earth ions also show the phenomenon of upconversion (UC). UC is the emission of light at shorter wavelengths than initially absorbed at for example the conversion of infrared to visible light. UC effects show great promise in the bioimaging field, providing narrow emission bandwidths and high-signal to noise ratio due to being able to use near infra-red sources of excitation. Rare earth halides are known to increase UC luminescence but chlorides and bromides are usually sensitive to moisture and not suitable for labelling biomolecules.

A new highlight shows the most popular way of synthesizing rare earth fluorides and their applications as luminescent labels. Thermal decomposition is the most common synthesis method and gives nanocrystals with well-defined shapes and good size selectivity. However there are drawbacks (such as the strict experimental conditions) which have led to the development of coprecipitation and microwave assisted methods among others. These nanoparticles with UC properties have also recently shown promise being used as multimodal imagers. Multimodal imaging uses more than one technique and work is being done to integrate magnetic components into UC nanocrystals to combine MRI and luminescent imaging.

Rare earth fluorides upconversion nanophosphors: from synthesis to applications in bioimaging

Find out more from the article:

Rare earth fluorides upconversion nanophosphors: from synthesis to applications in bioimaging
Song Wang, Jing Feng, Shuyan Song and Hongjie Zhang
CrystEngComm, 2013, Advance Article
DOI: 10.1039/C3CE40679B, Highlight


Josh CampbellJosh Campbell is a PhD student currently at the University of Southampton studying crystal structure prediction of organic semiconductors. He received his BSc from the University of Bradford.

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In-situ generation of supported MOF films and patterns

Posted on behalf of Gwenda Kyd, web writer for CrystEngComm

Metal-organic frameworks (MOFs) are porous networks with a wide range of potential applications including gas storage and sensing. For their potential to be fully realised in integrated systems, efficient methods of producing thin films and patterns are crucial. Although methods exist for MOFs, these are are less developed than for other materials such as ZnO.

A new paper shows how thin films or patterns of the MOF ZIF-8 can be produced by melting the required ligand, 2-methylimidazole , in contact with a ZnO film or pattern. If the process is carried out under vacuum with an excess of ligand, it is totally solvent- and waste-free. Using this method with ZnO supported films and patterns is demonstrated to replicate the morphologies in the resulting ZIF-8, as shown in the diagram below. ZIF-8 is highly stable and has many possible uses including molecular separation and as an insulator in microelectronics. The reported strategy could allow new applications for ZIF-8 films to be developed.

Solvent-free synthesis of supported ZIF-8 films and patterns through transformation of deposited zinc oxide precursors

For more information see the paper at:

Solvent-free synthesis of supported ZIF-8 films and patterns through transformation of deposited zinc oxide precursors
Ivo Stassen, Nicolò Campagnol, Jan Fransaer, Philippe Vereecken, Dirk De Vos and Rob Ameloot
CrystEngComm, 2013, Advance Article
DOI: 10.1039/C3CE41025K, Communication


Gwenda KydGwenda KydGwenda Kyd has a PhD in metallocarborane chemistry from the University of Edinburgh. Other research work includes the spectroscopic study of the structure of glasses and organometallic electron-transfer reactions and the preparation of new inorganic phosphors. Currently she works as a scientific database editor.

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Human enamel mimic whitens teeth

Over time, gleaming teeth become stained by repeated exposure to vices such as coffee, red wine or cigarettes. Current whitening methods include replacing the crown of the tooth or etching off stained enamel using chemical abrasives like hydrogen peroxide. These require the removal of part of a healthy tooth, and can lead to gum irritation and sensitive teeth.

Fluorapatite, polyethylene oxide and a polymer derived from the neurotoxin acrylamide have been combined by Chinese scientists to make a film that can restore teeth to their natural colour.

Read the full story at Chemistry World

PEO-assisted precipitation of human enamel-like fluorapatite films for tooth whitening

PEO-assisted precipitation of human enamel-like fluorapatite films for tooth whitening
Shize Liu, Yujing Yin and Haifeng Chen

CrystEngComm, 2013,15, 5853-5859
DOI: 10.1039/C3CE40388B, Paper

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HOT articles for August

Investigating and understanding the initial growth mechanisms of catalyst-free growth of 1D SiC nanostructures
Yoo Youl Choi and Doo Jin Choi

CrystEngComm, 2013,15, 6963-6970
DOI: 10.1039/C3CE40745D, Paper

Investigating and understanding the initial growth mechanisms of catalyst-free growth of 1D SiC nanostructures


Can self-assembly of copper(II) picolinamide building blocks be controlled?
Marijana Đaković, Diogo Vila-Viçosa, Nuno A. G. Bandeira, Maria José Calhorda, Bojan Kozlevčar, Zvonko Jagličić and Zora Popović

CrystEngComm, 2013, Advance Article
DOI: 10.1039/C3CE41011K, Paper

Can self-assembly of copper(II) picolinamide building blocks be controlled?


A graph theory approach to structure solution of network materials from two-dimensional solid-state NMR data
Darren H. Brouwer and Kevin P. Langendoen

CrystEngComm, 2013, Advance Article
DOI: 10.1039/C3CE41058G, Paper

A graph theory approach to structure solution of network materials from two-dimensional solid-state NMR data


The synthesis of Cu2Zn(GexSn1−x)Se4 nanocrystals with tunable band gaps
Kai Zong, SiHeng Lu, Hao Wang, YuXiu Sun, HuiJuan Zheng, JingBing Liu and Hui Yan

CrystEngComm, 2013, Advance Article
DOI: 10.1039/C3CE40953H, Paper

Synthesis of Cu2Zn(GexSn1-x)Se4 Nanocrystals with Tunable Band Gaps


The influence of nitro groups on the topology and gas sorption property of extended Zn(II)-paddlewheel MOFs
Phuong V. Dau and Seth M. Cohen

CrystEngComm, 2013, Advance Article
DOI: 10.1039/C3CE41124A, Communication

The Influence of Nitro Groups on the Topology and Gas Sorption Property of Extended Zn(II)-paddlewheel MOFs


Synthesis of Ni-doped NiO/RGONS nanocomposites with enhanced rate capabilities as anode materials for Li ion batteries
Jiantao Zai, Chao Yu, Liqi Tao, Miao Xu, Yinglin Xiao, Bo Li, Qianyan Han, Kaixue Wang and Xuefeng Qian

CrystEngComm, 2013,15, 6663-6671
DOI: 10.1039/C3CE40993G, Paper

Synthesis of Ni-doped NiO/RGONS nanocomposites with enhanced rate capabilities as anode materials for Li ion batteries


A new calculation strategy to analyze the vibrational free energy of a slab and calculate the vibrational contribution of the surface free energy
Marco Bruno and Mauro Prencipe

CrystEngComm, 2013,15, 6736-6744
DOI: 10.1039/C3CE40885J, Paper

A new calculation strategy to analyze the vibrational free energy of a slab and calculate the vibrational contribution of the surface free energy


Dinuclear Ag(I) metallamacrocycles of bis-N-heterocyclic carbenes bridged by calixarene fragments: synthesis, structure and chemosensing behavior
Cai-Xia Lin, Xiao-Fei Kong, Qing-Shan Li, Zheng-Zhi Zhang, Yao-Feng Yuan and Feng-Bo Xu

CrystEngComm, 2013, Advance Article
DOI: 10.1039/C3CE40918J, Paper

Dinuclear Ag(I) metallamacrocycles of bis-N-heterocyclic carbenes bridged by calixarene fragments: synthesis, structure and chemosensing behavior


Luminescence and magnetic properties of three metal–organic frameworks based on the 5-(1H-tetrazol-5-yl)isophthalic acid ligand
Antonio J. Calahorro, Alfonso Salinas-Castillo, José Manuel Seco, Javier Zuñiga, Enrique Colacio and Antonio Rodríguez-Diéguez

CrystEngComm, 2013, Advance Article
DOI: 10.1039/C3CE40869H, Communication

Luminescence and magnetic properties of three metal–organic frameworks based on the 5-(1H-tetrazol-5-yl)isophthalic acid ligand

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Removing impurities from biofuels using metal-oxide cubes and flowers

Posted on behalf of Gwenda Kyd, web writer for CrystEngComm

Biofuels, such as plant oils, are a potential alternative energy source. However, the presence of impurities like gums and phospholipids can hamper their use in diesel engines. Phospholipids (which are made up of a fatty acid, a simple organic group and a phosphate group) can be removed in the conventional refining process, but this causes loss of oil and nutrients and uses both water and chemicals.

A new paper shows how phospholipids can be efficiently removed using Y2O3 cubes and flowers, made hydrothermally, as shown in the figure below. Y2O3 is a Lewis acid and the positively charged metal atom attracts the negatively charged phospholipid, absorbing it onto the metal-oxide surface. Y2O3 flowers have a larger specific surface area than cubes, so absorb phopholipds more efficiently (approximately 90% rather than 80% of 870 ppm phospholipid in soyabean oil). This demonstrates that both flowers and cubes could have potential use in the separation of phospholipids from plant oils.

Hydrothermal Synthesis of Lewis Acid Y2O3 Cubes and Flowers for the Removal of Phospholipids from Soybean Oil

For more information see the paper at:

Hydrothermal synthesis of Lewis acid Y2O3 cubes and flowers for the removal of phospholipids from soybean oil
Yi-Feng Lin, Jhen-Huei Chen, Shih-Hong Hsu and Tsair-Wang Chung
CrystEngComm, 2013, Advance Article
DOI: 10.1039/C3CE40791H, Paper


Gwenda KydGwenda Kyd has a PhD in metallocarborane chemistry from the University of Edinburgh. Other research work includes the spectroscopic study of the structure of glasses and organometallic electron-transfer reactions and the preparation of new inorganic phosphors. Currently she works as a scientific database editor.

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Metallic Zinc nanoparticles via a chemical synthetic route

Posted on behalf of Josh Campbell, web writer for CrystEngComm 

Metal nanoparticles (NPs) are structures within the µm-nm range that exhibit amazing properties and morphologies. Photochemical and superparamagnetic effects have been reported while everything from nanostars to nanoreefs have been created. NPs are often thought to be a product of modern science but their use dates back hundreds of years, used in pottery finishes and for staining glass. Michael Faraday first described the effect of gold colloids on glass in 1857. NPs are usually prepared by physical or chemical methods, and each has its own advantages and problems. Physical methods such as vapour deposition and laser ablation do not offer complete control over the size of the NPs unless at extreme conditions. These typically require a solid substrate, limiting their use in producing liquid suspensions. Chemical methods involve the reduction of the metal ions dissolved in appropriate solvents and for noble metals have produced NPs down to micron level. However, this method does not work well for metals prone to oxidation.

This new paper describes the chemical synthesis of zinc nanoparticles which show exciting photoluminescence properties and a resistance to oxidation. ZnCl was dissolved in a phenylether and complexed with oleylamine before being reduced to Zn2+, after which it nucleates into the final structure. Hexagonal Zn particles form which have a diameter of 250-350nm and showed no oxide phases. The Zn particles also were found to emit light in the UV to blue range. The authors suggest that this is due to the 3d-Fermi gap being lowered compared to bulk zinc, and the sp band itself being discretized.

Chemical Synthesis of Blue-emitting Metallic Zinc Nano-hexagons

Find out more:

Chemical synthesis of blue-emitting metallic zinc nano-hexagons
Nguyen T. Mai, Trinh T. Thuy, Derrick M. Mott and Shinya Maenosono
CrystEngComm, 2013, Advance Article
DOI: 10.1039/C3CE40801A, Paper


Josh Campbell Josh Campbell is a PhD student currently at the University of Southampton studying crystal structure prediction of organic semiconductors. He received his BSc from the University of Bradford.

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Hot articles for July

The formation and transition behaviors of the mesophase in poly(D-lactide)/poly(L-lactide) blends with low molecular weights
Jun Shao, Jingru Sun, Xinchao Bian, Yunchun Zhou, Gao Li and Xuesi Chen

CrystEngComm, 2013, Advance Article
DOI: 10.1039/C3CE40748A, Paper

The formation and transition behaviors of the mesophase in poly(D-lactide)/poly(L-lactide) blends with low molecular weights


Cu2O–CuO composite microframes with well-designed micro/nano structures fabricated via controllable etching of Cu2O microcubes for CO gas sensors
Li Zhang, Zhimin Cui, Qiong Wu, Dan Guo, Yue Xu and Lin Guo
 

CrystEngComm, 2013, Advance Article
DOI: 10.1039/C3CE40595H, Paper

Cu2O–CuO composite microframes with well-designed micro/nano structures fabricated via controllable etching of Cu2O microcubes for CO gas sensors


Complexities of mechanochemistry: elucidation of processes occurring in mechanical activators via implementation of a simple organic system
Adam A. L. Michalchuk, Ivan A. Tumanov and Elena V. Boldyreva
 

CrystEngComm, 2013, Advance Article
DOI: 10.1039/C3CE40907D, Paper

Complexities of mechanochemistry: elucidation of processes occurring in mechanical activators via implementation of a simple organic system


Synthesis of nano-cubic ZnSn(OH)3 based on stannate reaction with liquid laser ablation-induced ZnO below room temperature
Xiaoxia Xu, Guotao Duan, Yue Li, Hongwen Zhang, Guangqiang Liu and Weiping Cai

CrystEngComm, 2013, Advance Article
DOI: 10.1039/C3CE40363G, Paper

Synthesis of nano-cubic ZnSn(OH)3 based on stannate reaction with liquid laser ablation-induced ZnO below room temperature


Dihalogen-templated synthesis of dodecanuclear silver dichalcogenophosphate clusters
Bing Li, Jian-Hong Liao, Yi-Juan Li and C. W. Liu

CrystEngComm, 2013, Advance Article
DOI: 10.1039/C3CE40829A, Communication

Dihalogen-templated synthesis of dodecanuclear silver dichalcogenophosphate clusters

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Colour tunable pigments by mechanochemical co-crystallisation

Posted on behalf of Gwenda Kyd, web writer for CrystEngComm

Pigments are solid colourants used in the production of materials such as paints, inks and plastics. For a given pigment, the colour is affected by particle size and morphology, among other things. Formation of a multi-componet system (co-crystal) may also affect the colour and, additionally, may alter properties like heat stability. However, pigments tend to be insoluble in common solvents, rendering production of co-crystals by conventional, solution-based, methods difficult.

A new paper shows how mechanochemical co-crystallisation (ie grinding the components in a small quantity of solvent) can produce co-crystals of the pigment fluorescein (see diagram below) quickly and in quantitative yields. Co-crystals with three different co-formers were produced each with a different colour. Attempts to produce co-crystals using solvent-based methods were also successful, but produced different co-crystals and less efficiently. Authors discuss the broad implications of the results for the pigment and dye industries, suggesting mechanochemical co-crystallisation as an efficient route to colour- and property-tunable pigments.

Advantages of mechanochemical cocrystallisation in the solid-state chemistry of pigments: colour-tuned fluorescein cocrystals

More information can be found in the full paper at:

Advantages of mechanochemical cocrystallisation in the solid-state chemistry of pigments: colour-tuned fluorescein cocrystals
Dejan-Krešimir Bučar, Stefan Filip, Mihails Arhangelskis, Gareth O. Lloyd and William Jones
CrystEngComm, 2013, Advance Article
DOI: 10.1039/C3CE41013G, Communication


Gwenda KydGwenda Kyd has a PhD in metallocarborane chemistry from the University of Edinburgh. Other research work includes the spectroscopic study of the structure of glasses and organometallic electron-transfer reactions and the preparation of new inorganic phosphors. Currently she works as a scientific database editor.

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7th International Conference on Materials for Advanced Technologies

CEC poster prize at 7th ICMAT

CrystEngComm poster prize presented by Professor Desiraju, which Pramod's supervisor collected on his behalf

The conference “7th International Conference on Materials for Advanced Technologies” was held in Singapore from 30 June- 5 July 2013. CrystEngComm sponsored a poster prize in Symposium X–Crystal Engineering of New Materials. The winner was Pramod Kumar Goswami from IIT-Delhi, with his poster titled “Salts, Salt Co-crystal Hydrate, Co-crystals and Co-crystal Polymorphs of P-aminosalicylic Acid”. Congratulations to Pramod!

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Peptide Microsphere Fabrication for Drug Delivery

Posted on behalf of Gwenda Kyd, web writer for CrystEngComm

Many important drug molecules are hydrophobic so methods to successfully introduce these into the body and make them bioavailable must be developed. Peptide-based molecules are an attractive delivery vehicle due to their biocompatibility, recognition properties, biodegradability and hydrophobic-hydrophilic balance.

A new paper shows how three gamma-peptides, with different degrees of flexibility, can self-assemble to form porous microspheres (see diagram below). The anticonvulsant drug carbamazepine has been encapsulated in these microspheres, which range in diameter from 300nm-1µm. The microspheres have limited water solubility, so there is a sustained release of the drug by dissolution of the microsphere. The authors suggest tailoring of the capsule properties could lead to controlled drug delivery and release.

Fabrication of microspheres from self-assembled γ-peptides

Find out more in the paper:

Fabrication of microspheres from self-assembled γ-peptides
Suman Kumar Maity, Santu Bera, Arpita Paikar, Apurba Pramanik and Debasish Haldar

CrystEngComm, 2013, Advance Article
DOI: 10.1039/C3CE40689J, Paper


Gwenda Kyd

Gwenda Kyd has a PhD in metallocarborane chemistry from the University of Edinburgh. Other research work includes the spectroscopic study of the structure of glasses and organometallic electron-transfer reactions and the preparation of new inorganic phosphors. Currently she works as a scientific database editor.
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