Green Chemistry Blog

Creating biodegradable electronics using shellac

25 Apr 2013

Scientists in Austria, Romania and Turkey have used the natural resin shellac to devise biocompatible organic field-effect transistors (OFETs), which could help make electronic gadgets biodegradable and allow easier use of OFETs in the body.

Multi-coloured row of nail polish bottles, illustrating a current application of shellac

Together with their better known cousins – organic photovoltaics (OPVs) and organic light-emitting diodes (OLEDs) – OFETs are already revolutionising the electronics industry, bringing us flexible displays and light-weight solar-powered chargers. Switching the synthetic substrate material and dielectric layer to the naturally occurring shellac has a number of advantages such as low cost, low toxicity and low environmental impact.

Currently used in the fashion and beauty industry as a hard-wearing nail varnish, shellac has also been used to make gramophone records and as a furniture finish. The material is composed of a mixture of aliphatic and alicyclic hydroxy acids that are easily cross-linked by heating, resulting in a smooth, glassy substrate for the OFET devices to be built upon. It is also easy to process.

Read the full article in Chemistry World

Read the original journal article in Green Chemistry:
Natural resin shellac as a substrate and a dielectric layer for organic field-effect transistors
Mihai Irimia-Vladu, Eric Daniel Głowacki, Günther Schwabegger, Lucia Leonat, Hava Zekiye Akpinar, Helmut Sitter, Siegfried Bauer and Niyazi Serdar Sariciftci
Green Chem., 2013, Advance Article
DOI: 10.1039/C3GC40388B, Communication

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Sieving silica sieves from biomass ash

18 Apr 2013

By Emma Eley, Deputy Editor.

Burning biomass for heat and power could produce as much as 2000 TWh by 2020, which would produce 4–15.6 million tonnes of waste ash, per year, in Europe alone. To address the problem of what to do with all this waste, scientists in the UK have developed a method to convert this ash into mesoporous silica.

Although some of the waste ash produced from the combustion of biomass is currently used in construction, most of it ends up in landfill. Therefore, extracting alkali silicates, which can be used in cement, detergents, catalysts and catalyst supports, is one way of reusing the potentially huge quantities of ash due to be produced in the future.

The team, led by Duncan Maquarrie at the University of York, developed an efficient route for extracting the silicates by forming alkali silicate solutions. The silicate solutions were converted into the porous silica, MCM-41, a useful catalyst and molecular sieve.

Read what Duncan Macquarrie has to say about the research in Chemistry World.

Read the original research published in Green Chemistry:

Alkali silicates and structured mesoporous silicas from biomass power station wastes: the emergence of bio-MCMs, J. R. Dodson, E. C. Cooper, A. J. Hunt, A. Matharu, J. Cole, A. Minihan, J. H. Clark and D. J. Macquarrie, Green Chem., 2013, DOI: 10.1039/C3GC40324F

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Recycling rare earth elements using ionic liquids

05 Apr 2013

By Anna Simpson, Executive Editor.

Recycling old magnets, so that rare-earth metals can be re-used, could help to solve an urgent raw material supply problem in the electronics industry. Researchers from the University of Leuven, Belgium, have used ionic liquids to separate neodymium and samarium from transition metals like iron, manganese and cobalt – all elements that are used in the construction of permanent rare-earth magnets, which are found in electronic devices ranging from hard drives to air conditioners and wind turbines.

‘The process involves the liquid-liquid extraction of rare-earth metals from the other elements present in neodymium-iron-boron and samarium-cobalt magnets,’ explains Koen Binnemans who leads the group developing the process. ‘These other elements – including iron, cobalt, manganese, copper and zinc – are extracted into the ionic-liquid phase, while the rare-earth metals are left behind in the aqueous phase,’ he says, adding that the ionic liquid itself – trihexyl(tetradecyl)phosphonium chloride – can also be re-used, after the transition metals have been stripped out.

In traditional liquid-liquid extractions of metal ions, an aqueous phase containing the metal salt is mixed with an organic phase containing an extraction agent. Simple though they are, these processes use organic phases comprising flammable and volatile solvents, like toluene, kerosene or diethyl ether. Ionic liquids are far more environmentally friendly, having very low vapour pressure and non-flammability.

Read the full article in Chemistry World

Read the original journal article in Green Chemistry:

Removal of transition metals from rare earths by solvent extraction with an undiluted phosphonium ionic liquid: separations relevant to rare-earth magnet recycling
Tom Vander Hoogerstraete, Sil Wellens, Katrien Verachtert and Koen Binnemans
Green Chem., 2013,15, 919-927

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Green Chemistry Issue 4 now online

27 Mar 2013

By Anna Simpson, Executive Editor.

Green Chemistry issue 4 is now online and you can read it here.

The cover features work by François Jérôme and co-workers from France. Their Paper, ‘Pretreatment of microcrystalline cellulose by ultrasounds: effect of particle size in the heterogeneously-catalyzed hydrolysis of cellulose to glucose’ demonstrates that activity of a sulfonated carbon in the heterogeneously-catalyzed hydrolysis of cellulose was greatly improved by assistance of ultrasound. The paper demonstrates that the sonication method was as effective as conventional pre-treatments such as ball-milling or ionic liquids.

Pretreatment of microcrystalline cellulose by ultrasounds: effect of particle size in the heterogeneously-catalyzed hydrolysis of cellulose to glucose
Qinghua Zhang, Maud Benoit, Karine De Oliveira Vigier, Joël Barrault, Gwenaëlle Jégou, Michel Philippe and François Jérôme, Green Chem., 2013, 15, 963-969

The inside front cover highlights a review article entitled ‘Green chemistry and the ocean-based biorefinery’ by Fran Kerton and co-workers at the Memorial University of Newfoundland in Canada. This review highlights that competition for land use could be minimized if marine sourced feedstocks were used for chemicals and materials production rather than crops grown on fertile land. It focuses on achievements and potential opportunities surrounding the use of algae and waste from shellfish and finfish processing.

Green chemistry and the ocean-based biorefinery
Francesca M. Kerton, Yi Liu, Khaled W. Omari and Kelly Hawboldt, Green Chem., 2013, 15, 860-871

These articles are free to access for 6 weeks!

Keep up-to-date with the latest content in Green Chemistry by registering for our free table of contents alerts.

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‘Super solvents’ shortlisted for most important British innovation of the 21st Century

20 Mar 2013

By Mary Badcock, Deputy Editor.

Work by scientists from Queen’s University Belfast on ionic liquid chemistry is in the running to be named the most important British innovation of the 21^st Century.

The work of staff in the Queen’s University Ionic Liquid Laboratories (QUILL) Research Centre is up against 11 other innovations from across the United Kingdom battling it out in a public vote to find the one that will have the greatest impact in the coming century. The vote is part of the Science Museum’s Initiative on Great British past and future Innovations.

Ionic liquids are salts which can remain liquid at room temperature and do not form vapours, and so can be used as non-polluting alternatives to conventional solvents. At QUILL, a team of nearly 100 scientists are exploring the potential of these green solvents and Fortune 100 energy giant Petronas is already using the technology in its plants. The mercury removal unit, using 15 tons of supported ionic liquid, was developed by a team led by Professor Ken Seddon, Co-Director of QUILL at Queen’s, and Dr John Holbrey also from QUILL, who were listed last year as the number one and two chemists in the UK based on citations of their work.Professor Ken Seddon said: “Being shortlisted for the most important British innovation of the 21^st century is recognition of the high calibre of research being undertaken at QUILL and throughout the University. We would encourage people to take a moment to vote for our research as its application will eventually have a bearing on most of our lives.”

Other notable British innovations in the hunt for the prize are Quantum Dots, Graphene, Raspberry Pi and the discovery of the Higgs-Boson – you can vote for your favourite here. Update Monday 25th March – Ionic Liquid Chemistry was voted the recent innovation that is most likely to shape the coming century.

Why not take a look at a collection of high quality research in this area from across RSC Journals – Increadible ionic liquids: an article collection.

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Green Chemistry issue 3 now online

27 Feb 2013

By Mary Badcock, Deputy Editor.

The latest issue of Green Chemistry is now available to read online.

Green Chemistry, issue 3, 2013, front cover The front cover of this issue highlights a Critical Review by Tom Welton and colleagues from Imperial College London (UK) and Umeå University (Sweden) on the deconstruction of lignocellulosic biomass with ionic liquids. The review begins by providing background information on ionic liquids and lignocellulosic biomass before going on to explore the solubility of lignocellulosic biomass in ionic liquids. The also describes the destruction effects brought about by the use of ionic liquids as a solvent, before finally looking at the practical considerations for design of ionic liquid based deconstruction processes.

Deconstruction of lignocellulosic biomass with ionic liquids, Agnieszka Brandt, John Gräsvik, Jason P. Hallett and Tom Welton, Green Chem., 2013, 15, 550-583

The inside front cover features work by Robert Brown and Kaige Wang from Iowa State University, USA, who report the catalytic pyrolysis of microalgae for production of valuable petrochemicals and ammonia. This promising microalgae biorefinery pathway (both from an economical and environmental point-of-view) used the HZSM-5 catalyst for pyrolysis to convert whole microalgae into aromatic hydrocarbons. The ammonia produced in the process can be recycled as a fertilizer for microalgae cultivation.

Catalytic pyrolysis of microalgae for production of aromatics and ammonia, Kaige Wang and Robert C. Brown, Green Chem., 2013, 15, 675-681

These articles are free to access for 6 weeks!

Keep up-to-date with the latest content in Green Chemistry by registering for our free table of contents alerts.

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Ohmic heating for efficient green synthesis

22 Feb 2013

By Bethany Johnson.

With environmental issues increasingly in the news, overcoming the challenges associated with greener chemistry has become a major focus of scientific research. To this aim, Portuguese scientists have developed a new ohmic-heating reactor for organic syntheses ‘on water,’ ie chemistry using an aqueous suspension of the reactants.

With ohmic heating the reaction medium itself serves as an electrical resistor, and is heated by passing electricity through it. Internal energy transformation occurs, from electrical to thermal energy, thanks to ion movement and friction within the reaction medium. Since the heating process depends on the resistivity of the medium, the exact conditions vary from reaction to reaction.

Lightning bolts hitting water, to illustrate ohmic heating

Read the full article in Chemistry World

Read the original journal article in Green Chemistry:
Ohmic heating as a new efficient process for organic synthesis in water
Joana Pinto, Vera L. M. Silva, Ana M. G. Silva, Artur M. S. Silva, José C. S. Costa, Luís M. N. B. F. Santos, Roger Enes, José A. S. Cavaleiro, António A. M. O. S. Vicente and José A. C. Teixeira
Green Chem., 2013, Advance Article
DOI: 10.1039/C3GC36881E

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HOT articles of the week

08 Feb 2013

By Mary Badcock, Deputy Editor.

Read some of the latest ‘HOT’ research to be published in Green Chemistry! These articles are all free to access until the 11th March 2013:

Resolving the dilemma of gaining conductivity but losing environmental friendliness in producing polystyrene/graphene composites via optimizing the matrix-filler structure, Gucheng Long, Changyu Tang, Ka-wai Wong, Changzhen Man, Meikun Fan, Woon-ming Lau, Tao Xu and Bin Wang, Green Chem., 2013, DOI: 10.1039/C3GC37042A

Application of a recyclable fluorous oxime in the convenient synthesis of 3-amino-1,2-benzisoxazoles and 4-amino-1H-2,3-benzoxazines, Wei Jie Ang, Chi-Yuan Chu, Tzyy-Chao Chou, Lee-Chiang Lo and Yulin Lam, Green Chem., 2013, DOI: 10.1039/C3GC36966H

Catalytic applications of a versatile magnetically separable Fe–Mo (Nanocat-Fe–Mo) nanocatalyst, Manoj B. Gawande, Paula S. Branco, Isabel D. Nogueira, C. Amjad A. Ghumman, Nenad Bundaleski, Adérito Santos, Orlando M. N. D. Teodoro and Rafael Luque, Green Chem., 2013, DOI: 10.1039/C3GC36844K