10 resultados para Sustainable chemistry

em QUB Research Portal - Research Directory and Institutional Repository for Queen's University Belfast


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Ionic liquid gel materials offer a way to further utilise ionic liquids in technological applications. Combining the controlled and directed assembly of gels, with the diverse applications of ionic liquids, enables the design of a heady combination of functional tailored materials, leading to the development of task specific / functional ionic liquid gels. This review introduces gels and gel classification, focusing on ionic liquid gels and their potential roles in a more sustainable future. Ionic liquid gels provide the ability to build functionality at every level, the solid component, the ionic liquid, and any incorporated active functional agents. This allows materials to be custom designed for a vast assortment of applications. This diverse class of materials has the potential to yield functional materials for green and sustainable chemistry, energy, electronics, medicine, food, cosmetics, and more. The discussion of the development of ionic liquid gel materials for applications in green and sustainable chemistry centres on uses of ionic liquid gels in catalysis and energy.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

An acid-functionalized ionic liquid was entrapped within a silica gel to yield a recyclable liquid phase catalyst for the dehydration of rac-1-phenyl ethanol. Hot filtration tests showed that the activity was within the gel. Comparison with an analogous SILP system revealed fundamental differences in the properties and behavior of the materials.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The ammoxidation of ethanol is investigated as a renewable process for the production of acetonitrile from a bio-feedstock. Palladium catalysts are shown to be active and very selective (>99%) to this reaction at moderate to low temperatures (150-240 °C), with acetonitrile yields considered a function of Pd morphology. Further investigations reveal that the stability of these catalysts is influenced by an unselective product, and that any deactivation observed is reversible. Interpretation of this deactivation allows operating conditions to be defined for the stable, high yielding production of acetonitrile from ethanol.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Microwave synthesis is shown to be a valuable route to novel fluorinated ionic liquid surfactants. 1-Methyl-3-(3,3,4,4,5,5,6,6,6-nonafluorohexyl)imidazolium iodide was prepared by treatment of 1-methylimidazole with 1-iodo-1H,1H,2H,2H-perfluorohexane in a microwave reactor, and this product underwent anion exchange to yield 1-methyl-3-(3,3,4,4,5,5,6,6,6-nonafluorohexyl)imidazolium nonafluoro-1-butanesulfonate. This catanionic surfactant showed intriguing phase behavior and low surface tension.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Over twenty years ago ‘Our Common Future’ presented a conceptualization and explanation of the concept of sustainable development. Since then numerous alternative definitions of the concept have been offered, of which at least some are exclusive to each other. At the same time, the role of business in the transition to sustainable development has increasingly received attention. Bringing these two trends in sustainable development together, this paper returns to the Brundtland version of the concept to examine to what extent the original principles of sustainable development are still embedded within key business guidelines, namely the UN Global Compact, the OECD Guidelines for Multinational Enterprises, the ICC Business Charter for Sustainable Development, the CAUX Principles, the Global Sullivan Principles and the CERES Principles. The findings suggest that these business guidelines tend to emphasize environmental rather than social aspects of sustainable development, in particular to the detriment of the original Brundtland prioritization of the needs of the poorest. Furthermore, the attention to environmental aspects stresses win-win situations and has a clear managerialist focus; whereas more conceptual environmental issues concerning systems interdependencies, critical thresholds or systemic limits to growth find little attention. The normative codes and principles targeted at the private sector thus not only add another voice to the multiple discourses on sustainable development but also contribute to a reinterpretation of the original agenda set by Brundtland towards conceptualizations of sustainable development around the needs of industrialised rather than developing countries. Copyright © 2011 John Wiley & Sons, Ltd and ERP Environment

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The crop management practice of alternate wetting and drying (AWD) is being promoted by IRRI and the national research and extension program in Bangladesh and other parts of the world as a water-saving irrigation practice that reduces the environmental impact of dry season rice production through decreased water usage, and potentially increases yield. Evidence is growing that AWD will dramatically reduce the concentration of arsenic in harvested rice grains conferring a third major advantage over permanently flooded dry season rice production. AWD may also increase the concentration of essential dietary micronutrients in the grain. However, three crucial aspects of AWD irrigation require further investigation. First, why is yield generally altered in AWD? Second, is AWD sustainable economically (viability of farmers' livelihoods) and environmentally (aquifer water table heights) over long-term use? Third, are current cultivars optimized for this irrigation system? This paper describes a multidisciplinary research project that could be conceived which would answer these questions by combining advanced soil biogeochemistry with crop physiology, genomics, and systems biology. The description attempts to show how the breakthroughs in next generation sequencing could be exploited to better utilize local collections of germplasm and identify the molecular mechanisms underlying biological adaptation to the environment within the context of soil chemistry and plant physiology.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Bioresorbable polymers such as PLA have an important role to play in the development of temporary implantable medical devices with significant benefits over traditional therapies. However, development of new devices is hindered by high manufacturing costs associated with difficulties in processing the material. A major problem is the lack of insight on material degradation during processing. In this work, a method of quantifying degradation of PLA using IR spectroscopy coupled with computational chemistry and chemometric modeling is examined. It is shown that the method can predict the quantity of degradation products in solid-state samples with reasonably good accuracy, indicating the potential to adapt the method to developing an on-line sensor for monitoring PLA degradation in real-time during processing.

Relevância:

30.00% 30.00%

Publicador: