What happens during natural protein fibre dissolution in ionic liquids

Here, we monitor the dissolution of several natural protein fibres such as wool, human hair and silk, in various ionic liquids (ILs). The dissolution of protein-based materials using ILs is an emerging area exploring the production of new materials from waste products. Wool is a keratin fibre, which is extensively used in the textiles industry and as a result has considerable amounts of waste produced each year. Wool, along with human hair, has a unique morphology whereby the outer layer, the cuticle, is heavily cross linked with disulphide bonds, whereas silk does not have this outer layer. Here we show how ILs dissolve natural protein fibres and how the mechanism of dissolution is directly related to the structure and morphology of the wool fibre

Differentiating between V‐ and G‐series nerve agent and simulant vapours using fluorescent film responses

In-field rapid and reliable identification of nerve agents is critical for the protection of Defence and National Security personnel as well as communities. Fluorescence-based detectors can be portable and provide rapid detection of chemical threats. However, most current approaches cannot differentiate between dilute vapors of nerve agent classes and are susceptible to false positives due to the presence of common acids. Here a fluorescence-based method is shown for rapid differentiation between the V-series and phosphonofluoridate G-series nerve agents and avoids false positives due to common acids. Differentiation is achieved through harnessing two different mechanisms. Detection of the V-series is achieved using photoinduced hole transfer whereby the fluorescence of the sensing material is quenched in the presence of the V-series agent. The G-series is detected using a turn-on mechanism in which a silylated excited state intramolecular proton transfer sensing molecule is selectively deprotected by hydrogen fluoride, which is typically found as a contaminant and/or breakdown product in G-series agents such as sarin. The strategy provided discrimination between classes, as the sensor for the G-series agent class is insensitive to the V-series agent, and vice versa, and neither responded to common acids

An investigation of the acid catalysed conversion of carbohydrates to platform chemicals

Methods to obtain useful chemicals derived from sources other than fossil fuels is particularly challenging. The chemical conversion of biomass, a carbohydrate rich feedstock, into useful liquid products has thus become an intensely researched field. In this study, catalysis mediated by various acid catalysts such as Lewis acids, mineral acids and heterogeneous acid resins were investigated for the conversion of fructose, glucose, sucrose, cellulose as well as microalgae into useful chemical products. High yields of products were obtained in the short-chained alcohol solvents, polar aprotic solvents as well as a biphasic system under various reaction conditions. The one-pot synthesis of n-alkyl levulinates and 5-alkoxymethylfurfural in high yields was obtained in short-chained primary alcohol solvents. The solid resin Amberlyst-15 at moderate temperatures and under atmospheric pressure catalysed these reactions. High yields (~80 mol% ) of combined products were obtained from fructose and sucrose with product selectivity dependent on acid concentration and time. Importantly, good yields of 50 mol% of combined products were obtained from glucose under these reaction conditions. Furthermore, microwave irradiation reduced the time required to obtain such products. The production of levoglucosenone (LGN) from the acid catalysed thermolysis of cellulose was investigated in various polar aprotic solvents. Of the solvents investigated, the acid catalysed conversion using mineral acids was the most successful in sulfolane. Levoglucosenone, a valuable chemical intermediate, which can undergo further reactions, was found to convert into 5-chloromethylfurfural with high isolated yields of 72 mol%. Likewise, under the same reaction conditions high combined yields of n-alkyl levulinates and 5-alkoxymethylfurfural from fructose, glucose and sucrose, of >80 mol% were obtained from LGN. In the final component of this study, whole microalga Nannochloropsis sp., was subjected to a one-pot biphasic system for the carbohydrate component conversion to 5 chloromethylfurfural (CMF) alongside lipid extraction. Good isolated yields of CMF (44 mol%) were obtained after 3 hours. Model compounds from both macroalgae and microalgae were also investigated in this study, however these were found to give significantly lower yields of CMF

An investigation of the acid catalysed conversion of carbohydrates to platform chemicals

Methods to obtain useful chemicals derived from sources other than fossil fuels is particularly challenging. The chemical conversion of biomass, a carbohydrate rich feedstock, into useful liquid products has thus become an intensely researched field. In this study, catalysis mediated by various acid catalysts such as Lewis acids, mineral acids and heterogeneous acid resins were investigated for the conversion of fructose, glucose, sucrose, cellulose as well as microalgae into useful chemical products. High yields of products were obtained in the short-chained alcohol solvents, polar aprotic solvents as well as a biphasic system under various reaction conditions. The one-pot synthesis of n-alkyl levulinates and 5-alkoxymethylfurfural in high yields was obtained in short-chained primary alcohol solvents. The solid resin Amberlyst-15 at moderate temperatures and under atmospheric pressure catalysed these reactions. High yields (~80 mol% ) of combined products were obtained from fructose and sucrose with product selectivity dependent on acid concentration and time. Importantly, good yields of 50 mol% of combined products were obtained from glucose under these reaction conditions. Furthermore, microwave irradiation reduced the time required to obtain such products. The production of levoglucosenone (LGN) from the acid catalysed thermolysis of cellulose was investigated in various polar aprotic solvents. Of the solvents investigated, the acid catalysed conversion using mineral acids was the most successful in sulfolane. Levoglucosenone, a valuable chemical intermediate, which can undergo further reactions, was found to convert into 5-chloromethylfurfural with high isolated yields of 72 mol%. Likewise, under the same reaction conditions high combined yields of n-alkyl levulinates and 5-alkoxymethylfurfural from fructose, glucose and sucrose, of >80 mol% were obtained from LGN. In the final component of this study, whole microalga Nannochloropsis sp., was subjected to a one-pot biphasic system for the carbohydrate component conversion to 5 chloromethylfurfural (CMF) alongside lipid extraction. Good isolated yields of CMF (44 mol%) were obtained after 3 hours. Model compounds from both macroalgae and microalgae were also investigated in this study, however these were found to give significantly lower yields of CMF

Rapid and effective cuticle removal from wool fibers using ionic liquid

Wool fibers are composed of cuticle and cortex cells, which are of obvious differences in many properties. The development of methods to isolate the two kinds of cells can provide platform to elucidate the roles they play in the characteristics of wool fibers. Here we demonstrate the cuticle can be completely and rapidly removed from the wool fibers by the use of ionic liquids, with inner cortex intact. Confocal microscope, SEM and FTIR have been applied to study the wool fibers after cuticle removal. In contrast to the traditional/long physical or chemical separation routes (>14 h), our method is very rapid (<1 h). This work demonstrates the ability of ionic liquid as a novel, rapid and efficient media for cuticle/ cortex isolation

Understanding key wet spinning parameters in an ionic liquid spun regenerated cellulosic fibre

The use of ionic liquid solvents for thespinning of regenerated cellulose fibres has thepotential to produce both technical and textile graderegenerated cellulose fibres. When spinning fibres,many parameters impact the material properties of thespun fibre. In this study, key wet spinning parametershave been investigated for the development of regeneratedcellulose fibres from ionic liquid solutions. Thecoagulation and associated diffusion equilibrium werecalculated for two imidazolium-based ILs, and it wasfound that the anion largely influenced the coagulationkinetics. This was likely due to the associationbetween the anion of the IL and cellulose. Theorientation of the polymer chains is known to influencethe mechanical properties greatly; previously, hotstretching was used to orientate cellulose acetate. Herewe investigated this influence on the mechanicalproperties of regenerated cellulose fibres by applying apost stretch at different stretch ratios