Browsing by Author "Eichhorn, Stephen J."
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Item Open Access Cellulose filaments derived from dissolution and spinning of paper sludge nanofibers using an ionic liquid Item(Cranfield University, 2020-04-17 09:08) Adu, Cynthia; Zhu, Chenchen; Jolly, Mark R.; Oksman, Kristiina; Eichhorn, Stephen J.; Richardson, RobertDataset posted on 2020-04-17, 10:08 authored by Cynthia Adu, Chenchen Zhu, Mark Jolly, Kristiina Oksman, Stephen J. Eichhorn, Robert M. Richardson, Kevin D. Potter This data set contains results from the experimental test conducted to dissolve and spin cellulose nanofibres into filaments. The CNF was derived from paper mill sludge by mechanical grinding and dissolved in ionic liquid at 9 and 12% CNF concentration. Fibre pinning was conducted by dry-jet wet spinning method to produce filaments with average tensile strength of 19 GPa and 26 GPa, and modulus of 223 MPa and 282 MPa respectively. Enclose is the data from the tensile tests, rheology of the spinning solution and the filament orientation obtained from the wide angle x-ray of the filament.Item Open Access Continuous and sustainable cellulose filaments from ionic liquid dissolved paper sludge nanofibres(Elsevier, 2020-10-03) Adu, Cynthia; Zhu, Chenchen; Jolly, Mark R.; Richardson, Robert M.; Eichhorn, Stephen J.The textile industry is resource intensive, which has a significant impact on global emissions and waste pollution. To meet the demand of textiles over a third of fibres used in manufacturing are sourced from fossil fuels. As the global demand for textiles continues to grow, manufacturers have having to seek innovative approaches to providing sustainable regenerative cellulose fibres. However, the latest climate change pressures on the textile industry has uncovered grave environmental issues associated with traditional regenerative cellulose production such as the viscose manufacturing process. The viscose process the required intensive use of hazardous chemicals which leads to water pollution and ecotoxicity. In addition, if forestry products are unsustainably sourced for the viscose production this can lead to resource scarcity and deforestation. To provide a holistic solution for mitigating these challenges this study uses the by-products of paper manufacturing dissolved in an ionic liquid to produce regenerated cellulose filaments. Paper mill sludge (PMS) is a cellulosic by-product typically used on animal bedding and land spreading. The material has been dissolved in an ionic liquid - 1-ethyl-3-methylimidazolium diethyl phosphate - with the aid of a co-solvent dimethyl sulfoxide (DMSO) - and spun into continuous filaments for textile production. The mechanical properties of paper sludge filaments are found to be competitive with commercial viscose, which is promising for their drop-in replacement. It is also demonstrated that by increasing the concentration of the PMS from 9% to 12.4%, an improvement of the filament properties can be achieved; an increase in modulus from ~19 GPa to ~ 26 GPa and ~ 223 MPa to ~ 282 MPa. These values are shown to be competitive with other commercial, less sustainable, regenerated cellulose fibresItem Open Access Deformation mechanisms in ionic liquid spun cellulose fibers(Elsevier, 2016-07-05) Wanasekara, Nandula D.; Michud, Anne; Zhu, Chenchen; Rahatekar, Sameer S.; Sixta, Herbert; Eichhorn, Stephen J.The molecular deformation and crystal orientation of a range of next generation regenerated cellulose fibers, produced from an ionic liquid solvent spinning system, are correlated with macroscopic fiber properties. Fibers are drawn at the spinning stage to increase both molecular and crystal orientation in order to achieve a high tensile strength and Young’s modulus for potential use in engineering applications. Raman spectroscopy was utilized to quantify both molecular strain and orientation of fibers deformed in tension. X-ray diffraction was used to characterize crystal orientation of single fibers. These techniques are shown to provide complimentary information on the microstructure of the fibers. A shift in the position of a characteristic Raman band, initially located at ∼1095 cm−1, emanating from the backbone structure of the cellulose polymer chains was followed under tensile deformation. It is shown that the shift rate of this band with respect to strain increases with the draw ratio of the fibers, indicative of an increase in the axial molecular alignment and subsequent deformation of the cellulose chains. A linear relationship between the Raman band shift rate and the modulus was established, indicating that the fibers possess a series aggregate structure of aligned crystalline and amorphous domains. Wide-angle X-ray diffraction data show that crystal orientation increases with an increase in the draw ratio, and a crystalline chain slip model was used to fit the change in orientation with fiber draw ratio. In addition to this a new model is proposed for a series aggregate structure that takes into better account the molecular deformation of the fibers. Using this model a prediction for the crystal modulus of a cellulose-II structure is made (83 GPa) which is shown to be in good agreement with other experimental approaches for its determination.Item Open Access High modulus regenerated cellulose fibers spun from a low molecular weight microcrystalline cellulose solution(American Chemical Society, 2016-07-27) Zhu, Chenchen; Richardson, Robert M.; Potter, Kevin D.; Koutsomitopoulou, Anastasia F.; van Duijneveldt, Jeroen S.; Vincent, Sheril R.; Wanasekara, Nandula D.; Eichhorn, Stephen J.; Rahatekar, Sameer S.We have developed a novel process to convert low molecular weight microcrystalline cellulose into stiff regenerated cellulose fibers using a dry-jet wet fiber spinning process. Highly aligned cellulose fibers were spun from optically anisotropic microcrystalline cellulose/1-ethyl-3-methylimidazolium diethyl phosphate (EMImDEP) solutions. As the cellulose concentration increased from 7.6 to 12.4 wt %, the solution texture changed from completely isotropic to weakly nematic. Higher concentration solutions (>15 wt %) showed strongly optically anisotropic patterns, with clearing temperatures ranging from 80 to 90 °C. Cellulose fibers were spun from 12.4, 15.2, and 18.0 wt % cellulose solutions. The physical properties of these fibers were studied by scanning electron microscopy (SEM), wide angle X-ray diffraction (WAXD), and tensile testing. The 18.0 wt % cellulose fibers, with an average diameter of ∼20 μm, possessed a high Young’s modulus up to ∼22 GPa, moderately high tensile strength of ∼305 MPa, as well as high alignment of cellulose chains along the fiber axis confirmed by X-ray diffraction. This process presents a new route to convert microcrystalline cellulose, which is usually used for low mechanical performance applications (matrix for pharmaceutical tablets and food ingredients, etc.) into stiff fibers which can potentially be used for high-performance composite materials.Item Open Access Properties of cellulose nanofibre networks prepared from never-dried and dried paper mill sludge(Elsevier, 2018-06-27) Adu, Cynthia; Berglund, Linn; Oksman, Kristiina; Eichhorn, Stephen J.; Jolly, Mark R.; Zhu, ChenchenPaper mills yield large volumes of sludge materials which pose an environmental and economic challenge for disposal, despite the fact that they could be a valuable source for cellulose nanofibres (CNF) production. The aim of the study was to evaluate the production process and properties of CNF prepared by mechanical fibrillation of never-dried and dried paper mill sludge (PMS). Atomic force microscopy (AFM) showed that average diameters for both never-dried and dried paper sludge nanofibres (PSNF) were less than 50 nm. The never-dried and dried sludge nanofibres showed no statistical significant difference (p > 0.05) in strength ∼92 MPa, and ∼85 MPa and modulus ∼11 GPa and ∼10 GPa. The study concludes that paper mill sludge can be used in a dried state for CNF production to reduce transportation and storage challenges posed on industrial scale.