The Experts below are selected from a list of 36 Experts worldwide ranked by ideXlab platform
Tom Lindström - One of the best experts on this subject based on the ideXlab platform.
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High strength, flexible and transparent nanofibrillated cellulose-nanoclay biohybrid films with tunable oxygen and water vapor permeability.
Nanoscale, 2012Co-Authors: Christian Aulin, German Salazar-alvarez, Tom LindströmAbstract:A novel, technically and economically benign procedure to combine vermiculite nanoplatelets with Nanocellulose Fibre dispersions into functional biohybrid films is presented. Nanocellulose Fibres o ...
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High strength, flexible and transparent nanofibrillated cellulose-nanoclay biohybrid films with tunable oxygen and water vapor permeability
Nanoscale, 2012Co-Authors: Christian Aulin, German Salazar-alvarez, Tom LindströmAbstract:A novel, technically and economically benign procedure to combine vermiculite nanoplatelets with Nanocellulose Fibre dispersions into functional biohybrid films is presented. Nanocellulose Fibres of 20 nm diameters and several micrometers in length are mixed with high aspect ratio exfoliated vermiculite nanoplatelets through high-pressure homogenization. The resulting hybrid films obtained after solvent evaporation are stiff (tensile modulus of 17.3 GPa), strong (strength up to 257 MPa), and transparent. Scanning electron microscopy (SEM) shows that the hybrid films consist of stratified nacre-like layers with a homogenous distribution of nanoplatelets within the Nanocellulose matrix. The oxygen barrier properties of the biohybrid films outperform commercial packaging materials and pure Nanocellulose films showing an oxygen permeability of 0.07 cm(3) μm m(-2) d(-1) kPa(-1) at 50% relative humidity. The oxygen permeability of the hybrid films can be tuned by adjusting the composition of the films. Furthermore, the water vapor barrier properties of the biohybrid films were also significantly improved by the addition of nanoclay. The unique combination of excellent oxygen barrier behavior and optical transparency suggests the potential of these biohybrid materials as an alternative in flexible packaging of oxygen sensitive devices such as thin-film transistors or organic light-emitting diode displays, gas storage applications and as barrier coatings/laminations in large volume packaging applications.
Christian Aulin - One of the best experts on this subject based on the ideXlab platform.
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High strength, flexible and transparent nanofibrillated cellulose-nanoclay biohybrid films with tunable oxygen and water vapor permeability.
Nanoscale, 2012Co-Authors: Christian Aulin, German Salazar-alvarez, Tom LindströmAbstract:A novel, technically and economically benign procedure to combine vermiculite nanoplatelets with Nanocellulose Fibre dispersions into functional biohybrid films is presented. Nanocellulose Fibres o ...
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High strength, flexible and transparent nanofibrillated cellulose-nanoclay biohybrid films with tunable oxygen and water vapor permeability
Nanoscale, 2012Co-Authors: Christian Aulin, German Salazar-alvarez, Tom LindströmAbstract:A novel, technically and economically benign procedure to combine vermiculite nanoplatelets with Nanocellulose Fibre dispersions into functional biohybrid films is presented. Nanocellulose Fibres of 20 nm diameters and several micrometers in length are mixed with high aspect ratio exfoliated vermiculite nanoplatelets through high-pressure homogenization. The resulting hybrid films obtained after solvent evaporation are stiff (tensile modulus of 17.3 GPa), strong (strength up to 257 MPa), and transparent. Scanning electron microscopy (SEM) shows that the hybrid films consist of stratified nacre-like layers with a homogenous distribution of nanoplatelets within the Nanocellulose matrix. The oxygen barrier properties of the biohybrid films outperform commercial packaging materials and pure Nanocellulose films showing an oxygen permeability of 0.07 cm(3) μm m(-2) d(-1) kPa(-1) at 50% relative humidity. The oxygen permeability of the hybrid films can be tuned by adjusting the composition of the films. Furthermore, the water vapor barrier properties of the biohybrid films were also significantly improved by the addition of nanoclay. The unique combination of excellent oxygen barrier behavior and optical transparency suggests the potential of these biohybrid materials as an alternative in flexible packaging of oxygen sensitive devices such as thin-film transistors or organic light-emitting diode displays, gas storage applications and as barrier coatings/laminations in large volume packaging applications.
German Salazar-alvarez - One of the best experts on this subject based on the ideXlab platform.
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High strength, flexible and transparent nanofibrillated cellulose-nanoclay biohybrid films with tunable oxygen and water vapor permeability.
Nanoscale, 2012Co-Authors: Christian Aulin, German Salazar-alvarez, Tom LindströmAbstract:A novel, technically and economically benign procedure to combine vermiculite nanoplatelets with Nanocellulose Fibre dispersions into functional biohybrid films is presented. Nanocellulose Fibres o ...
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High strength, flexible and transparent nanofibrillated cellulose-nanoclay biohybrid films with tunable oxygen and water vapor permeability
Nanoscale, 2012Co-Authors: Christian Aulin, German Salazar-alvarez, Tom LindströmAbstract:A novel, technically and economically benign procedure to combine vermiculite nanoplatelets with Nanocellulose Fibre dispersions into functional biohybrid films is presented. Nanocellulose Fibres of 20 nm diameters and several micrometers in length are mixed with high aspect ratio exfoliated vermiculite nanoplatelets through high-pressure homogenization. The resulting hybrid films obtained after solvent evaporation are stiff (tensile modulus of 17.3 GPa), strong (strength up to 257 MPa), and transparent. Scanning electron microscopy (SEM) shows that the hybrid films consist of stratified nacre-like layers with a homogenous distribution of nanoplatelets within the Nanocellulose matrix. The oxygen barrier properties of the biohybrid films outperform commercial packaging materials and pure Nanocellulose films showing an oxygen permeability of 0.07 cm(3) μm m(-2) d(-1) kPa(-1) at 50% relative humidity. The oxygen permeability of the hybrid films can be tuned by adjusting the composition of the films. Furthermore, the water vapor barrier properties of the biohybrid films were also significantly improved by the addition of nanoclay. The unique combination of excellent oxygen barrier behavior and optical transparency suggests the potential of these biohybrid materials as an alternative in flexible packaging of oxygen sensitive devices such as thin-film transistors or organic light-emitting diode displays, gas storage applications and as barrier coatings/laminations in large volume packaging applications.
Warren Batchelor - One of the best experts on this subject based on the ideXlab platform.
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effects of Fibre dimension and charge density on Nanocellulose gels
Journal of Colloid and Interface Science, 2018Co-Authors: Llyza Mendoza, Thilina Gunawardhana, Warren Batchelor, Gil GarnierAbstract:Abstract Hypothesis Carboxylated cellulose nanoFibres can produce gels at low concentrations. The effect of pulp source on the Nanocellulose Fibre dimension and gel rheology are studied. It is hypothesised that Fibre length and surface charge influence aspects of the gel rheological properties. Experiments TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl)- mediated oxidised cellulose nanoFibres from never-dried hardwood and softwood pulp and containing different charge levels were produced and characterized. Steady-state and dynamic rheological studies were performed to ascertain the effects of pulp type on gel behavior and properties. Findings Nanocellulose Fibres extracted from softwood (SW-TOCN) and hardwood (HW-TOCN) pulp exhibit similar widths but different length dimensions as shown via AFM analysis. Rheological measurements show that the dynamic moduli (G′ and G′′) of Nanocellulose gels are independent of pulp source and are mostly influenced by Fibre concentration. Differences in the steady-state behavior (i.e. viscosity) at constant surface charge can be attributed to differences in Fibre length. Increasing the surface charge density influences the critical strain and the viscosity at the percolation concentration (0.1 wt%) due to higher electrostatic interactions.
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Strong cellulose nanoFibre–nanosilica composites with controllable pore structure
Cellulose, 2017Co-Authors: Uthpala M. Garusinghe, Gil Garnier, Swambabu Varanasi, Warren BatchelorAbstract:Flexible Nanocellulose composites with silica nanoparticle loading from 5 to 77 wt% and tunable pore size were made and characterised. The pore structure of the new composites can be controlled (100–1000 nm to 10–60 nm) by adjusting the silica nanoparticle content. Composites were prepared by first complexing nanoparticles with a cationic dimethylaminoethyl methacrylate polyacrylamide, followed by retaining this complex in a Nanocellulose Fibre network. High retention of nanoparticles resulted. The structural changes and pore size distribution of the composites were characterised through scanning electron microscopy (SEM) and mercury porosimetry analysis, respectively. The heavily loaded composites formed packed bed structures of nanoparticles. Film thickness was approximately constant for composites with low loading, indicating that nanoparticles filled gaps created by Nanocellulose Fibres without altering their structure. Film thickness increased drastically for high loading because of the new packed bed structure. Unexpectedly, within the investigated loading range, the level of the tensile index on Nanocellulose mass basis remained constant, showing that the silica nanoparticles did not significantly interfere with the bonding between the cellulose nanoFibres. This hierarchically engineered material remains flexible at all loadings, and its unique packing enables use in applications requiring Nanocellulose composites with controlled pore structure and high surface area.
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Assembly of nanoparticles-polyelectrolyte complexes in nanofiber cellulose structures
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2017Co-Authors: Uthpala M. Garusinghe, Warren Batchelor, Swambabu Varanasi, Vikram Singh Raghuwanshi, Christopher J. Garvey, Christopher Hutchinson, Gil GarnierAbstract:Abstract We report the effect of cationic polyacrylamide (CPAM) addition on the structural assembly of silica nanoparticles (NPs) within a Nanocellulose Fibre matrix. Paper like composites are fabricated by first forming complexes of NPs with CPAM, then adding those to a suspension of Nanocellulose Fibres; followed by filtration, pressing and drying of the final suspension. Complementary small angle X-ray scattering (SAXS) and microscopy (SEM, TEM) investigations of these composites showed a lognormal bimodal distribution of NP sizes. Data analysis allows understanding interparticle interactions within assemblies of SiO2 NPs at the nanometer scale with respect to different dosage of CPAM. Increasing CPAM dosage increases retention of NPs within the cellulose matrix with stronger interparticle interactions and produces composites with smaller pores. The correlation length of NPs, indicative of the size of the NP clusters increased from 30 to 70 nm as the CPAM dosage increased from 16.5 to 330 mg/g NPs. Retention and assembly of SiO2 NPs by varying CPAM dosage results from the balance of different interaction forces between NPs, CPAM and Nanocellulose Fibres. Understanding the effect of CPAM dosage on the various NP and composite structural conformations enables us to engineer novel hierarchically and functional cellulose based structured materials.
Sabu Thomas - One of the best experts on this subject based on the ideXlab platform.
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cellulose nanocomposites with nanoFibres isolated from pineapple leaf fibers for medical applications
Carbohydrate Polymers, 2011Co-Authors: Bibin Mathew Cherian, Alcides Lopes Leao, Sivoney Ferreira De Souza, Ligia Maria Manzine Costa, Gabriel Molina De Olyveira, M Kottaisamy, E R Nagarajan, Sabu ThomasAbstract:Abstract Nanocellulose is the crystalline domains obtained from renewable cellulosic sources, used to increase mechanical properties and biodegrability in polymer composites. This work has been to study how high pressure defibrillation and chemical purification affect the PALF Fibre morphology from micro to nanoscale. Microscopy techniques and X-ray diffraction were used to study the structure and properties of the prepared nanofibers and composites. Microscopy studies showed that the used individualization processes lead to a unique morphology of interconnected web-like structure of PALF fibers. The produced nanofibers were bundles of cellulose fibers of widths ranging between 5 and 15 nm and estimated lengths of several micrometers. Percentage yield and aspect ratio of the nanofiber obtained by this technique is found to be very high in comparison with other conventional methods. The nanocomposites were prepared by means of compression moulding, by stacking the Nanocellulose Fibre mats between polyurethane films. The results showed that the nanofibrils reinforced the polyurethane efficiently. The addition of 5 wt% of cellulose nanofibrils to PU increased the strength nearly 300% and the stiffness by 2600%. The developed composites were utilized to fabricate various versatile medical implants.
