The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Mikael S Hedenqvist - One of the best experts on this subject based on the ideXlab platform.
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A facile way of making inexpensive rigid and soft protein Biofoams with rapid liquid absorption
Industrial Crops and Products, 2018Co-Authors: B. Alander, Antonio Jose Capezza, Qiong Wu, Eva Johansson, Richard T. Olsson, Mikael S HedenqvistAbstract:A novel and facile method to produce inexpensive protein Biofoams suitable for sponge applications is presented. The protein used in the study was wheat gluten (WG), readily available as a by/co-pr ...
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Conductive Biofoams of wheat gluten containing carbon nanotubes, carbon black or reduced graphene oxide
RSC Advances, 2017Co-Authors: Qiong Wu, Mikael S Hedenqvist, Henrik Sundborg, Richard L. Andersson, Kevin Peuvot, Leonard Gaston Guex, Fritjof Nilsson, Richard T. OlssonAbstract:Conductive Biofoams made from glycerol-plasticized wheat gluten (WGG) are presented as a potential substitute in electrical applications for conductive polymer foams from crude oil. The soft plasticised foams were prepared by conventional freeze-drying of wheat gluten suspensions with carbon nanotubes (CNTs), carbon black (CB) or reduced graphene oxide (rGO) as the conductive filler phase. The change in conductivity upon compression was documented and the results show not only that the CNT-filled foams show a conductivity two orders of magnitude higher than foams filled with the CB particles, but also that there is a significantly lower percolation threshold with percolation occurring already at 0.18 vol%. The rGO-filled foams gave a conductivity inferior to that obtained with the CNTs or CB particles, which is explained as being related to the sheet-like morphology of the rGO flakes. An increasing amount of conductive filler resulted in smaller pore sizes for both CNTs and CB particles due to their interference with the ice crystal formation before the lyophilization process. The conductive WGG foams with CNTs were fully elastic with up to 10% compressive strain, but with increasing compression up to 50% strain the recovery gradually decreased. The data show that the conductivity strongly depends on the type as well as the concentration of the conductive filler, and the conductivity data with different compressions applied to these Biofoams are presented for the first time.
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Freeze-dried wheat gluten Biofoams; scaling up with water welding
Industrial Crops and Products, 2017Co-Authors: Qiong Wu, Eva Johansson, Richard T. Olsson, Vilhelm Lindh, Mikael S HedenqvistAbstract:This paper presents a simple and rapid wet welding technique that enables the scaling up of freeze-dried protein (wheat gluten (WG)) Biofoams for e.g. thermal insulation applications. The welding occurred by first wetting faces of foam cubes in water and then pressing them together for a limited time period. The water plasticized thin cell-walls of the two foams formed a dense weld when the plasticized cells collapsed under the drying step. The welds were always stronger and stiffer than the surrounding cellular structure. Based on three-point bending, it was shown that welded specimens (four-cube samples) were 7 times stronger than specimens produced directly as one piece with similar total size. This illustrated the problem of freeze-drying larger products; by instead assembling smaller foams into a large object the overall foam structure became more homogeneous. In addition, the dense welds become “walls” that limit gas convection in the mainly open cell structure, beneficial for thermal insulation. This is the first report on combined freeze-drying and water welding. It shows the sustainable potential of the technique for foam production, since only water is used as a foaming/welding agent.
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Highly Absorbing Antimicrobial Biofoams Based on Wheat Gluten and Its Biohybrids
ACS Sustainable Chemistry & Engineering, 2016Co-Authors: Qiong Wu, Ulf W Gedde, Eva Johansson, Richard T. Olsson, Shun Yu, Matthias Kollert, Mekki Mtimet, Stephan V. Roth, Mikael S HedenqvistAbstract:This paper presents the absorption, mechanical, and antimicrobial properties of novel types of Biofoams based on wheat-gluten (WG) and its biohybrids with silica. The hybrid WG foams were in situ polymerized with silica using two different silanes. When immersed in water, the 90–95% porous WG and silica-modified hybrid WG foams showed a maximum water uptake between 32 and 11 times the original sample weight. The maximum uptake was only between 4.3 and 6.7 times the initial weight in limonene (a nonpolar liquid) but showed reversible absorption/desorption and that the foams could be dried into their original shape. The different foams had a cell size of 2–400 μm, a density of 60–163 kg/m3, and a compression modulus of 1–9 MPa. The integrity of the foams during swelling in water was improved by cross-linking with glutaraldehyde (GA) or by a thermal treatment at 130 °C, which polymerized the proteins. In the never-dried state, the foam acted as a sponge, and it was possible to squeeze out water and soak it r...
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a novel chitosan wheat gluten Biofoam fabricated by spontaneous mixing and vacuum drying
RSC Advances, 2015Co-Authors: Fei Chen, Mikael Gallstedt, Rickard Olsson, Ulf W Gedde, Mikael S HedenqvistAbstract:A new type of chitosan and wheat gluten Biofoam is presented. The pore structure achieved relied solely on the specific mixing and phase distribution when a film was cast from an aqueous mixture of ...
Guo Hong - One of the best experts on this subject based on the ideXlab platform.
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three dimensional functionalized carbon tin iv sulfide Biofoam for photocatalytical purification of chromium vi containing wastewater
ACS Sustainable Chemistry & Engineering, 2018Co-Authors: Yunlei Zhong, Haifeng Li, Dong Fang, Guo HongAbstract:Carbon-based materials are widely used for environmental remediation because of their unique and excellent performances. Because of the huge daily consumption of such materials, the economic and environmental friendly derivations from natural biomass are highly desired. Herein, a new biocarbon composite, carbonized loofah/tin(IV) sulfide (CLF@SnS2) foam, was successfully prepared using loofah Biofoam through an efficient and scalable method. The hierarchical CLF@SnS2 foam has a high-porous structure, which can provide channels for light traveling through the whole material. It is confirmed that such three-dimensional photocatalytic material can quickly purify Cr(VI)-containing wastewater under mild visible light irradiation, with a efficiency of 99.7% Cr(VI) reduction within 120 min. By contrast, CLF@SnS2 showed much better visible photocatalytic capacity than the uncarbonized counterpart (UCLF@SnS2), because the photoelectrons produced by the SnS2 nanosheets can be rapidly exported by the continuous chan...
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Three Dimensional Functionalized Carbon/Tin(IV) Sulfide Biofoam for Photocatalytical Purification of Chromium(VI)-Containing Wastewater
ACS Sustainable Chemistry & Engineering, 2018Co-Authors: Yunlei Zhong, Haifeng Li, Dong Fang, Guo HongAbstract:Carbon-based materials are widely used for environmental remediation because of their unique and excellent performances. Because of the huge daily consumption of such materials, the economic and environmental friendly derivations from natural biomass are highly desired. Herein, a new biocarbon composite, carbonized loofah/tin(IV) sulfide (CLF@SnS2) foam, was successfully prepared using loofah Biofoam through an efficient and scalable method. The hierarchical CLF@SnS2 foam has a high-porous structure, which can provide channels for light traveling through the whole material. It is confirmed that such three-dimensional photocatalytic material can quickly purify Cr(VI)-containing wastewater under mild visible light irradiation, with a efficiency of 99.7% Cr(VI) reduction within 120 min. By contrast, CLF@SnS2 showed much better visible photocatalytic capacity than the uncarbonized counterpart (UCLF@SnS2), because the photoelectrons produced by the SnS2 nanosheets can be rapidly exported by the continuous chan...
Manju Misra - One of the best experts on this subject based on the ideXlab platform.
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lignin as a reactive reinforcing filler for water blown rigid Biofoam composites from soy oil based polyurethane
Industrial Crops and Products, 2013Co-Authors: Amar K. Mohanty, Manju MisraAbstract:Abstract In this study, lignin (from bioethanol production) is used as a reactive reinforcing filler. A novel soy-based polyurethane Biofoam (BioPU) from two polyols (soybean oil-derived polyol SOPEP and petrochemical polyol Jeffol A-630) and poly(diphenylmethane diisocyanate) (pMDI) has been prepared by a self-rising method using water as a blowing agent with and without lignin. The BioPU samples were evaluated for mechanical and thermal properties, and density. The cell morphology of the resulting lignin reinforced Biofoam was examined by scanning electron microscope (SEM) and found to be in line with the cell structure modifications induced by the reinforcing lignin. Densities of the resultant composites were increased as a result of increased lignin content. Fourier transform infrared (FTIR) spectroscopy study exhibited characteristic peaks for lignin and BioPU. Mechanical properties of the samples were improved with the increase of lignin content, and the samples with 10% lignin had the best mechanical properties. Similarly, glass transition temperature (Tg) and storage modulus around and after Tg were increased over neat Biofoam without lignin. Dynamic mechanical analysis (DMA) results coincided with the improvement of mechanical properties and showed better thermal stability of the composites over the neat Biofoam. Thermogravimetric analysis showed improved thermal stability of the Biofoams reinforced with lignin. Therefore, this research has provided a simple method of preparing the Biofoam, while exploring the potential of using lignin in polyurethane applications.
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Water‐Blown Rigid Biofoams from Soy‐Based Biopolyurethane and Microcrystalline Cellulose
Journal of the American Oil Chemists' Society, 2012Co-Authors: Amar K. Mohanty, Manju MisraAbstract:A novel soy-based polyurethane Biofoam (BioPU) from two polyols (soybean oil-derived polyols SOPEP and petrochemical polyol Jeffol A-630 = 1:1 in weight) and poly (diphenylmethane diisocyanate) (pMDI) has been prepared by using a free-rise method with water as a blowing agent, and microcrystalline cellulose (MCC) as a reinforcement. The photographs of the samples show that the Biofoams have similar appearances, and the cell morphology of the resulting Biofoams was examined by scanning electron microscope. Density of the composites decreased as a result of increase in MCC content. FTIR study exhibited characteristic peaks for MCC and BioPU. Mechanical properties such as compressive strength, compressive modulus, flexural strength and flexural modulus of the samples were substantially improved with the increase in MCC content. Similarly, improvements in glass transition temperature (T g) and storage modulus around and after T g of the neat Biofoam were also observed with the composites. Dynamic mechanical analysis results showed an improvement in mechanical properties as well as better thermal stability of the composites over the neat Biofoam. Thermogravimetric analysis showed improved thermal stability of the Biofoams reinforced with MCC. This research has provided a simple method for preparing the Biofoam, while exploring the potential of substituting up to 50 % of the petroleum-based polyol in Biofoam applications.
Fei Chen - One of the best experts on this subject based on the ideXlab platform.
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a novel chitosan wheat gluten Biofoam fabricated by spontaneous mixing and vacuum drying
RSC Advances, 2015Co-Authors: Fei Chen, Mikael Gallstedt, Rickard Olsson, Ulf W Gedde, Mikael S HedenqvistAbstract:A new type of chitosan and wheat gluten Biofoam is presented. The pore structure achieved relied solely on the specific mixing and phase distribution when a film was cast from an aqueous mixture of ...
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A novel chitosan/wheat gluten Biofoam fabricated by spontaneous mixing and vacuum-drying
RSC Advances, 2015Co-Authors: Fei Chen, Mikael Gallstedt, Rickard Olsson, Ulf W Gedde, Mikael S HedenqvistAbstract:A new type of chitosan and wheat gluten Biofoam is presented. The pore structure achieved relied solely on the specific mixing and phase distribution when a film was cast from an aqueous mixture of ...
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a novel chitosan wheat gluten Biofoam fabricated by mixing and vacuum drying
2015Co-Authors: Fei Chen, Mikael Gallstedt, Ulf W Gedde, Richard T. Olsson, Mikael S HedenqvistAbstract:This thesis presents four different studis describing the characteristics and processing opportunities of two widely available biopolymers: chitosan and wheat gluten. The interest in these materials is mainly because they are bio-based and obtained as co- or by-products in the fuel and food sectorIn the first study, high solids content chitosan samples (60 wt.%) were successfully extruded. Chitosan extrusion has previously been reported but not chitosan extrusion with a high solids content, which decreases the drying time and increases the production volume. An orthogonal experimental design was used to assess the influence of formulation and processing conditions, and the optimal formulation and conditions were determined from the orthogonal experimental analysis and the qualities of the extrudates. The mechanical properties and processing-liquid mass loss of the optimized extrudates showed that the extrudates became stable within three days. The changes in the mechanical properties depended on the liquid mass loss.In a separate study, monocarboxylic (formic, acetic, propionic, and butyric) acid uptake and diffusion in chitosan films were investigated. It is of importance in order to be able to optimize the production of this material with the casting technique. The time of the equilibration uptake in the chitosan films exposed to propionic and butyric acid was nine months. This long equilibration time encouraged us study the exposed films further. The uptake and diffusivity of acid in the films decreased with increasing acid molecular size. A two-stage absorption curve was observed for the films exposed to propionic acid vapour. The films at the different stages showed different diffusivities. The acid transport was also affected by the structure of the chitosan films. X-ray diffraction suggested that the crystal structure of the original films disappeared after the films had been dried from their acid-swollen state, and that the microstructure of the dried films depended on the molecular size of the acid. Compared with the original films, the dried films retained their ductility, although a decrease in the molecular weight of the chitosan was detected. The water resistance of the acid-exposed films was increased, even though the crystallinity of these films was lower.The third study was devoted to chitosan/wheat gluten blend films cast from aqueous solutions. Different solvent types, additives and drying methods were used to examine their effects on the microstructures of the blended films. Chitosan and wheat gluten were immiscible in the aqueous blend, and the wheat gluten formed a discrete phase, and the homogeneity of the films was improved by using a reducing agent, compared with films prepared using only water/ethanol as cast media. Adding urea and surfactants resulted in a medium homogeneity of the films compared to those prepared with the reducing agents or with only water/ethanol. An elongated wheat gluten phase was observed in a film using glyoxal, in contrast to pure chitosan/wheat gluten blends. The opacity of the different films was studied. The mechanical properties and humidity uptake of the films increased with increasing chitosan content. The films containing 30 wt.% of wheat gluten showed the most promising mechanical properties, close to those of the pristine chitosan films.The final part describes the preparation and properties of a bio-foam composed of a blend of chitosan and wheat gluten. This foam was prepared without any porogen or frozen liquid phase to create porosity. A unique phase distribution of the chitosan and wheat gluten solutions formed without any agitation, and the foam was obtained when the liquid phase were withdrawn under vacuum. These foams showed high mass uptake of n-hexane and water in a short time due to their open pores and high porosity. The maximum uptake of n-hexane measured was 20 times the initial mass of the foam. The foams showed a high rebound resilience (94 % at 20 % compression strain) and they were not broken when subjected to bending.
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A Novel Chitosan/Wheat Gluten Biofoam Fabricated by Mixing and Vacuum-drying
2015Co-Authors: Fei Chen, Mikael Gallstedt, Ulf W Gedde, Richard T. Olsson, Mikael S HedenqvistAbstract:This thesis presents four different studis describing the characteristics and processing opportunities of two widely available biopolymers: chitosan and wheat gluten. The interest in these materials is mainly because they are bio-based and obtained as co- or by-products in the fuel and food sectorIn the first study, high solids content chitosan samples (60 wt.%) were successfully extruded. Chitosan extrusion has previously been reported but not chitosan extrusion with a high solids content, which decreases the drying time and increases the production volume. An orthogonal experimental design was used to assess the influence of formulation and processing conditions, and the optimal formulation and conditions were determined from the orthogonal experimental analysis and the qualities of the extrudates. The mechanical properties and processing-liquid mass loss of the optimized extrudates showed that the extrudates became stable within three days. The changes in the mechanical properties depended on the liquid mass loss.In a separate study, monocarboxylic (formic, acetic, propionic, and butyric) acid uptake and diffusion in chitosan films were investigated. It is of importance in order to be able to optimize the production of this material with the casting technique. The time of the equilibration uptake in the chitosan films exposed to propionic and butyric acid was nine months. This long equilibration time encouraged us study the exposed films further. The uptake and diffusivity of acid in the films decreased with increasing acid molecular size. A two-stage absorption curve was observed for the films exposed to propionic acid vapour. The films at the different stages showed different diffusivities. The acid transport was also affected by the structure of the chitosan films. X-ray diffraction suggested that the crystal structure of the original films disappeared after the films had been dried from their acid-swollen state, and that the microstructure of the dried films depended on the molecular size of the acid. Compared with the original films, the dried films retained their ductility, although a decrease in the molecular weight of the chitosan was detected. The water resistance of the acid-exposed films was increased, even though the crystallinity of these films was lower.The third study was devoted to chitosan/wheat gluten blend films cast from aqueous solutions. Different solvent types, additives and drying methods were used to examine their effects on the microstructures of the blended films. Chitosan and wheat gluten were immiscible in the aqueous blend, and the wheat gluten formed a discrete phase, and the homogeneity of the films was improved by using a reducing agent, compared with films prepared using only water/ethanol as cast media. Adding urea and surfactants resulted in a medium homogeneity of the films compared to those prepared with the reducing agents or with only water/ethanol. An elongated wheat gluten phase was observed in a film using glyoxal, in contrast to pure chitosan/wheat gluten blends. The opacity of the different films was studied. The mechanical properties and humidity uptake of the films increased with increasing chitosan content. The films containing 30 wt.% of wheat gluten showed the most promising mechanical properties, close to those of the pristine chitosan films.The final part describes the preparation and properties of a bio-foam composed of a blend of chitosan and wheat gluten. This foam was prepared without any porogen or frozen liquid phase to create porosity. A unique phase distribution of the chitosan and wheat gluten solutions formed without any agitation, and the foam was obtained when the liquid phase were withdrawn under vacuum. These foams showed high mass uptake of n-hexane and water in a short time due to their open pores and high porosity. The maximum uptake of n-hexane measured was 20 times the initial mass of the foam. The foams showed a high rebound resilience (94 % at 20 % compression strain) and they were not broken when subjected to bending.
D. A. Fitch - One of the best experts on this subject based on the ideXlab platform.
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Early radiographic and functional outcomes of a cancellous titanium-coated tibial component for total knee arthroplasty
MUSCULOSKELETAL SURGERY, 2016Co-Authors: D. D. Waddell, K. Sedacki, Y. Yang, D. A. FitchAbstract:Background Various surface coatings have been developed over the past decades to enhance fixation of cementless total knee arthroplasty (TKA). Biofoam^® (MicroPort Orthopedics Inc., Arlington, TN, USA) is a novel cancellous titanium surface coating intended to increase both initial and long-term fixation. The purpose of this study was to investigate the early functional and radiographic outcomes of this coating used in a TKA application. Materials and methods One hundred and four (104) primary TKAs in 85 subjects using Biofoam-coated tibial components were prospectively enrolled at four centers. Subjects were evaluated using Knee Society Scores and radiographic analysis at a minimum follow-up of 24 months. Results Knee Society Scores and flexion were all significantly improved at final follow-up compared to baseline. Radiographic analyses were satisfactory, with no progressive radiolucencies and only a single subject presenting with a radiolucency surrounding a tibial component. There were two revisions in the cohort: one for instability following a ruptured lateral collateral ligament and one for recurrent tibial insert dislocation. Conclusions This is the first study to report clinical outcomes associated with the Biofoam coating used in a cementless TKA application. Early functional scores and radiographic analyses are promising, but further investigations are needed to confirm long-term clinical success with these components.
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Early radiographic and functional outcomes of a cancellous titanium-coated tibial component for total knee arthroplasty
Musculoskeletal Surgery, 2015Co-Authors: D. D. Waddell, K. Sedacki, Y. Yang, D. A. FitchAbstract:Background Various surface coatings have been developed over the past decades to enhance fixation of cementless total knee arthroplasty (TKA). Biofoam® (MicroPort Orthopedics Inc., Arlington, TN, USA) is a novel cancellous titanium surface coating intended to increase both initial and long-term fixation. The purpose of this study was to investigate the early functional and radiographic outcomes of this coating used in a TKA application.
