The Experts below are selected from a list of 6690 Experts worldwide ranked by ideXlab platform
Alexander Bismarck - One of the best experts on this subject based on the ideXlab platform.
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surface modification of natural fibers using bacteria depositing bacterial cellulose onto natural fibers to create hierarchical fiber reinforced nanocomposites
Biomacromolecules, 2008Co-Authors: Marion Pommet, Julasak Juntaro, Jerry Y Y Heng, Athanasios Mantalaris, Karen Wilson, Gerhard Kalinka, Milo S P Shaffer, Alexander BismarckAbstract:Triggered biodegradable composites made entirely from renewable resources are urgently sought after to improve material recyclability or be able to divert materials from waste streams. Many biobased polymers and natural fibers usually display poor interfacial Adhesion when combined in a composite material. Here we propose a way to modify the surfaces of natural fibers by utilizing bacteria (Acetobacter xylinum) to deposit nanosized bacterial cellulose around natural fibers, which enhances their Adhesion to renewable polymers. This paper describes the process of modifying large quantities of natural fibers with bacterial cellulose through their use as substrates for bacteria during fermentation. The modified fibers were characterized by scanning electron microscopy, single fiber tensile tests, X-ray photoelectron spectroscopy, and inverse gas chromatography to determine their surface and mechanical properties. The Practical Adhesion between the modified fibers and the renewable polymers cellulose acetate butyrate and poly(L-lactic acid) was quantified using the single fiber pullout test.
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fluorinated carbon fibres and their suitability as reinforcement for fluoropolymers
Composites Science and Technology, 2007Co-Authors: Gerhard Kalinka, Michael Q Tran, Natalya V Polyakova, Alexander BismarckAbstract:The interaction between direct fluorinated carbon fibres and various fluoropolymers (ethylene-chlorotrifluoroethylene, poly vinylidene fluoride, fluorinated ethylene propylene copolymer and tetrafluoroethylene-perfluoro alkoxy vinyl ether copolymer) was studied by means of direct wetting measurements between fibres and the polymer melts and single fibre pull-out tests. The results of both techniques allow the Adhesion behaviour between the fibres and the matrices to be predicted. The results obtained show that a low degree of surface fluorination of carbon fibres leads to an improved wettability between the fibres and fluoropolymer melts and this is an indicator for an improved thermodynamic work of Adhesion. The apparent interfacial shear strength as measure of Practical Adhesion, determined by the single fibre pull-out test, increases with increasing degree of surface fluorine content up to a maximum, which depends on the degree of fluorination of the matrix used. The improved interaction between the fibre and the matrix is due to an enhanced compatibility at the fibre/matrix interface.
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interfacial behavior between atmospheric plasma fluorinated carbon fibers and poly vinylidene fluoride
Journal of Colloid and Interface Science, 2007Co-Authors: Kingsley K C Ho, Gerhard Kalinka, Steven Lamoriniere, E Schulz, Alexander BismarckAbstract:Atmospheric-plasma fluorination was used to introduce fluorine functionalities onto the surface of carbon fibers without affecting their bulk properties. The interfacial Adhesion between atmospheric-plasma-fluorinated carbon fibers and poly(vinylidene fluoride) (PVDF) was studied by means of direct wetting measurements and single fiber pullout tests. Measured contact angles of PVDF melt droplets on modified carbon fibers show that short exposure times of carbon fibers to atmospheric-plasma fluorination (corresponding to a degree of surface fluorination of F/C = 0.01 (1.1%)) leads to improved wettability of the fibers by PVDF melts. The apparent interfacial shear strength as a measure of Practical Adhesion, determined by the single-fiber pullout test, increases by 65% under optimal treatment conditions. The improved Practical Adhesion is not due to the formation of transcrystalline regions around the fibers or a change of the bulk matrix crystallinity or to an increased surface roughness; it seems to be due to the compatibilization of the interface caused of the atmospheric-plasma fluorination of the carbon fibers.
Mathieu Ducousso - One of the best experts on this subject based on the ideXlab platform.
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nondestructive evaluation of structural adhesive bonding using the attenuation of zero group velocity lamb modes
Applied Physics Letters, 2020Co-Authors: R Hode, Samuel Raetz, James Blondeau, N Chigarev, N Cuvillier, Vincent Tournat, Mathieu DucoussoAbstract:A laser ultrasonic method is proposed for the nondestructive evaluation (NDE) of structural adhesive bonding. Zero-group-velocity (ZGV) resonances were generated and detected in five trilayer assemblies composed of two asymmetric aluminum alloy plates bonded with an epoxy adhesive. Cohesive and adhesive defects were introduced to degrade the Practical Adhesion. The attenuation of the temporal signal of ZGV resonances was found to provide sufficient information to discriminate between strong and weak bonding. Two metrics characterizing the attenuation were identified, which allow us to quantitatively evaluate the differences between the manufactured samples. A 2D scan of a trilayer assembly with different bond defects demonstrates the imaging capability of this all-optical NDE method.
Gerhard Kalinka - One of the best experts on this subject based on the ideXlab platform.
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surface modification of natural fibers using bacteria depositing bacterial cellulose onto natural fibers to create hierarchical fiber reinforced nanocomposites
Biomacromolecules, 2008Co-Authors: Marion Pommet, Julasak Juntaro, Jerry Y Y Heng, Athanasios Mantalaris, Karen Wilson, Gerhard Kalinka, Milo S P Shaffer, Alexander BismarckAbstract:Triggered biodegradable composites made entirely from renewable resources are urgently sought after to improve material recyclability or be able to divert materials from waste streams. Many biobased polymers and natural fibers usually display poor interfacial Adhesion when combined in a composite material. Here we propose a way to modify the surfaces of natural fibers by utilizing bacteria (Acetobacter xylinum) to deposit nanosized bacterial cellulose around natural fibers, which enhances their Adhesion to renewable polymers. This paper describes the process of modifying large quantities of natural fibers with bacterial cellulose through their use as substrates for bacteria during fermentation. The modified fibers were characterized by scanning electron microscopy, single fiber tensile tests, X-ray photoelectron spectroscopy, and inverse gas chromatography to determine their surface and mechanical properties. The Practical Adhesion between the modified fibers and the renewable polymers cellulose acetate butyrate and poly(L-lactic acid) was quantified using the single fiber pullout test.
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fluorinated carbon fibres and their suitability as reinforcement for fluoropolymers
Composites Science and Technology, 2007Co-Authors: Gerhard Kalinka, Michael Q Tran, Natalya V Polyakova, Alexander BismarckAbstract:The interaction between direct fluorinated carbon fibres and various fluoropolymers (ethylene-chlorotrifluoroethylene, poly vinylidene fluoride, fluorinated ethylene propylene copolymer and tetrafluoroethylene-perfluoro alkoxy vinyl ether copolymer) was studied by means of direct wetting measurements between fibres and the polymer melts and single fibre pull-out tests. The results of both techniques allow the Adhesion behaviour between the fibres and the matrices to be predicted. The results obtained show that a low degree of surface fluorination of carbon fibres leads to an improved wettability between the fibres and fluoropolymer melts and this is an indicator for an improved thermodynamic work of Adhesion. The apparent interfacial shear strength as measure of Practical Adhesion, determined by the single fibre pull-out test, increases with increasing degree of surface fluorine content up to a maximum, which depends on the degree of fluorination of the matrix used. The improved interaction between the fibre and the matrix is due to an enhanced compatibility at the fibre/matrix interface.
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interfacial behavior between atmospheric plasma fluorinated carbon fibers and poly vinylidene fluoride
Journal of Colloid and Interface Science, 2007Co-Authors: Kingsley K C Ho, Gerhard Kalinka, Steven Lamoriniere, E Schulz, Alexander BismarckAbstract:Atmospheric-plasma fluorination was used to introduce fluorine functionalities onto the surface of carbon fibers without affecting their bulk properties. The interfacial Adhesion between atmospheric-plasma-fluorinated carbon fibers and poly(vinylidene fluoride) (PVDF) was studied by means of direct wetting measurements and single fiber pullout tests. Measured contact angles of PVDF melt droplets on modified carbon fibers show that short exposure times of carbon fibers to atmospheric-plasma fluorination (corresponding to a degree of surface fluorination of F/C = 0.01 (1.1%)) leads to improved wettability of the fibers by PVDF melts. The apparent interfacial shear strength as a measure of Practical Adhesion, determined by the single-fiber pullout test, increases by 65% under optimal treatment conditions. The improved Practical Adhesion is not due to the formation of transcrystalline regions around the fibers or a change of the bulk matrix crystallinity or to an increased surface roughness; it seems to be due to the compatibilization of the interface caused of the atmospheric-plasma fluorination of the carbon fibers.
R Hode - One of the best experts on this subject based on the ideXlab platform.
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nondestructive evaluation of structural adhesive bonding using the attenuation of zero group velocity lamb modes
Applied Physics Letters, 2020Co-Authors: R Hode, Samuel Raetz, James Blondeau, N Chigarev, N Cuvillier, Vincent Tournat, Mathieu DucoussoAbstract:A laser ultrasonic method is proposed for the nondestructive evaluation (NDE) of structural adhesive bonding. Zero-group-velocity (ZGV) resonances were generated and detected in five trilayer assemblies composed of two asymmetric aluminum alloy plates bonded with an epoxy adhesive. Cohesive and adhesive defects were introduced to degrade the Practical Adhesion. The attenuation of the temporal signal of ZGV resonances was found to provide sufficient information to discriminate between strong and weak bonding. Two metrics characterizing the attenuation were identified, which allow us to quantitatively evaluate the differences between the manufactured samples. A 2D scan of a trilayer assembly with different bond defects demonstrates the imaging capability of this all-optical NDE method.
Marion Pommet - One of the best experts on this subject based on the ideXlab platform.
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surface modification of natural fibers using bacteria depositing bacterial cellulose onto natural fibers to create hierarchical fiber reinforced nanocomposites
Biomacromolecules, 2008Co-Authors: Marion Pommet, Julasak Juntaro, Jerry Y Y Heng, Athanasios Mantalaris, Karen Wilson, Gerhard Kalinka, Milo S P Shaffer, Alexander BismarckAbstract:Triggered biodegradable composites made entirely from renewable resources are urgently sought after to improve material recyclability or be able to divert materials from waste streams. Many biobased polymers and natural fibers usually display poor interfacial Adhesion when combined in a composite material. Here we propose a way to modify the surfaces of natural fibers by utilizing bacteria (Acetobacter xylinum) to deposit nanosized bacterial cellulose around natural fibers, which enhances their Adhesion to renewable polymers. This paper describes the process of modifying large quantities of natural fibers with bacterial cellulose through their use as substrates for bacteria during fermentation. The modified fibers were characterized by scanning electron microscopy, single fiber tensile tests, X-ray photoelectron spectroscopy, and inverse gas chromatography to determine their surface and mechanical properties. The Practical Adhesion between the modified fibers and the renewable polymers cellulose acetate butyrate and poly(L-lactic acid) was quantified using the single fiber pullout test.