The formation of ice can be very detrimental to flight safety, since the ice accumulated on the s... more The formation of ice can be very detrimental to flight safety, since the ice accumulated on the surfaces of the aircraft can alter both the aerodynamics and the weight, leading in some cases to catastrophic lift reductions. Traditional active Ice Protection Systems (IPS) require high energy to work, add on weight to the aircraft and complexity to the manufacturing. On the other hand, the use of passive IPS, such as superhydrophobic/icephobic coatings, cannot be successful in harsh environmental conditions or for prolongated icing expositions. So, a valuable solution could be the combination of active and passive IPS with the aim to combine the advantage of both of them and mitigate their drawbacks. In this context, the present work proposes two innovative Hybrid IPS, based on an ultrasound piezoelectric system and on a thermoelectric system manufactured using carbon fibers as heater elements, both combined with a superhydrophobic coating with the aim to study the effect of the surfa...
Il lavoro di tesi illustra il processo di selezione, caratterizzazione ed integrazioni di matrici... more Il lavoro di tesi illustra il processo di selezione, caratterizzazione ed integrazioni di matrici sia termoindurenti che termoplastiche nanocaricate con nanotubi di carbonio in compositi fibrorinforzati. Le matrici nanocaricate sono state dapprima caratterizzate nella loro funzionalita piezoresistiva, dopodiche sono stati messi a punto dei processi di realizzazione di tali matrici in compositi fibrorinforzati. Infine sono state valutate le proprieta di piezo-resistivita dei compositi realizzati al fine di valutare la possibilita di utilizzare matrici nanocaricate come sistema intrinseco peril monitoraggio strutturale del composito. Un’ultima parte del lavoro e stata dedicata allo studio circa la possibilita di integrare capsule micrometriche contenenti un componente reattivo capace di riparare il composito in caso di delaminazione.
A suitably modified resin film infusion (RFI) process was used for manufacturing carbon fiber-rei... more A suitably modified resin film infusion (RFI) process was used for manufacturing carbon fiber-reinforced composites (CFRCs) impregnated with a resin containing nanocages of glycidyl polyhedral oligomeric silsesquioxane (GPOSS) for enhancing flame resistance and multi-wall carbon nanotubes (MWCNTs) to contrast the electrical insulating properties of the epoxy resin. The effects of the different numbers (7, 14 and 24) of the plies on the equivalent direct current (DC) and alternating current (AC) electrical conductivity were evaluated. All the manufactured panels manifest very high values in electrical conductivity. Besides, for the first time, CFRC strings were analyzed by tunneling atomic force microscopy (TUNA) technique. The electrical current maps highlight electrically conductive three-dimensional networks incorporated in the resin through the plies of the panels. The highest equivalent bulk conductivity is shown by the seven-ply panel characterized by the parallel (σ//0°) in-pl...
This paper proposes an effective manufacturing process developed to overcome drawbacks that can o... more This paper proposes an effective manufacturing process developed to overcome drawbacks that can occur using a nanofilled resin as matrix in aeronautical composites. Nanoparticles embedded in epoxy resins impregnating carbon fibers are able to improve a composite with new desired functionalities. As soon as the nanoparticles are dispersed in a resin, the viscosity dizzily rises and usually, the traditional manufacturing processes are not suitable to obtain a good quality of the manufactured panels. An alternative method has been developed starting from the Resin Film Infusion (RFI) process. This method has been firstly tested on several flat panels, and then it has been transferred on a more complex shaped panel with three stringers. In this work, a flame resistant resin based on a tetrafunctional epoxy precursor filled with carbon nanotubes to increase electrical conductivity, has been used for the panel manufacturing.
A very simple process to manufacture CFRCs was used. DC conductivity values (20 kS m−1 for the in... more A very simple process to manufacture CFRCs was used. DC conductivity values (20 kS m−1 for the in plane value and 3.9 S m−1 for the out of plane at T = 30 °C) are among the highest values found for CFRCs impregnated with MWCNTs based epoxy-resin.
The correlation between electrical conductivity and magnetic field response, due to multi-walled ... more The correlation between electrical conductivity and magnetic field response, due to multi-walled carbon nanotubes' (MWCNTs) distribution within the polymer matrix, has been demonstrated using a contactless and non-destructive technique. Multi-walled carbon nanotubes, both buckypaper and reinforced epoxy matrix specimens with different nanotube percentages, have been inspected using the eddy current technique based on an HTc SQUID magnetometer. The SQUID magnetic
ABSTRACT This work describes a successful attempt toward the development of CFRCs based on nanofi... more ABSTRACT This work describes a successful attempt toward the development of CFRCs based on nanofilled epoxy resins. The epoxy matrix was prepared by mixing a tetrafunctional epoxy precursor with a reactive diluent which allows to reduce the viscosity of the initial epoxy precursor and facilitate the nanofiller dispersion step. As nanofiller, multiwall carbon nanotubes (MWCNTs) were embedded in the epoxy matrix with the aim of improving the electrical properties of the resin used to manufacture CFRCs. Panels were manufactured by Resin Film Infusion (RFI) using a non-usual technique to infuse a nano-filled resin into a carbon fiber dry preform.
The formation of ice can be very detrimental to flight safety, since the ice accumulated on the s... more The formation of ice can be very detrimental to flight safety, since the ice accumulated on the surfaces of the aircraft can alter both the aerodynamics and the weight, leading in some cases to catastrophic lift reductions. Traditional active Ice Protection Systems (IPS) require high energy to work, add on weight to the aircraft and complexity to the manufacturing. On the other hand, the use of passive IPS, such as superhydrophobic/icephobic coatings, cannot be successful in harsh environmental conditions or for prolongated icing expositions. So, a valuable solution could be the combination of active and passive IPS with the aim to combine the advantage of both of them and mitigate their drawbacks. In this context, the present work proposes two innovative Hybrid IPS, based on an ultrasound piezoelectric system and on a thermoelectric system manufactured using carbon fibers as heater elements, both combined with a superhydrophobic coating with the aim to study the effect of the surfa...
Il lavoro di tesi illustra il processo di selezione, caratterizzazione ed integrazioni di matrici... more Il lavoro di tesi illustra il processo di selezione, caratterizzazione ed integrazioni di matrici sia termoindurenti che termoplastiche nanocaricate con nanotubi di carbonio in compositi fibrorinforzati. Le matrici nanocaricate sono state dapprima caratterizzate nella loro funzionalita piezoresistiva, dopodiche sono stati messi a punto dei processi di realizzazione di tali matrici in compositi fibrorinforzati. Infine sono state valutate le proprieta di piezo-resistivita dei compositi realizzati al fine di valutare la possibilita di utilizzare matrici nanocaricate come sistema intrinseco peril monitoraggio strutturale del composito. Un’ultima parte del lavoro e stata dedicata allo studio circa la possibilita di integrare capsule micrometriche contenenti un componente reattivo capace di riparare il composito in caso di delaminazione.
A suitably modified resin film infusion (RFI) process was used for manufacturing carbon fiber-rei... more A suitably modified resin film infusion (RFI) process was used for manufacturing carbon fiber-reinforced composites (CFRCs) impregnated with a resin containing nanocages of glycidyl polyhedral oligomeric silsesquioxane (GPOSS) for enhancing flame resistance and multi-wall carbon nanotubes (MWCNTs) to contrast the electrical insulating properties of the epoxy resin. The effects of the different numbers (7, 14 and 24) of the plies on the equivalent direct current (DC) and alternating current (AC) electrical conductivity were evaluated. All the manufactured panels manifest very high values in electrical conductivity. Besides, for the first time, CFRC strings were analyzed by tunneling atomic force microscopy (TUNA) technique. The electrical current maps highlight electrically conductive three-dimensional networks incorporated in the resin through the plies of the panels. The highest equivalent bulk conductivity is shown by the seven-ply panel characterized by the parallel (σ//0°) in-pl...
This paper proposes an effective manufacturing process developed to overcome drawbacks that can o... more This paper proposes an effective manufacturing process developed to overcome drawbacks that can occur using a nanofilled resin as matrix in aeronautical composites. Nanoparticles embedded in epoxy resins impregnating carbon fibers are able to improve a composite with new desired functionalities. As soon as the nanoparticles are dispersed in a resin, the viscosity dizzily rises and usually, the traditional manufacturing processes are not suitable to obtain a good quality of the manufactured panels. An alternative method has been developed starting from the Resin Film Infusion (RFI) process. This method has been firstly tested on several flat panels, and then it has been transferred on a more complex shaped panel with three stringers. In this work, a flame resistant resin based on a tetrafunctional epoxy precursor filled with carbon nanotubes to increase electrical conductivity, has been used for the panel manufacturing.
A very simple process to manufacture CFRCs was used. DC conductivity values (20 kS m−1 for the in... more A very simple process to manufacture CFRCs was used. DC conductivity values (20 kS m−1 for the in plane value and 3.9 S m−1 for the out of plane at T = 30 °C) are among the highest values found for CFRCs impregnated with MWCNTs based epoxy-resin.
The correlation between electrical conductivity and magnetic field response, due to multi-walled ... more The correlation between electrical conductivity and magnetic field response, due to multi-walled carbon nanotubes' (MWCNTs) distribution within the polymer matrix, has been demonstrated using a contactless and non-destructive technique. Multi-walled carbon nanotubes, both buckypaper and reinforced epoxy matrix specimens with different nanotube percentages, have been inspected using the eddy current technique based on an HTc SQUID magnetometer. The SQUID magnetic
ABSTRACT This work describes a successful attempt toward the development of CFRCs based on nanofi... more ABSTRACT This work describes a successful attempt toward the development of CFRCs based on nanofilled epoxy resins. The epoxy matrix was prepared by mixing a tetrafunctional epoxy precursor with a reactive diluent which allows to reduce the viscosity of the initial epoxy precursor and facilitate the nanofiller dispersion step. As nanofiller, multiwall carbon nanotubes (MWCNTs) were embedded in the epoxy matrix with the aim of improving the electrical properties of the resin used to manufacture CFRCs. Panels were manufactured by Resin Film Infusion (RFI) using a non-usual technique to infuse a nano-filled resin into a carbon fiber dry preform.
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