Multifunktionale Carbonfaser-Oberflächen und Grenzschichten in Verbundwerkstoffen
Zusammenfassung der Projektergebnisse
We have developed multifunctional fiber surfaces and composite interphases with 2D nanoplatelets. Firstly, this work highlights the potential opportunities to modification of fiber surface coatings to enhance mechanical properties of carbon or glass fibers. We found that the coated graphene nanoplatelets (GNPs) on fiber surfaces provide better protection against mechanical scrapes and also improvement of tensile strength. By healing the critical defects which limit the mechanical strength of fibers, the nanostructured carbon fibers show a maximum improvement in tensile strength up to 25%. Secondly, we have developed the coatings with 2D nanoplatelets, which can lead to fiber surfaces and composite interphases as smart sensor systems. A strategy was provided for overlapping nanoparticles on curved fiber surface based on fiber oriented capillary flow for suppressing the “coffee ring” effect. An electrically conductive carbon nanoparticle “skin” is developed, which integrates multifunctional sensing capabilities for the measurement of mechanical deformation at the nanoscale level, water vapor, RH (remote monitoring of human breathing), liquid–solid phase transition, and temperature. The overlapping nanoparticle “skin” reveals surprising freezing point far below 0 °C for liquid–solid phase transition of trance water on solid surface, which might be helpful to understand why some plants with thin cell walls survive below-freezing temperatures in winter. Thirdly, we reported a surprising observation of variable structural coloration in a composite interphase region from red, orange, yellow to green owing to the interaction of light with the mechanical tuning of periodic photonic nanostructures. Material failure usually starts with tiny nano-scale cracks and deformations, invisible to the eye, which possibly cause catastrophic fractures. Our method with incorporated variable structural coloration and electrical sensing functionality brings a first valuable step towards danger rating and the early warning of microcracks prior to a material’s failure, using a few colors for addressing danger, alarm and safety in a ‘‘traffic light’’ system. This is the first time that variable structural coloration has been used to perceive material deformation at the nanoscale, which is an important step for inspiring ‘greener’ technological applications with ideally ‘no’ power consumption, allowing for the materials to be labelled by variable coloration. Finally, we have developed microcapsules entrapped with healing-agent as new coating materials for self-healing functions, leading to much better survival to the weather/marine environment and surface wear. The nanometer-thick shells of graphene oxide microcapsules (GOMCs) were built by the liquid crystalline assembling of graphene oxide (GO) sheets. To conclude, we have contributed special pathways using 2D nanoplatelets for introduce multifunctionalities to conventional fiber and composite interphase. As modern composites move more toward lighter and stronger, they must also move toward “smarter.” An important open question emerging from our project is how to extend the achievement from basic research to large-scale manufacturing of novel self-healing and structural health monitoring by variable structural coloration.
Projektbezogene Publikationen (Auswahl)
- Verbesserte Grenzflächenhaftung. Carbon Composites Magazin., ISSN 2366-8024, 2 (2014) 38
S.L. Gao, E. Mäder and J. Hiller
- Multifunctional interphases in polymer composites. in Multifunctionality of Polymer Composites, Editors: Klaus Friedrich, Ulf Breuer, Publisher: Elsevier, ISBN: 978-0-323-26434-1, (2015) 338-360
S.L. Gao and E. Mäder
(Siehe online unter https://dx.doi.org/10.1016/B978-0-323-26434-1.00010-6) - Water vapour sensing by carbon nanoparticle skin. Adv. Mater. Interfaces, 2 (2015) 1500244
Y.H. Deng, J.W. Liu, E. Mäder, G. Heinrich and S.L. Gao
(Siehe online unter https://doi.org/10.1002/admi.201500244) - Self-assembled graphene oxide microcapsules in Pickering emulsions for selfhealing waterborne polyurethane coatings. Compos. Sci. Technol., 151 (2017) 282-290
J. Li, Q.K. Feng, J. Cui, Q. Yuan, H. Qiu, S.L. Gao, J.H. Yang
(Siehe online unter https://doi.org/10.1016/j.compscitech.2017.07.031) - Variable structural coloration of composite interphase. Mater. Horiz., 4 (2017) 389-395
Y.H. Deng, S.L. Gao, J.W. Liu, U. Gohs, E. Mäder and G. Heinrich
(Siehe online unter https://doi.org/10.1039/c6mh00559d)
