AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Weathering and Heating of a Carbon Nanotube/Epoxy Composites and the Impact on Particle Release and Toxicity
Lukas Schlagenhauf, Bahareh Kianfar, Tina Buerki-Thurnherr, Yu-Ying Kuo, Yeon Kyoung Bahk, Adrian Wichser, Frank Nüesch, Peter Wick, JING WANG, ETH Zurich/Empa
Abstract Number: 160 Working Group: Aerosol Exposure
Abstract Weathering causes a weakening of the nanocomposite matrix, and thus can induce a release of embedded carbon nanotubes (CNTs) when an abrasion process is applied. In this study, the impact on the release of particles from a CNT/epoxy nanocomposite by two weathering processes was investigated, for immersion in water and UV-light exposure. We measured the water uptake kinetics and chemical changes on the surface due to UV exposure. No additional release of CNTs due to weathering was detected when an abrasion process was applied. The toxicity tests revealed that abraded particles from the nanocomposites did not induce additional acute cytotoxic effects compared to particles from the neat epoxy.
One of the applications is to use the CNTs as flame retardants in nanocomposites. We performed experiments to decompose the samples in a furnace by exposure to increasing temperatures at a constant heating rate and under ambient air or nitrogen atmosphere. Different samples were investigated, incuding a neat epoxy, nanocomposites with 0.1 wt% and 1 wt% CNTs, and nanocomposites with functionalized CNTs. The results showed that the added CNTs had little effect on the decomposition kinetics of the investigated samples, but the weight of the remaining residues after decomposition was influenced significantly. Analysis of collected particles by TEM revealed that no detectable amount of MWCNTs was released, but micrometer sized fibrous particles were collected.