TY - JOUR

T1 - Influence of carbon nanoparticle modification on the mechanical and electrical properties of epoxy in small volumes

AU - Leopold, Christian

AU - Augustin, Till

AU - Schwebler, Thomas

AU - Lehmann, Jonas

AU - Liebig, Wilfried V.

AU - Fiedler, Bodo

N1 - Funding Information: This work was carried out with funding from the German Research Foundation (DFG) within the project number FI 688/5-1. This financial support is gratefully acknowledged. The second author kindly acknowledges the financial support from Landesforschungsförderung Hamburg (project: Health-Monitoring von Faserverbundstrukturen mit Hilfe von Sensorarrays, Grant No. LFF-FV 05). We thank OCSiAl, Russia for the support of the SWCNTs. Publisher Copyright: © 2017

PY - 2017/11/15

Y1 - 2017/11/15

N2 - The influence of nanoparticle morphology and filler content on the mechanical and electrical properties of carbon nanoparticle modified epoxy is investigated regarding small volumes. Three types of particles, representing spherical, tubular and layered morphologies are used. A clear size effect of increasing true failure strength with decreasing volume is found for neat and carbon black modified epoxy. Carbon nanotube (CNT) modified epoxy exhibits high potential for strength increase, but dispersion and purity are critical. In few layer graphene modified epoxy, particles are larger than statistically distributed defects and initiate cracks, counteracting any size effect. Different toughness increasing mechanisms on the nano- and micro-scale depending on particle morphology are discussed based on scanning electron microscopy images. Electrical percolation thresholds in the small volume fibres are significantly higher compared to bulk volume, with CNT being found to be the most suitable morphology to form electrical conductive paths. Good correlation between electrical resistance change and stress strain behaviour under tensile loads is observed. The results show the possibility to detect internal damage in small volumes by measuring electrical resistance and therefore indicate to the high potential for using CNT modified polymers in fibre reinforced plastics as a multifunctional, self-monitoring material with improved mechanical properties.

AB - The influence of nanoparticle morphology and filler content on the mechanical and electrical properties of carbon nanoparticle modified epoxy is investigated regarding small volumes. Three types of particles, representing spherical, tubular and layered morphologies are used. A clear size effect of increasing true failure strength with decreasing volume is found for neat and carbon black modified epoxy. Carbon nanotube (CNT) modified epoxy exhibits high potential for strength increase, but dispersion and purity are critical. In few layer graphene modified epoxy, particles are larger than statistically distributed defects and initiate cracks, counteracting any size effect. Different toughness increasing mechanisms on the nano- and micro-scale depending on particle morphology are discussed based on scanning electron microscopy images. Electrical percolation thresholds in the small volume fibres are significantly higher compared to bulk volume, with CNT being found to be the most suitable morphology to form electrical conductive paths. Good correlation between electrical resistance change and stress strain behaviour under tensile loads is observed. The results show the possibility to detect internal damage in small volumes by measuring electrical resistance and therefore indicate to the high potential for using CNT modified polymers in fibre reinforced plastics as a multifunctional, self-monitoring material with improved mechanical properties.

KW - Damage mechanisms

KW - Fractography

KW - Percolation behaviour

KW - Sensing

KW - Structural health monitoring

KW - True failure strength

KW - Engineering

UR - http://www.scopus.com/inward/record.url?scp=85026393969&partnerID=8YFLogxK

U2 - 10.1016/j.jcis.2017.07.085

DO - 10.1016/j.jcis.2017.07.085

M3 - Journal articles

C2 - 28763766

AN - SCOPUS:85026393969

VL - 506

SP - 620

EP - 632

JO - Journal of Colloid and Interface Science

JF - Journal of Colloid and Interface Science

SN - 0021-9797

ER -