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E u r o S c i C o n C o n f e r e n c e o n
Nanotechnology &
Smart Materials
Nano Research & Applications
ISSN 2471-9838
O c t o b e r 0 4 - 0 6 , 2 0 1 8
Am s t e r d a m , N e t h e r l a n d s
Nanotechnology & Smart Materials 2018
Page 59
T
his work examines the effects of nano-additives, including core-shell rubber
(CSR) nanoparticles, silica nanoparticles, multi-walled carbon nanotubes
(MWCNTs), graphene nanoplatelets and their hybrid combinations on the
mechanical properties, electrical conductivity and fracture toughness of epoxy
based structural adhesives and carbon reinforced plastics (CFRPs). The addition
of CSR nanoparticles significantly increased the fracture toughness of epoxies
with the main toughening mechanisms being rubber cavitation followed by plastic
void growth and shear band yielding. For example, the addition of 30 vol% CSR
nanoparticles increased the fracture energy of a structural adhesive joint by over
ten fold. However, the addition of CSR nanoparticles reduced the mechanical
properties, i.e. stiffness of the modified resin. Hybrid nano-composites where
silica/CSR nanoparticles weremixed into the resin at appropriate ratios eliminated
thisproblemandagoodbalancebetweenthetoughnessandmechanicalproperties
is achieved i.e. nano-composites with a fracture energy five times that of the
unmodifiedepoxywereobtainedwithnodiscernibledrop inmechanical properties.
The addition of a small amount ofMWCNTs/graphene yielded reasonable increase
in the fracture energy of epoxy. However, the agglomeration of MWCNTs/graphene
at a higher concentration resulted in decrease in the mechanical properties and
fracture toughness. Excellent electric conductivity was obtained for adding only
a small amount of MWCTNs/graphene (<0.5%) in the epoxies. The incorporation
of MWCNTs to bulk epoxy and CFRPs moderately increased the mode-I fracture
energy, and significantly increased the mode-II fracture energy, i.e. the average
mode-II fracture energy of CFRPs increased from 2026 J/m2 to 5491 J/m2 due
to the addition of 1 wt% MWCNTs. The superior toughening performance of
MWCNTs in mode-II fracture is attributed to two reasons: 1) increased MWCNT
breaking and crack deflection mechanisms under shear load, and 2) large fracture
process zone accompanied with extensive hackle markings and micro-cracks
ahead of the mode-II crack tip of CFRPs, which resulted in significant number of
MWCNTs contributing to toughening mechanisms.
Biography
AIvankovicisaProfessorofMechanicsofMaterials(since2004)
and Head of Mechanical Engineering Programs (since 2012),
(Head of Mechanical Engineering Discipline 2006-2011). He is
a Founding Director of UCD Centre of Adhesion and Adhesives
established in 2010, and UCD-Bekaert University Technology
Centre (UTC) established in 2015. He is also a Visiting Professor
at Imperial College London, ex Head of Structural Adhesives
Division of Adhesion Society (2014-2016), Irish ElectedMember
for International Fracture Society (2017-), an External Examiner
of ME Mechanical program at Trinity College Dublin (2016-).
Currently, he leads the research group of 5 MSc, 7 PhD students
and 4 PostDoc researchers. The main research focus of the
group is the process-structure-property relationship towards
materials by design, which involves multiscale characterisation
and modelling of thermo-mechanical, damage and fracture
behaviour and nanomodification and tailor design of polymers,
composites, adhesives and super hard materials. Recently, the
group’s research also focuses on additive manufacturing. The
group has access to excellent processing, thermo mechanical
testing, video, microscopy, analytical and high performance
computing facilities. His track record includes: i) 340
publications (105 journal, 5 book chapters, 230 conference),
ii) 25 graduated PhDs (4 of which are Full Professors), 25 MSc
students, 15 past Postdocs and 1 Marie Curie Research Fellow,
iii) 1 patent, iv) 1 licence, v) Strong links and collaboration with
industry and academia both nationally and internationally, vi)
Memberships of a number of scientific committees, Editorial
Boards, Review Panels, coordination of an international ESIS
Mixed Mode Round Robin. His area of expertise includes
fracture, modelling, polymers, composites, adhesives.
Alojz.ivankovic@ucd.ieTailoring the properties of structural
adhesives and fibre reinforced plastics
using nanoadditives
A Ivankovic
1
, N Murphy
1
, D Quan
1
, D
Carolan
2
, C Rounge
1
and J Labarga Urdaniz
3
1
University College Dublin, Ireland
2
FAC Technology, UK
3
Universidad Politecnica de Madrid, Spain
A Ivankovic et al., Nano Res Appl Volume:4
DOI: 10.21767/2471-9838-C6-024