Ki Myoung Yuna, b, Adi Bagus Suryamasa, Ferry Iskandara, d, Li Baoc, Hitoshi Niinumac and Kikuo Okuyamaa, 
, 
Polymer 
nanofiber
mats with various morphology structures (nanofiber, beaded-nanofiber, and composite particle/nanofiber) were prepared by electrospinning for application to aerosol particle filtration. The filtration performance of these polymer nanofiber
mats was evaluated based on quality factors generated from measurement
of penetration through the filter by sodium chloride (NaCl) aerosol
particles ranging from 20 to 300 nm. These filtration test results
showed that the quality factors of beaded-nanofiber
filter mats were the best, even though the aerosol particle penetration
of them was the highest of the morphology structures. The results of
the present study show that morphology optimization of polymer nanofibers
is an effective method for improvement of filtration performance, and
it must be the future direction for development of new filtration media.
Polymer nanofiber mats with various morphology structures (nanofiber, beade-nanofiber, and composite particle/nanofiber)
were prepared by electrospinning for application to aerosol particle
filtration. The filtration performance was evaluated based on quality
factors generated from measurement of penetration through the filter by
sodium chloride (NaCl) aerosol particles ranging from 20 to 300 nm.
-structured sandwich composites response to low-velocity impact Antonio F., , , Maria Gabriela R.
This paper investigates the influence of exfoliated nano-structures on sandwich composites under impact loadings. A set of sandwich composites plates made of fiberglass/nano-modified
epoxy face sheets and polystyrene foams was prepared. The core was
25 mm thick and the face sheets were made of eight layers of woven
fabric glass fibers and nano-modified epoxy (≈0.8 mm of thickness). The epoxy system was bisphenol A resin and an amine hardener. The fiber
volume fraction used was around 65%, while the nanoclay content varied
from 0 wt.% to 10 wt.%. The nanoclay used was Cloisite 30B from
Southern Clay. The sandwich panels were submitted to low-velocity
impact tests with energies from 5 J to 75 J. Two sets of experiments
were performed, i.e. high velocity + low mass and low velocity + high
mass. Damage caused by the two groups of experiments and peak forces
measured were dissimilar. The results show that the addition of 5 wt.%
of nanoclay lead to a more efficient energy absorption. The failure
modes were also analyzed, and they seems to be affected by the nanoclay
addition to face sheets.
Keywords: Sandwich composites; Nanocomposites; Low-velocity impact; Nanoclay; Mechanical properties; Modeling
- to meter-scale building Danijel, , Martin
The construction industry will have to find new ways of building to accomplish radical reductions of pollution and waste. Nano
and biotechnology along with information technology have the potential
to constitute a new building paradigm. The paper describes the concept
of nano-
to meter-scale building, which is based on this potential. The concept
is not focused on the application of nanomaterials like nanosilica or
carbon nanotubes, but on a new way of building, which unfolds from the nano into the meter range. It is based on bionanorobots, producing building materials using carbon extracted from CO2
in the air. Criteria and requirements regarding relevant technologies
are defined and compared to the current research in the fields of
bioengineering, nanorobotics, and characteristics and production of
carbon nanotubes. The paper also presents a concept of a new building
technology that would enable control and monitoring of construction at
the nano
level, as well as requirements regarding design methods and tools
including the building information model that will become the only
human input to the automated nano- to meter-scale building process. The paper concludes with suggestions for further research and development.
-clay on physico-mechanical properties of cement mortar M.S., a, , S.H.
In this work, several nanomaterials have been used in cementitious matrices: multi wall carbon nanotubes (MWCNTs) and nano-clays. The physico-mechanical behavior of these nanomaterials and ordinary Portland cement (OPC) was studied. The nano-clay used in this investigation was nano-kaolin. The metakaolin was prepared by thermal activation of nano-kaolin
clay at 750 °C for 2 h. The organic ammonium chloride was used to aid
in the exfoliation of the clay platelets. The blended cement used in
this investigation consists of ordinary Portland cement, carbon
nanotubes and exfoliated nano metakaolin. The OPC was substituted by 6 wt.% of cement by nano
metakaolin (NMK) and the carbon nanotube was added by ratios of 0.005,
0.02, 0.05 and 0.1 wt.% of cement. The blended cement: sand ratio used
in this investigation was 1:2 wt.%. The blended cement mortar was
prepared using water/binder ratio of 0.5 wt.% of cement. The fresh
mortar pastes were first cured at 100% relative humidity for 24 h and
then cured in water for 28 days. Compressive strength, phase
composition and microstructure of blended cement were investigated. The
results showed that, the replacement of OPC by 6 wt.% NMK increases the
compressive strength of blended mortar by 18% compared to control mix
and the combination of 6 wt.% NMK and 0.02 wt.% CNTs increased the
compressive strength by 29% than control.
Keywords: Carbon nanotube; Nano-clay; Cement mortar; Thermal analysis; Compressive strength; Microstructure
-reinforced epoxies S.A., a, , J.M.
In this paper, an atomistic-based
representative volume element (RVE) is developed to characterize the
behavior of carbon nanotube (CNT) reinforced amorphous epoxies. The RVE
consists of the carbon nanotube, the surrounding epoxy matrix, and the
CNT/epoxy interface. An atomistic-based continuum representation is
adopted throughout all the components of the RVE. By equating the
associated strain energies under identical loading conditions, we were
able to homogenize the RVE into a representative fiber.
The homogenized RVE was then employed in a micromechanical analysis to
predict the effective properties of the newly developed CNT-reinforced
amorphous epoxy. Numerical examples show that the effect of volume
fraction, orientation, and aspect ratio of the continuous fibres
on the properties of the CNT-reinforced epoxy adhesives can be
significant. These results have a direct bearing on the design and
development of nano-tailored adhesives for use in structural adhesive bonds.
Keywords: Atomistic-based continuum; Nano-reinforced epoxies; Representative volume element