Published at : 25 Nov 2019
Volume : IJtech
Vol 10, No 6 (2019)
DOI : https://doi.org/10.14716/ijtech.v10i6.3766
Eny Kusrini | Department of Chemical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus Baru UI Depok 16424, Indonesia |
Eko Adhi Setiawan | Department of Electrical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus Baru UI Depok 16424, Indonesia |
Mohammed Ali Berawi | Department of Civil Engineering, Faculty of Engineering, Universitas Indonesia, Kampus UI Depok, Depok 16424, Indonesia |
The pursuit of new materials and
engineering methods for energy sustainability has become an essential, exciting
research issue. Various studies have been conducted to explore new materials
and develop new engineering methods to process new material or re-use waste
material for new energy resources. However, new materials cannot be used
directly as sources of new energy; some of their characteristics need to be
explored to determine their energy potentials. New engineering methods are also
needed to process and prepare new materials, and advanced techniques are needed
to pre-process new materials to remove unused residues that reduce their
performance. Hence, finding new materials and innovating engineering methods to
process them are inextricably linked topics.
Graphene is
a particularly promissing new material because of its extraordinary mechanical,
electrical, thermal, and physical properties, providing many potential
applications in various fields. Graphene is allotrope of carbon with
two-dimensional crystal structure comprising planar sheets of sp2-bonded
carbon atoms densely packed in a honeycomb crystal lattice. The chemical
oxidation of graphite followed by its reduction has become the most potential method
and economical process to produce graphene in bulk quantity. To utilize it in some industrial applications, such as
a catalyst, an additive in water-based drilling fluid, and in advanced material
technology, its dispersion is an important issue, since it is usually applied
using solvent-assisted techniques, such as layer-by-layer assembly,
spin-coating, and filtration. To disperse graphene well, chemical modifications
can be applied on its surface to enhance the capability of graphene oxides to
disperse in water, but the requisite oxygen-containing groups significantly
decrease their electrical properties. To overcome this problem, other
functional groups have been introduced to the graphene structure. Graphene can
be functionalized with covalent and non-covalent modification techniques, both of
which follow the surface modification by reduction. Thermal stability, reduced
fluid loss, and lubricating capabilities are the main advantages of adding
graphene to drilling fluid.
Other issues in many countries include the contamination of anions, such
as fluoride, and heavy metal ions in groundwater, which varies by region based
on availability, level of industrialization, and level of environmental
responsibility. The concentration of fluoride anions in both surface water and
groundwater has been rising in various parts of the world because of discarded
effluents from semiconductors, electroplating, aluminum processing, the glass
and ceramic industries, beryllium extraction, power plants, and water
fluoridation.