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Chemistry and Ecology
ISSN: 0275-7540 (Print) 1029-0370 (Online) Journal homepage: http://www.tandfonline.com/loi/gche20
Titanium dioxide nanoparticles: synthesis,
characterisations and aquatic ecotoxicity effects
Amine Mezni, Samir Alghool, Badreddine Sellami, Nesrine Ben Saber & Tariq
Altalhi
To cite this article: Amine Mezni, Samir Alghool, Badreddine Sellami, Nesrine Ben Saber & Tariq
Altalhi (2018) Titanium dioxide nanoparticles: synthesis, characterisations and aquatic ecotoxicity
effects, Chemistry and Ecology, 34:3, 288-299, DOI: 10.1080/02757540.2017.1420178
To link to this article: https://doi.org/10.1080/02757540.2017.1420178
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RESEARCH ARTICLE
Titanium dioxide nanoparticles: synthesis, characterisations
and aquatic ecotoxicity effects
Amine Mezni
a
, Samir Alghool
a
, Badreddine Sellami
c
, Nesrine Ben Saber
b
and
Tariq Altalhi
a
a
Department of Chemistry –Faculty of Science, Taif University, Taif, Saudi Arabia;
b
Unité de recherche
‘Synthèse et Structure de Nanomatériaux’UR11ES30, Faculté des Sciences de Bizerte, Université de Carthage,
Jarzouna, Tunisie;
c
Institut National des Sciences et Technologies de la Mer, Tabarka, Tunisia
ABSTRACT
Little information is available on the potential ecotoxicity of
nanomaterials in the marine environment. In particular, the aquatic
ecotoxicity impact of titanium dioxide (TiO
2
) has been rarely
reported. To carefully address this issue, we report on the synthesis
of TiO
2
NPs using solvothermal process. The structure and
morphology of the prepared TiO
2
nanoparticles were characterised
using different techniques. To study the potential ecotoxicity effect
of TiO
2
, antioxidant system of mediterranean bivalves (Mytilus
galloprovincialis) was used, measuring three oxidative biomarkers
(ROS production, SOD activity and GSH/GSSG level). No
considerable effect was found in the digestive glands of any of the
groups treated with TiO
2
with concentration gradients ranging from
1 to 100 mg/L. Thus, the level of the superoxide anion, the activity
of an antioxidant enzyme superoxide dismutase (SOD) and the GSH/
GSSG ratio showed no significantly differences in digestive glands
of all treated groups compared to the control. However, slight
modifications were observed in the gills at high concentrations.
These results demonstrated that TiO
2
appears to exert little toxicity
on marine mussels after a short-term exposure at high
concentration. However, before considering the use of this
nanomaterial in various applications, further complementary studies
are required in order to ensure the environmental safety of these NPs.
ARTICLE HISTORY
Received 26 May 2017
Final Version Received 18
December 2017
KEYWORDS
Titanium dioxide;
nanoparticles; chemical
process; aquatic ecotoxicity
1. Introduction
The increasing use of nanomaterials in consumer products that are exposed to environ-
mental media has led to a need to understand their ecotoxicity effect. In particular, nano-
sized titanium dioxide or titania (TiO
2
) is one of the most popular manufactured
nanomaterials increasingly being incorporated into a variety of consumer products.
However, titanium dioxide nanoparticles are the most heavily investigated wide band
gap semiconductor in recent years [1–3]. TiO
2
nanoparticles are widely used as ingredients
for commercial products (sunscreens, cosmetics, pigment, paints, ointments and tooth-
paste), and are used in the decontamination of air, soil and water. These wide applications
© 2018 Informa UK Limited, trading as Taylor & Francis Group
CONTACT Amine Mezni aminemezni@yahoo.fr
Supplemental data for this article can be accessed at https://doi.org/10.1080/02757540.2017.1420178
CHEMISTRY AND ECOLOGY, 2018
VOL. 34, NO. 3, 288–299
https://doi.org/10.1080/02757540.2017.1420178
have led to a rapid increase in the production of TiO
2
. It is estimated that the worldwide
product ion of TiO
2
NPs will reach 2.5 million tons by 2025. However, TiO
2
NPs may enter
marine systems either directly through aerial deposition, effluents, dumping and run-off
or indirectly e.g. via river systems. The discharge of products with TiO
2
NPs into coastal
waters can make an impact on the marine food chain, especially for algae and zooplankton.
Kaegi [4] reported that TiO
2
NPs released from painted facades has concentrations as high as
3.5 × 10
8
particles/L in the run-off water. Keller [5] conducted a detailed analysis of the prop-
erties and behaviour of nanomaterials, including TiO
2
NPs, in a range of natural waters.
Indeed, TiO
2
nanoparticles are toxic to bacteria, cell lines and rodents, but little is known
about their toxicity to aquatic biota, especially to marine organisms. Risk assessment for
TiO
2
NPs releases to marine environments is essential to assure environmental safety and
human well-being. For this reason, it is important to test the environmental risks of NPs
before their use. Bivalve molluscs, such as Mytilus galloprovincialis have been widely used
in ecotoxicological studies for short-term exposure to nanoparticles [6]. The evaluation of
tissue-level biomarkers alterations in bivalve is one of the most important approaches to
assess the health status of individuals and population [7].
Oxidative stress is one of the many stressors that affect marine organisms. TiO
2
is a photo-
catalyst capable of producing highly oxidising reactive oxygen species (ROS) leading to oxi-
dative stress [8]. The impact of increasing background ROS levels in marine systems through
the introduction of nanomaterials may increase the level of oxidative stress in marine organ-
isms [8]. Consequently, the impact of TiO
2
could be even greater on bivalves, and deserves
further attention. In this context, to test the potential ecotoxicity effect of TiO
2
NPs, antiox-
idant system of mediterranean bivalves (M. galloprovincialis) was examined, measuring
three oxidative biomarkers (ROS production, SOD activity and GSH/GSSG level). The tita-
nium dioxide NPs used in this study was prepared according to a one-step solvothermal
process. The structure and morphology of the TiO
2
nanoparticles were characterised by
X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray
spectrometry (EDX) and high-resolution transmission electron microscopy (HRTEM).
2. Experimental procedure
2.1. Synthesis of TiO
2
nanoparticles
To synthesise TiO
2
NPs (as illustrated in scheme SI1), 5 mL of Titanium (IV) butoxide [Ti(OCH
2-
CH
2
CH
2
CH
3
)
4
), Aldrich, AR grade] were dissolved in 50 mL of Dimethyl Sulfoxide (DMSO)
[(CH3)
2
SO, Sigma] and then heated to 190°C and kept at this temperature for 2 h under
mechanical agitation. At the end of the reaction, the precipitate was separated by centrifu-
gation, washed several times with ethanol/acetone (2:1), and then dried in a vacuum at 50°C
for 12 h to yield a white dry TiO
2
powder. The as-prepared TiO
2
sample was calcined at 400°
C. The annealing of the TiO
2
NPs after the solvothermal treatment induces crystallinity and
completely removes the solvent molecules entrapped inside the particles.
2.2. Structural, morphological and optical characterisations
The crystalline structure of the as-obtained powder was characterised by XRD (with an
INEL diffractometer using cobalt Kαradiation (λ= 1.7890 Å)).The morphology of the
CHEMISTRY AND ECOLOGY 289
sample was observed under field emission TEM (JEOL 2011 microscope operating at
100 kV). The chemical composition of the TiO
2
NPs was determined by energy-dispersive
X-ray spectroscopy (EDX) attached to the TEM. HRTEM (Philips Tecnai F-20 SACTEM oper-
ating at 20.0 kV) images provided further insight into the structure of the TiO
2
NPs. The
crystallite sizes were calculated using Scherrer’s relation L= 0.94 l/λβcosθ, where λis
the wavelength of the X-ray radiation, βand θare, respectively, the Bragg angle and
full-width at half-maximum (FWHM) of the diffraction peak. The potential stability of the
TiO
2
seawater suspensions was studied using a zeta potential analyzer (Zetasizer Nano
Z, Malvern Instruments), around 24 h after ultrasonication. The optical absorption
spectra were acquired using a PerkinElmer Lambda 11 UV–visible spectrophotometer.
2.3. Mussels exposure and biochemical analyses
M. galloprovincialis (5.26 ± 0.32 cm shell length) were sampled from a clean area in the
Bizerte Lagoon (Tunisia) and acclimated to lab conditions for one week to performing
the experiments. Exposure was made in 3 L tanks containing natural aerated seawater
with ten mussels per aquarium. They were kept in 12 h light/dark cycle, at a temperature
of 18–19°C; they were fed and water was change in intervals of (48 h). Mussels were
exposed to each of the following treatments in triplicate (three tanks per treatment) for
8 days: control (seawater only), 1, 10 or 100 mg/L TiO
2
. The TiO
2
concentrations were
chosen based on the TiO
2
concentration found by Kaegi [4] that can be reached in the
aquatic environment and on earlier in vivo studies determining biological responses to
TiO
2
NPs by various organisms [9]. The TiO
2
concentrations used ranged from 1 to
100 mg/L corresponding to 1.5 × 10
7
particles/L (1 mg/L) and 1.5 × 10
9
particles/L
(100 mg/L). The TiO
2
nanoparticles concentration found in aquatic environments can
reach 3.5 × 10
8
particles/L.
The 8-day exposure of mussels to TiO
2
was based on earlier in vivo studies in our lab-
oratory using a range of toxicants [10] and was chosen to reflect this dosimetry and enable
some biochemical responses to the exposure, especially oxidative stress [11]. However, the
ethical constraint of using the minimum exposure period likely to achieve the scientific
objectives was also taken into consideration.
Compounds were poured directly into the tank and no mortality was observed under
any of the conditions used. During the experimental period, salinity, temperature, dis-
solved oxygen and pH were measured daily with a thermo-salinity meter (LF 196; WTW,
Weilheim, Germany), an oximeter (OXI 330/SET, WTW) and a pH meter (pH 330/SET-1,
WTW), respectively. Temperature was maintained at 18 ± 1°C, oxygen at 6.25 mg/L and
the salinity was 32‰. Tanks were filled with natural seawater and changed every 48 h.
The environmental parameters were the same as those used for the acclimation period.
At the end of the 8 day exposure period, mussel samples were taken from each treatment
and were subsequently dissected. The digestive gland and gills were removed, frozen in
liquid nitrogen and stored at −70°C. Samples were homogenised in a Tris buffer 0.1 M,
pH 7.5. The homogenate obtained was centrifuged at 9000gfor 20 min at 4°C. The S9 frac-
tions were collected and used to determine superoxide anion level (O
2
−
), SOD activity and
GSH/GSSG ratio. Protein content was estimated using the Bradford method [26], and with
bovine serum albumin (BSA) as standard. O
2
−
production in the mussels was detected
using a Diagnostic Reagent Kit based on the method described by Babior et al. [12].
290 A. MEZNI ET AL.
Spectrophotometric measurements were performed at 550 nm. The absorbance values
were converted into milligram of cytochrome c reduced/min. Superoxide dismutase
(SOD) was measured by the inhibition of self-catalytic adrenochrome formation rate at
480 nm, in a reaction medium containing 1 mM L
−1
adrenaline (pH 2.0) and 50 mM L
−1
glycine (pH 10.2) at 30°C for 3 min. Results were expressed as U Sod (units of enzyme
activity)/mg of protein. One unit is defined by the amount of enzyme that inhibits the
rate of adrenochrome formation by 50%. The GSH/GSSG ratio was measured spectrofluor-
imetrically in the digestive gland and gill using the methods described by Hissin and Hilf
[13]. GSH and GSSG were calculated from a calibration curve with GSH and GSSG as stan-
dards. Fluorescence at 420 nm was determined with excitation at 350 nm.
Results of superoxide anion, SOD activity and levels of GSH/GSSG ratio were reported as
mean ± SD. Statistical analysis was carried out using a statistical package (STATISTICA 8.0).
The variation of each parameter among TiO
2
concentration was tested by one-way ANOVA
(p< .05). Previously we tested the prerequisites for analysis of variance. When significant
differences were found, Tukey’s test was applied to determine which values differed
significantly.
3. Results and discussion
The XRD pattern of the powder revealed well-crystallised and pure TiO
2
particles. All the
diffraction peaks of TiO
2
can be indexed to the tetragonal anatase phase (space group
4
1
/a m d, lattice constants a= 3.7845 Å,c= 9.5143 Å,(JCPDS21-1276, Figure 1) with the
strong characteristic peak. The peak broadening in the XRD pattern clearly indicates
that small particles are present in the sample. The average size of the crystallites, estimated
from the FWHM of the TiO
2
(101) diffraction peak using the Debye–Scherrer relation, was
of the order of 3.2 nm for the TiO
2
NPs. The sample lattice parameters were refined using
the Rietveld method from the XRD diffractogram (recorded for 12 h) using the FULLPROF
Figure 1. XRD pattern of TiO
2
nanoparticles.
CHEMISTRY AND ECOLOGY 291
program (Figure S1). The lattice parameters of the TiO
2
NPs were found to be a= 3.7791 Å
and c= 9.4820Å, respectively. This decrease compared to the bulk material can be attrib-
uted to the nanoscale effect.
The TEM images (Figure 2) show that quasi-spherical TiO
2
nanoparticles with a good
dispersity are formed. Their size is between 10 and 15 nm with an average value of
11 nm (Histogram in Figure 2(c)). Selected-area electron diffraction (SAED) showed a
typical multiple rings pattern (Figure 2(d)) and the lattice planes of the TiO
2
anatase
(101), (200) and (211) were clearly indexed in the SAED patterns. The EDX spectrum pre-
sented in Figure S2, indicates that the nanoparticles are of a high purity, since only Ti
and O elements are detected. The presence of C and Cu is due to the copper grid used
for the TEM/EDX experiments. The HRTEM image in Figure S3 shows well-defined TiO
2
crystal planes thus corroborating the crystalline structure of the particles formed. Lattice
fringes can be clearly distinguished as 0.352 nm which correspond to the (101) plane of
the TiO
2
anatase.
The measurement of the zeta potential is a powerful technique which provides us to
obtain imagination about the potential stability of the suspension in seawater and the
nature of particle surface itself and then about the processes running on this surface
Figure 2. (a, b) TEM images, (c) particle size distribution and (d) shows a typical SAED pattern of TiO
2
nanoparticles.
292 A. MEZNI ET AL.
(e.g. adsorption, ion exchange and modification). It is also an aid in predicting long-term
stability. Figure 3 shows the zeta potential of the TiO
2
NPs seawater suspension performed
at room temperature. The zeta potential measured value was found to be negative and
reach −60 mV. This value indicates that the TiO
2
surface was saturated by oxygen ions.
Thus, this behaviour can enhance the potential stability of the suspension and conse-
quently improve the stability of TiO
2
NPs in seawater. According to the dynamic light scat-
tering (DLS) data (inset), the Z-average particle diameter is d
av
= 30 ± 1 nm and the
average relative half width of the distribution is σ= 10 ± 1 nm. As can be seen, the Z-
average particle diameter (d≈30 nm) exceeds the size dispersion obtained from TEM
images (TiO
2
NPs with an average size around 15 nm). However, from DLS we obtain
the hydrodynamic diameter of the nanoparticles, defined as a sphere with the same trans-
lational diffusion coefficient as the particle being measured (assuming a hydration layer
surrounding the particle or molecule). Hence we can attribute this small different
between the size of TiO
2
NPs obtained by DLS and TEM to the hydrodynamic diameter
measured and added by DLS. As a result, it is concluded according to DLS and TEM
data that TiO
2
NPs are stable in seawater and no agglomeration or aggregation was
observed. The particle size can be determined by measuring the random changes in
the intensity of light scattered from a suspension or solution this is the main principle
of DLS technique. Indeed, DLS measures Brownian motion and relates this to the size of
the particles. Brownian motion is the random movement of particles due to the bombard-
ment by the solvent molecules that surround them. Normally DLS is concerned with the
measurement of particles suspended within a liquid. The larger the particle, the slower
the Brownian motion will be. Smaller particles are ‘kicked’further by the solvent molecules
and move more rapidly. The size of a particle is calculated from the translational diffusion
coefficient by using the Stokes–Einstein equation; d(H)=kT/3πhD Where: d(H) = hydro-
dynamic diameter, D= translational diffusion coefficient, k= Boltzmann’s constant, T=
Figure 3. Zeta potential plot of TiO
2
NPs water suspension. The inset presents the Z-average of TiO
2
NPs in seawater measured by DLS technique.
CHEMISTRY AND ECOLOGY 293
absolute temperature and η= viscosity. Note that the diameter that is measured in DLS is a
value that refers to how a particle diffuses within a fluid so it is referred to as a hydrodyn-
amic diameter. The diameter that is obtained by this technique is the diameter of a sphere
that has the same translational diffusion coefficient as the particle. The translational diffu-
sion coefficient will depend not only on the size of the particle ‘core’, but also on any
surface structure, as well as the concentration and type of ions in the medium.
Optical absorbance is a powerful method to determine the energy gap and particle size
as well as the optical properties of samples. Indeed, in order to measure the absorption
characteristics the nano-powders were dispersed in ethanol and placed in a quartz
cuvette. Figure 5(a) shows the UV–visible absorption spectrum of the as-prepared
powder. As can be seen, the spectrum shows a UV absorbance peak at 340 nm character-
istic of the formation of TiO
2
nanoparticles. This peak position reflects the particle band
gap. It is well-known that the fundamental absorption is due to the transition of the elec-
tron excitation from the valence band to the conduction band which can be used to deter-
mine the value of the nanoparticle optical band gap. The treatment of this spectrum by the
Tauc method allows determine the energy gap (Eg) of the sample. Figure 4(b) shows the
plots of (αhν)
2
versus hνfor the TiO
2
nanoparticles. By extrapolating the straight section of
the graph onto the hνaxis at α= 0, the band gaps were found to be equal to 3.33 eV
(Figure 4(a)). This value is greater than the solid mass of TiO
2
(3.2 eV). It has previously
been reported that the band gap of semiconductor crystalline is a function of the particle
size. However, this blue-shift is mainly attributed to a strong quantum confinement effect
caused by the reduction in particle size.
One of the important issues to take into consideration before using nanoparticles is
their impact on the environment. The large number of applications of NPs will certainly
lead to their increased release into the environment with the probable effects they may
have on organism behaviours [14]. In the present study, after the mussels were exposed
to TiO
2
in seawater for 8 days, no mortality was observed, even in the treatment with
the highest exposure concentration (100 mg/L). Based on previous studies, TiO
2
appears
to have little to no toxic effect on marine species after a short-term exposure [15]. The oxi-
dative stress response including ROS production, SOD activity and the GSH/GSSG ratio has
been largely used to characterise the biochemical status of marine organisms exposed to
Figure 4. UV–visible absorption spectrum (a) and the plots of (Abs.hv)
2
photon energy of TiO
2
nanoparticles.
294 A. MEZNI ET AL.
NPs [16]. The capacity of producing ROS is a solid index that can be used to evaluate the
toxic effect of NPs [17]. TiO
2
is a photocatalyst capable of producing highly oxidising ROS.
The absorption of a photon with sufficient energy (3.2 eV for anatase) is the necessary con-
dition for photochemical reactions to proceed on the photocatalyst’s surface. When TiO
2
reaches an electronically excited state an electron (e
−
) is promoted from the valence band
to the conduction band, generating a hole in the valence band (h
+
)[18]. The resulting elec-
tron–hole pair can then recombine or migrate to the surface of the particle and may react
with H
2
OorOH
−
to form OH
•
or can directly oxidise the adsorbed species. The electrons
may also react with adsorbed molecular oxygen to form O
2
−•
ions. In the present study, the
production of (O
2
−
) in the mussels was measured to further confirm the presence of the
oxidative stress observed in the organisms that were exposed to TiO
2
. Our data showed
that the O
2
−
levels in the digestive gland of all the expose groups were not significantly
different from those in the control group (Figure 5). Similar results were observed in
marine abalone (Haliotis diversicolor supertexta) exposed to 10 mg/L of n-TiO
2
. However,
the O
2
−
levels in the gill of the mussels treated with 100 mg/L TiO
2
were significantly
greater than those in the control mussels. Due to their filter feeding habits, the bivalve
gills are the main interface between the organism and the surrounding environment,
and hence are the primary pathway of exposure to environmental contaminants. In
bivalves exposed to nanoparticles, gills represent the first targeted organ, by either
direct passage or particle uptake [19]. These facts explain the sensitivity of gills compared
to the digestive gland. Consistent with our results, ROS levels were significantly high in
mussels exposed to 100 mg/L of iron oxide NPs. Additionally, Canesi [20] reported an
increase of ROS levels in Mytilus edulis exposed to nano-TiO
2
in a concentration-dependent
pattern. Mytilus coruscus exposed to high concentrations of nano-TiO
2
showed increased
Figure 5. Effect of TiO
2
NPs on the production of the superoxide anion (O
2
−
) in the digestive gland and
gills of M. galloprovincialis. Each value is the mean ± SD (n= 30). (*) indicates significant differences
from the control (p< .05) (ANOVA, post hoc, Tukey HSD test, STATISTICA 8.0).
CHEMISTRY AND ECOLOGY 295
levels of ROS compared to the control. No effect was detected at concentrations ≤10 mg/L
suggesting the non-toxicity of TiO
2
in marine mussels at this nominal concentration.
In order to protect themselves from the damaging effects of activated free radicals,
various organisms can stimulate their antioxidant enzyme activities. Among the
common antioxidant enzyme, SOD is considered as the vital first-line defense against
oxygen toxicity [21]. SOD catalyses the dismutation of the superoxide anion (O
2
−
) produced
Figure 6. SOD activity in digestive glands and gills of M. galloprovincialis exposed for 8 days to TiO
2
.
Values shown are means ± SD (n= 30), (*) indicates significant differences from the control (p< .05).
(ANOVA, post hoc, Tukey HSD test, STATISTICA 8.0).
Figure 7. Levels of the GSH/GSSG ratio in the digestive glands and gills of M. galloprovincialis exposed
to TiO
2
for 8 days. Values shown are means ± SD (n= 30), (*) indicates significant differences from the
control (p< .05) (ANOVA, post hoc, Tukey HSD test, STATISTICA 8.0).
296 A. MEZNI ET AL.
in peroxisomes and mitochondria [22]. In the present study, the effects of acute exposure
to TiO
2
NPs on the SOD activity of M.galloprovincialis were analysed in digestive glands
and gills. The data indicated that the concentrations used in the treatments might be
insufficient for the induction of SOD in digestive glands even at high concentrations.
These observations can be explained by the modest level of oxidative stress caused by
TiO
2
at this concentration in these organs. In contrast, SOD activity in gills increased
after exposing mussels to 100 mg/L of TiO
2
. This demonstrates that M.galloprovincialis
has an increased oxidative defense capacity in its gills for the elimination of excess O
2
−
.
Other reports have suggested that TiO
2
increased SOD at high concentrations and
related this modification to the oxidative stress induced by ROS.
NPs can react directly with thiol-containing molecules such as GSH or may indirectly
cause an imbalance in the GSH/GSSG ratio during oxidative stress [23]. In the present
study, the GSH/GSSG ratio showed a statistically significant decrease (p= .002) only in
the gills exposed to the highest concentration of TiO
2
(100 mg/L). This result may be
due to the decrease of GSH following severe oxidative stress leading to its suppression
by the ROS [24]. It can also be related to its oxidation into the oxidised form of GSSG
under oxidative stress, a strategy used by mussels to eliminate the excess ROS [25]. This
small decrease can also be attributed to the consumption of GSH by glutathione transfer-
ase [26]. The obtained results suggest that mussels may be vulnerable to oxidative
damage if the exposure concentration is >10 mg/L. Park [27] showed GSH depletion
after exposure to TiO
2
nanoparticles. No effect was observed in the digestive gland,
which showed similar values for the ratio GSH/GSSG for all treatments (Figure 6). These
observations may support the view that the considered TiO
2
nanoparticles have no real
subtoxic effects in filter-feeding species, which could potentially affect their health.
4. Conclusion
In this work, a simple and efficient one-pot method for the synthesis of pure-phase anatase
TiO
2
nanoparticle with controlled morphology has been developed. Compared with most
prior work, the sample prepared here do not need the use of any amphiphilic surfactants,
capping agent or block copolymers, efficiently reducing the production costs. Analysis
using the XRD and TEM techniques indicated that the prepared TiO
2
NPs were pure-
phase anatase and uniformly dispersed. Considering the shown experimental plan, TiO
2
nanoparticles appear to exert limited oxidative effects in filter-feeding species. Hence,
these NPs could be considered for different applications after further experimental toxicity
assays.
Disclosure statement
No potential conflict of interest was reported by the authors.
Funding
Amine Mezni extends their appreciation to the KSA government and the Taif University for funding
this research work through #1-437-5049# project.
CHEMISTRY AND ECOLOGY 297
Notes on contributors
Amine Mezni received a B.Sc. in Chemistry from the Faculty of Sciences of Bizerte, Tunisia, in 2008,
received an M.Sc. in Solid State Chemistry from the Faculty of Mathematical, Physical and Natural
Sciences of Tunis, Tunisia, in 2010, and a Ph.D. in Physical Chemistry (with professors Leila-Samia
Smiri and Adnen Mlayah) from Paul Sabatier University, Toulouse-France, in 2013 and currently,
he is an Assistant Professor of Chemistry at the Taif University, Kingdom of Saudi Arabia (KSA).
Samir Alghool is an Assistant Professor. He joined the faculty of Science, Taif University, KSA, in 2014,
currently works at the Department of Chemistry, Port Said University. His principal research interests
are Inorganic Chemistry, Materials Chemistry and Polymer Chemistry.
Badreddine Sellami is apermanent researcher in the National Institute of Marine Sciences and Tech-
nologies, Tunisia. He published articles on ecotoxicology, focusing on biochemical and physiological
response of marine organism to several compounds such as pesticides, Hydrocarbons and
nanoparticles.
Nesrine Ben Saber is a Ph.D. researcher in the Laboratory “Synthese et Structure de Nanomateriaux”,
Faculte des Sciences de Bizerte, Universite de Carthage, Tunisia. She published articles on Synthesis
and Characterization of Metal Alkoxides fields. She is a postdoctoral researcher in nanotechnology.
Tariq Altalhi joined Department of Chemistry at Taif University, Saudi Arabia, as Assistant Professor in
2014. He received his doctorate degree from The University of Adelaide, Australia, in the year 2014.
His group is involved in fundamental multidisciplinary research in nanomaterials synthesis and
engineering, characterization, and their application in molecular separation, desalination, membrane
systems, drug delivery, and biosensing.
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