![The structure of calix[4]arene derivative 1 used as carrier.](https://www.researchgate.net/profile/Izzet-Sener-3/publication/233342822/figure/fig3/AS:667657800019970@1536193432079/The-structure-of-calix4arene-derivative-1-used-as-carrier_Q320.jpg)
Content uploaded by İzzet Şener
Author content
All content in this area was uploaded by İzzet Şener on Jan 29, 2016
Content may be subject to copyright.
This article was downloaded by:[ANKOS 2007 ORDER Consortium]
On: 15 August 2007
Access Details: [subscription number 772815469]
Publisher: Taylor & Francis
Informa Ltd Registered in England and Wales Registered Number: 1072954
Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK
Journal of Macromolecular Science,
Part A
Pure and Applied Chemistry
Publication details, including instructions for authors and subscription information:
http://www.informaworld.com/smpp/title~content=t713597274
Carrier-Mediated Transport of Hg(II) through Bulk and
Supported Liquid Membranes
Online Publication Date: 01 October 2007
To cite this Article: Alpoguz, H. Korkmaz, Kaya, Ahmet and Sener, Izzet (2007)
'Carrier-Mediated Transport of Hg(II) through Bulk and Supported Liquid
Membranes', Journal of Macromolecular Science, Part A, 44:10, 1061 - 1068
To link to this article: DOI: 10.1080/10601320701519559
URL: http://dx.doi.org/10.1080/10601320701519559
PLEASE SCROLL DOWN FOR ARTICLE
Full terms and conditions of use: http://www.informaworld.com/terms-and-conditions-of-access.pdf
This article maybe used for research, teaching and private study purposes. Any substantial or systematic reproduction,
re-distribution, re-selling, loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly
forbidden.
The publisher does not give any warranty express or implied or make any representation that the contents will be
complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses should be
independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings,
demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or
arising out of the use of this material.
© Taylor and Francis 2007
Downloaded By: [ANKOS 2007 ORDER Consortium] At: 09:52 15 August 2007
Carrier-Mediated Transport of Hg(II) through Bulk and Supported
Liquid Membranes
H. KORKMAZ ALPOGUZ, AHMET KAYA, and IZZET SENER
Faculty of Sciences Arts, Department of Chemistry, Pamukkale University, Denizli, Turkey
Received March, 2007, Accepted April, 2007
The transport of Hg (II) ions from an aqueous solution into an aqueous receiving solution through bulk and supported liquid membranes
containing a calix[4]arene derivative 1as a carrier was examined. The kinetic parameters of bulk liquid membrane studies were analyzed
assuming two consecutive, irreversible first-order reactions. The influence of temperature, stirring rate, carrier concentration and solvent on
the kinetic parameters (k
1
,k
2
,R
m
max
,t
max
,J
d
max
,J
a
max
) has also been investigated. The membrane entrance rate, k
1
, and the membrane exit rate,
k
2
, increased with increasing temperature and stirring rate. The activation energy values are calculated as 4.87 and 48.63 kj mol
21
for
extraction and reextraction, respectively. The values of calculated activation energy indicate that the process is diffusionally controlled
by species. Also, the transport behavior of Hg
2þ
from aqueous solution through a flat-sheet supported liquid membrane has been investi-
gated by the use of calix[4]arene derivative 1as carrier and Celgard 2500 as the solid support. A Danesi mass transfer model was used to
calculate the permeability coefficients for each parameter studied. The highest values of permeability were obtained with 2-nitrophenyloc-
tyl-ether (NPOE) solvent and the influence was found to be in the order of NPOE .chloroform .xylene.
Keywords: liquid membrane; calixarenes; transport of Hg (II); transport kinetics
1 Introduction
The toxicity of heavy metals is widely recognized due to their
adverse effects upon human health. Mercury is a particularly
toxic element of great environmental concern because it is
widespread in the lithosphere and in water (1, 2). Inorganic
mercury, especially soluble mercury species, can be trans-
formed into methyl mercury by the action of microorganisms
under aerobic conditions. The organomercury compounds
thus formed have a strong tendency to accumulate as they
pass through the food chain. Because of the great impact of
mercury, there is an imperious need to determine and to
recover it from water at low concentrations (2).
Calixarenes and derivatives can be used as receptors to
recognize a wide variety of ions and guest molecules,
forming host-guest or supramolecular complexes. This
ability has been exploited in different fields and calixarenes
and derivatives have been used extensively as selective
ligands for a wide range of metal ions in liquid-liquid extrac-
tion, in selective transport, as ionophores in ion-selective
electrodes and as chromophores in optical sensing (3, 4).
Several studies have been published which make a case
for calixarene derivatives as extractants for toxic metals
(5–9).
Several technologies can be used to remove these toxic
metals from liquid effluents, including precipitation, solvent
extraction, ion exchange, etc., among these, the liquid
membrane technique has acquired an importance for its use
in separation, concentration or even analytical application.
Though this technology is still in the research and develop-
ment stage, it holds a deserving position in the field of
membrane separations due to its advantages over convention-
al separation operations. Included in the liquid membrane
characteristics are their high specificity, low energy utiliz-
ation, ease of installation, etc. (10).
The different types of liquid membranes are reviewed in
the literature (11, 12). Bulk liquid membranes usually
consist of an aqueous donor and acceptor phase, separated
by a water-immiscible liquid membrane phase in a U-tube.
In supported liquid membranes, the extraction, stripping
and regeneration of the organic phase are combined in a
single stage (10).
Here, we report an investigation of co-transport of Hg
2þ
ion through liquid membranes. N,N0-bis(5-azo-25,26,27-tri-
benzoyloxy-28-hydroxycalix[4]arene)biphenyl (1) is the
carrier ligand (as presented in Figure 1), which was syn-
thesized according to the literature method (13). The kinetic
Address correspondence to: H. Korkmaz Alpoguz, Faculty of
Sciences Arts, Department of Chemistry, Pamukkale University,
20017 Denizli, Turkey. E-mail: hkalpoguz@pau.edu.tr
Journal of Macromolecular Science
w
, Part A: Pure and Applied Chemistry (2007) 44, 1061 –1068
Copyright #Taylor & Francis Group, LLC
ISSN: 1060-1325 print/1520-5738 online
DOI: 10.1080/10601320701519559
Downloaded By: [ANKOS 2007 ORDER Consortium] At: 09:52 15 August 2007
parameters of bulk liquid membrane studies were analyzed
assuming two consecutive, irreversible first-order reactions.
Also, the transport behavior of Hg
2þ
from aqueous solution
through a flat-sheet supported liquid membrane has been
investigated by the use of calix[4]arene derivative 1as
carrier and Celgard 2500 as the solid support.
2 Experimental
2.1 Materials
The chemical reagents used in bulk liquid membrane exper-
iments were mercury (II) nitrate (Merck), dichloromethane
(Merck), chloroform (Merck), carbon tetrachloride (Merck)
and picric acid, (Merck). Mercury (II) picrate solution was
prepared by the addition of a 1 10
22
M mercury (II)
nitrate to a 2.5 10
25
M aqueous picric acid solution and
shaken at 258C for 1 h. The aqueous solutions were
prepared using demineralized water.
The chemical reagents used in supported liquid membrane
experiments were mercury (II) nitrate, mecury (II) chloride
and xylene were obtained from Merck Co., 2-nitrophenyl
octyl ether from Fluka and used without further purification.
The polymeric film Celgard 2500 (thickness: 25 mm, porosity
45%) was obtained from Celgard Inc. (Samples were kindly
supplied by Oketek Co., Istanbul).
2.2 Bulk Liquid Membrane Experiments
Co-transport experiments were carried out in a U-type
cell inserted inside a thermostated (Grand mark, model
W14) apparatus (Figure 2). An organic solution (20 mL)
containing the ionophore was placed in the bottom of
the cell and two portions of aqueous donor and acceptor
solutions (10 mL) were carefully added on top of them.
Both surface areas were 2.5 cm
2
. The organic phase was
stirred at variable speeds magnetically (Chiltern mark,
model HS 31).
The initial phases consisted of the donor phase, which was
an aqueous mercury (II) picrate (2.5 10
25
M) solution,
while the membrane phase was made up by dissolving
carrier 1in the organic phase. The acceptor phase consisted
of doubly distilled water. Samples were taken from both
water phases (acceptor and donor phases) at various intervals
of time and the picrate ion concentration was analyzed by a
spectrophotometric method. The spectrophotometric
measurements were performed by means of an UV-Vis Spec-
trometer Shimadzu 160A. Experiments were performed with
no carrier present, indicating that no transport of mercury (II)
picrate occurred. The consecutive kinetic equations for a
transport system were used by applying a simple theoretical
approach which is discussed in detail elsewhere (14 – 20).
The experiments were repeated at least three times.
The variation of the metal picrate concentration with time
was directly measured in both the donor (C
d
) and acceptor
(C
a
) phases. In the experiments, the variation of picrate ion
concentration with time was directly measured in both
donor (C
d
) and acceptor phases (C
a
). The corresponding
change of picrate ion concentration in the membrane phase
was determined from the material balance between the
phases. For practical reason, the dimensionless reduced con-
centrations were used:
Rd¼Cd
Cd0
Rm¼Cm
Cd0
Ra¼Ca
Cd0
ð1Þ
where C
d0
is the initial Hg(II) ion concentration in the
donor phase, while C
d
,C
m
and C
a
represents the Hg
2þ
ion
concentration in donor, membrane and acceptor phases,
respectively. The material balance with respect to the
reduced concentrations can be expressed as R
d
þR
m
þR
a
¼1. From this expression, the kinetic behavior of
Fig. 2. Bulk liquid membrane apparatus for transport of Hg(II)
ions; d, donor phase; a, acceptor phase; m, membrane phase.
Fig. 1. The structure of calix[4]arene derivative 1used as carrier.
Alpoguz, Kaya, and Sener1062
Downloaded By: [ANKOS 2007 ORDER Consortium] At: 09:52 15 August 2007
the consecutive irreversible first order reactions can be
described as follows;
Cd!
k1Cm!
k2Cað2Þ
where k
1
and k
2
are the apparent membrane entrance and exit
rate constants, respectively. The kinetic scheme for consecu-
tive reaction systems can be described by considering the
reduced concentrations as follows;
dR
d
dt ¼k1Rd;Jdð3Þ
dR
m
dt ¼k1Rdk2Rmð4Þ
dR
a
dt ¼k2Rm¼Jað5Þ
where J represents the flux. When k
1
=k
2
, integrating
Equations (3–5), gives:
Rd¼expðk1tÞð6Þ
Rm¼k1
k2k1
expðk1tÞexpðk2tÞ½ð7Þ
Ra¼11
k2k1
k2expðk1tÞk1expðk2tÞ½ð8Þ
The kinetic parameters k
1
and k
2
were obtained by fitting
Equations 6–8 to this data. As an example, the variation of
the reduced concentration of Hg(II) ion through the liquid
membrane with 1 10
24
M of carrier 1in CHCl
3
at
300 rpm and 258C is presented in Figure 3. The observed
experimental results reveal that R
d
decreases exponentially
with time, accompanied by a simultaneous increase of R
a
,
whereas R
m
presents at maximum at intermediate times.
The maximum values of R
m
(when dR
m
/dt ¼0) and t
max
may be written as follows:
Rmax
m¼k1
k2
k2=ðk1k2Þ
ð9Þ
tmax ¼1
k1k2
ln k1
k2
ð10Þ
By considering the first-order time differentiation of
Equations. 6 – 8 at t ¼t
max
, one obtains:
dR
d
dt
max
¼k1
k1
k2
k1=ðk1k2Þ
;Jmax
dð11Þ
dRm
dt
max
¼0ð12Þ
dRa
dt
max
¼k2
k1
k2
k2=ðk1k2Þ
;Jmax
að13Þ
We see that at t ¼t
max
, the system is in steady state, because
the concentration of Hg(II) ions in the membrane does not
vary with time (Equation 12). Because the maximum
entrance (J
d
max
) and exit (J
a
max
) fluxes are equal but having
opposite signs:
Jmax
d¼Jmax
að14Þ
The actual numeric analysis was carried out by nonlinear
curve fitting by using Sigma-Plot software program. The
kinetic parameters k
1
and k
2
were obtained by fitting
Equations (6–8) to this data. The activation energy values
were obtained from the Arrhenius equation by using the k
1
and k
2
values at different temperature.
lnðkÞ¼lnðAÞ Ea
RT ð15Þ
2.3 Supported Liquid Membrane Experiments
The transport experiments were carried out in a permeation
cell consisting of two identical cylindrical compartments
(half-cell volume: 30 ml) (Figure 4), previously described
(21). The supported liquid membranes consisted of a thin,
microporous polypropylene film (Celgard 2500; thickness:
25 mm, porosity 45%) immobilizing the solution of carriers
in organic solvents. Aqueous mercury (II) nitrate and
mercury (II) chloride solutions were used as the feed phase,
and deionized water was used as the stripping phase. The
soaking time of the Celgard 2500 membrane is 24 h and the
stirring speed is chosen as 300 rpm in the all transport exper-
iments. The measurements were performed at a constant
temperature of 258C at least twice. The transported Hg
2þ
in
nitrate and chloride salt forms was determined by monitoring
the conductivity of the stripping phase as a function of time
(Philips PW 9527 conductivity meter). The standard devi-
ation in the transport measurements is about 15%.
Fig. 3. Time dependence of R
d
,R
m
, and R
a
for transport of Hg(II).
Membrane: 1 10
24
M of carrier 1in CHCl
3
(298 K and 300 rpm).
Theoretical curves calculated from Equations (6 –8).
Transport of Hg(II) through Liquid Membranes 1063
Downloaded By: [ANKOS 2007 ORDER Consortium] At: 09:52 15 August 2007
3 Results and Discussion
3.1 Bulk Liquid Membrane Studies
In our previous reports (14 – 16), the transport of Hg(II) ions
from aqueous phase was carried out by using derivatives of
calix[4]arenes as the carrier. In this work, the transport of
Hg(II) ion by derivative of azo calix[4]arene in the liquid
membrane was studied and the kinetic behavior of the trans-
port process as a function of concentration, temperature,
stirring rate, and solvents was investigated.
3.2 Effect of Carrier Concentration in Membrane on
Transport of Hg(II) Ions
The carrier concentration of organic phase has a significant
effect on the metal ion transport across the membrane. It is
generally expected to increase with the carrier concentration.
The transport experiments were carried out at three different
initial carrier 1concentrations 1 10
26
,110
25
, and
110
24
M in CHCl
3
at 298 K and 300 rpm. The obtained
kinetic parameters for the effect of concentration of carrier
1are presented in Table 1. It was found that the initial
carrier concentration influences the kinetic constants, as
well as flux values, in full agreement with previously
obtained results (9, 14–16). It can be seen that, both kinetic
constants k
1
and k
2
or fluxes are dependent on the carrier
concentration and increases steadily with the initial carrier
concentration, as shown in Figure 5. It had been reported
that in controlled conditions, k
1
and k
2
increases with increas-
ing carrier concentration, showing small and fractional
exponent value (22). This obviously can be assumed from
Equations (6–8) that the reduced dimensionless concen-
tration is related with the carrier concentration.
In addition, a blank experiment was performed with no
carrier present in the membrane. No detectable movement
of the Hg(II) ions through the liquid membrane was found
in the blank experiment, suggesting that the transport of
Hg(II) ions through the liquid membrane is fulfilled by the
carrier.
3.3 Effect of Temperature on Transport of Hg(II) Ions
The effect of temperature on the transport of Hg(II) ions across
the bulk liquid membrane was tested at 293, 298, 303 and
308 K, respectively. The experimental results are shown in
Table 2. It is quite obvious that k
1
and k
2
increases with an
increase in the temperature. Table 2 also shows that t
max
and
R
m
max
decreases with an increase of temperature. The
maximum R
m
values were found to lie between the 0.39 and
0.55 ranges. This shows that the membrane phase was also
effect on the transport. It is also seen that the t
max
values
was decreased upon increasing of temperature. It is immedi-
ately obvious that the extraction of Hg
2þ
from the donor
phase into the membrane occurs at a rate equal to the
release of mercury from the membrane into the acceptor
phase. As known, activation energy values are quite low for
diffusion-controlled processes, whose rate constants are
strongly affected by temperature. The E
a
values of diffusion-
controlled processes are lower than those of chemically con-
trolled processes. It was pointed out that the activation
energies of diffusion-controlled processes are lower than 20
kcal mol
21
(23). The activation energy values were obtained
from the Arrhenius equation by using the k
1
and k
2
values at
different temperature. An Arrhenius-type plot is followed per-
fectly in Figure 6. The activation energy values are 4.87 and
48.63 kj mol
21
for extraction and reextraction, respectively.
The calculated activation energy shows that the transport of
Hg
2þ
ions is diffusion controlled processes (23).
3.4 Effect of Stirring Rate on Transport of Hg(II) Ions
The influence of the stirring speed on Hg(II) ions transport
was studied in order to optimize uniform mixing of the
Fig. 4. Supported liquid membrane apparatus.
Table 1. The kinetic parameters for Hg(II) ions at different carrier 1concentrations in CHCl
3
(298 K and 300 rpm)
Concentration (M)
k
1
10
3
(min
21
)
k
2
10
3
(min
21
)R
m
max
t
max
(min)
J
d
max
10
3
(min
21
)
J
a
max
10
3
(min
21
)
110
26
1.12 3.64 0.18 467.14 20.66 0.66
110
25
3.55 4.16 0.34 260.00 21.41 1.41
110
24
9.69 4.38 0.52 149.53 22.28 2.28
Alpoguz, Kaya, and Sener1064
Downloaded By: [ANKOS 2007 ORDER Consortium] At: 09:52 15 August 2007
solution and to minimize thickness of aqueous boundary
layers. In the present investigation, the stirring rate of the
membrane phase was carried out at three different stirring
rate, 200, 300, and 400 rpm at 298 K when the carrier 1con-
centration was 1 10
24
M in CHCl
3
. The results are pre-
sented in Table 3, indicate that the stirring rate affects the
transport rate of Hg(II) through the liquid membrane. As
shown in Table 3, the membrane entrance (k
1
) and exit (k
2
)
rate constants increased by rising stirring rate.
3.5 Effect of Solvent on Transport of Hg(II) Ions
The experiments were accomplished with three different
solvents: CH
2
Cl
2
, CHCl
3
and CCl
4
. The kinetic parameters
are shown in Table 4 and Figure 7, indicate that the
highest efficiency has been obtained with CH
2
Cl
2
. It is also
found that the membrane entrance and exit rate constants, as
well as the flux values vary in order of CH
2
Cl
2
.CHCl
3
.
CCl
4
. In the ion transport, the polarity and viscosity of
solvents are very important. Due to the highest polarity and
the lowest viscosity of CH
2
Cl
2
, it is the most effective
solvent. This result is in harmony with the previous studies
(9, 14–16).
3.6 Supported Liquid Membrane Studies
The transport experiments were carried out with an apparatus
designed by Reinhoudt et al. (21) shown as in Figure 3. The
organic phase impregnated a microporous support of polypro-
pylene placed between the aqueous phases. The mass of
organic phase incorporated in a membrane was determined
by weighing the membrane before and after impregnation.
We have induced a coupled co-transport of Hg
2þ
ion and
nitrate and chloride anions, establishing a chemical gradient
between the feed and stripping solutions. According to the
mass transfer model described by Danesi (24), the per-
meability (P) is obtained using Equations (16) and (17).
Feed Solution :ln C
C0
¼1
S
VB
PFtð16Þ
Strip Solution :ln 1 C0
C0
¼1
S
VA
PStð17Þ
The initial flux of Hg
2þ
J
i
is obtained by Equation (18):
Ji = PC *=1ð18Þ
Where C/C0: concentration of the cation, respectively in
the feed/stripping solution at time t; C
0
: initial concentration
Fig. 5. Concentration dependence of k
1
and k
2
for transport of
Hg(II) (298 K and 300 rpm in CHCl
3
).
Fig. 6. Arrhenius plots for transport of Hg(II) in liquid membrane.
Membrane: 1 310
24
M of carrier 1in CHCl
3
at 300 rpm.
Table 2. The kinetic parameters of Hg(II) transport using carrier 1at different temperatures (Stirring rate is 300 rpm; solvent
is CHCl
3
).
Temperature (K)
k
1
10
3
(min
21
)
k
2
10
3
(min
21
)R
m
max
t
max
(min)
J
d
max
10
3
(min
21
)
J
a
max
10
3
(min
21
)
293 9.47 3.66 0.55 163.67 22.01 2.01
298 9.69 4.38 0.52 149.53 22.28 2.28
303 10.15 6.60 0.45 121.25 22.96 2.96
308 10.37 9.24 0.39 102.09 23.60 3.60
Transport of Hg(II) through Liquid Membranes 1065
Downloaded By: [ANKOS 2007 ORDER Consortium] At: 09:52 15 August 2007
of the cation in the feed solution; 1: porosity of supported
liquid membrane (%); S: membrane surface area (cm
2
); V:
volume of feed or stripping solution (cm
3
); C: the concen-
tration of carrier in the membrane.
P
F
and P
S
were determined graphically from the slope of
plots ln(C/C
0
) and ln(1 2C0/C
0
), respectively vs. t. In
ideal cases, P
F
is equal to P
S
.
In this study, supported liquid membrane transport works
for Hg(II) have been carried out by using Celgard 2500
model membrane and permeabilities and fluxes have been
determined by using versatile metal salts (Hg(NO
3
)
2
,
HgCl
2
) and different solvents (xylene, chloroform and
2-nitrophenyl octyl ether).
Depending upon these results, plots of ln(1 2C0/C
0
) vs. time
for the nitrate and chloride salts of the Hg
2þ
, together with the
carrier 1in NPOE solvent using Celgard 2500 as solid support
membrane are presented in Figures 8 and 9. Both plots give a
straight line with slopes, which verify that the transport effi-
ciency depends upon the type of anion and solvent. The
values of permeabilities (P) and fluxes (J
i
)aregiveninTable5.
The liquid membrane technique contains two processes in a
single stage: extraction of metal ion from the aqueous feed
solution to the organic phase containing the carrier molecules
(membrane) and a reextraction of this metal ion from the
membrane to the aqueous stripping phase. The overall trans-
port process consists of a mixture diffusion steps and com-
plexations/decomplexation reactions at two independent
and possible different interfaces.
The mechanism of the ion pair mediated transport (co-
transport) is given in Figure 10. L represents the ligand
carrier. At the interface between feed and membrane,
Table 3. The kinetic parameters of Hg(II) transport using carrier 1at different stirring rates (T ¼298 K; solvent is CHCl
3
)
Stirring rate (rpm)
k
1
10
3
(min
21
)
k
2
10
3
(min
21
)R
m
max
t
max
(min)
J
d
max
10
3
(min
21
)
J
a
max
10
3
(min
21
)
200 8.56 3.62 0.53 174.21 21.93 1.93
300 9.69 4.38 0.52 149.53 22.28 2.28
400 11.5 12.79 0.35 82.42 24.45 4.45
Table 4. The kinetic parameters for Hg(II) transport using carrier 1when different solvents are used (298 K and 300 rpm)
Solvent
k
1
10
3
(min
21
)
k
2
10
3
(min
21
)R
m
max
t
max
(min)
J
d
max
10
3
(min
21
)
J
a
max
10
3
(min
21
)
CH
2
Cl
2
19.72 16.68 0.40 55.07 26.66 6.66
CHCl
3
9.69 4.38 0.52 149.53 22.28 2.28
CCl
4
0.64 0.95 0.30 1274.81 20.28 0.28
Fig. 7. Solvent dependence of k
1
and k
2
for transport of Hg(II)
ions, where S1, S2 and S3 are CCl
4
, CHCl
3
and CH
2
Cl
2
, respect-
ively. Conditions of experiments, see Table 4.
Fig. 8. Hg
2þ
transport experiment with calix[4]arene derivative 1
for Celgard 2500 membrane. Feed solution: 0.01 M Hg(NO
3
)
2
,
organic membrane: 1¼10
23
M in NPOE, stripping solution: Deio-
nize water, V
F
¼V
S
¼30 cm
3
,S¼9.08 cm
2
,1¼0.45.
Alpoguz, Kaya, and Sener1066
Downloaded By: [ANKOS 2007 ORDER Consortium] At: 09:52 15 August 2007
Hg
2þ
X
2
ion pair forms (X:Cl
2
or NO
3
2
) complex with
ligand, then the [LHg]
2þ
X
2
complex diffuses through the
membrane. At the interface between membrane and stripping,
the carrier ion pairs are decomplexed and Hg
2þ
X
2
is liber-
ated into the stripping phase. Finally, the ligand carrier
diffuses back across the membrane aqueous boundary layers.
When compared with the chloride and nitrate forms, the trans-
port of Hg
2þ
was found to be higher in the chloride form. These
results can be ascribed to the low solubility of (NO
3
)
2
in organic
phase by the polarity of co-transport ion and it could also be
explained by the fact that the radius of chloride anion
(0.168 nm) is smaller more than that of nitrate anion (0.200 nm).
When the different solvents were used for carrier 1, the
values of permeabilities and fluxes obtained were also differ-
ent. It has been previously pointed out that the nature of
solvent has a great influence on the transport efficiency
through bulk liquid membranes (9, 14–16, 20). The results
obtained for permeability and flux with solvents are presented
in Table 5. It is apparent from the results that the permeability
and fluxes values are remarkably different in different solvents
and found to be in the order of NPOE .chloroform .
xylene. In the case of xylene and chloroform, the values of
permeabilities and fluxes are smaller than that of NPOE.
Nitrophenyl alkyl ethers (NPHE-hexyl; NPOE-octyl) were
used for supported liquid membrane studies because they
lead to a stable membrane due to their very low solubility in
water (25–28). Also, the polymeric support materials used
are very important in the stability of the membrane. The
requirement for a good polymeric support are high porosity,
small pore size, good mechanical strength, chemical resist-
ance, thinness, hydrophobicity, and low cost.
4 Conclusions
The Hg(II) ions can be effectively transported through a bulk
and supported liquid membranes containing calix[4]arene
derivative 1. The efficiency of the methods depends on
various parameters, i.e., the carrier concentration, type of
solvent and anion, stirring speed, temperature.
5 References
1. Mason, R.P., Reinfelder, J.R. and Morel, F.M.M. (1995) Water Air
Soil Pollut.,80, 915.
2. Shamsipur, M., Hashemi, O.R. and Lippolis, V. (2006) J. Membr.
Sci.,282, 322.
3. Reinhoudt, D. (1995) Sens. Actuators B,24–25, 197.
4. Mathew, V.J. and Khopkar, S.M. (1997) Talanta,44, 1699.
5. Schazmann, B., O’Malley, S., Nolan, K. and Diamond, D. (2006)
Supramolecular Chem.,18, 515.
6. Memon, S. and Yilmaz, M. (2000) Sep. Sci. Technol.,35(3), 457.
7. Memon, S., Uysal, G. and Yilmaz, M. (2000) Sep. Sci. Technol,
35(8), 1247.
8. Uysal, G., Memon, S. and Yilmaz, M. (2001) React. Funct. Poly.,
47(3), 165.
9. Alpoguz, H.K., Kaya, A., Yilmaz, A. and Yilmaz, M. (2005)
J. Macromol. Sci. Part A: Pure Appl. Chem.,A42, 577.
10. Alonso, M., Delgado, A.L., Sastre, A.M. and Alguacil, F.J. (2006)
Chem. Engineering J.,118, 213.
11. Sastre, A.M., Kumar, A., Shukla, J.P. and Sing, R.K. (1998) Sep.
Purif. Meth.,27, 213.
Fig. 9. Hg
2þ
transport experiment with calix[4]arene derivative 1
for Celgard 2500 membrane. Feed solution: 0.01 M HgCl
2
, organic
membrane: 1¼10
23
M in NPOE, stripping solution: Deionize
water, V
F
¼V
S
¼30 cm
3
,S¼9.08 cm
2
,1¼0.45.
Fig. 10. Mechanism of the ion pair mediated transport (co-trans-
port) of Hg
2þ
through supported liquid membrane X
2
:Cl
2
,NO
3
2
,
L: Ligand, [L-Hg]
2þ
X
2
: ion pair.
Table 5. Permeabilities (P) and fluxes (J
i
) for transport through
supported liquid membranes by calixarene derivative 1for Celgard
2500 membrane.
Ligand Ion pair Solvent
P10
5
(cm .dk
21
)
J
i
10
5
(mol .L
2
.dk
2
)
1 Hg(NO
3
)
2
Xylene 0.24 0.94
Chloroform 0.34 1.37
NPOE 1.45 5.81
1 HgCl
2
Xylene 6.59 26.36
Chloroform 11.05 44.12
NPOE 53.18 213.27
Transport of Hg(II) through Liquid Membranes 1067
Downloaded By: [ANKOS 2007 ORDER Consortium] At: 09:52 15 August 2007
12. Ho, W.S.W. (2003) Ann. NY Acad. Sci.,984, 97.
13. Tilki, T., S¸ener, I
˙, Karcı, F., Gu¨lce, A. and Deligo
¨z, H. (2005) Tet-
rahedron,61(40), 9624.
14. Alpoguz, H.K., Memon, S., Ersoz, M. and Yilmaz, M. (2002) New
J. Chem.,26(4), 477.
15. Alpoguz, H.K., Memon, S., Ersoz, M. and Yilmaz, M. (2004) Sep.
Sci. Technol.,39(4), 799.
16. Alpoguz, H.K., Kaya, A. and Deligo
¨z, H. (2006) Sep. Sci. Technol.,
41, 1155.
17. Szpakowska, M. and Nagy, O.B. (1999) J. Phys. Chem. A,103,
1553.
18. Szpakowska, M. and Naggy, O.B. (1990) Copper(II) ion transport
mono and binary liquid membranes. Bull. Soc. Chim. Belg.,
99(4), 243.
19. Szpakowska, M. (1994) J. Membr. Sci.,92(3), 267–273.
20. Alpaydin, S., Yilmaz, M. and Ersoz, M. (2004) Sep. Sci. Technol.,
39(9), 2189.
21. Visser, H.C., Reinhoudt, D.N. and Dejong, F. (1994) Chem. Soc.
Rev.,23, 75–81.
22. Szpakowska, M. and Nagy, O.B. (2000) J. Membr. Sci.,168(1–2),
183.
23. Lazarova, Z. and Boyadzhiev, L. (1993) J. Membr. Sci.,78(3), 239.
24. Danesi, P.R. (1984) Sep. Sci. Technol.,19, 857.
25. Arnaud-Neu, F., Bo
¨hmer, V., Dozol, J.F., Gru¨ ttner, C., Kraft, R.A.,
Mauprivez, D.O., Rouquette, H., Schwing-Weill, M.J., Simon, N.
and Vogt, W. (1996) J. Chem. Soc. Perkin Trans. 2,2(6), 1175.
26. Casnati, A., Pochini, A., Ungaro, R., Ugozzoli, F., Arnaud-Neu, F.,
Fanni, S., Schwing, M.J., Egbering, R.J.M., Jong, F. and
Reinhoudt, D.N. (1995) J. Am. Chem. Soc.,117, 2767.
27. Dozol, J.F., Simon, N., Lamare, V., Rouquette, H., Eymard, S.,
Tournois, B., Marc DCC/DESD/SEP, D.D. and Macias, R.M.
(1999) DIST/UDC. Sep. Sci. Technol.,34(6&7), 877.
28. Kim, J.K., Kim, J.S., Shul, Y.G., Lee, K.W. and Oh, W.Z. (2001)
J. Membr. Sci.,187,3.
Alpoguz, Kaya, and Sener1068
