Synthesis, characterization and investigation of different properties of three novel thiourea-based non-ionic surfactants

Article abstract of DOI:10.1007/s11743-014-1575-4

Three novel thiourea-based non-ionic surfactants, 3-decanoyl-1,1- diphenylthiourea, 3-dodecanoyl-1,1-diphenylthiourea and 1,1-diphenyl-3- tetradecanoylthiourea were synthesized from carbonyl chlorides, potassium thiocyanate and amines in high yield. The s

Full text of DOI:10.1007/s11743-014-1575-4

J Surfact Deterg
DOI 10.1007/s11743-014-1575-4
ORIGINAL ARTICLE
Synthesis, Characterization and Investigation of Different
Properties of Three Novel Thiourea-Based Non-ionic Surfactants
Imdad Ullah
Usman Ali Rana
Shahan Zeb Khan
•
Afzal Shah
•
Amin Badshah
•
•
•
Imran Shakir
•
Asad Muhammad Khan
•
Zia-ur-Rehman
Received: 29 September 2013 / Accepted: 17 February 2014
Ó AOCS 2014
Abstract Three novel thiourea-based non-ionic surfac-
tants, 3-decanoyl-1,1-diphenylthiourea, 3-dodecanoyl-1,1-
diphenylthiourea and 1,1-diphenyl-3-tetradecanoylthiourea
were synthesized from carbonyl chlorides, potassium
thiocyanate and amines in high yield. The synthesized
compounds were characterized by different techniques like
Keywords Synthesis Á Non-ionic surfactants Á Critical
micelle concentration Á pH effect Á Hydrophobic character
Introduction
1
13
H NMR, C NMR, FTIR and UV-Visible spectropho-
Non-ionic surfactants (NIS) have broad range applications
in industries, agriculture, cosmetics, food, paints and drugs
[1–5]. NIS are not dissociated in aqueous solution due to
the unavailability of an ionizable moiety in their structure.
The dispersion capability of such surfactants increases with
increasing chain length. Non-ionic surfactants are used as
excellent solubilizing agents due to their very low critical
micelle concentration [6–9]. Manufacturers are paying the
utmost attention to such surfactants due to their non tox-
icity, low cost and compatibility with ionic surfactants [10–
tometry. These surfactants are soluble in nonpolar and
polar organic solvents and resist solubility in water due to
the presence of thiourea group. Electronic absorption
spectroscopy was used to evaluate their critical micelle
concentration (CMC) in different solvents. The CMC was
found to decrease with increase in hydrophobic carbon
chain length as expected. Moreover, the effect of pH on
their spectral transition was investigated and the two peaks
were found to merge in highly alkaline conditions.
14]. Thus, spurred on by the peculiar characteristics and
wide applications of non-ionic surfactants, scientists have
sought new methods for the synthesis of other more
effective candidates of this class in high yield. Some NIS
can act as excellent ligands for complexation with metals
and thus such surfactants offer opportunities to the envi-
ronmentalists for the safe removal of toxic metals from
polluted water. Surfactants with an amine group have
appreciable water solubility and thus find use in hand
washing products and liquid soaps with favorable skin
effects [15–17]. Keeping cost affectivity, environmental
friendliness, compatibility and extensive applications of
non-ionic surfactant in consideration, we synthesized and
characterized three new thiourea-based NIS using common
laboratory materials as illustrated in Schemes 1 and 2. The
method used is harmless and easy to handle. The objectives
of this work are to draw the attention researchers towards
these novel thiourea-based non-ionic surfactants and to
emphasize the hidden aspects for further study.
I. Ullah (&) Á A. Shah Á A. Badshah Á S. Z. Khan Á
Zia-ur-Rehman
Department of Chemistry, Quaid-i-Azam University,
45320 Islamabad, Pakistan
e-mail: imdadktk70@gmail.com
A. Shah
e-mail: afzals_qau@yahoo.com
U. A. Rana Á I. Shakir
Deanship of scientific research, College of Engineering,
King Saud University, Riyadh 11421, Saudi Arabia
A. M. Khan
Department of Chemistry, COMSATS Institute of Information
Technology, 22060 Abbottabad, KPK, Pakistan
1
23

J Surfact Deterg
1
Experimental
H NMR (300 MHz, CDCl , d-ppm): 0.87–0.90 (3H, t,
3
3
CH3, J [ H, H] = 7 Hz), 1.07–1.65 (14H, m,7CH ),
1
1
2
3
1
1
Chemicals, Instruments and Methods
2.26–2.36 (2H, t, CH2. J [ H, H] = 7 Hz , 6.49–7.44
)
2 13
10H,m, CH,) 8.72 (1H, s, NH) C NMR (75.5 MHz
(
Lauryl chloride (98 %), potassium thiocyanate (99 %),
different aliphatic and aromatic primary and secondary
amines (98 %) were purchased from Sigma Aldrich. Fresh
analytical grade dry acetone was used as the solvent and
dried before experiments. The products were purified by
thin layer chromatography. NMR spectra were recorded on
CDCl3, d-ppm): 14.1 (C.15), 22.6–37.0 (C7–14),
117.7–120.2 (C1,1,3,3), 127.5–129.0 (C2,2,2,2), 142.5 (C,4,4),
-
1
169.6 (C ), 182.0 (C ). IR (t cm ): 3268.5, 3156.3 (N-H),
6
5
2
3
3035.8 (Ar-H, C-H, sp ), 2913.7, 2843.5, (sp , C-H),
1680.5 (CO).
1
Bruker AC Spectrometers at 300.13 MHz for H and
3-Dodecanoyl-1,1-diphenylthiourea
1
5.47 MHz for C. Thermo Nicolet-6700 FTIR spectro-
3
7
photometer was also used for IR characterization. A double
beam Shimadzu UV-1800 scan UV- Visible spectropho-
tometer was used for CMC determination and investigation
of pH and solvent effects.
For the synthesis of 3-dodecanoyl-1, 1-diphenylthiourea,
6.3 mmol potassium thiocyanate was dissolved in 50 mL
O
O
O
O
S
(
C6H5)2NH
KCl
C H
9
19
KSCN
KSCN
KSCN
3
-Decanoyl-1,1-diphenylthiourea
C H
9 19
N
H
N
-
Cl
For the synthesis of 3-decanoyl-1,1-diphenylthiourea
.709 g (0.00724 mol) potassium thiocyanate was dis-
0
solved in 50 mL dry acetone and introduced into a 250-mL
round-bottom flask followed by the addition of 3 mL
decanoyl chloride. Heating the solution for 40 minutes at
S
O
(
C6H5)2NH
C11H23
-
KCl
C11H23
N
H
N
Cl
9
0 °C, 1.224 g diphenylamine was added and the solution
was kept stirring for 12 hrs. Finally, the products collected
on condensing in ice water were washed with doubly dis-
tilled water for the removal of impurities. The pure product
with 78 % yield was obtained as a light yellow powder.
The structure of the compound can be seen in Scheme 1
and the stepwise preparation protocol is given in Scheme 2.
O
S
6 5 2
(C H ) NH
C13H27
-
KCl
C13H27
N
H
N
Cl
1
The purity of the compound was ascertained by H NMR,
1
C NMR and FTIR spectroscopy and the spectral details
3
Scheme 2 Synthetic method for the preparation of non-ionic thio-
urea-based surfactants
are given below:
Scheme 1 Chemical structures
and names of non-ionic
thiourea-based surfactants
2
2
1
1
2
3
3
2
2
1
1
2
3
3
1
2
4
4
N
1
2
3
3
4
4
N
5C
3
3
2
5C
S
2
HN
S
HN
6
6
17
C
1
5
C
O
7
O
7
3
-decanoyl-1,1-diphenylthiourea
3-dodecanoyl-1,1-diphenylthiourea
2
2
1
1
2
3
3
1
N
2
4
4
3
3
5C S
2
HN
6
19
C
O
7
1,1-diphenyl-3-tetradecanoylthiourea
1
23

J Surfact Deterg
1
dry acetone and introduced into a 250-mL round-bottom
flask followed by the addition of 1.5 mL dodecanoyl
chloride. After heating the solution for 40 minutes at 90
H NMR (300 MHz, CDCl , d-ppm): 0.88-0.92 (3H, t,
3
3
CH3, J [ H, H] = 7 Hz), 1.35–1.57 (18H, m, 9CH ),
1
2.23–2.56 (2H, t, CH2. J [ H, H] = 7 Hz , 6.96–7.52
1
1
2
3
1
)
2
13
°
C, 6.3 mmol diphenylamine was added and the solution
(10H,m, CH,) 8.53 (1H, s, NH) C NMR (75.5 MHz
CDCl3, d-ppm): 14.2 (C 17), 22.3–36.4 (C7–16),
119.7–120.2 (C1,1,3,3), 127.2–129.6 (C2,2,2,2), 140.5 (C,4,4),
kept stirring for about 12 hrs. The products were finally
collected on condensing in ice water and washed with
doubly distilled water to remove the impurities. The
product with 83 % yield was obtained as a light yellow
powder. The structure of the compound is shown in
Scheme 1 and the stepwise preparation protocol can be
seen in Scheme 2. The purity of the synthesized surfactant
-
1
172.3 (C ), 180.7 (C ). IR (t cm ): 3296.8, 3177.3 (N-H),
3048.5 (Ar-H, C-H,sp ), 2916.2, 2849.5, (sp , C-H), 1690.3
(CO).
6
5
2
3
1,1-Diphenyl-3-tetradecanoylthiourea
1
13
was ascertained by H NMR, C NMR and FTIR spec-
troscopy. The spectral details of the compound are given
below:
For the synthesis of 1,1-diphenyl-3-tetradecanoylthiourea,
11.2 mmol potassium thiocyanate was dissolved in 50 mL
A 1.2
B 1.50
1
1
0
0
0
0
.25
.00
.75
.50
.25
.00
0.0468mM
1
0
0
0
0
0
.0
.8
.6
.4
.2
.0
0
.0102mM
240
280
320
360
400
440
240 280 320 360 400 440 480 520 560 600
Wavelength (nm)
Wavelength (nm)
C 0.8
0
0
0
0
0
0
0
0
.7
.6
.5
.4
.3
.2
.1
.0
(B)
Concentration
(A)
0.028
240
280
320
360
400
440
Wavelength (nm)
Fig. 1 UV-Vis spectra of 3-decanoyl-1,1-diphenylthiourea (a), 3-dodecanoyl-1, 1- diphenylthiourea (b) and 1, 1-diphenyl-3-tetradeca-
noylthiourea (c) in ethanol
Table 1 Physical properties of
Code Mol. formula Molecular mass Color
mp (°C) Solubility
CMC (mM)
(
thiourea-based surfactants
C10, C12 and C14) non-ionic
C
10
C
12
C
14
C
23
C
25
C
27
H
30
H
34
H
38
2
N SO
2
N SO
2
N SO
382
410
438
Light yellow 50 Ethanol, methanol 0.023
Light yellow 78
Light yellow 87
Ethanol, methanol 0.013
Ethanol, methanol 0.009
1
23

J Surfact Deterg
dry acetone and introduced into a 250-mL round-bottom
flask along with 3 mL tetradecanoyl chloride. After heating
the solution at 90 °C for about 40 minutes, 1.9 g diphe-
nylamine was added and the solution kept stirring for about
C14 (B)
C14 (A)
C12
0.6
.4
0.2
0
CMC = 0.009mM
CMC = 0.009mM
1
2 hrs. Finally, the products collected on condensing in ice
0.6
water were washed with doubly distillated water for the
removal of impurities. The pure product with 88 % yield
was obtained as a light yellow powder. The structure of the
compound is represented in Scheme 1 and the preparation
method is given in scheme 2. The purity of the compound
0.4
0.2
1
1
0
0
0
.5
.2
.9
.6
.3
1
13
was ensured by H NMR, C NMR and FTIR spectros-
copy. The spectral details of the surfactant are given below:
1
H NMR (300 MHz, CDCl , d-ppm): 0.88–0.92 (3H, t,
3
3
1
CH3, J [ H, H] = 7 Hz), 1.35–1.57 (18H, m, 9CH ),
1
CMC = 0.013mM
2
3
.23–2.56 (2H, t, CH2. J [ H, H] = 7 Hz), 6.96–7.52
2 13
10H,m, CH,) 8.53 (1H, s, NH) C NMR (75.5 MHz
1
1
2
C10
(
0
0
.9
.6
CDCl , d-ppm): 14.1 (C ), 22.7–37.1 (C7–18), 117.7–120.9
3
19
CMC = 0.023mM
(
C1,1,3,3,3,3), 127.0–129.3 (C
), 145.3 (C4,4), 169.5
2,2,2,2
-
1
(
C ), 181.8 (C ). IR (t cm ): 3235.7, 3183.0 (N–H),
6
5
0.3
0.00
2
3
3
054.8 (Ar–H, C–H,sp ), 2916.6, 2849.4, (sp , C–H),
719.0 (CO).
0.01
0.02
0.03
0.04
0.05
1
Concentration/mM
Fig. 2 Absorbance versus concentration plots of C10, C12 and C14
compounds in ethanol
Results and Discussion
The critical micelle concentration was assessed by UV-
Visible spectrometry. The absorbance spectra were recor-
ded over a wavelength range of 200–800 nm. The spectra
of the synthesized three novel non-ionic thiourea based
surfactants obtained at room temperature hare presented in
Fig. 1a–c. The critical micelle concentration was deter-
mined by plotting absorbance versus concentration. In all
cases, the plots presented two linear parts with different
slopes and the critical micelle concentration was evaluated
from their intersection. The CMC values obtained from the
given UV-Visible data are listed in Table 1. The variation
in the hydrophobic part was found to alter the critical
micelle concentration of surfactants. The CMC values of
thiourea-based novel non-ionic surfactants decreased with
increases in the chain length of the carbons as documented
in the literature [18–22]. These compounds synthesized by
the reaction of diphenylamine showed different behaviors
towards UV-Visible light and different pH media. The
compound with a ten-carbon chain length gave a broad
peak at 282 nm, a surfactant with a twelve-carbon chain
gave a sharp peak whereas with fourteen carbons the
compound registered two broad peaks at 250 nm and
Table 2 CMC of (C10, C12 and C14) non-ionic thiourea-based sur-
factants in different solvents
Code Ethanol Methanol 50 % Water–
ethanol mixture
50 % Water–
methanol mixture
C
10
C
12
C
14
0.024
0.013
0.009
0.020
0.010
0.007
0.014
0.007
0.006
0.011
0.006
0.004
1
0
.0
(B)
pH 3
pH 5
pH 8
pH 11
pH 12
.8
(A)
0.6
0
0
0
.4
.2
.0
2
94 nm in ethanol solvent. The CMC was calculated from
absorbance versus concentrations plots as shown in Fig. 2.
In pre-micellar region, the surfactants exist in monomeric
forms which absorb more light as their chromophores are
exposed. While in aggregates, the chromophores remain
buried in micelles and thus get screened from UV-Vis light.
2
40
280
320
360
400
Wavelength (nm)
Fig. 3 UV-Vis spectrum of 1,1-diphenyl-3-tetradecanoylthiourea
(C14) obtained in different pH media
1
23

J Surfact Deterg
Hence, a lower increase in absorbance is evidenced in the
post micellar segment of the plot as compared to the pre-
micellar region.
geometric structure which could undergo an electronic
absorption transition at two wavelengths. The pH study
also reflects the most interesting phenomenon is the pre-
sence of two isosbestic points in the spectra. It is due to the
keto-thiol and enol-thio tautameric forms as represented in
Scheme 4. In these two, the OH in the enol-thio form is
more easily depronated than the SH in keto-thiol forms and
the sharpness of the peak is also related to the enol-thio
form. A further pH study is in progress for getting useful
insights into the indefinite aspects of thiourea-based non-
ionic surfactants for improved and environmentally
friendly applications.
The CMC of surfactants are pronouncedly influenced by
changing the solvent due to variation in polarity and a
corresponding alteration in solute- solvent interaction. The
non-polar part of the surfactants experiences a greater
hydrophobic effect with a concomitant decrease in CMC
by increases in polarity of the solvent. The mixing of
another solvent or co-solvent also alters the CMC of sur-
factant solution by a mechanism involving the penetration
of one solvent into the micellar core of the surfactant
solution. The study of our thio-based non-ionic surfactants
in different solvents like methanol and 50 % water-ethanol
mixture indicates the CMC to modulate with change in
solvent system. The results of UV-Vis spectroscopic
investigations reveal that the CMCs of these compounds in
methanol, in 50 % a water-ethanol mixture and a 50 %
water-methanol mixture became gradually lower with
increasing solvent polarity as depicted in Table 2. An
examination of Table 2 reveals that the increase in polarity
of the solvent affects the CMC due to greater repulsion
with the hydrophobic part of the compounds. The decrease
in CMC of thio-based non-ionic surfactants with increasing
polarity of the medium can be seen in Figs. S1–S4.
Thiourea-based non-ionic surfactants were also studied
in different pH media to visualize their electronic absorp-
tion behavior in acidic, neutral and basic media. The effect
of pH is shown in Figs. 3 and S-5. The results indicate that
absorbance of A C-14 based surfactant becomes lower with
a change in pH from 3 to 8 and the two peaks merge into a
single peak (at pH 10) whose absorption intensity increases
with a further rise in pH up to 11 and 12. In strongly
alkaline conditions of pH 11–12, the narrowness and
increase in peak intensity of all the three surfactants is
attributed to the deprotonation of –NH group and a con-
sequent increase in conjugation as shown in Scheme 3. The
spectra of compounds with ten and twelve carbon chain
lengths show a single peak at 282 nm where the fourteen
carbon-containing compound absorbs at 250 nm and
Conclusions
Three novel non-ionic thiourea-based surfactants were
successfully synthesized by a new method from simple raw
materials available in the laboratory. The synthesized sur-
1
factants were well characterized by UV-Visible, FTIR, H-
1
3
and C-nuclear magnetic resonance spectroscopy. These
compounds can possibly be tailored appreciably under
basic conditions as the results of the pH effect showed that
such surfactants offer resistance to acid media. Electronic
absorption spectroscopy was successfully employed for the
evaluation of the critical micelle concentration of the
synthesized surfactants from the intersection of the two
linear segments of the plots of absorbance versus concen-
tration. The solvent effect showed that the CMC is mod-
ulated by changing the polarity of the medium. The
H
O
C
S
C
1
2
N
N
R
O
S
C
1
N
C
H
Enol-thio
2
N
R
H
O
S
Keto-thio
1
N
2
94 nm. All the three surfactants have the same conjugated
C
2
N
C
R
hydrophilic moiety so these should give the same spectral
signature. However, unlike C-10- and C-12-based surfac-
tants, the UV-Vis spectrum of the C-14 surfactant gives a
second peak which may be due to its existence in such a
R = C H19, C11H23, C13H
27
9
Keto-thiol
Scheme 4 Tautomeric forms of non-ionic surfactants
Scheme 3 Demonstration of
O-
O
C
S
C
S
C
Ph
Ph
the increase in volume of the
chromophore of non-ionic
surfactants under alkaline
+ -
+
H O
2
R
NH
N
OH
R
C
N
N
conditions leading to a more
intense peak in UV-Vis spectra
Ph
R= C H , C H , C H Ph=C H5
Ph
9
19
11 23
13 27
6
1
23

J Surfact Deterg
washing water of these non-ionic surfactants is expected to
increase the fertility of soil by the provision of thiourea. As
introduction of thiourea group in the structure of a sur-
factant lowers its solubility in water, so, further study is in
progress to incorporate such moieties in thiourea-based
non-ionic surfactants to improve their water solubility,
cleaning action and biodegradability.
16. Maria VF, Epaminondas CV, Nikolaos S, Gill ME, George B,
Dimitrios PT, Peter JH (2001) Critical micelle concentrations of
nonionic surfactants in organic solvents: approximate prediction
with UNIFAC. J Colloid Interface Sci 240:277–283
17. Anna M, Buzenna RR (2010) Prediction of critical micelle con-
centration of nonionic surfactants by a quantitative structure –
property relationship. Comb Chem High Throughput Screen
1
3:39–44
1
8. Achouri ME, Alehyen S, Assioui A, Chami R, Bensajjay F, Prez
L, Rosa M (2013) Synthesis and physico-chemical studies of
ester-quat surfactants in the series of (dodecanoyloxy)propyl n-
alkyl dimethyl ammonium bromide. J Surf Deterg 16:473–485
Acknowledgments The authors gratefully acknowledge the finan-
cial support of Quaid-i-Azam University, Higher Education Com-
mission Islamabad, Pakistan, and the Deanship of Scientific Research
at King Saud University through the research group project no RGP-
VPP-312. We also acknowledge the funding of Higher Education
department Khyber Pakhtunkhwa, Pakistan.
19. Chakraborty S, Shukla D, Jain A, Mishra B, Singh S (2009)
Assessment of solubilization characteristics of different surfac-
tants for carvedilol phosphate as a function of pH. J Colloid
Interface Sci 335:242–249
2
0. Scramm LL, Stasiuk EN, Marangoni DG (2003) Surfactants and
their applications. Annual Rep Prog Chem Sect 99:3–48
1. Chlebicki J, Wegrzynska J, Maliszewska I (2005) Preparation,
surface-active properties, and antimicrobial activities of bisqua-
ternary ammonium salts from amines and epichlorohydrin. J Surf
Deterg 8:227–232
2
References
1
2
3
. Rosen MJ (1978) Surfactant and interfacial phenomena, John
Willy and Sons New York
. Rosen MJ (2004) Surfactants and interfacial phenomena, 3rd edn.
Wiley, New Jersey
. Qu G, Cheng J, Wei J, Yu T, Ding W, Luan H (2011) Synthesis,
characterization and surface properties of series sulfobetaine
surfactants. J Surf Deterg 14:31–35
. Xu B, Han F, Shui J, Zhou Y (2009) Synthesis and character-
ization of lauryl trimethyl ammonium surfactants with new
counteranion types. J Surf Deterg 12:351–354
2
2. Negm NA, Aiad IA (2007) Synthesis and characterization of
multifunctional surfactants in oil-field protection applications.
J Surf Deterg 10:87–92
Imdad Ullah is an assistant professor in the government college of
Khyber Pakhtunkhwa, Pakistan. After being awarded an M.Sc. gold
medal, he is now a Ph.D. graduate student under the supervision of
Dr. Afzal Shah in the Department of Chemistry, Quaid-i-Azam
University (QAU), Islamabad, Pakistan. He has synthesized more
than fifty new thiourea-based surfactants.
4
5
. Daoyong Y, Fang H, Hai X (2011) Determination of critical
concentrations by synchronous fluorescence spectrometry. The
Royal Society of Chemistry (S1–S18)
6
7
. Jean LS (2002) Surfactants - types and uses, (FIRP Booklet
300A) M e´ rida-Venezuela Versi o´ n # 2
. Seifert K, Domka F (2005) Inhibiting effect of surfactants and
heavy metal ions on the denitrification process. Pol J Environ
Stud 14:87–93
Afzal Shah is an assistant professor in Quaid-i-Azam University, and
received his Ph.D. in physical chemistry from QAU in 2010 under the
indigenous Ph.D. program launched by the Higher Education
Commission of Pakistan. His research interests include the elucida-
tion of electrode reaction mechanisms of biologically important
molecules and development of new synthetic routes for the prepa-
ration of environmentally friendly surfactants.
#
8
. Aldrich C, Feng D (2000) Removal of heavy metals from
wastewater effluents by biosorptive flotation. Minerals Eng
1
3:1129–1134
9
. Holmberg K, J o¨ nsson B, Kronberg B, Lindman B (2007) Surfac-
tants and polymers in aqueous solution, 2nd edn. Wiley, Chichester
Amin Badshah is a professor of chemistry at Quaid-i-Azam
University, Islamabad, Pakistan. He has focused on the synthesis,
characterization and applications of surfactants and medicinal com-
pounds. He is cited in the list of ‘‘Leading Scientists and Engineers of
OIC Member States’’, from COMSTECH Secretariat, Islamabad,
Pakistan.
1
0. Negm NA, Kandile NG, Mohamad MA (2011) Synthesis, char-
acterization and surface activity of new eco-friendly Schiff bases
vanillin derived cationic surfactants. J Surf Deterg 14:325–331
1. Minggui C, Xinqi H, Meilong F (2013) Novel synthesis of a new
surfactant 4-((4-bromophenyl) (dodecyl)amino)-4-oxobutanoic
acid containing a benzene ring using a copper catalyst cross-
coupling reaction and its properties. J Surf Deterg 16:581–585
2. P e´ ter S, L a´ szl o´ F, Zolt a´ n S, Istv a´ n R, P e´ ter B, Mohamed A, Antal
T, Gabriella F (2002) Novel general procedure for the preparation
of homogeneous nonionic surfactants. J Surf Deterg 5:353–357
3. Sujit KG, Pijus KK, Subhash CB (2003) Aggregation of non ionic
surfactant igepal in aqueous solution: fluorescence and light
scattering studies. Int J Mol Sci 4:562–571
1
Usman Ali Rana is an assistant professor at the King Saud
University, Riyadh, 11421, Saudi Arabia. He earned his Ph.D. from
Monash University, Clayton, VIC, Australia. His research interests
include electrochemistry, materials engineering and surfactants
synthesis.
1
1
1
Imran Shakir is an assistant professor at the King Saud University,
Riyadh Saudi Arabia. He earned his Ph.D. from Sungkyunkwan
University, Korea. His research interests include synthesis and
characterization of multifunctional nanoparticles, energy storage
devices and electrochemical sensor development.
4. Samik KH, Satya PM (2001) Determination of critical micelle
concentration (CMC) of nonionic surfactants by donor–acceptor
interaction with iodine and correlation of CMC with hydrophile–
lipophile balance and other parameters of the surfactants. J Surf
Deterg 4:303–309
1
5. Aguiar J, Carpena P, Molina BJA, Ruiz CC (2003) On the
determination of the critical micelle concentration by the pyrene
Asad Muhammad Khan is an assistant professor in the Department
of Chemistry, COMSATS Institute of Information Technology,
Abbottabad, Pakistan. His field of interest is colloids and surfactants.
1
:3 ratio method. J Colloid Interface Sci 258:116–122
1
23

J Surfact Deterg
Shahan Zeb Khan is a lecturer in Bannu University of Science and
Technology, Khyber Pakhtunkhwa, Pakistan. Currently he is pursuing
his Ph.D. at QAU under the supervision of Dr. Zia-ur-Rehman. His
research is focused on the synthesis and characterization of surfac-
tants and medicinal applications of metal based compounds.
at McGill University, Canada. Presently, he is an assistant professor
in the Department of Chemistry, Quaid-i-Azam University, Islama-
bad. His research interests include discovery of new metal-based
anticancer drugs and their targeted delivery via loading in micelles of
body compatible surfactants.
Zia-ur-Rehman earned his Ph.D. from the Department of Chemistry,
Quaid-i-Azam University, Islamabad in 2009 under the HEC
indigenous program. Through a HEC IRSEP scholarship he studied
1
23