:الملخص
We have investigated the phase behavior and characterized the microstructure of the phases that result from mixing of alkyltrimethylammonium hydroxides CxTAOH (x = 10.8) with 2-hydroxy 1-carboxy-naphthoate. We compare the results of this work with the published one of alkyltrimethylammonium 2-hydroxy-1-carboxy-naphthoate (CxTA 2,1 HCN, x = 16.14 or 12) [2]. With increasing counter-ion surfactant ratio r we observed transition from the isotropic L1-phase to multilamellar vesicles (MLV) Lα-phase. The single phases are separated by a two phase L1/Lα region. The phases were characterized with FF-TEM, rheological and SANS measurements. For 100mM solution of either C8TAOH/2,1 HNC or C10TAOH/2,1 HNC, both MLV phases behave like a weak gel and have a yield stress value. It is thus shown that it is possible to prepare viscoelastic surfactant solutions with a small yield stress value from single chain surfactants with decyl or octylchain.
R. Abdel-Rahem and J, " Dissolution Rate of Sodium Fatty Alcohol Sulfate FAS – Surfactants " , "Tenside Surfactants Detergents ",Vol.44,No.5, Hanser, Germany, 10/01/2007
:الملخص
We represent an applicable problem that arises when long chain surfactant fatty alcohol sulfate FAS is used in washing process. Octadecyl fatty alcohol sulfate C18-FAS is known for its strong washing performance, however it has the disadvantages of high Krafft point and its long dissolution rate. We demonstrate the factors that affect dissolution rates of FAS-surfactants, and how one can vary these factors in order to achieve particular dissolution rate. In this study, we have used a reproducible method for determining the rate of dissolution of anionic surfactants tablet and the effect of, temperature, hardness of FAS-tablets, stirring rate, FAS chain length, mixing with other surfactants and additives on the rate of dissolution of FAS have been studied.
R. Abdel-Rahem and A, " Surface Activity of Newly Nonionic Surfactants at Air/Water Interface and their Interaction with Clay and Teflon " , "Tenside Surfactants Detergents ",Vol.45,No.3, Hanser, Germany , 06/01/2008
:الملخص
The surface activity of newly nonionic hydroxyl mixed ether surfactants HMEn at air/water and solid/water interfaces was studied as a function of ethoxylation degree (n-value). The characteristics of this series of nonionic surfactant, including surface tension, critical micelle concentration cmc, adsorption onto hydrophilic saponite clay and hydrophobic Teflon are reported. The surface tension results indicate that cmc, surface tension after γcmc, and the minimum surface area per adsorbed HME-surfactant molecule Amin are all increased with n-value. Results of static light scattering are in agreements with those obtained using surface tension method. For HME-surfactants, strong adsorption measured by surface tension onto the hydrophilic synthetic clay mineral saponite. This result was also observed by atomic force microscopy AFM for HME9.7 onto hydrophilic mica surface. On the other hand, the adsorption of HME-surfactant onto hydrophobic polytetraflouroethylene PTFE (Teflon) is less than that measured onto saponite. However, the adsorption at both surfaces has the same dependency on n-value.
R. Abdel-Rahem, " The influence of hydrophobic counterions on micellar growth of ionic surfactants " , "Advances in Colloid and Interface Science",Vol.141,No.1-2, Elsevier, USA, 09/01/2008
:الملخص
This review covers the effects of hydrophobic counterions on the phase behavior of ionic surfactants and the properties of the phases. Mixing
hydrophobic counterions with ionic surfactant micellar solutions may initiate the micellar growth and transform the micellar microstructure into
different morphologies. This behavior may also be achieved by mixing ionic surfactants with hydrophilic counterions, although higher
counterionic concentrations are then required. First, the role of hydrophilic and hydrophobic counterions in regards to micelle growth is discussed.
Second, the effect of the hydrophobic counterion on the self-assembly of cationic and anionic surfactants and their viscoelastic behavior are
presented. Third, the relationships between geometry, hydrophobicity and their consequences on micellar growth for different hydrophobic
counterions are reviewed. Forth, the influence of hydrophobic counterion substituents (substitution pattern) on the phase behavior is discussed.
Some results we previously obtained for different isomers of hydroxy naphthaoic acids and the cationic surfactant cetyltrimethylammonium
hydroxide are included. With these systems the effect that the hydrophobic counterion microenvironment has on the phase behavior, rheological
behavior and the micellar microstructure is discussed. The results from other research groups are also discussed.
Ayman S. Ayesh and R, " Optical and Electrical Properties of Polycarbonate/MnCl2 Composite Films " , "Journal of Plastic Film and Sheeting",Vol.24,No.2, SAGE, USA, 08/21/2008
:الملخص
The dependence of the absorption coefficient () on photon
energy (h) is determined in the spectral range from 200 to 800nm at room
temperature for polycarbonate (PC)/MnCl2 composite films. The variation of the
absorption coefficient (), optical gap (Eopt), dielectric permittivity ("0), dielectric
loss ("00), loss tangent (tan ), impedance (Z), AC conductivity (ac), DC
conductivity (dc), and relaxation time () with salt concentration and frequency
are reported. The observed optical energy gap (Eopt) and energy gap tail (E) is
calculated from the measured absorption spectra. It is found that optical energy
gap decreases with increasing MnCl2 concentration and the absorption
coefficient reduces sharply (with reduction ratio of 79%) in the UV region at
concentration of 20 wt% compared with the PC host. All measured electrical
parameters of the composite sheets show frequency and content dependence.
Both AC conductivity and DC conductivity increase with MnCl2 concentration
while impedance decreases. Correlation between observed energy gap and AC
conductivity is presented.
R. Abdel-Rahem and , " Physiochemical Properties of Hydroxy Mixed Ether HMEn Surfactants and their Interaction with Sodium Dodecyl Sulfate SDS " , "Tenside Surfactants Detergents ",Vol.46,No.2, Hanser , Germany , 04/01/2009
:الملخص
This paper is focused on the phase behavior, interaction with anionic surfactant sodium dodecyl sulfate SDS, adsorption and wetting investigations of new hydroxy mixed ether nonionic surfactants HMEn. The phase diagrams of (0.1–100) %wt of HMEn (n-value is the ethoxylation number EO) at the temperature range 20–100°C have shown that the increasing of n-value raises the cloud boundary toward higher temperature. Remarkable result was obtained from the interaction between SDS and HMEB, at which the mixed system exhibits a unique homogeneity and a liquid crystal phase formation. Macroscopically, the liquid crystal region was found when the SDS concentration range between 8 and 24 mM mixed with 10% wt HMEB. The interaction between HMEn and mica was also investigated using atomic force microscopy AFM and a pronounced adsorption of HMEn on mica was observed. Moreover, contact angle results reveal that glass substrate shows strong wettability of HMEn surfactant solutions compared with polyethylene PE and polymethylmethaacrylate PMMA substrates. This wettability however also decreases with EO number.
Rami Abdel-Rahem, " Synergism in Mixed Anionic–Amphoteric Surfactant Solutions: Influence of Anionic Surfactant Chain Length " , "Tenside Surfactants Detergents",Vol.46,No.5, Hanser , Germany , 10/01/2009
:الملخص
The influence of chain length on the composition of mixed micelles in binary mixtures of N,N-dimethyldodecylamine oxide (DDAO) and sodium decyl-, sodium dodecyl- and sodium tetradecylsulfate (abbreviated as SDeS, SDS and STS, respectively) has been determined at 30°C. From the surface tension measurements, the critical micelle concentration (cmc) data were measured as a function of mixing composition. Cmc-values were then analyzed according to regular solution model. The composition of mixed micelles, the interaction parameter (β) and the activity coefficients were evaluated from the regular solution model for the all anionic-amphoteric mixed systems. The interaction parameter values indicated a synergistic interaction between DDAO and the three anionic surfactants at all mole fractions to be due to an overall attractive interaction in the mixed micelles. The strength of the interaction between the amphoteric surfactant and the sodium alkyl sulfate in three mixed systems obeys the following order: SDeS/DDAO > SDS/DDAO > STS/DDAO suggesting that the decrease in the length of anionic surfactant alkyl chain results in a stronger interaction with DDAO. On the other hand, the viscosity data reveals a viscosity increasing trend of STS/DDAO > SDS/DDAO > SDeS/DDAO.
Ayman S. Ayesh and, " Effect of Ba0.9725 (Ti(0.9)Sn0.1)O3 Ceramic Doping on the Optical, Thermal and Dielectric Properties of Polycarbonate Host " , "Bulletin of Materials Science ",Vol.33,No.3, Springer , India , 10/01/2010
:الملخص
Ba(Ti(0⋅9)Sn0⋅1)O3 (BTS) ceramic was prepared by a conventional ceramic processing. BTS–
polycarbonate (PC) composites were prepared at different BTS concentrations by weight in order to study
their optical and dielectric properties. The absorption coefficient (α) was determined in the wavelength range
from 250–600 nm at room temperature for all BTS–PC composites. The optical gap (E
opt) was also determined
for BTS–PC composites. The variation of the absorption coefficient (α) and optical gap (E
opt) with BTS content
are reported. It was found that BTS ceramic highly enhances the UV absorption of PC host at 300 nm.
The optical gap decreases up to the value of 3⋅93 eV as BTS content increases up to 35 wt% and this was attributed
to the formation of localized states in the forbidden gap. The relative dielectric permittivity, dielectric
loss and loss tangent were measured at temperature range from room temperature up to 150°C and at
frequency values 1 kHz, 10 kHz and 50 kHz. Addition of BTS to PC host, however, will increase relative dielectric
permittivity, dielectric loss and loss tangent. Besides, increasing of temperature will also increase relative
dielectric permittivity, dielectric loss and loss tangent especially above the glass transition temperature of
PC host and this behaviour was attributed to the segmental motion of polymer chains. On the other hand, this
study shows that there is a good agreement between SEM, DSC and dielectric results and also between optical
gap and a.c. conductivity results. Moreover, SEM and DSC results reveal that addition of BTS ceramic particles
to PC host will reduce the physical bond between polymer chains or may be will increase the free volume
in the polymer host and consequently will enhance the segmental motion of polymer chains and this behaviour
is independent of ceramic phase.
H. Hoffmann and R. A, " Influence of co-solvent on the rheological behavior of aqueous viscoelastic surfactant systems " , "Find out how to access preview-only content Colloid and Polymer Science ",Vol.288,No.6, Springer , Germany , 02/23/2010
:الملخص
We have studied the influence of glycerol on the
rheological behavior of viscoelastic surfactant solutions.
The measurements were carried out on the system CTAB
and NaSal. This system shows two viscosity maxima with
increasing NaSal concentration. When water is replaced by
glycerol, the viscosities and the structural relaxation times
at the viscosity maxima decrease while they increase at the
viscosity minimum. As a result of the opposite changes the
two maxima are replaced by a single maxima when 40%
water is replaced by glycerol. The change of the viscosities
is a consequence of a change of the structural relaxation
times while the storage moduli remain constant. The
opposite changes are a result of different mechanisms for
the relaxation times. At the maxima, the relaxation times
are reptation controlled and depend on the intermicellar
interaction energy. At the minimum, relaxation times are
kinetically controlled and depend on the intramolecular
interaction.
R. Abdel-Rahem, " Effect of Glycerol on the Swelling of Multilamellar Vesicles Composed of Cetyltrimethylammonium Bromide and Sodium Hydroxy-naphthoate " , "Journal of Dispersion Science and Technology",Vol.32,No.6, Taylor & Francis, UK, 05/23/2011
:الملخص
A biphasic solution containing an isotropic L1-phase and La-phase (multilamellar vesicles) was
illustrated in order to investigate the consequences of glycerol addition on the swelling behavior
of La-phase at different glycerol concentrations and temperature values. The multilamellar vesicles
were prepared from mixing cationic surfactant cetyltrimethylammonium bromide (CTAB)
and hydrophobic counterion sodium 3-hydroxynaphthalene 2-carboxylate (NaHNC) at the same
molar ratio. Different techniques were used in order to investigate the swelling behavior of the
La-phase by establishing the phase diagram, observing the solutions via polarizing microscopy,
and measuring different rheological parameters. A comparison study between the effect of glycerol
addition and temperature on the swelling behavior was performed. By adding glycerol to
water at 40%, the two-phase L1/La region was swollen to a single La phase and the solution
became transparent at 40C. On the other hand, the swelling of La-phase was observed in water
solvent at higher temperature values. The vesicles were with higher flexibility at low glycerol content
and became rigid when the glycerol content was increased. In addition, the complex viscosity,
g followed the same increase-decrease in two conditions. In the first case, g was varied with glycerol
content at constant temperature and in the second case g was varied with temperature at
constant glycerol content. Such a result indicates that the rheological behavior is also influenced
by the solvent properties. Furthermore, this study shows that with increasing glycerol content, the
swelling in the La phase was attributed with a decrease in the attraction energy between the vesicles.
Ultimately, it has shown that it is possible to convert the two-phase L1/La into a single La
phase by controlling some physical parameters of the medium as the static dielectric constant and
the refractive index. The results obtained are expected to be useful in many different applications
of surfactant solutions.
Rami Abdel-Rahem , A, " The Influence of Surfactant's Synergism on the Solubilization of Some Fluorescent Compounds " , "Tenside Surfactants Detergents",Vol.48,No.6, Hanser , Germany , 12/01/2012
:الملخص
Aqueous solutions of anionic surfactant sodium dodecylsulfate (SDS) and cationic surfactant cetyltrimethyammonium bromide (CTAB) were prepared at room temperature in order to investigate the influences of surfactants mixing on the solubilization of 2-naphthol-6-sulfonate and toluene. The phase behavior of CTAB/SDS was firstly investigated to obtain the optimum ratio of CTAB/SDS that result in an isotropic solution before reaching the two phase region. From the conductivity and surface tension measurements, the critical micelle concentrations (CMC) of single and mixed surfactant solutions were obtained and the interaction parameter (β) were evaluated. Water solubility enhancement of (0 – 3 wt.%) toluene by micellar solutions of single surfactant SDS, CTAB and mixed solutions of SDS-CTAB surfactants were then investigated by establishing the phase behavior and measuring the absorption and the emission spectra of these solutions. The toluene was completely solubilized by the micellar solution of single surfactants, whereas turbidity was observed at toluene concentration of about 1.5 wt.% in the micellar solution of SDS-CTAB. The fluorescence behavior of 2-naphthol-6-sulfonate (2NO6S) and toluene in the single and mixed surfactant solutions was also compared. The solubilization of toluene in surfactant solutions was explained in terms of hydrophobic interaction occurring within the surfactant core and the palisade layers.
Jibril Al-Hawarin, , " Dielectric and Thermal Properties of PEO Doped with Cadmium Chloride salt " , "Chinese Journal of Polymer Science",Vol.30,No.2, Springer , China, 11/30/2012
:الملخص
The main aim of this research is to investigate the effect of salt concentration on the dielectric properties (AC
(AC), permittivity ('), dielectric loss (''), and dielectric relaxation process) and melting behavior of polyethylene oxide
(PEO)/CdCl2 complexes. The dielectric study was carried out over a frequency range 10335 kHz and a temperature range
2545C. The AC conductivity, permittivity and dielectric loss of the PEO/CdCl2 complexes increase with increasing salt
concentration and temperature. Also, it was found that the addition of CdCl2 salt to PEO host reduced the melting
temperature of PEO host. Dielectric results reveal that the relaxation process of these complexes is due to viscoelastic
relaxation or non-Debye relaxation at room temperature. Additionally, it was found that relaxation behavior remained
viscoelastic at different temperatures and salt concentrations.
Rami A. Abdel-Rahe, " Micellar Parameters in Solutions with Cationic Surfactants and N,N-dimethyldodecylamine oxide: Influence of Cationic Surfactants Chain Length " , "Journal of Chemical and Engendering Data",Vol.57,No., American Chemical Society, USA, 01/27/2012
:الملخص
The influence of chain length on the composition of mixed
micelles in binary mixtures of N,N-dimethyldodecan-1-amine oxide (DDAO)
and decyl-, dodecyl-, and tetradecyl-trimethyl-ammonium bromide surfactants
(abbreviated as C10TAB, C12TAB, and C14TAB, respectively) has been
determined at 298 K. From the surface tension measurements, the critical
micelle concentration (cmc) data were measured as a function of mixing
composition. The cmc values were then analyzed according to regular solution
model. The composition of mixed micelles, the interaction parameter (β), and
the activity coefficients were evaluated from the regular solution model for all
cationic−amphoteric mixed systems. The interaction parameter values indicated
somehow a small deviation from ideality for the three mixed surfactant systems,
for all investigated mole fractions. The strength of the interaction between the
amphoteric surfactant and the alkyl-trimethyl-ammonium bromide surfactants in
three mixed systems obeys the following order: (C10TAB + DDAO) > (C12TAB + DDAO) > (C14TAB + DDAO) suggesting
that the decrease in the length of cationic surfactant alkyl chain results in a stronger interaction with DDAO. Rheological
measurements of these solutions in the presence of sodium salicylate, NaSal, for the three mixed systems were also measured.
The viscosity data reveal a viscosity increasing trend of (C14TAB + DDAO) > (C12TAB + DDAO) > (C10TAB + DDAO).
Rami A. Abdel-Rahem<, " 1,3-butanediol as a co-solvent for the surfactant solutions " , "Colloid Polym Sci",Vol.290,No.10, Springer , Germany , 07/01/2012
:الملخص
A biphasic solution containing water and precipitated phosphocholine (PC) is presented in order to investigate the consequences of 1,3-butanediol addition on the phase behavior of PC at different 1,3-butanediol concentrations and temperature values. With increasing the concentration of 1,3-butanediol in the mixed solvent at room temperature, the biphasic solution converts into turbid phase, two phase, and finally to a clear phase that is birefringent when viewed between two crossed polarizers. The birefringent phase moves to lower 1,3-butanediol contents at higher temperature values. The birefringent phase was observed via polarizing microscopy, and its rheological parameters were measured with cone plate method. In high 1,3-butanediol contents, solutions with 2.5% of PC behave as a gel with high yield stress value. The micellization of cetyltrimethyammonium bromide (CTAB) in a series of 1,3-butanediol/water mixed solvent at room temperature was also investigated. From the conductivity measurements, the critical micelle concentration and the degree of counterion dissociation of CTAB were obtained as a function of 1,3-butanediol. Standard free energy of micellization, as a function of 1,3-butanediol contents, was also estimated and discussed. Gibbs energies of micellization were found to have a good correlation with dielectric constant and Gordon parameters.
Rami Abdel-Rahem and, " Rheological Investigations on the Viscoelastic Properties of alkyimethylammonium 2-hydroxy-1-carboxy-naphthoate and 2-hydroxy-1-carboxy-naphthoate in aqueous Solutions " , "Journal of Dispersion Science and Technology",Vol.34,No.1, Taylor & Francis, UK, 12/26/2012
:الملخص
The rheological behavior of alkyimethylammonium 2-hydroxy-1-carboxy-naphthoate, CxTA-2.1-
HCN (x¼16, 14, 12, 10, and 8) is presented. With increasing 2.1 HNC/CxTAOH (x¼16, 14,
12) ratio, the viscoelasticity of the solutions changes due to a transition in the micellar shape from
small micelles to rodlike micelles and finally to multilamellar vesicles (MLV). On the other hand,
a transition from small micelles to multilamellar vesicles (MLV) was observed for solution with
CxTA-2.1-HCN (x¼10 and 8). The MLV phases behave like a weak gel and have a yield stress
value. Rheological measurements were performed for these viscoelastic systems in order to find out
the dependency of the viscoelastic behavior on the surfactant chain length and hydrophobic counterion
concentration. Some theoretical models as reptation mechanism was also applied in order to get some
structural details and to illustrate the rheological behavior of these viscoelastic systems. Some models
that correlate MLV-modulus on the surfactant morphology are also presented and discussed.
Rami A. Abdel-Rahem, " The Adsorption of Newly Hydroxyl Mixed Ether Nonionic Polymeric Surfactants at Air/Water and Solid/Water Interfaces: Influence of Surfactant Molecular Structure " , "Journal of Surfactants and Detergents ",Vol.16,No.1, Springer & AOCS, USA, 01/01/2013
:الملخص
This paper reports the adsorption of four nonionic
Hydroxyl Mixed Ether (HME) polymeric surfactants
at air/water and solid/water interfaces. The characteristics
of these nonionic surfactants, including surface tension,
critical micelle concentration (CMC) and adsorption onto
saponite and Teflon are investigated. At the air/water
interface, the surface activity of the HME-surfactants
decreases with an increasing degree of ethoxylation. The
surface tension results indicate that CMC, surface tension
at CMC (cCMC), and the minimum surface area per
adsorbed HME-surfactant molecule (Amin) all increased
with the degree of ethoxylation for surfactants with similar
hydrocarbon chain lengths. Additionally, a strong adsorption
onto the saponite (synthetic clay) was measured and
found dependent on both the degree of ethoxylation and the
hydrocarbon chain length. This adsorption was also
observed by atomic force microscopy (AFM). On the other
hand, the adsorption of HME-surfactants on Teflon was
independent of the hydrocarbon chain length.
Rami A. Abdel-Rahem, " Influence of Glycerol and Temperature on the Phase Behavior and Micellization of CTAB and SDS in Aqueous Solutions " , "Journal of Dispersion Science and Technology",Vol.34,No.7, Taylor & Francis Group, UK, 07/03/2013
:الملخص
In this work the micellization of sodium dodecylsulfate (SDS) and cetyltrimethyammonium bromide (CTAB) in water-glycerol mixed solvent have been investigated at 25, 35, and 45°C, respectively. The micellization of both surfactants in pure water at different temperatures has also been studied. The phase diagrams of the surfactants in water-glycerol mixed solvent were also established. From the conductivity measurements, the critical micelle concentration (CMC) and the degree of counterion dissociation (β) were obtained as a function of glycerol-water ratio and temperature. Standard free energy of micellization (ΔG°mic) as a function of glycerol contents and temperature was calculated and discussed. It has been found that the micellization of the two surfactant in solutions with glycerol at 25°C and in pure water at higher temperatures are not the same although they have equal dielectric constants values.
Rami A. Abdel-Rahem,, " Rheology of Aqueous Solutions Containing SLES, CAPB,and Microemulsion: Influence of Cosurfactant and Salt " , "Journal of Dispersion Science and Technology",Vol.35,No.1, Taylor & Francis, UK, 12/20/2013
:الملخص
Aqueous solutions containing sodium lauryl ether sulphate (SLES) and cocamidopropyl Betaine
(CAPB) with a constant total surfactant concentration (10 wt%) but different volume mixing
ratios were prepared. A remarkable increase in the solutions’ viscosity at a volume mixing ratio
of 34 v/v% SLES to 66 v/v% CAPB was observed. By increasing the volume ratio of SLES
(r-value) in the binary mixture, the viscosity of 10 wt% SLES, which is close to that of water,
increases to a maximum, but then drops down drastically at high r values (>45 v/v%). The
maximum viscosity (Vmax) is 2.8 Pas, whereas the minimum is 2 mPas. The rheological behavior
at Vmax has the remarkable feature of a simple Maxwell fluid over a large frequency range with
one relaxation time. By adding a microemulsion (Plantasil Micro), the value of Vmax decreases
extremely, whereas adding cosurfactants like isodecyltrietheleneoxide (IT3) or salts, like calcium
chloride, leads to a pronounced increase in the value of Vmax. At 0.76 wt% CaCl2, Vmax is 140 Pas
and 150 Pas in the presence of 1 wt% IT3. By increasing the SLES volume mixing ratio in the
solution the maximum viscosity is shifted to higher CaCl2 amounts. The increasing viscosity
can be explained by a transformation of the micelle shape from spherical to rod-like. Whereas
adding cosurfactants or salts leads to an increased entanglement between the rod-like micelles.
Consequently, higher microemulsion amounts can be added before reaching the minimum
viscosity.
Rami A. Abdel-Rahem, " Influence of 1,3-Butanediol on the Viscoelasticity of Surfactant Solutions " , "Journal of Surfactants and Detergents",Vol.17,No.2, Springer, USA, 03/01/2014
:الملخص
The rheological behavior of rodlike micelles in a 1,3-butanediol/water mixed solvent was investigated. The rodlike micelles were prepared by mixing sodium salicylate, with cetyltrimethylammonium bromide. When water was replaced by 1,3-butanediol, the viscosity maxima decreased drastically. The viscosity minimum, on the other hand, increased at low 1,3-butanediol contents and decreased again at higher amounts of 1,3-butanediol. As a result of the opposite changes the two maxima were replaced by a single maxima when the content of 1,3-butanediol was 15 %. The change in the viscosity was a consequence of a change in the structural relaxation times while the storage moduli remained constant. The stress relaxation was due to a reptation mechanism at maximum points while at the minimum of the viscosity the mechanism was due to a kinetic controlled mechanism.
Ayman S. Ayesh, S. S. Ibrahim, Abdullah A. Al-Jaafari, Rami A. Abdel-Rahem, Nadeem S. Sheikh, and H. Mahfoz Kotb,, " Electrical and Mechanical Properties of β-Hydroxynaphthoic Acid-MWCNTs Polystyrene Nanocomposites " , " Journal of Thermoplastic Composite Materials",Vol.28,No.6, SAGE, USA, 05/15/2015
:الملخص
The effect of -hydroxynaphthoic acid (-HNA) addition on electrical and mechanical
properties of multiwalled carbon nanotubes (MWCNTs)–polystyrene (PS) composite at
a fixed amount of MWCNTs (0.85 wt%) are delineated. Obtained electrical, mechanical,
morphological, and Fourier transform infrared results showed that addition of -HNA
up to 1 wt% to MWCNTs-PS composite enhanced the dispersion of MWCNTs in the
neat PS, formation of MWCNTs-PS network, relative permittivity, dielectric loss, and
the electrical conductivity increased by about three orders of magnitude for the prepared
composite. Dielectric relaxation results showed that at the domain frequency
range, the relaxation process below 1.0 wt% -HNA was mostly due to polymer molecular
relaxation process, while at 1.0 wt% -HNA, the composite relaxation behavior
was mostly due to charge conductivity relaxation. Mechanical results showed that addition
of -HNA to composite system up to 1.0 wt% increased the elastic modulus, yieldstress, and tensile strength of the composites by about 12.2, 17.1, and 10.0%, respectively,
which indicated that the addition of -HNA to composite system improved
MWCNTs dispersion in PS matrix and enhanced the interfacial bond in the -HNAMWCNTs-
PS network.
Altwaiq, A., Rami Abdel-Rahem, AlShamaileh, E., Al-luaibi, S., Khouri,, " Sodium lignosulfonate as a friendly-environment corrosion inhibitor for zinc metal in acidic media " , "Eurasian Journal of Analytical Chemistry",Vol.10,No.1, iSER , Turkey , 01/01/2015
:الملخص
The corrosion inhibition property of sodium lignosulfonate is investigated by three different
independent monitoring techniques. These methods include weight loss measurements, electrical
conductance and potentiodynamic polarization. Solutions with and without sodium lignosulfonate in
0.01 M HCl and 0.1 M HCl were prepared at 20 oC to study the influence of sodium lignosulfonate on
the corrosion of zinc sheets. The results obtained from the three different methods indicate the
protection role of sodium lignosulfonate, which is considered as a friendly-environment corrosion
inhibitor, in the corrosion of zinc sheets. The reduction of the zinc corrosion in solutions with HCl and
different concentrations of sodium lignosulfonate using potentiodynamic polarization followed the
order: 30 mM > 10 mM > 5 mM >1 mM. The obtained results from weight loss, potentiodynamic
polarization and electrical conductance experiments were in good agreement with each other.
Rami A. Abdel-Rahem, Abdelmnim M. Altwaiq, Eman S. Zaben & Mohammad M. Alnass’a, " Zinc Corrosion in Acidic Solutions Containing Single and Mixed Surfactants " , "Journal of Surfactants and Detergents",Vol.,No., Springer , USA, 02/27/2016
:الملخص
Abstract The influence of surfactant synergism on Zn corrosion inhibition in 0.1-M HCl aqueous solutions has been determined at room temperature. Solutions of single and mixed surfactants consisting of sodium dodecylsulfate (SDS) and N,N dimethyldodecan-1-amine oxide (DDAO) in water and in 0.1-M HCl were also prepared at room temperature. Critical micelle concentration (CMC) data were obtained through surface tension measurements as a function of mixing composition. A regular solution model was considered to analyze CMC values. The interaction parameter (b), the composition of mixed micelles (x) and the activity coefficients (f) were estimated by a regular solution model for all amphoteric–anionic mixed systems. b Values showed synergism for the binary mixtures of these solutions in the absence and presence of 0.1-M HCl at all investigated compositions. Zinc corrosion in single and binary SDS/DDAO mixed solutions at 5-mM total surfactant concentrations in the presence of 0.1-M HCl was also investigated at static and dynamic conditions. The weight loss data revealed corrosion inhibition activity obeyed the following order: binary (0.75 DDAO ? 0.25 SDS)[binary (0.50 DDAO : 0.50 SDS)[single DDAO[single SDS, suggesting an enhancement in the corrosion inhibition activity of DDAO in the presence of a proper amount of SDS. Conductivity time measurements show a similar trend as that obtained by a weight loss method at (0.50 DDAO : 0.50 SDS). The results were illustrated on the basis of synergistic interaction between the mixed surfactants.
S.S. Ibrahim, Ayman S Ayesh and Rami A. Abdel-Rahem, " Investigation on the physical properties of multiwalled carbon nanotube–polystyrene nanocomposites treated with 2,3-hydroxy-2-naphthoic acid " , "Journal of Thermoplastic Composite Materials",Vol.,No., SAGE, , 09/01/2017
:الملخص
In continuation to our previous work, the current investigation focuses on the effect of static applied pressure on the electrical and dielectric properties of multiwalled carbon nanotube (MWCNT)–polystyrene (PS)/2,3-hydroxy-2-naphthoic acid (β-HNA) nanocomposites. Additionally, optical properties o
Rami A. Abdel-Rahem, Ayman S. Ayesh, S. S. Ibrahim, Abdullah A. Al-Jaafari,Nadeem S. Sheikh1, and Essam Yasin, " Novel Dispersion of MWCNTs in Polystyrene Polymer Induced by the Addition of 3- Hydroxy-2-napthoic Acid " , "Journal of Dispersion Science and Technology",Vol.,No., Taylor & Francis, , 05/04/2015
:الملخص
This article reports an extensive investigation of the unique dispersion behavior of solutions with multi-walled carbon nanotubes (MWCNTs) and 3-hydroxy-2-napthoic acid (β-HNA) in tetrahydrofuran (THF) solvent, which results into a multifold enhancement in the electrical properties of polystyrene (P
Emad AM Farrag , Rami A Abdel-Rahem, SS Ibrahim and Ayman S Ayesh, " Electrical and optical properties of well-dispersed MWCNTs/PVA nanocomposites under different pH conditions " , "Journal of Thermoplastic Composite Materials",Vol.,No., SAGE, , 02/21/2018
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Series of polymer nanocomposites films consisting of pretreated multiwalled carbon nanotubes (PT-MWCNTs) and poly (vinyl alcohol) (PVA) were prepared at room temperature. The MWCNTs were initially pretreated with 1.0 M sulfuric acid (PT-MWCNTs) and then allowed to disperse in aqueous solutions at di
Mahmoud S Dahoud, Rami A Abdel-Rahem, Emad AM Farrag, SS Ibrahim, Ayman S Ayesh and Adil Alshoaibi, " Rheological and electrical properties of multiwalled carbon nanotubes–polyvinyl alcohol nanocomposites treated at different pH conditions " , "Journal of Thermoplastic Composite Materials",Vol.,No., SAGE, USA, 09/13/2018
:الملخص
This work demonstrates the physical properties of polymer nanocomposites of polyvinyl alcohol (PVA) and functionalized multiwalled carbon nanotubes (MWCNTs) at different weight ratios. The results demonstrate that the rheological and electrical properties are significantly improved. The improvement
Rami A. Abdel-Rahem, Nabil M. Eldurini, Abdelmnim M. Altwaiq, Saleh Qutaishat, Ahmad Q. Daraosheh and Hana' Qashmar , " Adsorption of Single and Mixed Surfactants onto Jordanian Natural Clay " , "Tenside Surfactants Detergents",Vol.56,No., Hanser , Germany , 03/01/2019
:الملخص
The adsorption of sodium dodecyl sulfate (SDS) and N,N-dimethyldodecan-1-amine oxide (DDAO) and their mixtures from their solutions, onto Jordanian Natural Clay (JNC) was investigated at room temperature. The clay was firstly analyzed with X-ray fluorescence technique. The surface tension of the sin
Abdelmnim M. Altwaiq Rami A. Abdel?Rahem, " Reaction between Zinc and Hydrochloric Acid in Solutions Containing Alkyltrimethylammonium Bromide CnTAB (n = 8, 10, and 12) Cationic Surfactants: Influence of Surfactant Chain Length " , "Journal of Surfactants and Detergents",Vol.22,No., Wiley, USA, 02/19/2019
:الملخص
The influence of CnTAB cationic surfactant chain length (n = 8, 10, and 12) on the reaction rate of zinc powder and 0.1 M HCl hydrochloric acid in aqueous solutions was determined at room temperature. Solutions of single surfactants consisting of dodecyl, decyl, and octyl‐trimethyl‐ammonium bromide
Abdelmnim M. Altwaiq Rami A. Abdel?Rahem, " Reaction between Zinc and Hydrochloric Acid in Solutions Containing Alkyltrimethylammonium Bromide CnTAB (n = 8, 10, and 12) Cationic Surfactants: Influence of Surfactant Chain Length " , "Journal of Surfactants and Detergents",Vol.22,No., Wiley, USA, 02/19/2019
:الملخص
The influence of CnTAB cationic surfactant chain length (n = 8, 10, and 12) on the reaction rate of zinc powder and 0.1 M HCl hydrochloric acid in aqueous solutions was determined at room temperature. Solutions of single surfactants consisting of dodecyl, decyl, and octyl‐trimethyl‐ammonium bromide
Abdelmnim M. Altwaiq, Sa’ib J. Khouri, Rami A. Abdel-Rahem, Ahmad K. Alkhawaldh, " Conductivity Method as a New Monitoring Technique for Corrosion and Corrosion Inhibition Processes of Zinc Metal " , "American Journal of Analytical Chemistry",Vol.11,No., Scientific Research , USA, 11/01/2020
:الملخص
The electrical conductivity method was successfully applied as a new monitoring technique to monitor the corrosion and corrosion inhibition processes of zinc metal. Measurements of electrical conductivity at 20.0˚C of three different corrosive solutions (HCl, NaOH, and NaCl) were performed with two
Nisrein Jaber, FaisalAl-Akayleh, Rami A.Abdel-Rahem, MayyasAl-Remawib, " Characterization ex vivo skin permeation and pharmacological studies of ibuprofen lysinate-chitosan-gold nanoparticles " , "Journal of Drug Delivery Science and Technology",Vol.62,No., Science Direct , USA, 04/01/2021
:الملخص
Chitosan-gold nanoparticles (CS-AuNPs), at different molar ratios (1:1, 1:2, 1:4 and 1:6) of chloroauric acid (HAuCl4) to chitosan (CS), were prepared at room temperature. The CS-AuNP 1:6 ratio showed pronounced physical stability. The results indicated a shift in wavelength of maximum absorbance (λ
Daraosheh, Ahmad Q and Abul-Futouh, Hassan and Abdel-Rahem, Rami A and Goerls, Helmar and Stachel, Hans-Dietrich and Weigand, Wolfgang, " Synthesis and Electrochemical Investigations of the [FeFe]-Hydrogenase H-Cluster Mimics Mediated by Bicyclic Dithiols Derivative " , "ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE",Vol.647,No., WILEY-V CH VERLAG GMBH , GERMANY, 01/06/2021
:الملخص
Biomimic of the active site of [FeFe]-hydrogenase containing bicyclic dithiols as bridging linker has been synthesized and characterized using different spectroscopic methods. The influence of this linker on the redox properties and the catalytic behavior of the resulted binuclear complex was invest
Rami A. Abdel-Rahem, M Al-Remawi, AQ Daraosheh, H Hoffmann, " Rheological behavior of wormlike micelles (WLMs) in alcohol/water mixed solvent: influence of alcohol chain length " , "Colloid and Polymer Science ",Vol.299,No., Springer Berlin Heidelberg, Germany, 06/12/2021
:الملخص
The influence of replacing water with ethanol, propanol, and butanol in alcohol–water mixtures on the rheological properties of wormlike micelles (WLMs) consisting of sodium salicylate (NaSal) and cetyltrimethylammonium bromide (CTAB) is investigated at 25 °C. At maximum viscosity of 100 mM CTAB and
Rami A. Abdel-Rahem, Mayyas Al-Remawi, Karl Jan Clinckspoor & Heinz Hoffmann , " Comparison of the influence of 1-propanol and of 2-propanol on the viscoelastic solutions of cetyltrimethylammonium bromide (CTAB) and sodium salicylate (NaSal) " , "Colloid and Polymer Science ",Vol.1,No., Springer Berlin Heidelberg, Germany, 11/01/2020
:الملخص
It is known that mixtures of CTAB and NaSal form viscoelastic solutions. For a 100 mM CTAB solution and increasing NaSal concentration, the viscosity increases strongly at a concentration of 10 mM NaSal, reaches a maximum at 60 mM NaSal, decreases then to a minimum at 100 mM, and, on further, increa
Rami A. Abdel-Rahem, Sana Niaz, Abdelmnim M. Altwaiq, Muayad Esaifan, Mohammad Bassam Al Bitar and Abeer Al Bawab, " Synergistic interaction between sodium dodecyl benzene sulfonate (SDBS) and N,N-dimethyldodecan-1-amine oxide (DDAO) and their adsorption onto activated charcoal and Jordanian natural clay " , "Tenside Surfactants Detergents",Vol.59,No., Walter de Gruyter GmbH, Germany, 02/28/2022
:الملخص
Solutions of sodium dodecyl benzene sulfonate (SDBS) and N,N-dimethyldodecan-1-amine oxide (DDAO) with mole fractions of 0.00, 0.25, 0.50, 0.75 and 1.00 were prepared and their surface tension was measured as a function of total surfactant concentration. The critical micelle concentration (CMC) valu
Rami A. Abdel-Rahem, Sana Niaz, Abdelmnim M. Altwaiq, Muayad Esaifan, Ehab AlShamaileh and Abeer Al Bawab, " Sodium dodecyl benzene sulfonate (SDBS) and N,N-dimethyldodecan-1-amine oxide (DDAO) in single and mixed systems as corrosion inhibitors of zinc in hydrochloric acid " , "Tenside Surfactants Detergents",Vol.60,No., Walter de Gruyter GmbH, Germany, 03/14/2022
:الملخص
The influence of surfactant synergism between sodium dodecyl benzene sulfonate (SDBS) and N,N-dimethyldodecan-1-amine Oxide (DDAO) on zinc corrosion in 0.05 M hydrochloric acid (HCl) solutions at 25 °C was investigated. Firstly, solutions of SDBS and DDAO with mole fractions of 0.00, 0.25, 0.50, 0.7