E. M. S. Azzam

Surface and thermodynamic studies of N-((octyl, dodecyl, and cetyl) oxycarbonylmethyl) pyridinium bromide

SummaryN-Octyloxycarbonylmethyl pyridinium bromide (C8), N-dodecyloxycarbonylmethyl pyridinium bromide (C12) and N-cetyloxycarbonylmethyl pyridinium bromide (C16) were prepared. Several studies were carried out with their aqueous solutions. Surface tensions, electrical conductivities, and biodegradabilities were evaluated. The antibacterial and antifungal activities of the cationic surfactants were studied. Surface properties, particularly critical micelle concentration (CMC), effectiveness (ΠCMC), efficiency (Pc20), maximum surface excess (Γmax), and minimum surface area (Amin) were investigated at different concentrations at 20, 35, and 50°C respectively. Free energies, enthalpies, entropies of micellization, and adsorption of the surfactants in the aqueous solution were studied.ZusammenfassungVerschiedene Untersuchungen an wäßrigen Lösungen von N-Octyloxycarbonylmethyl-pyridiniumbromid (C8), N-Dodecyloxycarbonylmethyl-pyridiniumbromid (C12) und N-Cetyloxycarbonylmethyl-pyridiniumbromid (C16) wurden durchgeführt. Oberflächenspannungen, elektrische Leitfähigkeiten und biologische Abbaubarkeit wurden bestimmt. Die bakterizide und fungizide Aktivität der kationischen Tenside wurde untersucht. Oberflächenparameter, insbesondere kritische Micellenkonzentration (CMC), Effektivität (ΠCMC), EffizienzPc20), maximaler Oberflächenüberschuß (Γmax) und minimale Oberfläche (Amin) wurden bei verschiedenen Konzentrationen und bei Temperaturen von 20, 35 und 50°C untersucht. Die freien Energien, Enthalpien, Entropien und die Asorption der Tenside in wäßriger Lösung wurden bestimmt.

Surface Activity of Monomeric and Polymeric (3-alkyloxy aniline) Surfactants

ABSTRACT The adsorption and micellization processes of 3-alkyloxy aniline namely [3-decyloxy aniline (C10M), 3-dodecyloxy aniline (C12M) and 3-cetyloxy aniline (C16M)] and their polymers [C10P, C12P and C16P] have been investigated using surface tension (γ) measurements at different temperatures. The synthesized monomers and polymers have been characterized by IR and elemental analysis. The surface and thermodynamic parameters of these monomeric and polymeric surfactants are investigated. The results show that the critical micelle concentration (CMC) of the polymeric surfactants is lower than that of monomers. The CMC values decreases as the hydrophobic chain lengthens for both monomeric and polymeric surfactants. The surface parameters show the ability of monomeric and polymeric surfactants to adsorb at the air/water interface and decrease the surface tension. The thermodynamic parameters reveal that the micellization process is spontaneous for all investigated surfactants. The specific conductance measurements show that the specific conductance increases with increasing chain length of the substituted alkyl groups, the synthesized polymeric surfactants have higher values of specific conductance than the corresponding monomers and the specific conductance increases with rising solution temperature.

Oxidative chemical polymerization of some 3-alkyloxyaniline surfactants and characterization of the obtained polymers

Meta-hydroxyaniline was reacted with decyl bromide, dodecyl bromide, and cetyl bromide to produce new aniline derivative surfactants. The monomers (0.4 mol/L) were polymerized in aqueous solution of hydrochloric acid (1.0 mol/L) using sodium dichromate (0.1 mol/L) as oxidant at room temperature. The crstallinity of the prepared polymer samples was investigated by X-ray diffraction and electron microscopic analysis. The thermal behavior of these polymers was studied by thermogravimetric analysis (TGA), also the electrical properties of the obtained polymer samples were measured and discussed. The a.c.-electrical conductivity was found to be increased by the increase of number of carbon atoms in the substituted alkyl group in the following order (cetyl > dodecyl > decyl).

Surface and thermodynamic properties of octyl, dodecyl, and cetyl sulfoacetates

SummaryThree anionic surfactants (Na-octysulfoacetate (A8), Na-dodecylsulfoacetate (A12), and Na-cetylsulfoacetate (A16) were prepared from alkyl bromoacetate. Several studies were carried out with aqueous surfactant solutions including surface tension, and electrical conductivity measurements. Surface properties, in particular, critical micelle concentration (CMC), effectiveness (∏CMC), efficiency (Pc20), maximum surface excess (γmax), and minimum surface area (Amin) were investigated at different concentrations at 20, 35 and 50°C, respectively. Free energies, enthalpies, entropies of micellization, and adsorption of the surfactants in the aqueous solution were studied.ZusammenfassungDrei anionische Tenside (Na-Octylsulfoacetat (A8), Na-Dodecylsulfoacetat (A12) und Na-Cetylsulfoacetat (A16)) wurden aus Bromessigsäurealkylestern hergestellt. An wäßrigen Lösungen der Tenside wurden deren Oberflächenspannung und elektrische Leitfähigkeit gemessen. Oberflächeneigenschaften, insbesondere kritische Micellenkonzentration (MCC), Effektivität (∏CMC), Effizienz (Pc20) maximaler Oberflächenüberschuß (γmax) und minimale Oberfläche (Amin) wurden bei verschiedenen Konzentrationen und bei Temperaturen von 20, 35 und 50°C untersucht. Die freien Energien, Enthalpien, Entropien und die Adsorption der Tenside in wäßriger Lösung wurden bestimmt.

Detection of Heavy Metal Ions Using Synthesized Amino Thiol Surfactants Assembled on Gold Nanoparticles

In this work, we synthesized amino thiol surfactants, namely, 10-(4-aminophenoxy)-decane-1-thiol and 12-(4-aminophenoxy)-dodecane-1-thiol. The self-assembling of the synthesized surfactants on gold nanoparticles (AuNPs) was investigated using different techniques such as ultraviolet analysis, x-ray diffraction, and transmission electron microscopy. The synthesized surfactants show the ability to assemble on gold nanoparticles and form stable nanostructure with it. We used the synthesized surfactants and their nanostructures with gold nanoparticles for the detection of Zn and Ni ions in aqueous solution using the ultraviolet spectrophotometer technique. The synthesized amino thiol surfactants showed the ability to detect Zn and Ni ions at low concentration. The results showed that gold nanoparticles can enhance the detection of Zn and Ni ions using the nanostructures of the synthesized surfactants.

Fabrication of SPR Nanosensor Using Gold Nanoparticles and Self-Assembled Monolayer Technique for Detection of Cu2+ in an Aqueous Solution

In this work, we investigated the fabrication of surface plasmon resonance (SPR) nanosensor using gold nanoparticles (AuNPs) chemisorbed onto self assembled monolayer of 10-(3-amino phenoxy) decane-1-thiol on gold substrate. The fabrication process of SPR nanosensor was characterized using different techniques such as infrared reflection-absorption spectra (IRRAS), xX-ray photoelectron spectroscopy (XPS), and atomic force microscope (AFM). The fabricated SPR nanosensor was used for detection of Cu2+ in an aqueous solution using surface plasmon resonance refractometer. The results confirm the fabrication of new SPR nanosensor. The fabricated SPR nanosensor showed a good activity toward the detection of Cu2+. The detection of Cu2+ in an aqueous solution using the fabricated SPR nansensor was enhanced in the presence of gold nanoparticles.

Synthesis and characterization of poly(2-aminothiophenol-co-2-methylaniline)/silver nanoparticles as antisulfate-reducing bacteria

ABSTRACT Poly(2-aminothiophenol) (P2ATH), poly(2-methylaniline) (P2MeANI), and poly(2ATH-co-2MeANI) are synthesized using ammonium persulfate as an oxidant in aqueous hydrochloric acid (HCl) medium at room temperature. The obtained polymeric samples are assembling on silver nanoparticles. The structures of prepared polymeric samples are characterized by ultraviolet–visible, infrared, proton nucleus magnetic resonance (1H NMR), X-ray diffraction, electron microscope, transmittance electron microscope, and thermogravimetric analysis. The antibacterial efficiency of the prepared polymeric and polymer/Ag nanoparticle samples is studied for the removal of sulfate-reducing bacteria. The results reveal that the assembling of both P2ATH and P2MeANI on Ag nanoparticles enhances the antisulfate-reducing bacteria’s efficiencies, but in a case of P2ATH-co-2MeANI the efficiency is more than its Ag nanoparticles. GRAPHICAL ABSTRACT

Kinetic preparation and antibacterial activity of nanocrystalline poly(2-aminothiophenol)

Poly(2-aminothiophenol) (PATH) was prepared by oxidative chemical polymerization of 2-aminothiophenol in aqueous HCl medium using ammonium persulfate as oxidant. The obtained polymer sample was characterized using different techniques. The kinetics of polymerization reaction were investigated. The data show that both initial and overall reaction rates increase with increasing monomer, oxidant and HCl concentrations. Also both initial and overall polymerization reaction rates increase with increasing temperature. The nanostructure of the prepared PATH was fabricated with silver nanoparticles. The antibacterial activity of the synthesized polymer and its nanostructure with silver nanoparticles was studied against sulfate-reducing bacteria. The synthesized polymer and its nanostructure showed good antibacterial activity.