Synergistic enhancing of micellization and thermodynamic properties of some Gemini cationic surfactants related to benzo[d]thiazol-3-ium bromide.

Herrin, three Gemini cationic surfactants related to benzo[d]thiazol-3-ium bromide with variable hydrocarbon chain lengths (TBC n = 6, 12, and 18) were synthesized successfully and confirmed by using IR and HNMR spectroscopies. Critical micelle concentration and different thermodynamic properties of all surfactants under study were measured using conductivity, density, molal volume, and refractive index techniques. The Critical micelle concentration of TBC 6, TBC 12, and TBC 18 surfactants measured from the different techniques shows an acceptable agreement.

Aggregation behavior of newly synthesized Gemini cationic surfactants in absence and in presence of different inorganic salts in 15% DMSO-water solvent.

In this study, three Gemini cationic surfactants related to thiazol-2-amine with three hydrocarbon chain lengths including 3-hexylthiazol-3-ium (TAC6), 3-dodecylthiazol-3-ium (TAC12) and octadecylthiazol3-ium (TAC18) were prepared. Surfactant structures were confirmed with IR and HNMR Spectroscopies. Critical micelle concentrations for all surfactants in 15% DMSO-Water solvent were measured using conductometric, refractometric, and densitometric techniques.

Design, green synthesis, and quorum sensing quenching potential of novel 2-oxo-pyridines containing a thiophene/furan scaffold and targeting a R gene on .

The current trend in fighting bacteria is attacking the virulence and quorum-sensing (QS) signals that control bacterial communication and virulence factors, especially biofilm formation. This study reports new Schiff bases and tetracyclic rings based on a pyridine pharmacophore by two methods: a green approach using CAN and a conventional method. The structure of designed derivatives was confirmed using different spectroscopies (IR and H/C NMR) and elemental analysis.

Electrochemical, surface analysis, computational and anticorrosive studies of novel di-imine Schiff base on X65 steel surface.

The inhibitory effect of di-imine-SB namely ((NZ, NE)-N, N-bis (4 (dimethylamino) benzylidene) butane 1,4-diamine) on X65-steel in 1 M HCl has been investigated experimentally and theoretically. The electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), and weight loss outcomes display the anticorrosion properties of "di-imine- SB". The inhibitory efficiency exceeds 90% at the optimal concentration of 1 × 10 M "di-imine- SB".

The Role of Some Cationic Surfactants Based on Thiazine as Corrosion Inhibitors in Petroleum Applications: Experimental and Theoretical Approach.

Two cationic surfactants based on thiazine, dodecyl thiazin bromide (DTB) and hexyl thiazin bromide (HTB), were synthesized, characterized, and investigated as corrosion inhibitors for API X-65 type steel in oil wells' formation water under an HS environment. Various spectroscopic techniques such as FTIR and H NMR were used to confirm the DTB and HTB chemical structures. The corrosion inhibition efficiency of the selected compounds was investigated using both potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements.

Novel cationic aryl bithiophene/terthiophene derivatives as corrosion inhibitors by chemical, electrochemical and surface investigations.

Two novel bithienyl fluorobenzamidine derivatives namely, 4-([2,2':5',2''-terthiophen]-5-yl)-2-fluorobenzamidine hydrochloride salt (MA-1615), 5'-(4-amidino-3-fluorophenyl)-[2,2'-bithiophene]-5-carboxamidine dihydrochloride salt (MA-1740) were synthesized, characterized and their corrosion inhibition properties were evaluated by electrochemical methods for carbon steel (C-steel) in 1 M HCl. Experimental investigations revealed that the inhibition effectiveness of the investigated inhibitors (INHs) by the Tafel polarization method followed the order: MA-1740 (96.9%) > MA-1615 (95.

Surface Activity and Electrochemical Behavior of Some Thiazine Cationic Surfactants and Their Efficiency as Corrosion Inhibitors for Carbon Steel in a Sour Environment.

The inhibition efficiency of cationic surfactants such as 1-ethyl-4-benzo[d][1,3]thiazin-1-ium bromide (BTB) and -ethyl--dioctyloctan-1-aminium bromide (DAB) for X-65 type carbon steel in oil well formation water under a HS environment has been studied using potentiodynamic polarization and electrochemical impedance spectroscopy measurements. Fourier transform infrared and nuclear magnetic resonance spectroscopy techniques were used to confirm the chemical structures of BTB and DAB. The novelty of this work lies in modifying the long chains in the inhibitor, which leads to high efficiency.

Synthesis, Characterization, and Computational Chemical Study of Aliphatic Tricationic Surfactants as Corrosion Inhibitors for Metallic Equipment in Oil Fields.

Aliphatic tricationic surfactants were prepared by the esterification reaction, followed by a quaternization reaction to protect oil well facilities from corrosion problems. Microelemental analysis and Fourier transform infrared and H NMR spectroscopic techniques were performed to explore the obtained motifs. The performance of these amphiphiles as inhibitors for metallic S90 steel corrosion in formation water was investigated through electrochemical tests (potentiodynamic polarization and electrochemical impedance spectroscopy).

Micellization and Solvation Properties of Newly Synthesized Imidazolium- and Aminium-Based Surfactants.

This work aimed to study the solvation properties of newly synthesized cationic surfactants: 1-hexyl-1-methyl-1-imidazol-1-ium bromide (RIm), 1-dodecyl-1-methyl-1-imidazol-1-ium bromide (RIm), ,,-tributylhexan-1-aminium bromide (RN), and ,,-tributyldodecan-1-aminium bromide (RN) in water and ethanol-water solvents with a 0.237 mole fraction of ethanol at 298.15 K using conductivity, refractive index, surface tension, and density measurements.

The synthesis and characterization of benzotriazole-based cationic surfactants and the evaluation of their corrosion inhibition efficiency on copper in seawater.

This study aims at preparing three cationic surfactants based on benzotriazole and evaluating their efficiencies as corrosion inhibitors for copper electrodes in seawater using different electrochemical techniques (potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and atomic force microscopy (AFM)). FTIR and H NMR spectroscopic techniques confirmed the chemical structures of the as-prepared cationic compounds. The inhibition efficiency increased with the increase the concentration of the as-prepared compounds in the solution.

Adsorption characteristics and inhibition effect of two Schiff base compounds on corrosion of mild steel in 0.5 M HCl solution: experimental, DFT studies, and Monte Carlo simulation.

In this work, we report the synthesis of two Schiff bases of substituted gallic acid derivatives amidation reaction and their characterization using H-NMR spectroscopy to study their inhibition performance on the aggressive attack of HCl on mild steel (MS). The inhibitive performance was examined using chemical (weight loss) and electrochemical (Tafel and EIS) test methods. The results indicate that these derivatives significantly suppress the dissolution rate of mild steel adsorption phenomena, which correlates to the Langmuir adsorption model.

Novel screen-printed electrode for the determination of dodecyltrimethylammonium bromide in water samples.

The construction and electrochemical response characteristics of a screen-printed electrode (SPE) for the determination of dodecyltrimethylammonium bromide (DTAB) are described. The sensor was based on the use of DTA-tetraphenylborate ion association complex as an electroactive material in screen-printed electrode with dioctylsebacate (DOS) as a solvent mediator. In aqueous solution of pH 3, the sensor displayed a stable response for six months with reproducible potential and linear response for surfactant over the concentration range 1.

Septonex-tetraphenylborate screen-printed ion selective electrode for the potentiometric determination of Septonex in pharmaceutical preparations.

A screen-printed electrode (SPE) was fabricated for the determination of 1-(ethoxycarbonyl)pentadecyltrimethylammonium bromide (Septonex) based on the use of Septonex-tetraphenylborate as the electroactive substance, and o-nitrophenyloctylether (o-NPOE) as the plasticizing agent. The electrode passes a near-Nernstian cationic slope of 59.33 ± 0.

Potentiometric determination of cetylpyridinium chloride using a new type of screen-printed ion selective electrodes.

A new type of screen-printed ion-selective electrode for the determination of cetylpyridinium chloride (CPC) is presented. These new electrodes involve in situ, modified and unmodified screen-printed ion-selective electrodes for the determination of CPC. The screen-printed electrodes (SPEs) show a stable, near-Nernstian response for 1 x 10(-2) to 1 x 10(-6) M CPC at 25 degrees C over the pH range 2-8 with cationic slope 60.

Anatomic variation of prescription points and treatment volume with fractionated high-dose rate gynecological brachytherapy.

The purpose of this report is to evaluate the geometric movement (relative to the bony pelvis) and dose variation of brachytherapy reference points in the same patient at repeated high-dose rate (HDR) intracavitary implants. A study was also concluded to find the variation in treatment volume from repeated fractions. Twenty-five consecutive cervical cancer patients (all stages) treated with external beam and fractionated HDR intracavitary implants at the University of Wisconsin were reviewed.

Comparison of two planning systems for HDR brachytherapy gynecological application.

Purpose: This report compares the Nucletron NPS and PLATO planning system for patients treated for cervix cancer.

Materials And Methods: This study compares calculations generated using the older NPS (version 11.43) planning system and the more recent PLATO (version 14.