Presence Of Cetylpyridinium Chloride Research Articles

INTERACTION OF HAFNIUM(IV) WITH 6,7-DIHYDROXY‑4-CARBOXYL‑2- PHENYLBENZOPYRYLLIUM SALTS IN BINARY SYSTEMS AND IN THE PRESENCE OF CATIONIC SURFACTANTS

In the current study, the peculiarities of the complexation of Hafnium(IV) with 6,7-dihyroxy‑4-carboxyl‑2-phenylbenzopyrylium salts (CDC) in binary systems and in the presence of cationic surfactants (Surf) were studied. The CDC was synthesized by condensation of pyrogallol A with benzoylpyruvic acid in an acetic acid medium in the presence of perchloric acid. To obtain KDC bromide and chloride, the synthesis was carried out in the presence of bromide acid or by sparging of dry hydrogen chloride, respectively. Using classical spectrophotometric methods of molar ratios and Bent-French, it was found that at pH 2.5 in binary system one complex with stoichiometry Hf(IV): CDC1:2 was formed. Molar absorptivity coefficient was calculated for Hf(IV) complex with CDC and it was equal 3,9⸱104. It was shown that in the presence of cetylpyridinium chloride or cetyltrimetrylammonium bromide complexes with a molar ratio of Hf(IV): CDC: Surf = 1:2:2 were formed. It is noted that the complexes were formed within 10–15 minutes, and the absorbance of the solutions remains constant for at least 2 hours. It was established that the nature of the anion, which is part of the reagent, does not significantly affect the characteristics of the analytical form. It is shown that in the presence of cationic surfactants, the optimal pH of complex formation shifts to a more acidic region. In addition, the introduction of cationic surfactants leads to a batachromic shift of the absorption band by 10–15 nm and an increase in the molar absorptivity to 5.8⸱104 and 6.4⸱104 when cetylpyridinium chloride or cetyltrimetrylammonium bromide were used respectively. It is noted that the found analytical forms can be used as a basis for the development of combined spectroscopic methods for determining trace amounts of Hafnium(IV).

Mixed micellar solubilization for procion blue MxR entrapment and optimization of necessary parameters for micellar enhanced ultrafiltration

In this study, micellar enhanced ultrafiltration, MEUF, being an active methodology, has been employed to remove Procion Blue MxR (PBM) from synthetic effluent. MEUF is being applied to reduce the toxicity level of aqueous system using the micellar media of cationic surfactants i.e. Cetyl trimethylammonium bromide (CTAB) and cetylpyridinium chloride (CPC). Subsequently, the effect of addition of nonionic surfactant, Triton X-100 (TX-100), on solubilizing power of cationic surfactants is investigated. The values of partition coefficient and free energy of partition reflect the extent of interaction of the dye with the surfactants. Initially molecules of pollutants i.e. dye form ion pairs with ionic surfactants and, later on, the same is incorporated within micelle. Maximum value of free energy of partition ΔGp has been found to be −55.49 kJmol-1 and -50.43 kJmol in the presence of CPC and CTAB, respectively. The size of pollutant, thus, increases and, consequently, can be easily filtered. The effect of various factors i.e. concentration of surfactant, concentration of electrolyte (NaCl), transmembrane pressure, revolutions per minute (RPM) and pH, have been investigated to find the optimum conditions for maximum removal of PBM from aqueous system. The efficiency of MEUF has been assessed by calculating the values of rejection percentage and permeate flux. Both the surfactants were observed as strong candidates for PBM encapsulation but overall, maximum rejection percentage (R%) of 96.90% was attained by CPC.

SPECTROPHOTOMETRIC DETERMINATION OF STIBIUM (III) WITH 6,7-DIHYDROXY‑4-CARBOXYL‑2- PHENYLBENZOPYRILIUM PERCHLORATE

In the current study, the peculiarities of the complexation of Stibium(III) with 6,7-dihydroxy‑4-carboxyl‑2-phenylbenzopyrylium perchlorate (CDC) in binary systems and in the presence of cationic surfactants (Surf) were studied. Using classical spectrophotometric methods of molar ratios and equilibrium shift, it was found that in two systems two complexes with stoichiometry Sb(III): CDC are formed: 1:2 and 1:3 at pH 2.5 and pH 6.0, respectively. Molar absorptivity coefficients were calculated for Sb(III) complexes with CDC, which are 1.2⋅104 and 1.1⋅104, respectively. It is shown that in the presence of cetylpyridinium chloride or cetyltrimetrylammonium bromide complexes with a molar ratio of Sb(III): CDC: Surf =1:3:3 are formed. In the presence of cationic surfactants there is no shift in the optimal pH of complexation, but there is an increase in the number of coordinated reagent molecules due to the loosening of the hydrate shell of the ion Sb(III) due to hydrophobic hydration of the complex. In addition, the introduction of cationic surfactants leads to a batochromic shift of the absorption band by 10–15 nm and an increase in the molar absorptivity to 2.8⋅104 and 3.4⋅104 when cetylpyridinium chloride or cetyltrimetrylammonium bromide were used respectively. The method of spectrophotometric determination of Stibium(III) was developed using an analytical form based on the ternary complex Sb(III): KDC: Surf = 1:3:3, which was tested during the analysis of samples of polymer materials (polyethylene terephthalate). It is noted that the developed technique is characterized by satisfactory reproducibility and is not inferior in sensitivity to known analogues.

Spectrophotometric Determination of Lanthanum (III) With Bromopyrogallol Red And Cetylpridinium Chloride -Applications in Natural Waters and Urine

A highly sensitive spectrophotometric procedure for the estimation of lanthanum in aqueous medium has been established. The method was involved the reaction of lanthanum with bromopyrogallol as chelating agent in the presence of cetylpyridinium chloride at pH4.61 to produce a soluble blue colour ternary complex exhibited maximum absorption at 661nm. The method adheres to Beer's low over the concentration range 0.125 –5.0 μg/ml with coefficient determination (r2= 0.9987). The molar absorptivity(ℇ) of the ternary complex (La(III)-BPR-CPC) is 5.39x104 M-1cm-1 which corresponds to Sandell's sensitivity index of 0.00258 μg.cm-2. The stoichiometric composition of the ternary complex was estimated and found to be (1:2:4) (La:BPR:CPC), respectively. The values of detection limit (DL) and quantitation limit (QL) were calculated and found to be 0.0630 and 0.0817 μg.ml-1, respectively. A recovery% was found in the range 95.3% to 103.5%, while the precision (RSD) was estimated in the range 0.126 to 1.705. The proposed procedure has been applied successfully for the determination of lanthanum in natural waters and urine sample.

SPECTROPHOTOMETRIC DETERMINATION OF BISMUTH (III) WITH 6,7-DIHYDROXY‑4-CARBOXYL‑2-PHENYLBENZOPYRILIUM PERCHLORATE

In the current study, the peculiarities of the complexation of Bi(III) with 6,7-dihyroxy‑4-carboxyl‑2-phenylbenzopyrylium perchlorate (CDC) in binary systems and in the presence of cationic surfactants (Surf) were studied. Using classical spectrophotometric methods of molar ratios and equilibrium shift, it was found that in two systems two complexes with stoichiometry Bi(III): CDC are formed: 1:2 and 1:3 at pH 2.0 and pH 4.5, respectively. Molar light absorption coefficients were calculated for Bi(III) complexes with CDC, which are 1.4⸱104 and 1.0⸱104, respectively. It is shown that in the presence of cetylpyridinium chloride or cetyltrimetrylammonium bromide complexes with a molar ratio of Bi(III): CDC: Surf =1:3:3 are formed. In the presence of cationic surfactants there is no shift in the optimal pH of complexation, but there is an increase in the number of coordinated reagent molecules due to the loosening of the hydrate shell of the ion Bi(III) due to hydrophobic hydration of the complex. In addition, the introduction of cationic surfactants leads to a batochromic shift of the absorption band by 10–15 nm and an increase in the molar absorption coefficient to 3.1⸱104 and 4.1⸱104 when using cetylpyridinium chloride or cetyltrimetrylammonium bromide, respectively. Methods of spectrophotometric determination of Bi(III) with the use of analytical forms based on complexes of 1:2 and ternary complex 1:3:3 were developed, which were tested in the analysis of pharmaceuticals, alloys and model solutions. It is noted that the proposed methods are characterized by satisfactory reproducibility and are not inferior in sensitivity to known analogues.

Interaction of methylene blue with SDS in the premicellar solution of CPC in the aqueous and methanol-water system

Interactions between sodium dodecyl sulfate (SDS) and methylene blue (MB) have been studied in presence of cetylpyridinium chloride (CPC) in aqueous and methanol-water binary solvents via conductometric and tensiometric methods. The experiment was conducted to see the possibility of a synergistic effect of the SDS+CPC system and changes in the interactional behavior of SDS with MB in presence of CPC. The value of the molecular interaction parameter for micellization (βM) was found to be negative from the experimental results and the value of |βM| was found to be greater than ln(CMCSDS / CMCCPC), which didn’t describe synergism completely but indicated the strong striking interactions between the oppositely charged surfactants. However, the CMC of the SDS+CPC system was found to be very low as compared to the CMC of SDS alone. This result of CMC based on striking interactions between oppositely charged surfactants was used to calculate various parameters like Gibb’s free energy of micellization (∆Gmo), surface excess(Γmax), minimum surface area (Amin), surface pressure πCMC, standard free energy of adsorption (∆Gadso), pC20, minimum surface free energy (Gmins), packing parameter (P) and association equilibrium constant (K). The addition of methanol as a cosolvent enhances the CMC and α value of the SDS+CPC as well as the SDS+CPC-MB system. Correlation of ∆Gmo with different solvent parameters namely Gordon parameter (G), Reichardt's parameter (ET (30)), viscosity (ηo), and solvophobic parameter (SP) has also been evaluated.

Biochar enhance functional stability of ammonia-oxidizing bioprocess against toxic chemical loading

This study investigated the inhibitory consequences of cetylpyridinium chloride (CPC) on nitrification and the role of the addition of biochar (BC) in enhancing nitrification functional stability. A concentration of 10–40 mg/L CPC led to the pulsed disturbance of ammonium oxidation (AO) (an immediate disruption of 11–41%, followed by recovery) and the press disturbance of nitrite oxidation (NO) (a prolonged disruption of 14–39%). A BC-dosed bioreactor demonstrated significantly higher AO stability against CPC in terms of buffering and resilience to chemical disruption. The addition of BC limited the fraction of freely dissolved CPC in an aqueous (i.e., decreasing the bioavailable CPC) via preferential adsorption, thus mitigating CPC toxicity. While CPC reduced 90% of Nitrosomonas (particularly N. oligotropha) and 93% of Nitrospira (particularly Candidatus Nitrospira defluvii) in the suspended microbiome, which are responsible for AO and NO, respectively, the Nitrosomonas inhibited by CPC was largely recovered in the biofilm microbiome formed on the surface of the BC, enhancing the stability of AO in the presence of CPC. Our study provides a mechanistic explanation for nitrification disruption by toxic chemicals and suggests BC as an effective biowaste-derived additive for the mitigation of the chemical disruption.

Synthesis of Pd nanorod arrays on Au nanoframes for excellent ethanol electrooxidation.

Au-Pd hollow nanostructures have attracted a lot of attention because of their excellent ethanol electrooxidation performance. Herein, we report a facile preparation of Au nanoframe@Pd array electrocatalysts in the presence of cetylpyridinium chloride. The reduced Pd atoms were directed to mainly deposit on the surface of the Au nanoframes in the form of rods, leading to the formation of Au nanoframe@Pd arrays with a super-large specific surface area. The red shift and damping of the plasmon peak were ascribed to the deposition of the Pd arrays on the surface of the Au nanoframes and nanobipyramids, which was verified by electrodynamic simulations. Surfactants, temperature and reaction time determine the growth process and thereby the architecture of the obtained Au-Pd hollow nanostructures. Compared with the Au nanoframe@Pd nanostructures and Au nanobipyramid@Pd arrays, the Au nanoframe@Pd arrays exhibit an enhanced electrocatalytic performance towards ethanol electrooxidation due to an abundance of catalytic active sites. The Au NF@Pd arrays display 4.1 times higher specific activity and 13.7 times higher mass activity than the commercial Pd/C electrocatalyst. Moreover, the nanostructure shows improved stability towards the ethanol oxidation reaction. This study enriches the manufacturing technology to increase the active sites of noble metal nanocatalysts and promotes the development of direct ethanol fuel cells.

Synthesis of Different Ligand Complex Mo (VI) with Stillbazo and Cetylpyridinium Chloride

The complex of molybdenum (VI) with stilbene-2,2’-disulfonic acid-4,4’’bis (azo-1’’)-3’’, 4’’ dioxybenzene (stillbazo) in the presence of a cationic surfactant cetylpyridinium chloride (CPCl) was studied spectrophotometrically. It was found that in the presence of CPCl, a mixed-ligand complex with a component ratio of 1:2:4 is formed. The effect of pH, time, temperature, the concentration of reagents, and CPCl in the formation of homogeneous ligand and mixed-ligand complexes were studied. The stability constants (lgβk = 86 × 108) and the molar absorption coefficient of the mixed-ligand complex (εк = 11,835) were determined. It was found that Beer’s law is observed at a concentration of 0.05 - 17.00 μg/ml. A method has been developed for the spectrophotometric determination of molybdenum (VI) in complex industrial facilities.

FLUORESCENCE CHARACTERISTICS OF RHODAMINE 6G AND RHODAMINE C IN WATER-MICELLAR SURFACTANT ENVIRONMENTS

The influence of cationic, anionic, nonionic surfactants and their mixtures on the fluorescence characteristics of rhodamine 6G and Rho-damine C solutions has been investigated. The fluorescence intensity of aqueous solutions of rhodamine 6G and in the presence of cetylpyridinium chloride and sodium dodecyl sulfate has almost unchanged throughout the pH range. The fluorescence intensity of aqueous and water-micellar rhodamine C solutions has been increased in the pH 1-4 range; the signal has been remained unchanged at high pH values. The studies have been carried out at pH 4 for rhodamine 6G and at pH 10 for rhodamine C. The fluorescence characteristics of water-micellar dye - surfactant - non-ionic surfactant systems have been performed at a concentration of Triton X-100 of 3.4·10‑2 mol/l. The interaction with cationic surfactants has shown differences character between the I=f(n) dependences for aqueous solutions of highly hydrophobic rhodamine 6G and more hydrophilic rhodamine C. The study of the effect of the hydrocarbon radical length on the intensity of the fluorescence of rhodamine 6G and rhodamine C has been carried out at two concentrations of cationic surfactants: under the condition of the formation of stoichiometric associates dye with cationic surfactant and in the region of the micellar concentrations of cationic surfactants. The character of the influence of the length of the hydrocarbon radical cationic surfactants on the fluorescence intensity of the dyes can be explained by the increasing role of hydrophobic interactions and the enhancement of solubilization in systems involving long-chain surfactants. The difference in the nature of the associates of rhodamine 6G and rhodamine C with hydrophobic and moderately hydrophobic cationic surfactants has been counterbalanced in the presence of Triton X-100. Reduction of fluorescence intensity of rhodamine 6G in domicile solutions of anionic sodium dodecyl sulfate has been established. The method of fluorescence detection of sodium dodecyl sulfate in reaction with rhodamine 6G has been proposed. The method has been tested in determining of anionic surfactants in the waters after washing clothes.

Decelerated Calcite Deformation in the Presence of Cetylpyridinium Chloride

The effect of an aqueous solution of a cationic surfactant, cetylpyridinium chloride, on the deformation rate of a calcite powder has been studied. It has been proven that the deceleration of the creep rate results from adsorption of this surfactant on the calcite surface.

The Coordination Compound of Ga(III) with Stillbazo in the Presence of Cetyl Pyridinium Chloride as a Surface Active Compound

The coordination compound of gallium (III) with stillbazo-stillbene-4,4'-bis [(1-azo)3,4-dihydroxybenzene]-2,2'-disulfonic acid has been investigated by spectrophotometric method in the presence of cetyl pyridinium chloride (CPC) as surface active compound. It has been determined that the mixed ligand complexes were formed with the ratio of 1:2:4 in CPC-mediated phase. The molar coefficient and the stability constant of the complex compound βк = 6.8 × 109, eк = 66,834 have been studied by various spectrophotometric methods. The effect of pH, time, temperature, concentration of the reagents and CPC on formation of the unmixed and mixed ligand coordination compounds has been also studied. It has been determined that the Beer’s law is respected within 0.008 - 10 μg of Ga(III) in 25 mL solution. The technique of the photometric determination of gallium in natural compositive objects and industrial objects has been developed.

ADSORPTION PROPERTIES OF TITANIA-SILICA MEMBRANES OBTAINED ON CERAMIC SUBSTRАTE

Titania-silica membranes on a porous quartz substrate are prepared by its direct contact with metal silicate sol at various Ti/Si ratios in the conditions of coagel sedimentation and presence of cetylpyridinium chloride. The study of textural and adsorption properties of membranes is conducted by low-temperature nitrogen adsorption-desorption, including methods of t-plots and DFT theory. It was shown that obtained membranes have mesoporous structure with the specific surface area and pore hydraulic diameter varied in intervals of 64–217 m2 /g and 4–11 nm, respectively. Developed values of surface area remain up to molar ratio of Ti/Si = 50/50.

Micellar catalyzed hydrolysis of mono-2,3-dichloroaniline phosphate

ABSTRACTThe kinetics of micellar catalyzed hydrolysis of mono-2,3-dichloroaniline phosphate in the presence of different surfactants has been studied at 303 K. The rate of reaction has been found to be first order with respect to both [substrate] and [HCl]. The cationic micelles of cetylpyridinium chloride (CPC), anionic micelles of di-octyl sodium sulphosuccinate (AOT), and non-ionic micelles of polyoxyethylene sorbitan monooleate (Tween 80) enhanced the rate of reaction to a maximum value and after that the increase in concentration of surfactant decreased the reaction rate. The applicability of different kinetic models has been tested to explain the observed micellar effects. The various thermodynamic activation parameters (Ea, ΔH≠, ΔS≠, ΔG≠) have been evaluated. The added salts viz. KCl, KNO3, K2SO4 enhanced the rate of reaction in the presence of CPC, AOT, and Tween 80 micelles. The kinetic parameters were determined from the rate (surfactant) profile and a suitable mechanism consistent with the experimental finding has been proposed.

Micellar Properties and Antimicrobial Activityof a Mixed Surfactant System Constituted by Sodium Dodecyl Sulfate and Cetylpyridinium Chloride

Abstract: Objective: Micellar properties of sodium dodecyl sulfate (NaDS) was examined in the presence of cetylpyridinium chloride (CPC) by means of surface tension, viscosity, dye solubilization, cloud point (CP) measurements.Antimicrobial activities of single and binary systems were also investigated. Results: A decrease in critical micelle concentration (CMC) and increase in solubilizing power for NaDS was observed with increasing CPC concentration. At the highest CPC concentration studied (0.1 M), the surface tension decreased up to 51 mN / m.Also, viscosity results showed growth in NaDS micelles (50 mM) up to the 0.1 M CPC concentration. Antimicrobial activity of NaDS, CPC and NaDS in presence of CPC was investigated against ten different strains of bacteria and ayeast which was not investigated up to now. The susceptibilities of the microorganism were determined by the agar diffusion method. The results showed that NaDS and CPC have a antimicrobial activity but NaDS in presence of CPC has not antimicrobial activity on the bacterial and yeast. Key words: Mixed Micellization, NADS, CPC, Antimicrobial Activity.

Photolysis of 2-mercaptobenzothiazole in the presence of surfactants

The quantum yield of the photolysis of 2-mercaptobenzothiazole (MBT) in the molecular form increases by a factor of 20 in the presence of the surfactants cetyltrimethylammonium bromide (CTAB) and cetylpyridinium chloride (CPCl) in comparison with aqueous solution. In the photolysis of the MBT ionic form, the quantum yield does not change in the presence of CTAB and decreases in the presence of CPCl. The maximums of the MBT absorption spectra shift with an increase in the surfactant concentration for both the molecular and ionic forms. Simultaneously, the MBT photolysis quantum yield increases. It has been shown that the quantum yield of MBT photolysis in water increases in the presence of compounds containing heavy atoms.

Cetylpyridinium chloride functionalized silica-coated magnetite microspheres for the solid-phase extraction and pre-concentration of ochratoxin A from environmental water samples with high-performance liquid chromatographic analysis.

A new method based on cetylpyridinium chloride coated ferroferric oxide/silica magnetic microspheres as an efficient solid-phase adsorbent was developed for the extraction and enrichment of ochratoxin A. The determination of ochratoxin A was obtained by high-performance liquid chromatography with fluorescence detection. In the presence of cetylpyridinium chloride, the adsorption capacity of ferroferric oxide/silica microspheres was 5.95mg/g for ochratoxin A. The experimental parameters were optimized, including the amounts of ferroferric oxide/silica microspheres (20mg) and cetylpyridinium chloride (0.18mL, 0.5mg/mL), pH value of media (9), ultrasonic time (5min), elution solvent and volume [2(1+1)mL (washed twice, 1mL each time) 1% acetic acid acetonitrile]. Under optimal experiment conditions, ochratoxin A had good linearity in the range of 2.5-250.0ng/L in water samples with correlation coefficient of the calibration curve 0.9995. The limit of detection for ochratoxin A was 0.83ng/L, and the recoveries were 89.8-96.8% with the relative standard deviation of 1.5-3.5% in environmental water samples. Furthermore, ferroferric oxide/silica microspheres show excellent reusability during extraction procedures for no less than six times.

Simultaneous determination of antimony and boron in beverage and dairy products by flame atomic absorption spectrometry after separation and pre-concentration by cloud-point extraction

ABSTRACTA new cloud-point extraction (CPE) method was developed for the pre-concentration and simultaneous determination of Sb(III) and B(III) by flame atomic absorption spectrometry (FAAS). The method was based on complexation of Sb(III) and B(III) with azomethine-H in the presence of cetylpyridinium chloride (CPC) as a signal-enhancing agent, and then extraction into the micellar phase of Triton X-114. Under optimised conditions, linear calibration was obtained for Sb(III) and B(III) in the concentration ranges of 0.5–180 and 2.5–600 μg l−1 with LODs of 0.15 and 0.75 μg l−1, respectively. Relative standard deviations (RSDs) (25 and 100 μg l−1 of Sb(III) and B(III), n = 6) were in a range of 2.1–3.8% and 1.9–2.3%, respectively. Recoveries of spiked samples of Sb(III) and B(III) were in the range of 98–103% and 99–102%, respectively. Measured values for Sb and B in three standard reference materials were within the 95% confidence limit of the certified values. Also, the method was used for the speciation of inorganic antimony. Sb(III), Sb(V) and total Sb were measured in the presence of excess boron before and after pre-reduction with an acidic mixture of KI-ascorbic acid. The method was successfully applied to the simultaneous determination of total Sb and B in selected beverage and dairy products.

Controlled Clustering in Binary Charged Colloids by Adsorption of Ionic Surfactants.

We report on the controlled clustering of oppositely charged colloidal particles by the adsorption of ionic surfactants, which tunes charge numbers Z of particles. In particular, we studied the heteroclustering of submicron-sized polystyrene (PS) and silica particles, both of which are negatively charged, in the presence of cetylpyridinium chloride (CPC), a cationic surfactant. The surfactant concentration Csurf was selected below the critical micelle concentration. As CPC molecules were adsorbed, Z values of the PS and silica particles decreased, inverting to positive when Csurf exceeded the isoelectric point Ciep. Hydrophobic PS particles exhibited much lower Ciep than hydrophilic silica particles. At Csurf valuess between their Ciep values, the particles were oppositely charged, and clustering was enabled. To explain the clustering behavior, we investigated adsorption isotherms of the CPC and screened-Coulomb-type pair potential. Expected applications of the present findings are the control of colloidal associations and construction of various particle types into heterogeneous colloidal clusters.

Influence of a cationic surfactant on adsorption of p-nitrophenol by a magsorbent based on magnetic alginate beads

The paper focuses on the removal of p-nitrophenol by an adsorption process. A magnetic adsorbent was synthesized by encapsulation of magnetic functionalized nanoparticles using alginate as a green biopolymer matrix. A cationic surfactant, cetylpyridinium chloride (CPyCl), was used to confer a hydrophobic character to the magnetic beads and thus to promote their adsorption efficiency. The effect of different parameters such as initial concentrations of both PNP and CPyCl, contact time and solution pH value on the adsorption of PNP in the presence of CPyCl was investigated. It should be noted that combination of magnetic and adsorption properties in a same material is an interesting challenge which could overcome the recovery problems of pollutant-loaded adsorbent.