Surfactant Cetylpyridinium Chloride Research Articles

Enhancing Kaolin's Structure for Efficient Removal of Lead Ions from Aqueous Solutions

This research demonstrates a novel methodology for structurally modifying kaolin clay to efficiently remove toxic lead ions from water through adsorption. Kaolin was systematically treated with hydrochloric acid, cetylpyridinium chloride surfactant, and calcium chloride to enhance its physico-chemical properties. BET surface area analysis, transmission electron microscopy, scanning electron microscopy, and BJH pore size measurements confirmed successful intercalation of surfactants between kaolin sheets, increasing the surface area from 43.2 to 57.1 m2 g-1 and inducing larger mesopores. Operational factors such as pH, dosage of adsorbent, time spent in contact, starting lead concentration, and temperature were tuned using batch adsorption tests. Maximum lead uptake of 29.58mgg-1 was attained at pH 5, 20mg adsorbent dose, 30mgL-1 initial lead concentration, 80min contact time, and 30°C temperature. Pseudo-second order kinetics and Sips isotherm models aptly characterized the adsorption, indicating chemisorption on heterogeneous sites. Positive enthalpy and entropy changes signified an endothermic and irreversible process. Regeneration studies demonstrated stable performance over five adsorption-desorption cycles. This comprehensive methodology integrates acid, surfactant, and cationic treatments to synthesize an eco-friendly kaolin adsorbent with enhanced selectivity and adsorption capacity for removing toxic lead from water.

Effect of TX-100 on solubilizing power of CTAB and CPC for H Acid: An experimental and computational analysis

The present research work investigates the solubility of an anionic dye 8-amino-1-naphthol-3,6-disulfonic acid (H Acid) within the micellar mediaof two cationic surfactants cetylpyridinium chloride (CPC) and cetyltrimethylammonium bromide (CTAB) as well as in the mixed micellar mediaof each cationic surfactant with Triton X-100 (TX-100). The data from differential absorption spectroscopy across a concentration range spanning from pre-micellar to post-micellar regions was used to determine the degree of solubilization by calculating the partition coefficient (Kx), binding constant (Kb) and Gibbs free energy associated with the relevant processes. Electrical conductivity of each cationic surfactant in the presence of H Acid was recorded in aqueous media and used to determine the CMC and subsequent thermodynamic parameters including entropy (ΔSm), enthalpy (ΔHm) and Gibbs free energy change (ΔGm) associated with the process of micellization. The computational analysis was carried out with GAUSSIAN 09 using a 6-311G + basis set with a DFT/ B3LYP hybrid approach and each set of energy minimization was executed to perform frequency calculations for Frontier molecular orbital analysis and to evaluate absorption spectra. Moreover, the molecular electrostatic potential surfaces (MESP) were also computed to find their suitable hydrophobic and hydrophilic interactions.

Effect of Addition of Cetylpyridinium Chloride Cationic Surfactant on the Antimicrobial Activity of Chlorhexidine Endodontic Irrigant.

Endodontic irrigants are essential for disinfecting the root canal system. None of the currently available irrigants perfume sufficiently. However, most products contain surfactants, which enhance the antimicrobial properties of the irrigants. To evaluate the effect of cetylpyridinium chloride (CPC) surfactant on the antimicrobial activity of chlorhexidine and compare it with that of chlorhexidine (CHX) and Biopure MTAD against Enterococcus faecalis, Staphylococcus aureus, and Candida albicans. In this in vitro study, three microorganisms were used (E. faecalis, S. aureus, and C. albicans), and each organism was treated with three different irrigants: 2% CHX, 2% CHX + 0.2% CPC, and 100% Biopure MTAD. The antimicrobial activity was evaluated by direct contact assay for 5 min of contact time. The colony-forming unit per mL was calculated after antimicrobial treatment and 24 hr of incubation at 37°C. The data were statistically analyzed using Statistical Package for Social Science (SPSS) version 22. The Kruskal-Wallis and the multiple Wilcoxon sum rank tests were used. The level of significance was set at 0.05. The result showed a nonsignificant difference between the different irrigants against E. faecalis. Among S. aureus subgroups, 2% CHX was statistically significant and more efficient than MTAD. Among C. albicans subgroups, 2% CHX and combined irrigant (2% CHX + 0.2% CPC) were statistically more efficient than MTAD. The 2% CHX and combined irrigants were equally effective against all the tested microorganisms. All the used irrigants have comparable effects against E. faecalis after 5 min. CHX have a comparable effects to that of the combined irrigant and more efficient against S. aureus than MTAD. CHX and the combined irrigant have potent antimicrobial activity against C. albicans superior to MTAD. CPC surfactant can be used with CHX to overcome its clinical drawbacks or limitations without altering or reducing its antimicrobial activity.

Comparison of dodecyl trimethyl ammonium bromide (DTAB) and cetylpyridinium chloride (CPC) as corrosion inhibitors for mild steel in sulphuric acid solution

Two essential cationic surfactants, dodecyl trimethyl ammonium bromide (DTAB) and cetyl pyridinium chloride (CPC) with differences in the alkyl chain, were investigated as corrosion inhibitors on mild steel (MS) in 0.5 M H2SO4 with weight loss (WL) and the potentiodynamic polarization (PDP) method. Three different temperatures were used to maintain the reported sample solutions (298.15, 308.15, and 318.15 K) for concentrations ranging below, above, and at the optimum critical micelle concentration (CMC) of the cationic surfactants. Results show that 0.5 M DTAB having ammonium group gave higher inhibition efficiency than 0.5 M CPC having pyridinium group by PDP method. The inhibition efficiencies were determined as 98.6% for 0.5 M DTAB and 89.38% for 0.5 M CPC after 24 h immersion at 298.15 K. The extreme inhibition efficiency depends on the chain length and decreases with an increase in temperature as well as increases with the addition of concentration of cationic surfactants. Around CMC, both surfactants CPC and DTAB showed the highest inhibition efficiency which follows the isotherm of Langmuir adsorption and illustrates a mixed type of corrosion inhibitors with the predominance of cathodic reactions. Additionally, the proposed mechanisms of inhibitors showing both physical and chemical adsorption confirmed by the free energy of adsorption (-ΔGads0) for DTAB were >28–34.5 kJ/mol and for CPC were >31.07–42.91 kJ/mol.

Study of Anti-Corrosion Properties of Sodium Dodecyl Sulphate and Cetyl Pyridinium Chloride

Surfactant is a surface-active agent. Surfactants have both hydrophilic (water-attracting) and hydrophobic (water-repelling) portions in their molecular structure, effective inhibitors for the protection of mild steel in an acidic medium, the weight loss methods were used at lab temperature to evaluate the effect of surfactant cetyl pyridinium chloride (CPC) and sodium dodecyl sulfate (SDS) on the corrosion protection behavior of Mild steel in 0.5 M H2SO4 solution. Inhibition efficiency, weight loss, corrosion rate, and surface coverage area of Mild steel in different concentrations of surfactant were studied. The results showed that the Inhibition efficiency of cetyl pyridinium chloride is 99.86%, which is greater than that of sodium dodecyl sulfate (99.85%) in the presence of 0.5 M H2SO4.

Formation of vesicles between negatively charged carbon quantum dots and cationic surfactant cetylpyridinium chloride (CPC) due to oxidative photo induced electron transfer

The tuning of photo physical properties of highly emissive carbon quantum dots which was synthesized from citric acid in DMF medium through solvothermal method is investigated inside micelles formed by different types of surfactants like cationic surfactant cetylpyridinium chloride (CPC), cetrimonium bromide (CTAB), anionic surfactant sodium dodecyl sulfate (SDS) and neutral surfactant polyethylene glycol tert-octyl phenyl ether (TX100), polyoxoethylene lauryl ether (BRIJ-35). Interestingly, only CPC interacts with greater extent and formed co-assembly with negatively-charged carbon quantum dots (CQDs) whereas other surfactants like CTAB, SDS, TX100 and BRIJ-35 do not alter the fluorescence intensity extensively. This results in the formation of a non fluorescent vesicle. No phase separation was observed over the large concentration barrier of the CPC surfactant. However, no such vesicle formation takes place for another cationic surfactant CTAB excluding the role of only electrostatic interaction. The synthesized vesicle is characterized by various techniques including HRTEM, DLS. For the aqueous solution of CQDs having concentration of 0.5 mg/ml, addition of CPC leads to formation of different sized vesicles of size 40 nm to 100 nm. The driving force behind this formation of non-fluorescent vesicles is oxidative photo induced electron transfer which is revealed by the highest occupied molecular orbital (HOMO) –lowest unoccupied molecular orbital (LUMO) interaction between the donor (CQDs) and the acceptor (CPC). We trust such type vesicle can be a suitable alternative for drug carriers, biomarkers and other various applications also.

Electrochemical Sensor Based on CuO Nanoparticles-Modified Graphite Electrode for the Detection of Malachite Green

In this study, the development of a graphite paste electrode (GPE) modified by copper oxide nanoparticles (CuO@GP) to be used as a practical and economical sensor for the electrochemical sensing of malachite green (MG) has been elucidated. The sol–gel technique was applied for the synthesis of CuO nanoparticles (NPS) from copper chloride (CuCl[Formula: see text], where the surfactant cetylpyridinium chloride (C[Formula: see text]H[Formula: see text]NCl) played the role of a capping agent. The synthesized CuO NPS were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). A bare GPE was modified using these CuO NPS and thus developed; the new electrode was used as a working electrode (WE) in a 3-electrode system for studying the cyclic voltammetry (CV) and differential pulse voltammetry (DPV) responses of MG. Phosphate buffered saline (PBS) with a pH value of 6 was used as the optimum buffer. Using DPV, a widely linear operational range of 1–1000 [Formula: see text]M was obtained with a detection limit of 0.18 [Formula: see text]M. This CuO@GP provided excellent repeatability, reproducibility and prolonged stability for the MG molecule. For the selectivity study, various common interfering agents were used to observe MG’s corresponding peak current variation. Moreover, this electrode demonstrated a successful application for detecting MG in pond water and fish flesh. This method is effective for similar other applications.

Effect of Cetylpyridinium Chloride Surfactant and Polyethylene Glycol on the Process and Properties of Whey Protein Isolate Modification

Effect of Cetylpyridinium Chloride Surfactant and Polyethylene Glycol on the Process and Properties of Whey Protein Isolate Modification

Comparative Study of Protection Efficiency of C-Steel Using Polystyrene Clay Nanocomposite Coating Prepared from Commercial Indian Clay and Local Khulays Clay

This work aimed to compare the coating protection efficiency of C-steel using two kinds of clay: a local Khulays clay (RCKh) from Saudi Arabia and a commercial clay (CCIn) from India. Clay-based polymer nanocomposites have a unique layered structure, rich intercalation chemistry, and availability at low cost. They are promising reinforcements for polymers. The raw clay for both clay types was washed before being treated with NaCl to produce sodium clay (NaC). The cationic surfactant cetylpyridinium chloride (CPC) was then used to convert the NaC into the organoclay (OC) form. Polystyrene/organoclay nanocomposites (PCNs) were prepared by combining different concentrations of organoclay (1%, 3%, and 5% OC) in toluene solvent and polystyrene (PS) as the matrix. To ensure the success of the PCN modification process, the organoclay and PCN films were characterized using a variety of techniques, including Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The shifts in the FT-IR spectra after the CPC treatment of NaC confirmed the presence of CPC in the organoclay samples and the presence of OC in the PCNs. The exfoliated structure was obtained from the XRD spectrum for low clay loading (1–3% PCN), while the intercalated structure was the dominant form for the 5% PCN. The XRD results were confirmed by TEM images. To calculate the coating efficiency of the PCNs, various electrochemical methods were used. The electrochemical measurements included electrochemical impedance spectroscopy (EIS), the electrochemical frequency modulation (EFM) method, and Tafel plots. The PCN with a concentration of 1 wt.% OC has a fully exfoliated structure and higher coating efficiency than the PCNs with partially exfoliated structures (3 wt.% and 5 wt.%). It was found from the Tafel plots that commercial Indian clay has better corrosion protection (81.4%) than local Khulays clay (60.2%). A comparison with other studies using current density values shows that our results are superior to those of many studies.

Micelle formation and physico-chemical variables for the sodium dodecyl sulfate/cetylpyridinium chloride and their mixture in aqueous propranolol hydrochloride drug solvent: Conductivity and theoretical analysis

Herein, study of both single and mixed micelle development of an anionic surfactant sodium dodecyl sulfate (SDS) and a cationic surfactant cetylpyridinium chloride (CPC) in propranolol hydrochloride (PPH) drug medium has been performed using a conductometric technique at different temperatures and compositions. The critical micelle concentration (CMC) along with degree of ionization (g) were assessed from the specific conductivity (κ) versus [surfactant] plots. Within the concentration of surfactant studied, a single CMC was achieved in the situations of pure and mixed surfactant micellization. The CMC and g values have been noticed reliant on the employed drug concentrations, variations of mole fractions of the mixture of surfactants and experimental temperature. For the micellization of single SDS/ CPC surfactants in aq. PPH drug medium, PPH drug causes delayed micelle development which has been detected as the upsurge of CMC values of SDS/CPC in PPH drug media. For the association of SDS/ CPC surfactants in aq. PPH drug medium, the CMC values experienced a lessening with the growth of study temperature. At a fixed temperature, the experimental CMC values, of the SDS + CPC mixture, endure a decline through the upsurge of mole fractions of CPC (α1), attain a minimum value and the CMC values tend to enhance at and above α1= 16.2 × 10-5. The ideal critical micelle concentrations (CMCid) are detected always as higher values than experimental CMC up to the α1= 10.8 × 10-5. The -β values and |β| > |ln(CMC1/ CMC2)| for the present study reveal that the interaction among the amphiphiles under analysis is synergistic. The negative free energy (-ΔGmO) of micellization were obtained throughout the study. The enthalpy (ΔHmO) and entropy (ΔSmO) of micellization reveal the presence of hydrophobic interaction as the principal type of interaction among the studied constituents. The negative excess free energy (ΔGex) values inferred that stable mixed micelles are formed for the mixture of SDS + CPC in aq. PPH drug medium. The micellar mole fractions (both experimental and ideal values), activity coefficients of components in mixed micelles as well as enthalpy–entropy compensation parameters were also measured and illustrated. It is possible that the knowledge gained from the current analysis may be used to enhance pharmaceutical formulations, drug delivery carriers, along with drug act proficiency.

Reduction-triggered Disassembly of Organic Cationic Nanorods Produces a Cysteine Protease Mimic (Miravet et al.).

The emergence of catalytic activity associated with a disassembly process is reported, reminiscent of complex biological systems. A cystine derivative with pendant imidazole groups self-assembles into cationic nanorods in the presence of the cationic surfactants cetylpyridinium chloride (CPC) or cetyltrimethylammonium bromide (CTAB). Disulfide reduction triggers nanorod disassembly and the generation of a simple cysteine protease mimic, which shows a dramatically improved catalytic efficiency in the hydrolysis of p-nitrophenyl acetate (PNPA).

High-efficient removal of tetrabromobisphenol A from waste mobile phone printed circuit boards leached solution by micellar enhanced ultrafiltration

Background: Tetrabrombisphenol A (TBBPA) is one of the major brominated flame retardants (BFRs) used in waste mobile phone printed circuit boards (WMPPCB) that accounts for approximately 60% of the total BFR market. Methods: The potential of TBBPA removal from WMPPCB leached solution was investigated using micelle-enhanced ultrafiltration (MEUF) in the presence of cationic, anionic, and nonionic surfactants. The efficiency of several parameters including surfactant concentration, transmembrane pressure (TMP), pH, and TBBPA concentration, was evaluated to improve the MEUF. The optimal conditions were used to assess the MEUF for removing TBBPA in a real sample. Results: The cationic surfactant cetylpyridinium chloride (CPC) showed better performance than other surfactants in removing TBBPA due to its electrostatic interactions with anionic forms of TBBPA. The removal efficiency of TBBPA increased from 48.99% to 99.10% by adding a surfactant (less than the critical micelle concentration). Increasing the pH in the range of 5 to 11 increased the efficiency of TBBPA removal due to the increase in the TBBPA solubility in the micelles. TMP had the most significant effect on permeate flux compared to other parameters but did not significantly affect the TBBPA removal efficiency. The MEUF process effectively removed (above 99%) TBBPA in the concentration range of 20 to 80 mg L-1 under optimal conditions. The HPLC-UV analysis of the real sample indicated the removal efficiency of 100% of TBBPA. Conclusion: MEUF using CPC is a critical performance technology for removing TBBPA from the leached solution of electronic waste.

Hydrophobization of aerogels based on chitosan, nanocellulose and tannic acid: Improvements on the aerogel features and the adsorption of contaminants in water

Hydrophobic chitosan aerogels are promising adsorbents for immiscible contaminants such as oils and organic solvents. However, few studies have reported the application of hydrophobic aerogels as adsorbent for organic contaminants dissolved in water. Herein, novel highly hydrophobic chitosan (CS) beads containing cellulose nanocrystals (CNC) and hydrophobized tannic acid (HTA) composite were prepared with different CS and CNC−HTA content to achieve an optimized adsorbent to remove emerging contaminants from water in batch and fixed-bed assays. The CS@CNC−HTA beads properties were assessed by FTIR, XRD, SEM, XPS, Micro-CT, WCA, and zeta potential. Supramolecular interactions and physical interlacements between CS and CNC−HTA enabled the formation of CS@CNC−HTA beads with high porosity (98.6%), great volume of open pore space (10.16 mm3) and hydrophobicity (121.8°). The 1:1 CS@CNC−HTA beads showed the best performance for removing the pharmaceutical sildenafil citrate, the basic blue 26 dye, and the surfactant cetylpyridinium chloride, reaching adsorption capacities of 86 (73%), 375 (84%), and 390 (90%) mg.g−1, respectively. The 1:1 CS@CNC−HTA beads efficiently removed sildenafil citrate, basic blue 26 and cetylpyridinium chloride in fixed-bed experiments with exhaustion times of 890, 300, and 470 min, respectively. Theoretical calculations and adsorption assays indicate that the main attractive interactions are pyridinium−π, π−π, electrostatic and hydrophobic.

Influence of the Type and the Amount of Surfactant in Phillipsite on Adsorption of Diclofenac Sodium

Modified phillipsite samples were prepared with two different amounts (monolayer and bilayer coverage) of surfactants octadecyldimethylbenzylammonium chloride (O) and dodecylamine (D). Composites were characterized by Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR–ATR), thermal analysis and determination of zeta potential, and subsequently tested for removal of diclofenac sodium (DCF). Drug adsorption experiments were performed under different initial DCF concentrations and different contact times. In order to investigate the influence of the chemical structure of surfactants used for modification of phillipsite on the preparation and properties of composites and DCF adsorption, experimental data were compared with previously published results on DCF adsorption by composites containing phillipsite and the same amounts of surfactants cetylpyridinium chloride (C) and Arquad®2HT-75 (A). DCF adsorption isotherms for O and D composites showed a better fit with the Langmuir model with maximum adsorption capacities between 12.3 and 38.4 mg/g and are similar to those for C and A composites, while kinetics run followed a pseudo-second-order model. Composites containing either benzyl or pyridine functional groups showed higher adsorption of DCF, implying that surfactant structure has a significant impact on drug adsorption. Drug adsorption onto O, D, C and A composites was also confirmed by FTIR–ATR spectroscopy and zeta potential measurements.

Investigating the morphological transitions in an associative surfactant ternary system.

Associative surfactants systems involving polar oils have recently been shown to stabilize immiscible liquids by forming nanostructures at the liquid interface and have been used to print soft materials. Although these associating surfactant systems show great promise for creating nanostructured soft materials, a fundamental understanding of the self-assembly process is still unknown. In this study, a ternary phase diagram for a system of cationic surfactant cetylpyridinium chloride monohydrate (CPCl), a polar oil (oleic acid), and water is established using experiment and simulation, to study the equilibrium phase behavior. A combination of visual inspection, small-angle X-ray scattering (SAXS), and rheological measurements was employed to establish the phase behavior and properties of the self-assembled materials. Dissipative particle dynamics (DPD) is used to simulate the formation of the morphologies in this system and support the experimental results. The ternary phase diagram obtained from the simulations agrees with the experimental results, indicating the robustness of the computational simulation as a supplement to the mesoscale experimental systems. We observe that morphological transitions (e.g., micelle-to-bilayer and vesicle-to-lamellar) are in agreement between experiments and simulations across the ternary diagram. DPD simulations correctly predict that associative surfactant systems form new nanoscale phases due to the co-assembly of the components. The established ternary phase diagram and the DPD model pave the way towards predicting and controlling the formation of different mesostructures like lamellar or vesicles, opening new avenues to tailor and synthesize desired morphologies for applications related to liquid-in-liquid 3D printing.

Voltammetric Behavior of Acidic Catecholamine Metabolites in Presence of Cationic Surfactants

The voltammetric behavior of two acidic catecholamine metabolites, vanillylmandelic acid (VMA) and homovanillic acid (HVA) in the presence of cationic, anionic, or nonionic surfactants was monitored at the disposable screen-printed electrodes. In basic medium above their pKa values, the cationic surfactant cetylpyridinium chloride (CPC) enhanced the oxidation peak current based on electrostatic and hydrophobic interactions with the ionized carboxylic group and stabilization of some of the electrochemical reaction intermediates. Under the optimum measuring conditions at pH 9.5, calibration graphs were linear within HVA concentration range from 0.25 to 2.5 × 10−6 mol l−1 and LOD 0.021 × 10−6 mol l−1. Simultaneous assay of HVA in the presence of VMA within the submicromolar concentration range can be performed with acceptable average recovery of 106.0 ± 3.4%. This preliminary study represents the base for simultaneous quantification of both compounds in of urine samples for Neuroblastoma diagnosis.

An integrated in silico and in vivo approach to determine the effects of three commonly used surfactants sodium dodecyl sulphate, cetylpyridinium chloride and sodium laureth sulphate on growth rate and hematology in Cyprinus carpio L

The purpose of this work is to evaluate the homology modeling, in silico prediction, and characterization of somatotropin and erythropoietin from Cyprinus carpio as well as molecular docking and simulation experiments between the modeled proteins and surfactants sodium dodecyl sulfate (SDS), sodium laureth sulfate (SLES) and cetylpyridinium chloride (CPC). Using the best fit template structure, homology modeling of somatotropin and erythropoietin of Cyprinus carpio respectively was conducted. The model structures were improved further with 3Drefine, and the final 3D structures were verified with PROCHEK, ERRATA and ProQ. The physiochemical, as well as the stereochemical parameters of the modeled proteins, were evaluated using ExPASy's ProtParam. Molecular docking calculations, protein-ligand interactions, and protein flexibility analysis were carried out to determine the binding pattern of each ligand to the targeted proteins and their effect on the overall proteins’ conformation. Our in silico analysis showed that hydrophobic interactions with the active site amino acid residues of the modeled proteins (somatotropin and erythropoietin) were more prevalent than hydrogen bonds and salt bridges that affect the flexibility and stability of the somatotropin and erythropoietin as revealed from our protein flexibility analysis. The in vivo analysis showed that sublethal concentrations of SDS, SLES, and CPC negatively affected the growth and hematological parameters of Cyprinus carpio. Hence, it may be inferred from the study that the alterations in the flexibility of somatotropin and erythropoietin of Cyprinus carpio upon addition of SDS, CPC and SLES might be attributable to the reduction in growth and hematological parameters.

Возможные механизмы деструкции спор вакцинного штамма Bacillus anthracis СТИ-1 под воздействием спиртозолей наночастиц металлов

The results are presented of a comparative study of the sporicidal activity of alcohol sols of nanoparticles of titanium, copper, zinc and tantalum metals in the course of their interaction with a rehydrated lyophilized culture of spores of the vaccine strain Bacillus anthracis STI-1 with the loss of the ability of spores to germinate in nutrient media under optimal conditions using bacteriology and electronic microscopy. The most pronounced sporicidal effect is observed when titanium alcohol sol is exposed to spores. At the same time, spores of B. anthracis STI-1 in titanium alcohol sol are affected by ethyl alcohol, which causes dehydration and denaturation of the protein, the antiseptic cetylpyridinium chloride as a surfactant, which is also a strong electrophilic agent that destroys the exosporium and spore shells, and titanium nanoparticles, which, due to the high surface energy when exposed to spores, cause their pronounced massive adhesion. In addition, titanium nanoparticles, the zeta (? -) value of the potential of which is -44.5 mV, cause a stable energy state of the dispersed system of alcohol sol, which acts as a biocatalyst for intracellular enzymes, causing the hydrolysis of polymer structures of the spore shells and cortex, as well as destroyed nucleoid – an area of spores containing structured genetic material. Spores that do not have a nucleoid in electron microscopy acquire the form of "shadows". As a result of the action of titanium alcohol sol, the activation of germination and the formation of the so-called "metabolic" spores, from which the vegetative cells of B. anthracis STI-1 should have been formed, are prevented. The reason for the high sporicidal efficiency of the alcohol sol of titanium nanoparticles is associated both with the structure and properties and with the technology of synthesis of titanium nanoparticles in the low-temperature plasma zone with the formation, due to the excess of the surfactant cetylpyridinium chloride, of a two-layer shell around the metal nanoparticles, which leads to their "conservation" until the moment of contact with spores and a sharp slowdown in their oxidation in the aquatic environment. The destruction of the formed two-layer shell of metal nanoparticles begins with contact with spores with the simultaneous onset of the formation of titanium ions from the phase of nanoparticles, which actively destroy chemically the shells of the spores. Keywords: microorganisms, Bacillus anthracis STI-1, spores, metal nanoparticles, zeta potential, disinfectant compositions, sporicidal activity.

Effect of temperature and composition of mixed solvent media on the interaction of bromocresol Green dye with cetylpyridinium chloride

The study of dye-surfactant interaction is very important in achieving an optimal dyeing process in textile industries. Conductivity measurements of the cationic surfactant cetylpyridinium chloride (CPC) in the presence of bromocresol green dye (BCG) in various solvents were performed, in order to provide insight into the interaction between BCG and CPC. Three critical micelle concentrations (cmc) were observed over the studied CPC concentration range. The observed cmc values of the BCG + CPC system were found to change significantly as a function of BCG concentration. The cmc values of the BCG + CPC system showed U-shaped variation, with increasing temperature in aqueous and propanol media, while decreasing monotonically in ethanol media. The concentration of additives (ethanol, propanol, and propylene glycol) also affected the cmc values significantly. The values of counterion binding (β) were also found to be dependent on the temperature and concentration of additives. Different thermodynamic parameters, e.g. Gibbs free energy (), enthalpy (), and entropy () changes, as well as their transfer properties associated with micellization of the BCG + CPC system, were determined. The ΔH o m and ΔS o m values reveal the presence of hydrophobic, ion-dipole, or dipole-diploe interactions amongst employed constituents.

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.