Cationic Surface-active Agents Research Articles

Sustained antibacterial coating with graphene oxide ultrathin film combined with cationic surface-active agents in a wet environment

Antimicrobial surfactants contained in mouthrinse have excellent efficacy, but are not retained on the tooth surface (are rinsed away) due to their low water resistance and thus do not exhibit sustained antibacterial activity. We have developed a new coating method using graphene oxide (GO) that retains the surfactant on the tooth surface even after rinsing with water, thus providing a sustained antibacterial effect. Ultra-thin films of GO and an antimicrobial agent were prepared by (1) applying GO to the substrate surface, drying, and thoroughly rinsing with water to remove excess GO to form an ultrathin film (almost a monolayer, transparent) on the substrate surface, then (2) applying antimicrobial cationic surface active agents (CSAAs) on the GO film to form a composite coating film (GO/CSAA). GO/CSAA formation was verified by scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and ζ-potential and contact angle measurements. GO/CSAA was effective at inhibiting the growth of oral pathogens for up to 7 days of storage in water, and antibacterial activity was recovered by reapplication of the CSAA. Antibacterial GO/CSAA films were also formed on a tooth substrate. The results suggest that GO/CSAA coatings are effective in preventing oral infections.

SORPTION-LUMINESCENT DETERMINATION OF OROTIC ACID IN MEDICINAL DRUGS

Luminescent properties of orotic acid (vitamin B13), known bioactive substance, have been evaluated in this research. It has been shown that inside a coordination complex of orotic acid with terbium (III) an intermollecular excitation energy transfer from a ligand to a lanthanide ion occurs which causes sensitization of terbium (III) ion luminescence. Intensity of the terbium (III) ion luminescence (ILum) increases in the presence of anionic and cationic surfaceactive agents as a result of displacement of water molecules from coordination sphere of the complex. As a consequence of this process, a non-radiative deactivation of excitation energy decreases and more efficient excitation energy transfer from a ligand to a lanthanide ion occurs. It has been established that after absorption of analyte of interest onto a polymer matrix of a solid phase extraction sorbent with subsequent increasing of its molecular rigidity more efficient excitation energy transfer is observed followed by elevation of luminescence (ILum) intensity of the coordination complex being studied. Intensity of luminescence of coordination complex of orotic acid with terbium (III) in the form of a sorbate salt has been estimated involving different types of sorbents (Phosphalugel, SFG-75, Calflo E, Celite 545, Silicagel Merck). Most suitable results have been achieved by the use of Silica gel Merck as a solid-phase matrix (sorbent). The removal rate of the complex from the solution in this case reaches to 97%. The most effective conditions for determination of orotic acid have been specified. The highest values of luminescence intensity is obtained by conducting of sorption using 5 mL of solution and 100 mg of sorbent. Luminescence intensity of the complex in the form of a sorbate salt, during a sorption process, increases in presence of ethonium, cationic dimeric surface-active agent. Decrease in luminescence intensity of the complexes in the form of a sorbate salt in presence of other surface-active agents may be caused by solubilization of the complex in the solution and thereby reduced level of its sorption. On the basis of presented research work a new analytical procedure has been developed for the solid-phase luminescence determination of orotic acid and orotic acid salts in pharmaceutical drugs. Determination of orotic acid salts has been performed in pharmaceutical drugs ‘Magnerot’ (magnesium orotate) and ‘Potassium orotate’. The proposed analytical procedure for determination of orotic acid salts is remarkable by good metrological characteristics and relative simplicity of performance. The relative standard deviation, Sr, is 3,6 - 4,3%.

Ir-Ni based mono and bimetallic nanocrystals: synthesis, characterization and effect of cationic, anionic, and non-ionic stabilizers

Nickel based bimetallic nanocrystals, iridium-nickel play an imperative role in catalysis, electrocatalysis, and magnetic applications. In the present work Ir-Ni bimetallic nanoalloys were synthesized by modified polyol reduction method with different cationic, anionic, and non-ionic surface active agents like CTAB, SDS, TSC, and PVP. The non-ionic surface active agent PVP produced a better effect on nanoparticle size than cationic and anionic surfactants. The synthesized bimetallic nanocrystals were characterized by UV-Vis, XRD, FTIR, FESEM, and HRTEM techniques. XRD and FTIR verify the nature of synthesized bimetallic nanocrystals and the interaction between stabilizers and nanoparticles. HRTEM studies reveal that the PVP stabilized Ir-Ni (3:1) and Ir-Ni (1:1) bimetallic nanocrystals are small in size and less dispersed. Particle size range of these nanoparticles is from (1.77-2.36) nm. FESEM images show that nanoparticles are in quasi spherical shape. EDX analysis indicates that the resultant particles are core shell structure with Ni core and Ir shell.

Core-shell nanoparticles for medical applications: effects of surfactant concentration on the characteristics and magnetic properties of magnetite-silica nanoparticles

Objective(s): The use of cationic surface-active agents (surfactant) in the synthesis of nanoparticles, with formation of micelle, can act as a template for the formation of meso-porous silica. Changes in the concentration of surfactants can affect the structures and properties of the resulting nanoparticles.Materials and Methods: Magnetite nanoparticles were prepared as cores using the coprecipitation method. Silica shells were formed on the prepared cores using sol-gel through the single-step process. During synthesis, cetrimonium bromide (CTAB) was used as a surfactant at low (0.1 g), medium (1 g), and high concentrations (7 g), and the effects on the properties of the nanoparticles were investigated. The core-shell nanoparticles were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). In addition, the surface porosities of the nanoparticles were evaluated using the BET and BJH methods. The vibrating sample magnetometer (VSM) was also employed to assess the magnetic characteristics of the synthesized samples. Results: The results of XRD indicated that the nanoparticles were composed of magnetite and silica, while the SEM and TEM images confirmed the presence of uniform spherical particles with a core-shell structure. According to the results of the VSM tests, all nanoparticles showed super-paramagnetic behaviors. Moreover, the increased concentration of CTAB led to an increment in saturation magnetization (Ms), size, and volume of the surface pores, while the specific surface area of the nanoparticles decreased. Conclusion: According to the results, the properties of the silica shell could be adjusted in terms of pore characteristics and magnetic behavior by changing the concentration of the surfactant.

Novel Cationic Polyurethane Surfactants Containing Saturated Chains- Part 1: Synthesis, Characterization and Surface Activity

Novel cationic polymeric surfactants were synthesized throughout the reaction of monoester of triethanol amine and two saturated fatty acids (palmitic acid and stearic acid) and TDI (toluene diisocyanate). The obtained polyurethane (PU) then was reacted by acetyl chloride to yield the desired surfactants. The structures of the produced compounds were described by using Fourier Transform Infrared Spectroscopy (FTIR) and their average molecular weights. Silver nanocomposite of the prepared cationic PU surfactants were characterized via physical combination by chemically prepared silver nanoparticles. The structure of the silver composite was determined using: Ultra-violet spectroscopy, Transmission Electron Microscopy (TEM), and Dynamic Light Scattering (DLS) spectroscopy. The effect of the hydrophobic chains on the surface activities of the synthesized cationic polymeric surface active agents and their silver nanocomposite was studied.

Selected anionic and cationic surface active agents: case study on the Kłodnica sediments

Abstract Surface active agents (surfactants) are a group of chemical compounds, which are used as ingredients of detergents, cleaning products, cosmetics and functional products. After use, wastes containing surfactants or their degradation products are discharged to wastewater treatment plants or directly into surface waters. Due to their specific properties of SAAs, compounds are able to migrate between different environmental compartments such as soil, sediment, water or even living organisms and accumulate there. Surfactants can have a harmful effect on living organisms. They can connect with bioactive molecules and modify their function. Additionally, they have the ability to migrate into cells and cause their damage or death. For these reasons investigation of individual surfactants should be conducted. The presented research has been undertaken to obtain information about SAA contamination of sediment from the River Kłodnica catchment caused by selected anionic (linear alkylbenzene sulfonates (LAS C10-C13)) and cationic (alkylbenzyldimethylammonium (BDMA-C12-16), alkyl trimethyl ammonium (DTMA), hexadecyl piridinium chloride (HP) chlorides) surfactants. This river flows through an area of the Upper Silesia Industrial Region where various companies and other institutions (e.g. coal mining, power plants, metallurgy, hospitals) are located. To determine their concentration the following analytical tools have been applied: accelerated solvent extraction– solid phase extraction – high performance liquid chromatography – UV-Vis (anionic SAAs) and conductivity (cationic SAAs) detectors. In all sediments anionic SAAs have been detected. The concentrations of HTMA and BDMA-C16 in tested samples were higher than other cationic analytes. Generally, levels of surfactants with longer alkyl chains were higher and this observation can confirm their higher susceptibility to sorption on solid surfaces.

Change of montmorilonite surfaсe structure with cationic surfactants adsorption

This paper shows the influence of cationic surface-active agents (SAA) with a different structure of the hydrophobic chain on the modification of the surface structure of silicate mineral montmorillonite and adsorptive properties of the resultant sorbent for extracting ions of chromium (VI) and cobalt (II) from aqueous media. Macroelectrophoresis and sorption methods for designating the selected samples were used in the research. It was proved that increasing the amount of surfactants added to a dispersed system, long-chain surfactants tend to form more stable hemicellar structure on the clay surface and more fully recharge it. It was found that the increasing the number of the hydrocarbon chain links from 1 to 16 the physicochemical characteristics of the obtained materials are changed dramatically: the adsorption of chromium increases to about 45 mg/g, while the adsorption of cobalt falls to zero in the full range of the surface-active agents concentrations. The research results will be useful and important in obtaining sorbents for extracting chromium (VI) ions from aqueous media.

Inhibition effect of synthesized cationic surfactant on the corrosion of carbon steel in 1 M HCl

Three cationic surface active agents were synthesized from the chemical modification of 2-aminobenzothiazole. The chemical structures of these surfactants were confirmed, IR and 1H NMR spectra. The synthesized compound showed high surface activity. The inhibition of the cationic surfactant on the corrosion of carbon steel in acidic media of 1M HCl was studied by weight loss measurements, potentiodynamic and electrochemical impedance spectroscopy (EIS). The inhibition efficiency depends on both of concentration and length of hydrophobic chain. The inhibition efficiencies obtained from the used techniques were in good agreement with each other. The adsorption of the inhibitors obeyed Langmuir adsorption model. Polarization measurements showed the mixed type behavior of the synthesized inhibitors, which inhibits the cathodic and anodic parts of the corrosion reaction in the acidic media.

Determination of Surfactants in Environmental Samples. Part I. Cationic Compounds / Oznaczanie Surfaktantów W Próbkach Środowiskowych. Część I. Związki Kationowe

Abstract Compounds from the group of cationic surfactants are widely applied in household, industrial, cleaning, disinfectant, cosmetic and pharmaceutical products as their specific properties (antimicrobial, emulsifying, anticorrosion, softening). After use, cationic surfactants are disposed to wastewater-treatment plants and finally with effluent water to surface waters due to their incomplete degradation. Moreover, they can freely circulate in different environmental compartments including living organisms. It becomes indispensable to recognize in more detail behavior, fate and biological effects of cationic surfactants. This analytical problem can be solved with use sensitive and reliable analytical techniques at sample preparation step and final determination step. In recent years, during isolation analytes from environmental samples mainly were used liquid-liquid extraction (LLE) - liquid matrices or solid-liquid extraction (SLE) - solid matrices. This technique involves application of toxic solvents (chloroform), is time-consuming and interferences are co-extracted. Nowadays, in scientific centers are carried out research to replace this traditional technique. So far, the following techniques were applied: solid-phase extraction (SPE) or it modification (HF-LPME) - liquid samples; accelerated solvent extraction (ASE) and supercritical fluid extraction (SFE) - solid samples. During the determination of total content of cationic surface active agents in environmental samples were used a traditional spectrophotometry technique and potentiometric titration technique. But those techniques are susceptible of interferences on analysis results (anionic and non-ionic compounds). The chromatographic technique (liquid chromatography) applied at the final determination step gives possibility to determine individual cationic surfactants in solvent extracts of environmental samples. The LC systems coupled with mass spectrometers are most powerful tools during such analysis.

Preparation of Quinolinium Salts Differing in the Length of the Alkyl Side Chain

Quaternary quinolinium salts differing in alkyl chain length are members of a widespread group of cationic surfactants. These compounds have numerous applications in various branches of industry and research. In this work, the preparation of quinoline-derived cationic surface active agents differing in the length of the side alkyl chains (from C8 to C20) is described. An HPLC method was successfully developed for distinction of all members of the series of prepared long-chain quinolinium derivatives. In conclusion, some possibilities of intended tests or usage have been summarized. In vitro testing using a microdilution broth method showed good activity of a substance with a C12 chain length against Gram-positive cocci and Candida species.

A novel reagent for spectroscopic determination of Mo(VI)

AbstractA new reagent for spectrophotometric determination of Mo(VI) was developed utilizing micellar effects. For this purpose, differences in the ultraviolet and visible spectral properties of Mo(VI), gallic acid, L-serine, and their binary and ternary solutions were studied in the presence and absence of cationic, anionic, and non-ionic surface active agents. L-serine was observed to form binary complexes and a ternary complex with Mo(VI) and gallic acid below its isoelectric point. The maximum Mo(VI) sensitivity was exerted by the Mo(VI) + gallic acid + L-serine + hexadecyltrimethylammonium bromide system at pH of 4.5. This system was proposed for use in the spectrophotometric determination of Mo(VI) as a superior alternative to the Mo(VI) + gallic acid + hexadecyltrimethylammonium bromide system and to most of the instrumental analysis methods referred to in the literature. The mechanism of micellar effects was discussed on the basis of the spectral data obtained above and below the isoelectric point of L-serine and explained in terms of the molecular charge of the substrates and the surfactants.

The temperature dependence of the critical micelle concentrations cationic surface-active agents.

The temperature dependence of the critical micelle concentrations cationic surface-active agents.

Synthesis, Characterization and Surface Activity of New Eco‐friendly Schiff Bases Vanillin Derived Cationic Surfactants

AbstractThree eco‐friendly cationic surface active agents were synthesized from the chemical modification of vanillin. The chemical structures of these surfactants were confirmed using elemental analysis, IR and NMR spectra. The surface activity measurements showed their high tendency towards adsorption and micellization and their good surface tension reduction, low interfacial tension. The emulsion stability measurements showed acceptable efficiency as emulsifying agents for short term emulsions. The biodegradability tests revealed that these compounds are eco‐friendly and had completely degraded in 30 days.

Preparation of the Pyridinium Salts Differing in the Length of the N-Alkyl Substituent

Quaternary pyridinium salts with chains ranging from C8 to C20 belong in the large group of cationic surfactants. In this paper, the preparation of such cationic surface active agents based on the pyridinium moiety and differing in the length of the N-alkyl chain is described. Additionally, HPLC technique was established to distinguish each prepared pyridinium analogue. This study represents universal method for preparation and identification of quaternary pyridinium detergents.

Solubilization Behaviors of Nonpolar Substrates Using Double Tailed Cationic Surfactants

A series of double hydrophobic tails of N-methyl diethanolammonium bromide cationic surface active agents were synthesized. Their chemical structures were elucidated using different analytical tools including elemental analyses, FTIR, mass fragmentation, and 1H-NMR spectroscopy. Their surface parameters including critical micelle concentration (CMC), effectiveness (π CMC ), efficiency (Pc 20), maximum surface excess (Γ max ), and minimum surface area (A min ) were calculated. The behaviors of the synthesized molecules in their solutions were discussed based on the data of surface parameters, micellization and adsorption thermodynamics at 25°, 40°, and 55°C. The experimental data of surface activity showed that these molecules are tends to form micelles in the bulk of their solutions at lower temperatures. On contrarily, they prefer to adsorb at higher temperatures. The synthesized cationic surfactants were used as solubilizing agent for nonpolar substrate (paraffin oil) at 25°C. The results of solubilization measurements showed good ability for the used surfactants towards solubilizing paraffin oil in aqueous medium. The results showed that the chemical structure of the solubilizate plays an important rule in its solubilization. Several factors were found to influence the extent of solubilization including: number of alkyl chains within surfactant molecule, symmetry of molecules and chain length of hydrophobic parts. The results were rationalized by the Kraft point and HLB values of the used surfactants. Furthermore, solubilization curves showed the steady state solubilization of each surfactant used.

New Trends in the Development of Chemical Admixtures in Japan

This paper describes the history and new trends in the development of chemical admixtures in Japan. PC (polycarboxylic acid)-based agents are the main products in the superplasticizer market. A low-stickiness type PC-based superplasticizer has been developed based on the conventional PC-based superplasticizer. The flowing speed of concrete with low stickiness type PC-based superplasticizer is faster than that with the conventional PC-based superplasticizer. By addition of a new viscosity agent consisting of a mix of anionic and cationic surface active agents, the three dimensional reticulation structures is formed in fresh cement paste and the viscosity of the cement paste can be increased and segregation can be prevented. The hydration of cement in sludge water is controlled by addition of a set-retarder, and the specific surface area of cement does not increase while a large amount of unreacted alite remains in the sludge water. Recycling of concrete at ready mixed concrete plants is possible without adversely influencing the properties of concrete when sludge water with the set-retarder containing gluconate salt is used. The slurry type and powder type calcium aluminate based accelerator (CA) and calciumsulfoaluminate based accelerator (CSA) for shotcrete have been developed. In the case of CA, the final setting time of the mortar is accelerated by increasing the dosage. By adding of CSA, both the initial and final setting times of mortar are shortened with increased dosages.

Ｎｉ／ＳｉＣ複合めっきに対するカチオン性界面活性剤の影響

In order to control the SiC content in Ni/SiC composite plating, cationic surface-active agents with different alkyl chain length, which were of the hydrophobic group, were added to a Ni/SiC composite plating bath to change the surface charge of the SiC particles from negative to positive. The influence of the cationic surfactant on the Ni plating was also studied. The crystallite size of Ni deposits decreased with the addition of the cationic surface-active agents, and an excess addition of cationic surface-active agents in the bath caused cracks in the Ni deposits. In the Ni/SiC plating, we can easily control the SiC amount in the Ni/SiC plating between about 10 and 30 vol%, changing the alkyl chain lengths of the added cationic surfactants and their concentration to change the surface potential of SiC particles.

Inhibition effect of some surface active agents on dissolution of copper in nitric acid

AbstractThe inhibitive efficiency of some nonionic, amphoteric, cationic, and anionic surface active agents (surfactants) on the dissolution of copper in 4·5M HNO3 was studied at 25°C by the weight loss method. The percentage inhibition I increases as the concentration of the cationic, nonionic, and amphoteric substances increases and reaches a limiting value. It is suggested that this is due to the formation of a monolayer on the surface of the metal; the Langmuir adsorption isotherm was confirmed. In the case of anionic surface agents, the percentage inhibition values were at their highest at low surfactant concentrations and decreased as the concentration of the surfactant increased.

Synthesis and surface active properties of cationic surface active agents from crude rice bran oil

Cationic surfactants of 2-hidroxy-3-(2- alkylamidopolyethyl amino) propane-1-triethylammonium hydroxides (ix-xui) a-d were prepared from fatty acids (i) a-d [palmitic, stearic, oleic, linoleic acid] and mixed fatty acids of crude rice bran oil i e [RBO]. The reaction of these acids with ethylenediamine, diethylenetriamine, triethylenetetramine andletraethylenepentamine (ii) a-d produced (iii-vii) a-d . The produced amidopolyethylamine (iii-vii) a-d reacted with 2-epoxypropylenetriethylammonium chloride (viii) to give the cationic surfactants (ix-xiii) a-d . The produced derivatives were purified and characterized by microanalysis, molecular weight determination, infra-red (IR), and proton nuclear magnetic resonance ( 1 H NMR) spectra. The surface active properties and inhibition efficiency of the prepared cationic surfactants were determined.

Quantitation of Cationic Surface-Active Agents in Natural Waters

Quantitation of Cationic Surface-Active Agents in Natural Waters