The Synthesis of Oleic Acid Polyglycol Ester Catalyzed by Solid Super Acid

A SO₄ ²⁻/ZrO₂ super acid was prepared and the effect of different kinds of catalysts on the esterification reaction reviewed. The results showed that the SO₄ ²⁻/ZrO₂ super acid had higher catalytic activity and reactive selectivity in the synthesis of oleic acid polyglycol ester. Under optimum conditions the product was a monoester and the rate of production was more than 90%. The reaction product was characterized.

Morphologies of Sol–Gel Derived Thin Films of ZnO Using Different Precursor Materials and their Nanostructures

We have shown that the morphological features of the sol–gel derived thin films of ZnO depend strongly on the choice of the precursor materials. In particular, we have used zinc nitrate and zinc acetate as the precursor materials. While the films using zinc acetate showed a smoother topography, those prepared by using zinc nitrate exhibited dendritic character. Both types of films were found to be crystalline in nature. The crystallite dimensions were confined to the nanoscale. The crystallite size of the nanograins in the zinc nitrate derived films has been found to be smaller than the films grown by using zinc acetate as the precursor material. Selected area electron diffraction patterns in the case of both the precursor material has shown the presence of different rings corresponding to different planes of hexagonal ZnO crystal structure. The results have been discussed in terms of the fundamental considerations and basic chemistry governing the growth kinetics of these sol–gel derived ZnO films with both the precursor materials.

Micellization of Cetyl Triphenyl Phosphonium Bromide Surfactant in Binary Aqueous Solvents

The effect of the different binary aqueous organic solvents viz. 1,4-dioxane, acetonitrile, dimethylsulfoxide, ethylene glycol, and methanol, on the micelle formation and thermodynamics of a cationic surfactant cetyl triphenyl phosphonium bromide has been studied conductometrically at 298–318 K. From the conductivity data critical micelle concentration, degree of counter ion dissociation (α) and thermodynamic parameters of micellization have been determined. It is observed that micellization tendency of the surfactant decreases in the presence of binary aqueous solvents. The entropies of micellization are all positive, and they compensate the enthalpies of the process.

Pure N-Alkylaminopropionic Acid and N-Alkylaminodipropionic Acid Sodium Salts: Synthesis, Characterization, and Physicochemical Properties

Fourteen pure β-aminopropionic acid amphoteric surfactants were synthesized from methyl acrylate using primary amines. The synthesis was done in two steps. First, Michael addition of a primary amine to methyl acrylate gave two separable addition products. Second, because the resulting esters gave, by the classical saponification procedure, undesired retro-Michael products, they were treated with sodium trimethylsilanolate to give the corresponding pure anhydrous acid salt under mild non-aqueous reaction conditions. Two types of amphoteric surfactants were obtained: the monocarboxylate and the dicarboxylate series. The pure surfactants were characterized by IR, ¹H NMR, and ¹³C NMR spectroscopy. The surfactant critical micelle concentrations were evaluated. From these the Gibbs free energy of micellizations [∆G(–CH₂–)_mic] were calculated. These are related to the methylene units that contribute an average of −1.0 (±0.3) kJ mol⁻¹ for both the monocarboxylate and the dicarboxylate series.

A Study of the Technical Route of the Synthesis of Alkylbenzenes for Use as an Oil Displacement Agent

This paper describes the technology of synthesizing alkylbenzenes containing C_16–19 alkyl chains. The heavy alkylbenzenes were prepared by C_16–19 liquid paraffin dehydrogenation, followed by alkylation with benzene. A novel catalyst containing Pt and Sn as its main components for the dehydrogenation of C_16–19 paraffins to alkenes was prepared by vacuum impregnation and the catalyst exhibited high stability and selectivity. The alkylation of the C_16–19 alkenes and benzene had a conversion yield of 86.15% and a selectivity of 81.21%. The main alkylbenzenes was identified as monoalkylbenzene by IR and chromatography analysis. C_16–19 alkylbenzene sulfonates are found to give an ultra-low interfacial tension when mixing with crude oil/reservoir water.

New Gold-Doped Foams by Copolymerization of Organogold(I) Monomers for Inertial Confinement Fusion (ICF) Targets

The incorporation of metallic elements, such as gold, into porous polymeric foams is an important focus for inertial confinement fusion (ICF) experiments. Incorporation was attempted from copolymerization of new organogold(I) monomers and various co-monomers by three development methods. This report describes the preparation of new polymeric gold foams, polymerizable high internal phase emulsion (polyHIPE) foams, divinylbenzene (DVB) foams and acrylate foams (TMPTA foams). The resulting gold-doped foams are characterized by elemental analysis, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). A very homogeneous distribution of gold into the polymeric structure is obtained.

Synthesis and Biological Activity of 8-Hydroxyquinoline and 2-Hydroxypyridine Quaternary Ammonium Salts

Two series of quaternary cationic surfactant were synthesized by reaction of 8-hydroxyquinoline and 2-hydroxypyridine with long chain alkyl halides (dodecyl, tetradecyl- and hexadecyl-bromide). Surface tension was measured in aqueous solution for different concentrations at 25 °C. Various surface properties of the synthesized surfactants were evaluated, particularly critical micelle concentration (CMC), efficiency (Π_CMC) as well as maximum surface excess (Γ_max) and minimum surface area (A _min). Micellization and adsorption in liquid/air interfaces thermodynamics were investigated. The synthesized cationic surfactants were evaluated for their biocidal activity. All compounds prepared showed good antibacterial and antifungal activities.

Synthesis,Surface Properties and Antimicrobial Activity of Bolaamphiphile/Oppositely Charged Conventional Surfactant Mixed Systems

Four ionic bolaamphiphiles were synthesized from four bolasingle systems and the surface properties of bolasingle systems and bola\oppositely charged conventional mixed surfactant systems were studied. Variations in the structure of the hydrophobic chain of bolaamphiphiles has a great influence on their antimicrobial activities. The bolaform surfactants prepared have significant antimicrobial and antifungal activities relative to their conventional analogues. The Г_∞ (saturated adsorption amount) and A _min (minimum average area per surfactant molecule) of these bolaamphiphiles in both water and 0.1 M NaCl solutions were calculated and CMC of the mixed systems with oppositely charged conventional surfactants in both water and 0.1 M NaCl solutions were determined.

Solubilization,Surface Active and Thermodynamic Parameters of Gemini Amphiphiles Bearing Nonionic Hydrophilic Spacers

A series of novel nine symmetric diquaternary gemini amphiphiles was synthesized having the formula:

Synthesis of Unsymmetrical Bolaform Surfactants with a Sulfonate Group and a Carboxyl Group

Three unsymmetrical bolaform surfactants with different aromatic rings and a ω-carboxyalkyl chain were synthesized and their molecular structures were characterized by ESI–MS and ¹H NMR. The percentages of conversion of alkylation were judged by the iodine value measurements and the effect of reaction temperature on sulfonate content of synthesized products has also been discussed.

Modified low molecular weight acrylics in coating application: synthesis and property evaluation

Low molecular weight resins containing relatively high levels of acrylic acid were converted to oxidatively curable materials by reacting the carboxylic acid groups with oxazoline functional alkenes. The oxazolines were obtained by reacting fatty acid with 2-amino-2-methyl-1-propanol. The oxazolines were then reacted with the acrylic resins at elevated temperature. Relatively high yields of the desired reaction products were obtained in relatively short reaction times. The resulting resins were formulated into aqueous coatings and films were made over metal substrates. The films were cured oxidatively and evaluated for property development. The films had good general solvent resistance but poor resistance to dilute sodium hydroxide.

Preparation and Application of Fluorinated Cationic Surfactants

Four fluorinated cationic surfactants were prepared by condensing 2,2,3,3, tetrafluoro-1-propyl chloroacetate with stoichiometric amounts of pyridine, 2-hydroxypyridine, 8-hydroxyquinoline and 8-hydroxyquinaldine to produce four quaternary ammonium salts. The surface and biocidal properties of these surfactants were investigated. Surface properties of their solutions including surface tension, critical micelle concentration (CMC), effectiveness (Π_cmc), maximum surface excess (Γ_max) and minimum surface area (A _min) were investigated with respect to different concentrations at 25 °C. Standard free energies of micellization and adsorption of the prepared surfactants in the aqueous solution were studied. The biocidal activity was determined via the inhibition zone diameter of prepared compounds which tested against six strains as a representative group of microorganisms.

Investigation on crystallization of aluminophosphate gel in the presence of 4-dimethylaminopyridine/hydrofluoric acid system

The crystallization behavior of gel composition xR:1.0Al₂O₃:1.0P₂O₅:0/0.5HF:40 H₂O (0.75 ≤ x ≥ 3.0) is investigated, where R is 4-dimethylaminopyridine, under microwave-hydrothermal conditions. The crystallized products were characterized by means of powder X-ray diffraction, high temperature X-ray diffraction, nitrogen adsorption–desorption measurement at 77 K, solid state NMR (²⁷Al-MASNMR), thermogravimetric analysis, and scanning electron microscopy (SEM). The obtained results reveal the crystallization of AlPO-5 phase and its transition to BPC-1, a novel crystalline framework and EMM-8 like framework, as a function of template concentration and crystallization time. Both these crystallized frameworks are found to transform to SSZ-51 (SFO) like framework upon calcination. The studies also reveal the importance of optimum concentration of 4-dimethylaminopyridine (4-DMAP) for crystallization of EMM-8 as well as BPC-1.

Influence of Sodium Ions on Micelles of Surfactin-C16 in Solution

The properties of surfactin-C₁₆ aqueous solution in the presence of Na⁺ ions, produced by Bacillus subtilis, were studied by the fluorescence method. The critical micelle concentration (CMC) of surfactin-C₁₆ was measured as 24.7 μM in 0.05 M Tris buffer (pH 8.5–8.6). With an increase in Na⁺ concentration, the CMC value and micropolarity of surfactin-C₁₆ decreased while the microviscosity increased, which means that the addition of Na⁺ improves the surface activity and enhances the micellization of the surfactin-C₁₆ in solution. The preliminary aggregation number (N) was obtained by the steady-state fluorescence method.

Enhancement of the Antitumour Activity for the Synthesised Dodecylcysteine Surfactant using Gold Nanoparticles

In this paper, the surfactant dodecylcysteine hydrochloride was synthesised. The surface parameters of the synthesised surfactant were studied using a surface tension technique. The surface parameters show a good surface activity of the prepared surfactant in aqueous solution. The self-assembling behaviour of the synthesised surfactant comparing with that of cysteine compound on the prepared gold nanoparticles was confirmed using transmission electron microscope (TEM) measurements. The effect of self-assembling of this surfactant on the size of gold nanoparticles was studied using TEM images. The antitumour activity of the prepared surfactant without and with the gold nanoparticles was investigated. The results show that the antitumour activity of the prepared surfactant was enhanced with the presences of the gold nanoparticles.

Micellization Behavior of Mixtures of Sodium Dioctylsulfosuccinate with Sodium Dodecylsulfate in Water

Mixtures of sodium dioctylsulfosuccinate (AOT) and sodium dodecylsulfate (SDS) that were studied in water at 25 °C by using surface tension, conductance, emf and fluorescence emission methods exhibit synergism in the region where the mole fraction of AOT in the bulk solution (α ₁) is less than 0.7 and ideality in the region where α ₁ ≥ 0.7. The molal conductance versus the concentration behavior of an aqueous solution of AOT is found to be different from that of other ionic surfactants with the exception of bile salts. Composition of the mixed micelle was evaluated and discussed using the Rubingh’s and the Rodenas–Valiente–Villafruela (RVV) treatments. The values of the counter ion binding constant determined from the emf data show that the counter ion binding behavior of the mixed micelle is controlled entirely by AOT. The free energy for mixed micelle formation was calculated using a modified equation. The aggregation number determined by the fluorescence quenching method indicated that in the mixed micelle, as α ₁ increases, the number of molecules of AOT remains constant and that of SDS decreases. Characteristics of the adsorption layer of the mixed surfactant system were also examined using the theoretical treatment of Rosen and Hua.

Degradation of Pesticides Wastewater by Silyl Based Cationic Surfactants

New stable silayl cationic surfactants have been studied for the destruction of toxic organophosphorus pesticides. Hexadecyl, dodecyl trimethyl silane ammonium chloride or iodide surfactants were synthesized and evaluated in the degradation of pesticides such as Diazinon, Malathion or Chlorpyrifos. The hydrolytic efficiency of each surfactant was tested by measuring the kinetics of model substrates cleavage under a pseudo-first order reaction. The iodo silayl based surfactants showed more destructive power than the chloro derivatives. Meanwhile, the hexadecyl moiety showed more effective pesticide degradation than the corresponding dodecyl moiety.

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Syntheses and Characterization of Some Cationic Surfactants

A series of novel cationic surfactants were synthesized from the quaternization of triethyl amine and various long chain alkyl halide. The chemical structure of the prepared compounds was confirmed using elemental analysis, FTIR and ¹H-NMR spectra. The physical properties of the synthesized surfactants including, electrical conductivity, critical micelle concentration, (CMC) and the degree of ionization of the micelle, (β) were studied. The thermodynamic parameters of micelle formation, standard free energy ΔG _m°, enthalpy ΔH _m°, and entropy ΔS _m° were calculated. The results of the surface parameter determination were correlated with their chemical structures. It was found that the hydrocarbon chain length is the main factor which has an effect on the value of the thermodynamic parameters.

Aggregation of Alcohols Ethoxylates in n-Heptane

The solubility and aggregation process of polyethoxylated non-ionic surfactants, of general formula C _i H_2i+1–(O–CH₂–CH₂) _j –OH with i = 6, 8, 10 and j = 3–6 (C _i EO _j ), in heptane were studied. The aggregation of C _i EO _j surfactants in heptane was investigated by using methylene blue (MB) as an absorption probe. In solutions of MB in the presence of these surfactants in heptane, at concentrations larger than the re-dissolution concentration, the UV bands associated to free MB (A ₁) and MB–EO complex (A ₂) were detected. The ratio of these intensities A ₂/A ₁, was used to study the kinetics of the complex formation in pure surfactant. The value of A ₂/A ₁ depends on the surfactant structure and the media wherein MB is dissolved, being larger in the pure surfactant than in heptane solutions. These results are explained in terms of solvent effect and aggregate structures on the complex formation.

Interactions of Sodium Dodecyl Benzene Sulfonate and Sodium Dodecyl Sulfate with Gelatin: A Comparison

The interaction of SDS/SDBS in aqueous gelatin solutions is studied above the gelation temperature by viscosity and circular dichroism (CD) measurements. The steep rise observed in the relative viscosity can be due the structural transitions leading to micellar growth of higher order. Circular dichroism spectra indicated that gelatin helped in inducing the sphere→rod transition, without suffering any conformational changes within it. The findings are particularly significant in terms of the head group contribution, hydrophobic interaction and the formation of formulated complexes.