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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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.

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.

Synthesis of Sulfated Sodium Salts of 1-Alkylamino-3-alkyloxy-2-propanols and N,N-Di-(2-hydroxy-3-alkyloxy propyl) Alkylamines as Potential Surfactants

1-Alkylamino-3-alkyloxy-2-propanols, V (a–g) and N,N-di-(2-hydroxy-3-alkyloxy propyl) alkylamines, VI (a–g) were prepared with the same chain length both for alkyl amino and alkyloxy groups by condensation of alkyl glycidyl ethers with long chain alkylamines by employing thermal and microwave-assisted methods. All the products were characterized by ¹H-NMR, IR and fast atom bombardment mass spectrometry studies. These compounds were further sulfated and evaluated as their sodium salts for surfactant properties namely surface tension, critical micelle concentration, emulsifying property, wetting, foaming power and calcium tolerance. Sulfated 1-dodecylamino-3-dodecyloxy-2-propanol, VII c and sulfated N,N-di-(2-hydroxy-3-dodecyloxy propyl) dodecylamine, VIII c were found to exhibit superior surfactant properties among the respective series of monomers and dimers.

Microwave-Assisted Synthesis and Properties of a Novel Cationic Gemini Surfactant with the Hydrophenanthrene Structure

A novel cationic gemini surfactant with the hydrophenanthrene structure has been synthesized from dehydroabietic acid by use of conventional thermal conditions and microwave irradiation. Its structure was confirmed by IR, ¹H NMR, and ¹³C NMR spectroscopy. It was found that microwave-assisted synthesis is an efficient means of preparation of this cationic gemini surfactant, with shorter reaction times and higher yields. The title compound had high surface activity. The CMC was 3.1 × 10⁻⁵ mol L⁻¹, γ _CMC was 26.3 mN m⁻¹, and emulsifying power (with benzene) reached five days. Comparison of this gemini surfactant and its monomeric counterpart proved the gemini surfactant was more surface active.

Multi-level Modeling of Silica–Template Interactions During Initial Stages of Zeolite Synthesis

Zeolite synthesis is driven by structure-directing agents, such as tetrapropyl ammonium ions (TPA⁺) for Silicalite-1 and ZSM-5. However, the guiding role of these organic templates in the complex assembly to highly ordered frameworks remains unclear, limiting the prospects for advanced material synthesis. In this work, both static ab initio and dynamic classical modeling techniques are employed to provide insight into the interactions between TPA⁺ and Silicalite-1 precursors. We find that as soon as the typical straight 10-ring channel of Silicalite-1 or ZSM-5 is formed from smaller oligomers, the TPA⁺ template is partially squeezed out of the resulting cavity. Partial retention of the template in the cavity is, however, indispensable to prevent collapse of the channel and subsequent hydrolysis.

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.

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.

Copolymerization of Chlorocyclotriphosphazene Derivatives Containing the Methacycloylbutenedioxy and <Emphasis Type="Italic">N</Emphasis>-(Ferrocenylmethyl)-<Emphasis Type="Italic">N</Emphasis>-Methylamino Substituents with Methylmethacrylate

The mixed substituent chlorocyclophosphazene monomers 2,2^′-N₃P₃Cl₄[O(CH₂)₄OC(O)C(Me)CH₂][C₅H₅FeC₅H₄CH₂NMe](1) and 2,2^′,4-N₃P₃Cl₃[O(CH₂)₄OC(O)C(Me)CH₂][C₅H₅FeC₅ H₄CH ₂NMe]₂ (2) undergo radical addition copolymerization with methylmethacrylate to produce a broad range of copolymers having pendant cyclophosphazenes containing a ferrocenyl substitutent. In both bulk and solution copolymerization, the conversion decreased with increasing amount of 1 in the monomer feed with no copolymer formation observed in co-monomer mixtures containing greater than 50% of 1. NMR studies of the copolymers show that the copolymer composition is the same as the monomer feed and that the triad tacticity is constant throughout the series for 1 but an increase in syndiotactic triads is observed for 2. TGA studies indicate an increase in char yield with an increase in the phosphazene content of the copolymer.

Synthesis of Ethyl 5 Z ,9 Z ,12 Z -octadecatrienoate (ethyl pinolenate) and Methyl 12 Z ,15 Z -octadecadienoate

Pinolenic acid (5Z,9Z,12Z-octadecatrienoic acid, 1a), one of the most abundant trienoic fatty acids in nature, is very difficult to obtain in quantity in a pure state from the highly complex mixture of unsaturated tall oil fatty acids. For this reason its chemistry has been little studied when compared to linolenic or linoleic acids. A simple synthesis of esters of 1a and of 12Z,15Z-octadecadienoic acid 3 using the one pot double Wittig procedure is described here. The products of double Wittig reactions were purified by argentation chromatography, and their structural purity was established by ¹H-, ¹³C-NMR and 2D-NMR spectroscopies.

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.

Self-Metathesis of 1-Octene Using Alumina-Supported Re<Subscript>2</Subscript>O<Subscript>7</Subscript> in Supercritical CO<Subscript>2</Subscript>

In this contribution we describe the use of heterogeneous catalysts for the liquid-phase self-metathesis of 1-octene in supercritical CO₂. Our work aims at addressing the mass-transfer problems associated with such reaction systems. By coupling a heterogeneous supported Re₂O₇ catalyst with the use of scCO₂, the self-metathesis of 1-octene takes place by and large much more rapidly than in traditional solvent media, and furthermore, by using scCO₂ the overall efficiency and sustainability of the transformation can be improved.

Synthesis of Polyaniline/Pd Nanoparticles via Ligand Exchange

Polyaniline/Pd nanoparticles were synthesized via ligand exchange. Pre-prepared water soluble starch/Pd nanoparticles were treated with polyaniline, and washed with water, leading to the small and well-dispersed polyaniline/Pd nanoparticles. The redox state of polyaniline was preserved during the ligand exchange reaction.

Quantitative Monitoring of the Amidation Reaction Between Coconut Oil and Diethanolamine by Attenuated Total Reflectance Fourier Transform Infrared Spectrometry

An analytical procedure was developed to monitor the batch reaction of coconut oil and diethanolamine which also would determine the cocodiethanolamide (CDEA) content of the final product. The method was based on attenuated total reflectance Fourier transform infrared spectrometry utilizing partial least squares regression. The calibration was modeled in the 1,781–1,714 and 1,658–1,639 cm⁻¹ spectral regions for coconut oil and CDEA respectively. The models were then applied to predict the amidation process yield and to monitor the in situ kinetics of reactions between coconut oil and DEA. The root mean square error of prediction was 0.590 and 0.336 for coconut oil and CDEA respectively. The proposed method can also be successfully applied to the determination of purity in commercial grade CDEA samples and would give reliable results in comparison with the potentiometric titration reference method.

Assessment of UV-permeability in nano-ZnO filled coatings via high throughput experimentation

The degree of UV protection afforded by nano-ZnO in a polyurethane/acrylic clear topcoat was investigated. The influence of nano-ZnO concentration and dry film thickness on the optical properties (e.g., UV permeability and visible transmittance) of the coating was probed using a library of 28 samples that were prepared by high throughput techniques. A model for predicting the UV permeability of nano-ZnO filled coatings was developed and the nano-ZnO loading condition required to block >99% UV radiation was determined to be 2.0 g/m². This model can be used to assist in the development of coatings and other polymeric systems embedded with nano-ZnO to protect the coating and underlying materials (i.e., substrate) from UV degradation.

Surface and Biological Activity of Some Novel Cationic Surfactants

In this study, steps were taken toward the development of bactericidal and fungicidal synthetic cationic surfactants by reacting decyl, dodecyl or tetradecyl amine with acetic or hydrochloric acid to produce a series of amine salts which consequently converted to copper or cobalt cationic complexes via complexing the first series compounds with copper (II) or cobalt (II) ions. Surface properties such as interfacial tension and emulsifying power of these surfactants were investigated. The surface parameters including critical micelle concentration (CMC), maximum surface excess (Γ_max) and minimum surface area (A _min) were studied. Free energy of micellization (ΔG°_mic) and adsorption (ΔG°_ads) were calculated. The antimicrobial activity was determined via the inhibition zone diameter of the prepared compounds, which measured against five strains of a representative group of microorganisms. FTIR spectra, elemental analysis and H¹ NMR spectrum were performed to confirm compound structure and purity.

Investigation of the Structure-Directing Effect of Surfactants on the Distribution of Silicate Species Using <Superscript>29</Superscript>Si-NMR Spectroscopy

Silicate anions were studied using ²⁹Si NMR to investigate the structure-directing effect of a surfactant (sodium dodecylsulfate-SDS) on the distribution of silicate species present in alkaline silicate solutions. The distribution of the anions in the presence of polyelectrolytes was also investigated by ²⁹Si NMR through the use of different bases including tetramethyl ammonium hydroxide (TMAOH) and sodium hydroxide (NaOH). Both SDS and the polyelectrolytic solutions were shown to stabilize low molecular weight silicate species and thus inhibit polymerization.

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.

Microwave Synthesis of Cationic Fatty Imidazolines and their Characterization

This paper describes an efficient method for the synthesis of long chain dialkyldiamido imidazolines by the reaction of diethylenetriamine and several fatty acids under non-solvent microwave irradiation using calcium oxide as support This synthesis required much less time in comparison to conventional thermal condensation and is carried out in an open vessel and the products obtained by this method were found to be in good yields and of high purity. Fatty imidazolines were then quaternized by using dimethyl sulfate as a quaternizing agent and isopropanol as a solvent, to produce cationic imidazolinium salts which were evaluated for yield and cationic content. The instrumental techniques, viz. FT-IR and ¹H NMR verified the formation of imidazolines and its subsequent quaternization. This method produced imidazolines in the very low time of 5–10 min and gave a yield of 89–91% as compared to a very long time of 8–10 h and a lower yield of 75–80% by the conventional thermal condensation method.

The Effect of Morphology Changes on Polymer Photodegradation Efficiencies: A Study of Time-Dependent Morphology and Stress-Induced Crystallinity

The effects of time-dependent morphology changes on the photochemical degradation efficiencies of polymers were investigated using the segmented polyurethane 1. A segmented polyurethane was chosen for this study because segmented polyurethanes have distinct hard (crystalline) and soft (amorphous) morphologies in the solid-state. It is known that, as these polymers cure, the hard and soft domains expand in the days and weeks following preparation. Experiments showed that the quantum yields for degradation of thin films of polymer 1 decreased over a period of about 30 days following preparation of the polymer films. Infrared spectroscopy showed an increase in crystallinity in the polymer during this curing period. These results are consistent with the hypothesis that the rate of photodegradation in polymer systems is controlled by the separation rate of the photogenerated radical pair relative to the rate of radical-radical recombination (Scheme 3). An important factor that controls the ratio of these two rates is the crystallinity of the polymer; an increase in crystallinity favors the radical-radical recombination reaction. The effect of tensile stress on photodegradation efficiencies was also studied. Two samples of the same polymer, one more crystalline than the other, were examined. The quantum yields for degradation of the more crystalline sample were less affected by tensile stress than the less crystalline sample. Tensile stress is known to order polymer chains and the results are again interpreted as being consistent with the idea that crystallinity is an important factor in controlling the efficiency of polymer photodegradation.