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The removing of oil from waste silk is carried out widely by microbial fermentation. However, it is difficult to remove the oil completely. In this study, surfactants were used to enhance microbial oil removing. In seven of the surfactants that were tested, 0.1% of the anionic surfactants inhibited the growth of bacteria and 0.1% of the nonionic surfactants partially inhibited the growth of bacteria. When only the surfactant was used to remove oil, all of the tested surfactants helped remove oil from the waste silk and treatment that added 0.1% AEO-9 gave the lowest oil content.

When surfactants were combined with bacteria to remove oil, the oil content was further reduced and the lowest oil content was obtained by combining AEO-9 and bacteria. The optimum conditions for oil removing by combining AEO-9 with bacteria were pH8.0, temperature 40°C, 4% (v/v) inoculum size and 3 days incubation time. Compared with untreated silk, silk treated by combining surfactants with bacteria resulted in a decrease in oil content and improvement in appearance. Scanning electron micrographs showed that treated samples had a clean surface.

To evaluate mild steel corrosion using a new surfactant‐inhibition model which was derived, in part, from the concept of intermolecular energy and molecular separation distance.

A Gamry potentiostat was used for polarization resistance tests to determine corrosion rate and the level of adsorption of surfactant at the solution‐metal interface was determined using UV‐spectroscopy. The relationship between inhibition and surfactant adsorption as well as metal corrosion was investigated using a traditional surfactant‐inhibition model, which assumes inhibition is directly proportional to surfactant coverage and new model.

The comparison of adsorption data and corrosion inhibition data shows inhibition was not directly proportional to physical coverage as assumed by the traditional inhibition model. Instead, it was found that coverage was related to inhibition through a power‐law dependency that is similar to that used to determine molecular interaction energies.

The new model was evaluated only for dodecyl pyridinium chloride mild steel system. The evaluation of the new model for various surfactant‐metal systems is suggested for future research.

The new model was found to more accurately predict the relationship between inhibition and coverage rather than traditional models for dodecyl pyridinium chloride‐mild steel system.

A series of sulfate-based Gemini anionic surfactants were synthesized via etherification, ring opening and sulfation reactions using epichlorohydrin, fatty alcohol, ethylene glycol and chlorosulfonic acid as the main raw materials. Orthogonal experiments for 1,8-bisalkoxymethylene-3,6-dioxin-1,8-octane disulfate were performed on the sulfation reaction to determine the optimal reaction conditions.

A series of sulfate-based Gemini anionic surfactants were synthesized via etherification, ring opening and sulfation reactions using epichlorohydrin, fatty alcohol, ethylene glycol and chlorosulfonic acid as the main raw materials. Orthogonal experiments for 1,8-bisalkoxymethylene-3,6-dioxin-1,8-octane disulfate were performed on the sulfation reaction to determine the optimal reaction conditions. The structures of the intermediate and final products were characterized by FT-IR (Fourier transform infrared spectroscopy analysis), ¹H-NMR (proton nuclear magnetic resonance spectroscopy) methods. The thermal performance of surfactants was analyzed using thermogravimetric analysis (TGA). The thermogravimetric results showed that the sulfate-based Gemini surfactants had good heat resistance (the thermal decomposition temperature of which was in the range of 140∼170?). The Krafft point, surface tension, foaming, Hydrophile–Lipophile Balance Number (HLB), emulsifying, wetting, and lime-soap dispersing performance were measured by visual observation, hanging drop method, aqueous surfactant solution method and Borghetti–Bergman method, respectively. The results have shown that all the sulfate-based Gemini surfactants had good water solubility and lime-soap dispersing ability. When spacer group was -(CH2)2-, with the increase of the carbon chain length from C12 to C14, the micellar concentration critical micelle concentration and surface tension (CMC) gradually increased from 8.25 × 10^–4 mol/L to 8.75 × 10^–4 mol/L and 27.5 mN/m to 30.9 mN/m, respectively. Also, the sulfate-based Gemini surfactants with the different length of the spacer group had a different effect on their performance on foaming properties and foam properties, HLB and emulsifying ability and wetting ability.

In view of the important role of the spacer group and the general use of anionic surfactants in oil fields, this article considers the preparation of a series of sulfate-based Gemini surfactants by changing the spacer group and the chain length of the hydrophobic group and evaluating their surface activity, and finally its Kraffi, on the foam properties, HLB value, emulsifying performance, lime soap dispersing ability etc.

Sulfate-based Gemini surfactants have broad application prospects in the fields of oil and gas exploitation, environmental protection, chemistry and daily chemical industry and so on.

A novel two series of self‐sequestering surfactants have been prepared by the reaction of itaconic acid, phthalic anhydride, citric acid with oxypropylated 1,4‐butane diol and oxypropylated 1,6‐hexane diol. The structure features of these surfactants have been confirmed by IR and ¹H NMR spectra. These surfactants exhibit excellent properties of self‐sequestering. Besides good surface active properties including surface tension, interfacial tension, low foaming, good wetting properties, good stability towards acidic and basic media, emulsifying power and dispresent properties, solubilization properties and good biodegradability, they possess autonomous sequestering ability without any help of additional sequestering agent.

In this research, the microstructure and corrosion behavior of Ni-Mo alloy coatings obtained from a citrate bath solution containing sodium dodecyl sulfate (SDS) as an anionic surfactant, and cetyltrimethylammonium bromide (CTAB) as a cationic surfactant, have been investigated.

For this purpose, the Cathodic polarization curves were plotted using a potentiostat/galvanostat set. Scanning electron microscopy and energy dispersive spectroscopy were, respectively, used to investigate the morphology and chemical composition of the coatings.

The results of the corrosion test showed that the corrosion resistance of the coatings obtained from electroplating bath only containing CTAB surfactant was deteriorated. On the other hand, SDS anionic surfactant positively affected on the corrosion resistance of the coatings when it was added to the electroplating bath.

For this purpose, the Cathodic polarization curves were plotted using a potentiostat/galvanostat set. Scanning electron microscopy and energy dispersive spectroscopy were respectively used to investigate the morphology and chemical composition of the coatings.

Surfactants are important corrosion inhibitors that are used in different applications. This paper utilizes the recently developed methodology and formulae to predict mild steel corrosion inhibition by alkyl pyridinium chloride and alkyl trimethyl ammonium bromide compounds. By utilizing different surfactants of varying chain lengths in different acidic media and determining the associated corrosion inhibition, the relationship between surfactant concentration, surfactant hydrocarbon chain length, surfactant critical micelle concentration, and corrosion inhibition can be evaluated. The results from this study can be used to improve relevant industrial uses of surfactants for corrosion inhibition.

Surfactants have been reported to have high inhibition efficiencies for corrosion of steel. This paper aims to study the performance of a low toxic copolymer of polydimethylsiloxane and polyoxyalkylene (POA) surfactant named as POPS, as a corrosion inhibitor for mild steel (ASTM 1005) in hydrochloric acid (HCl) solution at 25°C.

To evaluate POPS efficiency as a corrosion inhibitor, the following techniques were used: surface tension measurements, weight loss measurements, open circuit potential monitoring, potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), scanning electron microscopy and contact angle measurements.

Results indicated that POPS acted as a mixed corrosion inhibitor and led to a hydrophobic protector film on the metal surface. The adsorption process obeyed the Langmuir adsorption isotherm by chemisorption. The maximum efficiency of the surfactant studied was achieved in a concentration around the critical micelle concentration.

Surfactant (POPS) of low level of toxicity acts as a mixed corrosion inhibitor in HCl medium. Inhibitor film formation was characterized by EIS results. A mechanism for corrosion inhibition is proposed.

A lamellar zinc pigment reacts in aqueous alkaline media (e.g. water‐borne paints) with the evolution of hydrogen. This corrosion reaction can be inhibited by certain surfactants. The most important structural part of the examined surfactants is the hydrophilic group; only anionic phosphate or phosphonate hydrophilic groups are effective corrosion inhibitors. Surfactants with carboxylate, sulfonate, amphoteric, cationic and non‐ionic hydrophilic groups are ineffective. There seems to be also an influence of the hydrophobic group of the surfactants because a partial ester of phosphoric acid with a fluorinated hydrophobic group was the most effective corrosion inhibitor in this study.

The purpose of this investigation is the evaluation of the inhibitive performance of a new “gemini” surfactant in the series of bis‐quat: N, N, N′, N″, N″‐pentamethyl diethyleneamine‐N, N″‐di‐[tetradecylammonium bromide] on the corrosion of iron in 1 M HCl by gravimetric, potentiodynamic and electrochemical impedance measurements. The effect of the temperature on the corrosion behavior of iron in 1 M HCl without and with inhibitor is studied in the temperature range (298‐333 K). This work also attempts to correlate thermodynamic and kinetic parameters with the inhibition effect.

The inhibition efficiency of gemini synthesized is investigated by weight loss, potentiodynamic polarization and impedance spectroscopy methods.

The synthesized gemini bis‐quat acted as a good inhibitor in 1 M HCl, and inhibition efficiency increased with inhibitor concentration and temperature. Polarization curves showed that the surfactant was a mixed‐type inhibitor in hydrochloric acid. Impedance spectroscopy measurements showed that the inhibitor acted through the formation of a multilayer film at the iron surface. The adsorption of inhibitor on the iron surface obeyed the Langmuir adsorption isotherm equation. The inhibition effect was satisfactorily explained by both thermodynamic and kinetic parameters.

The adsorption of surfactants in the metal surface can markedly change the corrosion resisting property of the metal. So the study of the relation between the adsorption and corrosion inhibition is of a great importance. This was the first attempt to study the inhibition properties of gemini surfactants at the host laboratory.

The present work aims to deal with ultrasound-assisted organic pigment (phthalocyanine blue and green) dispersion and its comparison with the conventional approach.

Ultrasound is expected to give beneficial results based on the strong shear forces generated by cavitational effects. The dispersion quality for preparation using an ultrasound-based method has been compared with dispersion obtained using high-speed dispersion mill. Effects of different operating parameters such as probe diameter and use of surfactants on the physical properties of dispersion and the colour strength have been investigated. Calculations for the energy requirement for two approaches have also been presented.

The use of sodium dodecyl sulphate and Tween 80 surfactants shows better performance in terms of the colour properties of dispersion prepared in water and organic solvent, respectively. Ultrasound gives better dispersion quality as compared to the conventional approach.

The present work presents a new approach of ultrasound-assisted dispersion of phthalocyanine blue and green pigments. Understanding into the effect of surfactants and type of solvent also presents new important design-related information.