Acid Surfactant Research Articles

Oleic acid surfactant in polycaprolactone/hydroxyapatite-composites for bone tissue engineering.

Bone substitutes are required to repair osseous defects caused by a number of factors, such as traumas, degenerative diseases, and cancer. Autologous bone grafting is typically used to bridge bone defects, but suffers from chronic pain at the donor-site and limited availability of graft material. Tissue engineering approaches are being investigated as viable alternatives, which ideal scaffold should be biocompatible, biodegradable, and promote cellular interactions and tissue development, need to present proper mechanical and physical properties. In this study, poly(ε-caprolactone) (PCL), oleic acid (OA) and hydroxyapatite (HAp) were used to obtain films whose properties were investigated by contact angle, scanning electron microscopy, atomic force microscopy, tensile mechanical tests, and in vitro tests with U2OS human osteosarcoma cells by direct contact. Our results indicate that by using OA as surfactant/dispersant, it was possible to obtain a homogenous film with HAp. The PCL/OA/Hap sample had twice the roughness of the control (PCL) and a lower contact angle, indicating increased hydrophilicity of the film. Furthermore, mechanical testing showed that the addition of HAp decreased the load at yield point and tensile strength and increased tensile modulus, indicating a more brittle composition vs. PCL matrix. Preliminary cell culture experiments carried out with the films demonstrated that U2OS cells adhered and proliferated on all surfaces. The data demonstrate the improved dispersion of HAp using OA and the important consequences of this addition on the composite, unveiling the potentially of this composition for bone growth support. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1076-1082, 2016.

A Catalyst Platform for Unique Cationic (Co)Polymerization in Aqueous Emulsion.

Sodium dodecyl benzene sulfonate (DBSNa) surfactants, with a polydisperse and hyperbranched structure, combined with different rare earth metal salts generate highly water-dispersible Lewis acid surfactant combined catalysts (LASCs). This platform of new complexes promotes fast, efficient cationic polymerization of industrially relevant monomers in direct emulsion at moderate temperature. The process described here does not require high shearing, long polymerization time, or large catalyst content. It allows the reproducible generation of high-molar-mass homopolymers of pMOS, styrene, and isoprene, as well as random or multiblock copolymers of the latter two, in a simple and straightforward one-pot reaction.

A Catalyst Platform for Unique Cationic (Co)Polymerization in Aqueous Emulsion

AbstractSodium dodecyl benzene sulfonate (DBSNa) surfactants, with a polydisperse and hyperbranched structure, combined with different rare earth metal salts generate highly water‐dispersible Lewis acid surfactant combined catalysts (LASCs). This platform of new complexes promotes fast, efficient cationic polymerization of industrially relevant monomers in direct emulsion at moderate temperature. The process described here does not require high shearing, long polymerization time, or large catalyst content. It allows the reproducible generation of high‐molar‐mass homopolymers of pMOS, styrene, and isoprene, as well as random or multiblock copolymers of the latter two, in a simple and straightforward one‐pot reaction.

Effect of Fatty Acid and Non-ionic Surfactant on the Deinkability of Mixed Recovered Paper

Recovered paper has been widely used as a main raw material of papermaking in Korea. Recycling of recovered paper helps to reduce production cost and preserve an environment. To recycle recovered paper efficiently, de-inking is a key process in recycling mills. De-inking process would be affected by various influencing factors such as the type of de-inking agent, mixed ratio of recovered paper, season, and process conditions. In this study, fatty acid and nonionic surfactant were used as the de-inking agent in froth-flotation process of mixed recovered paper. De-inking properties of mixed recovered paper were investigated according to the addition level of each chemical. Nonionic surfactant had a small effect on de-inking efficiency of mixed recovered paper due to decreased reject. As the additional level of fatty acid increases, fragmented ink particles increased and then optical properties of recycled paper decreased because fragmented ink particles adsorbed onto the fiber surface.

Improving oxidative stability of peanut oil under microwave treatment and deep fat frying by stearic acid–surfacant–tea polyphenols complex

In this work we present a study of the influence of a stearic acid–surfactant–tea polyphenols complex (SSTC) on the oxidative and thermal stability of peanut oil under microwave heating and simulated deep fat frying. Changes of the quality parameters of all oil samples containing different SSTCs were very obvious, compared with those of pure peanut oil. Especially for the oil sample containing SSTC‐P, the p‐anisidine value decreased 48.89% and 14.90% after microwave heating and simulated deep fat frying. For K232, it decreased 36.90% and 33.18%, respectively. By GS–MS analysis, the content of unsaturated fatty acids in peanut oil containing SSTC‐P was 8.7 times more than that in pure peanut oil after microwave treatment. As an efficient food antioxidant, the self‐assembled complex of tea polyphenols in edible oil prepared by this novel method may have great market potential.Practical applications: Oxidation processes are one of the major problems encountered in oil consumption and storage. The addition of natural antioxidants is a major way to inhibit oxidation processes in edible oils. Tea polyphenols are excellent source of phenolic compounds, which have been reported to show good antioxidant activity. The results of this study suggest that oil‐soluble tea polyphenols can be prepared based on a stearic acid–surfactant–tea polyphenols complex. The dispersion of SSTC into peanut oil can improve oxidative and thermal stability of edible oil. Therefore, the complex of tea polyphenols in edible oil may have great market potential of food antioxidant.Tea polyphenols solution was used as the aqueous phase. Stearic acid containing appropriate amount of surfactant were poured into a 50 mL centrifuge tube, and kept in a water bath maintained at 80°C and stirred at 500 rpm until a homogeneous clear solution was obtained. Then, the aqueous phase and the oil phase were mixed using a homogenizer at 26 000 rpm for 2 min to form a stable W/O emulsion. The resulting emulsion was frozen rapidly in liquid nitrogen, and lyophilized using a freeze‐drying machine for 48 h. Finally, all of the stearic acid–surfactant–tea polyphenols complexes (SSTC) were obtained. The SSTC was dispersed in peanut oil. Oxidation products of the oil sample were analyzed by GC–MS under microwave heating.

Surface and Antimicrobial Properties of N-Palmitoyl Amino Acid–Based Surfactants

Synthesized sodium N-pamitoyl amino acids were evaluated for surface and antimicrobial properties and compared with sodium lauryl sulfate (SLS). Emulsion stability of the amino acid surfactants and calcium tolerance of the sodium N-palmitoyl isoleucine were better as compared to SLS. Wetting ability and foaming properties of the palmitic acid-based surfactants were inferior to SLS. N-Acyl amino acids exhibited better antibacterial activity compared to sodium salts of N-acyl amino acids and standard compounds against Staphylococcus aureus MLS-16 and Bacillus subtilis. These studies revealed that the palmitoyl amino acid surfactants can be exploited in household, skin care formulations, and industrial applications.

Electrodeposition of Cu–Sn alloys: theoretical and experimental approaches

In this study, Cu–Sn alloy was electrodeposited from aqueous electrolytic bath onto Mo electrode. Before electrodeposition, some calculations using MATLAB software to obtain the dominant complex of Cu–citrate in different pH values and cyclic voltammetry (CV) experiments was performed. The potential range in which the alloy electrodeposition process could be carried out in a solution containing CuSO4, SnSO4, and Na3C6H5O7 was determined by CV. In addition, the effects of boric acid and cetyl trimethyl ammonium bromide (CTAB) surfactant on codeposition potential were studied. The microstructural properties and alloy composition were investigated by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), respectively. Alloy composition up to 49.5 at.% of Sn was obtained. Alloy composition of 33 at.% Sn corresponding to Cu2SnS3 was obtained at solution containing 0.04 M SnSO4, 0.02 M CuSO4 and 0.4 M Na3C6H5O7 at Potential −0.75 V.

QENS investigation of proton confined motions in hydrated perfluorinated sulfonic membranes and self-assembled surfactants

We report on QuasiElastic Neutron Scattering (QENS) investigations of the dynamics of protons and water molecules confined in nanostructured perfluorinated sulfonic acid (PFSA) materials, namely a commercial Aquivion membrane and the perfluorooctane sulfonic acid (PFOS) surfactant. The former is used as electrolyte in low-temperature fuel cells, while the latter forms mesomorphous self-assembled phases in water. The dynamics was investigated as a function of the hydration level, in a wide time range by combining time-of-flight and backscattering incoherent QENS experiments. Analysis of the quasielastic broadening revealed for both systems the existence of localized translational diffusive motions, fast rotational motions and slow hopping of protons in the vicinity of the sulfonic charges. The characteristic times and diffusion coefficients have been found to exhibit a very similar behaviour in both membrane and surfactant structures. Our study provides a comprehensive picture of the proton motion mechanisms and the dynamics of confined water in model and real PFSA nanostructures.

Surfactant Assisted Separation Spectrophotometric Procedure for the Trace Analysis of Copper (II) in Drug and Water Samples Using a Heterocyclic Pyridyl Azo Dye

4-(2-pyridyl-Azo) resorcinol mono sodium mono hydrate (NaPAR), a heterocyclic azo dye, was investigated for the flotation of copper (II). The metal ion forms a faint red complex with NaPAR in aqueous solution. An intense clear red layer was formed in the scum, after flotation, by adding an oleic acid (HOL) surfactant. The composition of the float is 1:2 (Cu(II): NaPAR). A highly selective and sensitive spectrophotometric procedure was proposed for the determination of micro-amounts of Cu(II) as its floated complex in the pH range 3.0-5.0. Beer’s law was obeyed up to 5x10-5 mol l-1. The Interferences from various foreign ions were avoided by adding excess NaPAR. The molar absorptivities of Cu-NaPAR and Cu-NaPAR-HOL systems are 5.3×104 and 6.1×105 mol-1cm-1 for the colored complexes in the aqueous and scum layers, respectively. The Cu-NaPAR complexes formed in aqueous solution and in the HOL were characterized by infrared spectral studies. The method was successfully applied to the analysis of Cu(II) in water and drug samples with a recovery >95% and a RSD <1.5%. The separation mechanism is explained.

Preparation and thermoelectric properties of flower-like nanoparticles of Ce-Doped Bi2Te3

Ce-doped CexBi2-xTe3 (x = 0, 0.1, 0.2, 0.3) flower-like nanoparticles were synthesized by a hydrothermal method through a careful adjustment of the amount of ethylenediamine tetraacetic acid surfactant. The nanopowders of flower-like nanoparticles were hot-pressed into bulk pellets and the thermoelectric properties of the pellets examined. The results showed that Ce-doping increased the power factor effectively at low temperature; however, the thermal conductivity of the nanopowder too increased because of the lighter atomic mass of Ce compared to Bi. As a result, a ZT value of 1.22, higher than that of the undoped sample, was attained at 386 K for the Ce0.1Bi1.9Te3 sample.

Binding interaction of an anionic amino acid surfactant with bovine serum albumin: physicochemical and spectroscopic investigations combined with molecular docking study

Exploration of binding interaction between anionic amino acid surfactant and BSA.

Quantitative analysis of the relationship between the dispersion stability of mixed-surfactant Ag nanoparticles and their composition

The dispersion stability of Ag NPs could be greatly enhanced by mixing n-alkylcarboxylic acid surfactants with two different chain lengths.

Composite photocatalytic membrane prepared by embedding porous SiO2 shell/void/TiO2 core particles into polycarbonate for photodegrading and removing pollutant from water

In order to solve the problem of immobilizing and recycling TiO2 particles, the porous SiO2 shell/void/TiO2 core particles (SVT) were first prepared under the synergetic effect of oleic acid and non-ionic surfactant P123 to enhance light and mass transfer, and then embedded into polycarbonate to prepare composite photocatalytic membranes (CPMs). SVT were characterized by TEM while CPMs were characterized by FT-IR and SEM, showing that SVT were successfully synthesized and embedded into polycarbonate. Namely, the CPMs were successfully prepared. The optimum preparation conditions of CPMs were investigated and determined via porosity test of CPMs as follows: the content of PC, DMC and CH2Cl2 of the casting solution is 13wt%, 15wt% and 72wt%, respectively; the mass ratio of SVT/PC (g:g) is 1:1. The photocatalytic properties of CPMs were investigated through photodegrading methyl orange in water and oil in sewage containing oil, respectively. The results show that SVT have a porous structure, and CPMs have a better degradation rate for photodegrading methyl orange in water and oil in sewage containing oil, and the photocatalytic degradation rate does not decrease obviously after recycling many times, indicating CPMs possess better photocatalytic performance without degrading the polymer supports. The different cleaning methods of CPMs were also investigated to recover photocatalytic performance of recycled CPMs. Therefore, CPMs as a novel TiO2-immobilized structure will have a promising application in the immobilization and recycle of TiO2 catalyst with a better photodegrading and removing performance for pollutants from water.

Preparation and characterization of Fe3O4 magnetic nanoparticles modified by perfluoropolyether carboxylic acid surfactant

Conventional surfactants-modified Fe3O4 magnetic nanoparticles (MNPs) are not satisfying in special areas, especially in corrosive and extreme temperature conditions. In this study, bare Fe3O4 MNPs were synthesized by co-precipitation without protective gas in atmosphere, and then modified by perfluoropolyether carboxylic acid surfactant (PCAS). Both the bare and the modified Fe3O4 MNPs were characterized. According to the results of characterization, the modified Fe3O4 MNPs are globular shaped and monodisperse whose average particle size decreased from 30~40nm to 11nm and in narrow distribution. In addition, characteristic peaks of PCAS and bare Fe3O4 both appear in FT-IR spectrum of modified Fe3O4 which suggest that Fe3O4 MNPs have been coated by PCAS. The surface coating won׳t alter Fe3O4 crystal morphology or superparamagnetism. However, it can slightly reduce saturation magnetization from 74.684emu/g to 55.392emu/g. The modified layer will be completely destroyed at near 380°C. The mass ratio of the modified layer to bare Fe3O4 core is close to 39:53 according to thermal analysis. In summary, these results collectively showed that PCAS was successfully decorated at the surface of Fe3O4 MNPs and the performance of modified Fe3O4 MNPs has been greatly improved.

Investigation on the ion pair amphiphiles and their in vitro release of amantadine drug based on PLGA–PEG–PLGA gel

The amantadine drug and oleic acid surfactant are used to form amantadine-based ion pair amphiphiles based on proton transfer reaction between the drug and the surfactant molecules. The ion pair amphiphiles are characterized by 1H-nuclear magnetic resonance, Fourier transform infrared spectroscopy, and X-ray diffraction. Self-assembly properties of amantadine-based ion pair amphiphiles are studied by surface tension determination, transmission electron microscopy, zeta potential, and dynamic light scattering. The aggregation behavior studies indicate that the as-prepared ion pair amphiphiles can self-assemble into vesicles with the size of 200–300 nm in aqueous solution. The drug release results show that the amantadine release rate could be well controlled by incorporating the amantadine-based ion pair vesicles in poly (lactic-co-glycolic acid)-poly (ethylene glycol)-poly (lactic-co-glycolic acid) (PLGA–PEG–PLGA) copolymer hydrogel. The drug release from the AT–OA vesicle-loaded PLGA–PEG–PLGA hydrogel is significantly inhibited in comparison with the AT-loaded PLGA–PEG–PLGA hydrogel. The present work thus demonstrates that the vesicle-loaded hydrogel is a good candidate for the drug delivery system with long-term controlled drug release behavior.

Efficient Synthesis of Spiro[diindenopyridine-indoline]triones Catalyzed by PEG-OSO3H-H2O and [NMP]H2PO4

One-pot, three-component synthesis of spiro[diindenopyridine-indoline]triones has been reported via the reaction of 1,3-indandione, aromatic amines, and isatins with (PEG-OSO3H) as an efficient, polymeric acid surfactant–based catalyst in water and also in presence of acidic ionic liquid [NMP]H2PO4, which acts both as a medium and catalyst under conventional heating and ultrasonic irradiation. The reactions were complete in short reaction times with excellent yield of products. Surfactant-based PEG-OSO3H could be recycled and reused several times without any significant loss of activity. The compounds exhibit fluorescence in methanol with large Stokes shift.

Study on Decolouration of Reactive Dyes by Laccase

Five different structural reactive dyes (Reactive Brilliant Blue K-3R, Everacion Blue H-ERD, Moderzol Blue FBR, Atuzol Black B and Moderzol Blue HEGN) were treated with laccase (Denilite II US) in order to determine the optimum decolouration conditions. The experiments showed that laccase had distinct decolouration effects on these five dyes. Under optimum conditions, the colour removal rates of Everacion Blue H-ERD and Moderzol Blue HEGN were over 90%. Furthermore, the effects of different additives, such as acid ion, metal ion, and surfactants on the decolouration rate of Reactive Brilliant Blue K-3R were discussed. The results show that the decolouration rate is significantly promoted through the addition of Cu2+ and Al3+, while it is inactivated with Fe2+ and ion surfactants. Moreover, the COD removal rates of the five dyes are more than 75%.

Quantifying Surfactant Alkyl Chain Orientation and Conformational Order from Sum Frequency Generation Spectra of CH Modes at the Surfactant-Water Interface.

We combine second-order nonlinear vibrational spectroscopy and quantum-chemical calculations to quantify the molecular tilt angle and the structural variation of a decanoic acid surfactant monolayer on water. We demonstrate that there is a remarkable degree of delocalization of the vibrational modes along the backbone of the amphiphilic molecule. A simulation-based on modeled sum frequency generation (SFG) spectra offers quantitative insights into the disorder of surfactant monolayers at the water-air interface. It is shown that an average of one gauche defect in the alkyl chain suffices to give rise to the methylene stretch intensity similar in magnitude to the methyl stretch.

Valorization of tannery wastes: Lipoamino acid surfactant mixtures from the protein fraction of process wastewater

Abstract The first stages of the transformation process of hides into leather (beamhouse process) generate an important waste in the tanning industry, since a considerable fraction of solubilized proteins ends up in waste water with the corresponding increase in contamination parameters, especially when the process is carried out without hair recovery (hair-pulping process). The objective of this work was the valorisation of this waste (the separated protein fraction) which conveniently hydrolyzed to amino acid level constituted the starting material for the production of biodegradable surfactants. The lipoamino acid surfactants were obtained by acylation of the amino acids from the protein hydrolysate. These surfactants were characterized and their physico-chemical and biological properties evaluated. They exhibit very low cmc values (about 40 mg/L). These surfactants are readily biodegradable and present an aquatic toxicity significantly lower than many common commercial surfactants derived whether from renewable or petrochemical feedstock. The mixtures of surfactants obtained are able to form oil/water emulsions that remain stable for at least 1 year. The results obtained in this work confirmed that it is possible the production of biodegradable and efficient lipoamino acid surfactant mixtures from the protein fraction present in beamhouse process wastewaters. This study constitutes a promising approach for the reduction of the pollution load from industrial tannery wastes and its valorisation as raw material for the production of surfactants with excellent environmental properties and good technical properties.

Morphology Controlled 1-D Iron Oxide Nanochains with Tunable Magnetic Properties

Magnetic 1-dimension (1-D) ordered nanostructures has stimulated great interests attributed to their potential applications including magnetic resonance imaging, data storage, magnetic sensor, and drug delivery. Self-assembly of 1-D hierarchical nanostructures with aids of surfactant using bottom-up wet chemistry method can provide controllable magnetic properties. Herein, an unusual polymeric additive- polypropylene grafted maleic anhydride (PP-g-MA, 2500 g/mole) has demonstrated its unique capability, i.e., to synthesize 1-D ferromagnetic hard (292.7 Oe) γ-Fe2O3 nanochains made of 24 nm nanoparticles vs. PP-g-MA with 8000 g/mole for the synthesis of 1-D ferromagnetic soft (70.5 Oe) γ-Fe2O3 nanochains (30 nm) made of flowerlike nanoparticles (NPs). Experimental The synthesis procedures of γ-Fe2O3 nanochains were demonstrated as below. First, solid PP-g-MA (0.25 g, Molecular weight, Mn≈8000 or ≈2500) was added into a three-neck flask with 100 mL xylene and heated to reflux (140 °C) for 30 min. Second, brown Fe(CO)5 (3.50 g) was injected into the hot mixed solution (solution turned from transparent to yellow). Then, the solution was further refluxed for 3 hours at 140 °C constantly to form a black colloid. After cooling, the final colloidal solution was used for morphology characterization, while the powder product from drying the colloidal was used for magnetic property measurement. Results and Discussion By using PP-g-MA (Mn≈ 8000), the formation of 1-D nanochains (diameter: ~30.0 nm) was observed in the TEM image, Fig. 1a. The enlarged TEM image in Fig. 1b demonstrates that the building blocks of these nanochains are consisted of unique flower-shape NPs, Selected area electron diffraction (SAED) ring pattern confirm the soleexistence of γ-Fe2O3 in the nano-chains.17 The self-assembled 1-D nanochains can be realized via replacing PP-g-MA (Mn≈ 8000) with PP-g-MA (Mn≈ 2500). When PP-g-MA (Mn ≈ 2500) was used, the formed colloidal NPs were observed to assemble into 1-D nanochains consisting of quasi-spherical NPs instead of the flower shape NP building blocks, when drop-cast on the carbon coated copper TEM grid, the average diameter was ~24.0 nm, Fig. 1c and d. SAED patterns also indicate the sole existence of γ-Fe2O3.1 Figure 1 EM images of γ-Fe2O3 nanochains with a, b) PP-g-MA (Mn≈8000); and c, d) PP-MA (Mn≈2500). Average chain diameter is: a, b) ~30.0 nm, and c, d) ~ 24.0 nm, respectively. The difference in nanochain morphologies are caused by the different capping strength from varying the Mn of PP-g-MA on the magnetic NPs. The MA group in PP-MA can be tightly chemisorbed onto the magnetic NPs2 similar to the carboxylic acid surfactant. 3Larger Mn PP-MA resulted in low MA density in the reaction system, and a lower capping strength on the surface of magnetic NPs was thus observed. At low concentrations, for example, 0.25 g PP-MA (Mn≈ 8000), the aggregation of small magnetic clusters led to the formation of flower-shape NPs grown from the highly concentrated nuclei upon thermal-decomposition of Fe(CO)5. The further assembly of these flower ‘‘aggregates’’ is driven by the balance between attractive forces (magnetic dipolar attractions) and the steric hindrance from the coordinating PP-MA backbones.Beside the morphological difference, different magnetic properties were also observed. Materials with coercivity (H c ) greater than 200 Oe is defined as ferromagnetic hard; while H c smaller than 200 Oe is defined as ferromagnetic soft. Room temperature magnetic property reveals that the γ-Fe2O3 nanochains (30 nm diameter) have higher saturation magnetization (M s ) than that of γ-Fe2O3 nanochains (24 nm diameter), More importantly, the H c of 30 nm γ-Fe2O3 nanochains is about 70.5 Oe, reflecting a ferromagnetic soft material; while the H c of 24 nm γ-Fe2O3 nanochains is 292.7 Oe, corresponding to a ferromagnetic hard material. It can be concluded that the magnetic property such as coercivity (ferromagnetic soft vs. hard) of thus synthesized 1-D nanochains can be easily controlled by only changing the molecular weight of PP-MA. It is believed that the size and aspect ratio, shape anisotropy and magnetization reversal mechanism are responsible for the observed different magnetic property. Conclusion A facile one-pot bottom up approach has been demonstrated to synthesize well defined 1-D γ-Fe2O3 nanochains with easily controlled building block configurations, self-assembly morphologies towards the further manipulation of magnetic property. PP- MA with proper MA grafting density and reaction concentration is of key importance to achieve these evolved different 1-D γ-Fe2O3nanochains. These 1-D nanochains are promising for a variety of applications such as high-density magnetic storage and sensors.