Decylphosphonic Acid Research Articles

FeOOH-polypyrrole-multiwalled carbon nanotube ternary nanocomposite fabricated by liquid-liquid co-extraction technique for supercapacitors application

FeOOH-polypyrrole-multiwalled carbon nanotube (FeOOH-PPy-MWCNT) ternary nanocomposite for supercapacitor negative electrodes are prepared by liquid-liquid co-extraction (LLCE) technique using decylphosphonic acid (DPPA) as efficient co-extractor. LLCE offers advantages of reduced agglomeration and facilitates mixing of the individual components. This technique allows direct particle transfer from the reaction medium to the electrode fabrication slurry. The mechanism of LLCE extraction is analyzed. The synergetic effect of FeOOH, PPy and MWCNT significantly enhances charge storage properties of the FeOOH-PPy-MWCNT ternary nanocomposite electrodes. The FeOOH-PPy-MWCNT ternary nanocomposite electrode shows an integral capacitance of 5.1 F cm−2 (137.9 F g−1) in a negative potential window, which is significantly higher than capacitances of binary FeOOH-MWCNT and PPy-MWCNT nanocomposites. Moreover, the ternary composite offers advantages of a larger voltage window. Testing results for the ternary composites at different electrode potentials show reduced AC impedance. The asymmetric supercapacitor device composed of FeOOH-PPy-MWCNT anode and MnO2-MWCNT cathode exhibits a high areal capacitance of 2.5 F cm−2 at scanning rate of 2 mV s−1 in a voltage window of 1.6 V at an extremely small impedance. This facile LLCE fabrication technique opens a door for fabrication of advanced nanocomposite materials for supercapacitor applications.

Modulating MnO2 Interface with Flexible and Self-Adhering Alkylphosphonic Layers for High-Performance Zn-MnO2 Batteries.

Metal oxides are essential electrode materials for high-energy-density batteries, but it remains highly challenging to modulate their interfacial charge-transfer process and improve their cycling stability. Here, using MnO2 nanofibers as an example, we describe the application of self-assembled alkylphosphonic modification layers for significantly improved cycling stability and high-rate performance of Zn-MnO2 batteries. Two modifier organic molecules with the same phosphonic functional group but different alkyl tail lengths were employed and systematically compared, including butylphosphonic acid (BPA) and decylphosphonic acid (DPA). The phosphonic groups form strong interfacial covalent bonding and assist the generation of conformal and flexible coatings with few nanometers thickness on a MnO2 surface. The intertwined alkylphosphonic molecules in the modulation layers have interconnected phosphonic groups, which improve interfacial charge transfer of H+ ions for fast conversion of MnO2 to MnOOH without compromising electrolyte wetting. Importantly, the coating layers effectively reduce dissolutive loss of Mn2+ from MnO2 during battery cycling since diffusion of both water molecules and divalent Mn2+ cations was inhibited across the modification layers. The flexible coatings could readily adapt to the morphological changes of MnO2 during battery cycling and provide long-lasting protection. Overall, we identified that BPA has the optimal balance of hydrophobic-hydrophilic components and enabled modified MnO2 cathodes with >30% improved discharge capacity compared with unmodified MnO2 cathodes, together with substantially improved long-term cycling stability with >60% capacity retention for 400 cycles in aqueous ZnSO4 electrolytes without any Mn2+ additive. This work provides new insights into tuning electrochemical pathways that move away from the prevailing rigid, ceramic coating-based surface modifications.

Stabilization of a molecular water oxidation catalyst on a dye\u2212sensitized photoanode by a\xa0pyridyl anchor

Understanding and controlling the properties of water-splitting assemblies in dye-sensitized photoelectrosynthesis cells is a key to the exploitation of their properties. We demonstrate here that, following surface loading of a [Ru(bpy)3]2+ (bpy = 2,2′-bipyridine) chromophore on nanoparticle electrodes, addition of the molecular catalysts, Ru(bda)(L)2 (bda = 2,2′-bipyridine-6,6′-dicarboxylate) with phosphonate or pyridyl sites for water oxidation, gives surfaces with a 5:1 chromophore to catalyst ratio. Addition of the surface-bound phosphonate derivatives with L = 4-pyridyl phosphonic acid or diethyl 3-(pyridin-4-yloxy)decyl-phosphonic acid, leads to well-defined surfaces but, following oxidation to Ru(III), they undergo facile, on-surface dimerization to give surface-bound, oxo-bridged dimers. The dimers have a diminished reactivity toward water oxidation compared to related monomers in solution. By contrast, immobilization of the Ru-bda catalyst on TiO2 with the 4,4′-dipyridyl anchoring ligand can maintain the monomeric structure of catalyst and gives relatively stable photoanodes with photocurrents that reach to 1.7 mA cm−2 with an optimized, applied bias photon-to-current efficiency of 1.5%.

Synthesis of Red-Emitting CdSe/CdS/ZnS Core/Shell/Shell Quantum Dots

CdSe/CdS/ZnS Core/Shell/Shell Quantum Dots is synthesized of using a different surfactant, which is a mixture of octa decyl phosphonic acid (ODPA) and Oleic Acid (OA). An interfused CdSe//ZnS core formation was generated, which showed a significant blue shift from CdSe QDs. The interfused core showed the maximum QY. The CdSZnS shell favourably resulted in a significant red-shift in PL is useful for the fabrication of high power white blight LEDs

Colloidal-electrochemical fabrication strategies for functional composites of linear polyethylenimine

Colloidal-electrochemical fabrication strategies have been developed for the deposition of linear polyethylenimine (LPEI) composite materials. Electrophoretic deposition (EPD) allowed for the fabrication of composite films containing Mn3O4 and ZnO nanoparticles, as well as advanced flame retardant materials, such as halloysite nanotubes and memory-type Al-Mg-Zr complex hydroxide (AMZ) in the matrix of the water-insoluble LPEI. A liquid-liquid extraction method has been designed for the agglomerate-free processing of AMZ particles. Efficient extraction was achieved using decylphosphonic acid as an extractor. A conceptually new polymer complex (PC)-EPD method has been developed, which is based on the use of LPEI-metal ion complexes. Proof-of-concept studies involved the fabrication of LPEI-Ni(OH)2 and LPEI-MnOx nanocomposites. The composites showed valuable flame retardant and charge-storage properties. The analysis of basic EPD and PC-EPD mechanisms as well as complexing properties of LPEI has driven the development of new strategies for the fabrication of organic composites. Hemoglobin was used as a model protein for the fabrication of composite films. Another important finding was the fabrication of composites, containing cyclodextrin, which is a unique carrier of various functional organic molecules. EPD and PC-EPD are versatile methods, which allow for the deposition of novel LPEI based composites containing various functional materials.

Partial Transformation of Imogolite by Decylphosphonic Acid Yields an Interface Active Composite Material.

The phosphonic acid moiety is commonly used as an anchoring group for the surface modification of imogolite. However, the impact of the reaction on its structure has never been clearly analyzed before. We study the reaction of imogolite and decylphosphonic acid by combining infrared spectroscopy, X-ray scattering, scanning electron microscopy, transmission electron microscopy, and solid-state nuclear magnetic resonance spectroscopy. Instead of a surface functionalization, we observe the formation of a lamellar phase interconnected with imogolite bundles. Although we find no evidence for grafted imogolite tubes, we observe the expected dispersion characteristics and stabilization of water in toluene emulsions described in the literature. Based on the surface chemistry of imogolite, we propose an explanation for the observed reactivity and link the structural features of the obtained composite material to its dispersibility in toluene and its observed properties at the toluene-water interface.

Adsorption from Neutral Solutions of Sodium Alkyl Phosphonates on Zinc and Its Passivation

Ellipsometry is used to study the adsorption of the sodium salt of decyl phosphonic acid (SDP) on zinc in a borate buffer solution with pH 7.4. It is found that adsorption of SDP is described by the Tyomkin equation on both oxidized and reduced zinc surfaces, and its adsorption activity on the reduced surface is higher. The inhibiting effect the sodium salt of dodecyl phosphonic acid (SDDP) has on zinc is studied in a chloride-containing borate buffer solution with pH 7.4. It is shown that SDDP has better passivating ability than SDP. The passivating effect of SDDP depends on a certain threshold concentration of the inhibitor. Increasing the alkyl phosphonate concentration and the duration of electrode conditioning in the solution enhances the protective properties of films formed when it is present on zinc.

Route to Universally Tailorable Room-Temperature Liquid Metal Colloids via Phosphonic Acid Functionalization

Eutectic gallium–indium nanoparticles (EGaIn NPs) were produced and subsequently functionalized with decylphosphonic acid under various conditions with the goal of producing highly stable room-temp...

Synthesis and characterization of decyl phosphonic acid, applications in emulsion polymerization and anti-corrosion coating

Alkyl phosphonic acids are amphiphilic structures consisting of non-polar organic hydrophobic groups and anionic inorganic hydrophilic groups, which makes them be able to behave as surfactants as well as smart corrosion inhibitors. A simple and high yield (up to 87%) pathway for synthesizing decyl phosphonic acid (DPA) is described. 1H and 13C-NMR) as well as FTIR spectroscopy were used to characterize chemical structures and purity of the obtained product. Thermal properties and crystal structure of DPA were investigated using differential scanning calorimetry analysis (DSC) and thermogravimetric analysis (TGA). The stability of DPA in Oil-in-Water (O/W) and Water-in-Oil (W/O) emulsions was improved in the presence of ammonium persulfate (APS), which allowed us to measure their specific characteristics such as particle size and zeta potential (ξ) of micelles. Both emulsions were used for synthesizing polyaniline (PANI) by emulsion polymerization. Wettability of DPA on the mild steel surface was examined using contact angle measurements. Moreover, corrosion-inhibition properties studied by using electrochemical impedance spectroscopy (EIS) technique and salt spray test results revealed that DPA can be an efficient ingredient for anti-corrosion coating.

Adsorption kinetics of phosphonic acids and proteins on functionalized Indium tin oxide surfaces using electrochemical impedance spectroscopy

Phosphonic acids (PAs) are known to have a spontaneous affinity for chemisorption onto several metal oxide surfaces. The self – assembled monolayer (SAM) of phosphonates provides a platform for further surface modifications using biomolecules that can be adopted for the development of sensors and biosensors. With this in view, we studied adsorption kinetics of different phosphonic acids of short chain lengths such as phosphonopropionic acid (PPA), aminobenzylphosphonic acid (ABPA), benzylphosphonic acid (BPA), butylphosphonic acid (BuPA), and a long chain decylphosphonic acid (DecPA) on ITO surface using electrochemical impedance spectroscopy (EIS) at short and long time scales. The dependence of solution concentration on formation kinetics is studied and the existences of two discrete kinetics were revealed. We show from our studies that the rate of adsorption is controlled by diffusion at small time scales. Further, the phosphonic acid modified surface is also used as a substrate for the adsorption of cytochromeC (CytC) (a heme protein) and urease (an enzyme) and the kinetics of their adsorption has been studied.

Aqueous dispersion of multiwall carbon nanotubes with phosphonic acid derivatives

The dispersing power of different phosphonic acid (PA) surfactants on multiwalled carbon nanotubes (MWCNTs) was examined: benzylphosphonic acid (BPA), hexylphosphonic acid (HPA) and decylphosphonic acid (DPA). UV-vis absorbance, transmission electron microscopy and zeta potential were employed to characterize the dispersion of MWCNTs in the aqueous phase. Among the three surfactants, DPA provided maximum dispersion stability while BPA and HPA provided minimum dispersion stability. We have shown that there exists an optimum weight ratio of surfactant to MWCNT of 1.5-1 for the effective dispersion of MWCNTs. The-potential values of the DPA-nanotube dispersion increased as the DPA concentration increased to reach a maximum value of-62 mV. The long hydrophobic chain of DPA was found to play a central role for the formation of stable MWCNT dispersions. The DPA-modified MWCNTs dispersions were used for the preparation of waterborne anticorrosive coatings. DPA-modified MWCNTalkyd coatings offers better corrosion protection to steel compared with the surfactant-free coating. The positive effect of DPA on the anticorrosion performance of MWCNT-alkyd coatings was related to its dispersing power on MWCNT and to its corrosion inhibitive properties. (C) 2016 Elsevier B.V. All rights reserved.

Assembly of polyaniline nanotubes by interfacial polymerization for corrosion protection.

Polyaniline (PANI) was synthesized by the oxidation of aniline with ammonium peroxydisulfate as an oxidant in an immiscible organic/aqueous biphasic system and with decylphosphonic acid (DPA) or benzylphosphonic acid (BPA) in the aqueous phase. Nanofibers of aniline oligomers were produced using BPA in the aqueous phase while high quality polyaniline nanotubes were produced using DPA in the aqueous phase. PANI nanotubes have a outer diameter 160-240 nm, an inner diameter of 50-100 nm and a length of the order of several μm. The understanding of the formation of PANI nanotubes was examined by isolation of reaction intermediates and their ex situ characterization by atomic force microscopy. The roles of BPA and DPA on the morphology formation of the PANI nanostructures were discussed. A nanofibrillar template produced by aniline oligomers was found to guide the growth of PANI to nanotubular morphology. PANI nanotubes are thus not derived from DPA vesicles. Preliminary corrosion tests exhibit high corrosion protection efficiency of PANI nanotubes because of their high surface area and corrosion inhibitive properties of DPA dopant.

Determination of Homopolymerization Kinetics of 10‐(N‐Methylacrylamido)‐decylphosphonic acid, Its Diethyl ester, and 10‐(Methacryloyloxy)‐decylphosphonic acid, and Their Copolymerization with Methyl methacrylate

Two polymerizable phosphonic acids destined to be constituents of self‐etch adhesives as well as a diethyl phosphonate bearing an N‐methylacrylamide group are examined for their polymerization and copolymerization activity in methanol between 45 and 65 °C. Polymerization proceeds readily through a thermal free radical initiator. The intensity exponents for the monomer and initiator are only slightly over 1 and ≈0.5, respectively, in accordance with the results typically observed for an ideal free radical polymerization with bimolecular termination. The specific feature of this process is the absence of auto‐acceleration during the phosphonic acid monomer polymerization and polymer network formation in case of the phosphonate monomer. The kinetics of copolymerization with methyl methacrylate (MMA) are monitored by online 1H NMR spectroscopy. Two copolymerization reactions for each pair of comonomers are sufficient to evaluate the kinetic data using the Jaacks method, the Fineman–Ross method, and the nonlinear least squares method. All three methods give similar results for particular monomer/MMA couples. image

Monomers for adhesive polymers, 17.a Synthesis, photopolymerization and adhesive properties of polymerizable phosphonic acids bearing urea groups

Four polymerizable phosphonic acids bearing urea groups 4a, 4b, 9a, and 9b as well as the 10-(methacryloyloxy)decylphosphonic acid 10 were synthesized in four to six steps. They were characterized by 1H, 13C, and 31P NMR spectroscopy and by high-resolution mass spectroscopy. Contrary to methacrylates 4a and 4b, methacrylamides 9a and 9b were hydrolytically stable in deuterated water/deuterated ethanol solutions. The photopolymerization behavior of acidic monomers 4a, 4b, 9a, 9b, and 10 and their corresponding phosphonates were studied using a differential scanning calorimeter. Homopolymerizations and copolymerizations with N-butyl-N-ethylacrylamide were carried out. The presence of a urea group was found to significantly increase the rate of polymerization. Monomers bearing a phosphonic acid group were more reactive than their corresponding phosphonates. Self-etch adhesives based on monomers 4a, 4b, 9a, and 9b were able to provide a strong bond between a composite and the dental hard tissues (dentin and enamel). The presence of a urea group led to a significant increase in the shear bond strength to both dentin and enamel.

Influence of modification time and high frequency ultrasound irradiation on self-assembling of alkylphosphonic acids on stainless steel: Electrochemical and spectroscopic studies

Self-assembly of alkylphosphonic acids on stainless steel was investigated under different conditions. Four different alkylphosphonic acids exhibiting alkyl chain of various size were synthesized and studied: butylphosphonic acid (C4P), octylphosphonic acid (C8P), decylphosphonic acid (C10P), and hexadecylphosphonic acid (C16P). Electrochemistry experiments were extensively carried out in order to determine electrochemical surface blocking of adsorbed layers in function of grafting time. In term of surface blocking, an 8h modification time was optimal for all alkylphosphonic acids. Longer immersion times lead to degradation of adsorbed layers. For the first time, grafting of C16P was studied under high frequency ultrasound irradiation. Interestingly, grafting process is highly accelerated under sonication and well-covering C16P modified substrates are obtained after 1h of immersion under ultrasound irradiation. This would allow to elaborate high-quality alkylphosphonic acids modified samples within much shorter times. Water contact angles measurements and X-ray Photoelectrons Spectroscopy (XPS) confirmed presence of adsorbed alkylphosphonic acids on stainless steel surface. A very tight link between electrochemical blocking, surface hydrophobicity and species chemical grafting was established.

Synthesis and characterization of polyaniline nanoparticles in phosphonic acid amphiphile aqueous micellar solutions for waterborne corrosion protection coatings

ABSTRACTPolyaniline (PANI) dispersions consisting of 270 to 380 nm sized particles were prepared by oxidation with ammonium peroxydisulfate (APS) in n‐decylphosphonic acid (DPA) micellar solutions. The green dispersions do not undergo macroscopic precipitation for more than a year. The synthesized DPA doped PANI exhibited enhanced electrical conductivity (3.6 S cm−1) compared with DPA‐PANI (2.3 x 10−4 S cm−1) prepared by postsynthesis treatment of the PANI‐base with DPA. It was shown that through protonation with decylphosphonic acid, polyaniline showed a significantly enhanced solubility in common organic solvents like chloroform, xylene, etc. The synthesized PANI was characterized by intrinsic viscosity, solubility, FT‐IR, conductivity, SEM, and TGA measurements. The wide‐angle X‐ray diffraction study revealed the appearance of a peak located at low angles (d = 29.4–35.3 Å) suggesting the formation of layered structure of PANI backbone separated by long alkyl side chains of DPA. The anticorrosive performance of the bilayer coatings composed of a bottom layer of DPA doped polyaniline covered with a polyvinyl butyral topcoat, have been demonstrated for steel exposed to neutral saline solutions. It was found that the inhibitive properties of DPA dopant provides further protection to the base metal through smart release when damage is produced on the surface of the coating. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1606–1616

Preparation and characterization of polyaniline in reversed micelles of decylphosphonic acid for active corrosion protection coatings

Polyaniline (PANI) was synthesized by using ammonium peroxodisulfate as an oxidant in reversed micellar solutions consisting of decylphosphonic acid (DPA) and water in a 2:1 mixture (v/v) of heptane and chloroform. The polymerization rate increased as the DPA concentration in the feed decreased, and this result was explained based on the packing density of DPA molecules in the surfactant shell being a decisive factor affecting the diffusion of aniline into the inner water cavity. The synthesized PANI was characterized by intrinsic viscosity, solubility, FTIR, conductivity SEM and TGA measurements. PANI prepared in reversed micelles of DPA demonstrated conductivity increased by three orders of magnitude when compared with DPA doped PANI prepared by postsynthesis treatment of the PANI-base with DPA. The anticorrosive performance of a polyvinyl butyral resin loaded with 2wt% of DPA PANI was tested on steel by exposure of the coated metal to neutral saline conditions (salt spray and immersion in 3.5% NaCl solution). The corrosion process was monitored by measuring the concentration of the iron ions released to the corrosive media and by electrochemical impedance spectrometry. The results demonstrated that the efficiency of protection increases with the doping level of DPA PANI pigments.

The effect of functional monomer chain spacer length on the bond strength of an experimental dental adhesive

The study evaluated the effect of the carbon-chain spacer of monomers on the bonding effectiveness of two-step self-etching adhesive systems (SES). We investigated three acrylamidophosphonic acid monomers which vary only by the length of the carbon chain, 2-(N-methylmethacrylamido)ethylphosphonic acid, 6-(N-methylmethacrylamido)hexylphosphonic acid and 10-(N-methylmethacrylamido)decylphosphonic acid, on their effect in bonding performance while formulated in a self-etching primer with dentin and enamel. The results correlated well with those obtained from Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM).It is concluded that there are no significant differences in terms of immediate Shear Bond Strength (SBS) on either enamel or dentin by using experimental self-etching primer (SEP) of different spacer chain length.

Monomers for adhesive polymers: 11. Structure-adhesive properties relationships of new hydrolytically stable acidic monomers

The synthesis of six new hydrolytically stable acidic monomers is described. Those monomers are N,N-disubstituted acrylamides bearing either a phosphonic acid group or a diphosphonic acid group. They were fully characterized using 1H NMR, 13C NMR and 31P NMR spectroscopy and high-resolution mass spectrometry. The copolymerization of each acidic monomer with N,N′-diethyl-1,3-bis(acrylamido)propane was investigated using photo-differential scanning calorimetry. Self-etching enamel–dentin adhesives were formulated and evaluated in terms of both dentin and enamel adhesion. The influence of the monomer structure (nature of either the spacer or the acidic group, nature of the acrylamide substitution) on the adhesive properties is discussed. The adhesives based on 10-(N-ethylacrylamido)decylphosphonic acid and 10-(N-methylacrylamido)decylbisphosphonic acid are able to achieve a strong bond between a dental composite and both dentin and enamel. © 2013 Society of Chemical Industry

Effect of Interfacial Engineering in Solid‐State Nanostructured Sb2S3 Heterojunction Solar Cells

Surface treatment by decyl-phosphonic acid (DPA) reduces the recombination and increases the open circuit voltage and the fill factor of the inorganic–organic Sb2S3 hetrojunction solar cell. It is revealed that the DPA attaches to both surfaces, the uncovered TiO2 surface and the Sb2S3 surface. This cell produces a power conversion efficiency of 3.9% under 1 sun intensity.