Monoalkyl Phosphates Research Articles

Fe3+-crosslinked alkyl phosphate ester as thickener for oil-based fracturing fluids

To reduce damage to the formation of water locking and water sensitivity causing poor fracturing effect during the fracturing by water-based fracturing fluid in shale oil and gas reservoirs, the oil-based fracturing fluid as anhydrous fracturing fluid were prepared with dialkyl phosphate (PO(OH)(OR)(OR’)) as gelling agent, complexed iron ion solution as activating agent, n-hexane or kerosene as base fluid. The dialkyl phosphate was synthesized by two-step processes. In the first step, the optimal reaction conditions for preparing monoalkyl phosphate intermediate were the reaction time 5 h, reaction temperature 85 °C, molar ratio of triethyl phosphate to phosphorus pentoxide 3.4:1. In the second step, the optimal synthesis conditions for preparing dialkyl phosphate esters were the reaction time 4 h, reaction temperature 80 °C, molar ratio of the intermediate monoalkyl phosphate esters to the mixed alcohol 1:1.4. Complexed iron ion solution as activating agent was prepared by a consisting of 30 wt% trisodiun citrate, 10 wt% ethanediol, 30 wt% ferric sulfate (Fe2(SO4)3) and 30 wt% deionized water. The effects of gelling agent, activating agent and based fluid on oil-based fracturing fluid performance were examined. The experiments showed that with the increase of gelling agent dosage, the gelation time was significantly shortened and the viscosity gradually increased. When the amounts of gelling agent and activating agent were 2.5 wt% and 4 wt%, respectively, the gelling time and the viscosity of fracturing fluid was up to 166 s and 450 cP. The viscosities of the fracturing fluid were always greater than 100 cP after it was sheared by shear rate of 170 s−1 for 1 h at 80 °C, indicating that the fracturing fluid have good shearing resistance and temperature resistance. The viscosity of the fracture fluid with n-hexane as based fluid was 1.32 cP at 70 °C when the sodium acetate as broken gent was 0.40 wt%, thus the broken gelation effect was remarkable. And the core damage rate of prepared oil-based fracturing fluid was also much lower than that of the common water-based fracturing fluids.

Thermolabile Organotitanium Monoalkyl Phosphates: Synthesis, Structures, and Utility as Epoxidation Catalysts and Single-Source Precursors for TiP2O7.

The reaction of [Cp*TiCl3] (Cp* = C5Me5) with monoalkyl phosphates (RO)PO3H2 (R = Me, Et, and iPr) in tetrahydrofuran (THF) at 25 °C leads to the formation of binuclear complexes [Cp*2Ti2(μ-O2P(OH)OR)2(μ-O2P(O)OR)2] [R = Me (1), Et (2), and iPr (3)]. On the other hand, the reaction of ( tBuO)2PO2K with [Cp*TiCl3] in acetonitrile or THF results in isolation of either the dinuclear [Cp*2Ti2(μ-O2P(OH)O tBu)2(μ-O2P(O)O tBu)2] (4) or the trinuclear titanophosphate [Cp*3Ti3(μ-O3PO tBu)2(μ-O)2(μ-O2P(O tBu)2)] (5), respectively. The formation of compounds 4 and 5 is facilitated by partial hydrolysis of the tert-butoxy groups of ( tBuO)2PO2K. New titanophosphates 1-5 have been characterized by spectroscopic and analytical methods, and the molecular structures have further been confirmed by single-crystal X-ray diffraction studies. Thermal decomposition studies of 1-5 reveal the initial loss of thermally labile alkyl substituents of the organophosphate ligands, followed by the loss of C5Me5 groups to form an organic-free amorphous titanophosphate in the temperature range 300-500 °C. This material transforms to highly crystalline titanium pyrophosphate TiP2O7 at 800 °C. Compounds 1-5 and the TiP2O7 materials obtained at 300, 500, and 800 °C through the thermal decomposition of 3 have been employed as efficient homogeneous catalysts for the alkene epoxidation reaction. Using hydrogen peroxide as the oxidant in an acetonitrile medium, these catalysts exhibit >90% alkene conversion with >90% epoxide selectivity in 4 h at temperatures below 100 °C.

The synthesis of mono-alkyl phosphates and their derivatives: an overview of their nature, preparation and use, including synthesis under plausible prebiotic conditions.

Nucleic acids, phospholipids and other organic phosphates play central roles in biological pathways. n-Alkyl phosphates and their derivatives have been recognized as amphiphilic molecules for nearly two centuries. In the last 50 years, n-alkyl phosphate derivatives such as di-alkyl phosphates, mono-alkyl phosphatidyl ethanol amines and mono-alkyl phosphocholines have become predominant compounds with applications in different areas, from food chemistry to life science. The aim of this review is to summarize the most relevant progress made in the field of the synthesis of these molecules and to provide a concise perspective on the use of these amphiphiles as possible prebiotic membrane constituents. The first part of the review is dedicated to the analysis of the most relevant syntheses carried out in recent years with respect to those reported from the second half of the nineteenth century. The second part is dedicated to a description of the latest reports on prebiotic synthesis of mono-alkyl phosphates. In this part, the authors did not report the phosphorylation of other relevant biomolecules, such as nucleosides, which have been excellently reviewed elsewere.

Manipulation of partially oriented hydroxyapatite building blocks to form flowerlike bundles without acid-base regulation

The application of hydroxyapatite (HAP) in different fields depends greatly on its morphology, composition and structure. Besides, the main inorganic building blocks of human bones and teeth are also HAP. Therefore, accurate shape and aggregation control and of hydroxyapatite particles will be of great interest. Herein, oriented bundles of flowerlike HAP nanorods were successfully prepared through hydrothermal treatment without acid-base regulation, with the mono-alkyl phosphate (MAP) and sodium citrate as surfactant and chelating agent, respectively. The prepared samples were characterized by the X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and zeta potential, the pH value and conductivity value of suspension were characterized by pH meter and conductivity measurement. The results showed that the MAP and citrate play an important role in assembly of HAP nanorods without acid-base regulation. Citrate calcium complex could decompose slowly and release citrate ions at hydrothermal conditions. Besides, the further decomposition of citrate ions could release aconitic acid as the reaction time prolongs. Moreover, the possible scheme for the formation process was discussed in detail.

Corrosion Inhibition of Iron in Acidic Solutions by Monoalkyl Phosphate Esters with Different Chain Lengths

The inhibition effect of three amphiphilic monoalkyl phosphate esters with different chain lengths—mono-n-butyl phosphate ester (BP), mono-n-hexyl phosphate ester (HP), and mono-n-octyl phosphate ester (OP)—on the corrosion of iron in 0.5 M H2SO4 solutions was investigated by using electrochemical impedance spectroscopy (EIS) and polarization curve methods. The electrochemical results indicate that BP, HP, and OP all acted as mixed-type corrosion inhibitors with a dominant cathodic effect. BP shows the lowest inhibition efficiency as compared to HP or OP. However, the inhibition efficiency of HP is almost the same with that of OP under similar conditions because the molecular aggregation state at the iron/solution interface plays a more important role. X-ray photoelectron spectroscopic (XPS) characterization demonstrates that three alkyl phosphate esters adsorbed on the iron surface through the un-ionized P–OH groups. The adsorption of BP, HP, and OP fitted well with the Langmuir model.

Controllable self-assembly of mesoporous hydroxyapatite

In this paper, mesoporous hydroxyapatite (HAp) of controllable pore size was tailored with the template of a biodegradable mono-alkyl phosphate (MAP) via a simple route by hydrothermal treatment. A serial study of the various experimental parameters on pore size of HAp was investigated. The additive amount of MAP and hydrothermal temperature were important factors for the pore structure and pore size. Powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and nitrogen adsorption–desorption (BET, BJH) were used to characterize the structure and composition of the HAp samples. Both XRD and BJH results indicated that regular mesoporous HAp nanoparticles (with a mean pore size of 3.5nm) were successfully produced. As shown in transmission electron microscopy (TEM), orderly uniform pore structure appeared in the HAp particles. Because of the special structure of the MAP and the interaction between ionized MAP and other ions in solution, the product presents uniform mesoporous structure with well-defined pore size.

高純度長鎖モノアルキルリン酸塩の特異な会合挙動

界面活性剤などの両親媒性物質が形成する自己組織体は学術的にも工業的にも利用価値が高く、多くの研究がなされている。近年、従来は不安定であると考えられていたαゲルが多くの注目を集め、様々な研究が行われている。 我々も新たにαゲルを構築しうる素材の開発を進め、その結果、モノアルキル純度を高めたアルキルリン酸が中和剤の選択により非常に安定なαゲルを構築することを見出した。 本稿では特に化粧品分野で行われてきたαゲルの研究例を示しながら、我々が見出したαゲル形成素材について述べる。

直鎖型モノアルキルリン酸エステルの特異な会合挙動と化粧品への応用

直鎖型モノアルキルリン酸エステルの特異な会合挙動と化粧品への応用

A Novel Dumbbell-like Polyoxometalate Assembled of Copper(II)-Disubstituted Monovacant Keggin Polyoxoanions with a Tetranuclear Copper Cluster

A dimeric Keggin polyoxometalate, [Cu(bpy)(μ2-OH)]4[(H2O)(bpy)2HPW11Cu2O39]2·2CH3CH2OH·10H2O (1), constructed from two dicopper(II)-substituted monovacant Keggin polyoxoanions bridged by a Cu4 cluster, has been hydrothermally synthesized. Magnetic analysis indicates predominantly an antiferromagnetic interaction between copper(II) centers. Compound 1 also shows very high catalytic activity for the esterification of phosphoric acid with equimolar lauryl alcohol to monoalkyl phosphate ester.

The Effect of Monoalkyl Phosphates and Fluoride on Dissolution of Hydroxyapatite, and Interactions with Saliva

The aims were to investigate the effect of monoalkyl phosphates (MAPs) and fluoride on dissolution rate of native and saliva-coated hydroxyapatite (HA). Fluoride at 300 mg/l (as NaF) inhibited dissolution of native HA by 12%, while potassium and sodium dodecyl phosphates (PDP, SDP), at 0.1% or higher, inhibited dissolution by 26-34%. MAPs, but not fluoride, also showed persistence of action. MAPs at 0.5% and fluoride at 300 mg/l were then tested separately against HA pre-treated with human saliva for 2 or 18 h. Agents were applied with brushing to half the specimens, and without brushing to the other half. In control (water-treated) specimens, pre-treatment of HA with human saliva reduced dissolution rate on average by 41% (2 h) and 63% (18 h). Brushing did not have a statistically significant effect on dissolution rate of saliva-coated specimens. In brushed specimens, fluoride significantly increased the inhibition due to 2- or 18-hour saliva pre-treatment. It is hypothesised that brushing partially removes the salivary film and allows KOH-soluble calcium fluoride formation at the surfaces of HA particles. Inhibition was reduced by PDP in 2-hour/non-brushed specimens and in 18-hour/brushed specimens. PDP did not affect dissolution rates in the remaining groups and SDP did not affect dissolution rate in any group. Possible reasons for these variable results are discussed. The experiments show that pre-treatment with saliva can significantly modify results of tests on potential anti-erosive agents and it is recommended that saliva pre-treatment should be a routine part of testing such agents.

Precipitate Deposition around CMC and Vesicle-to-Micelle Transition of Monopotassium Monododecyl Phosphate in Water

Monoalkyl phosphate (MAP) salts are a kind of bivalent anionic surfactants. The difference of properties between half-neutralized monosalt and completely neutralized disalt is very interesting. In this study, the aggregation behavior of monopotassium monododecyl phosphate (MAP-12K) in aqueous solution with an increase in concentration was investigated by surface tension (γ), elemental analysis, gas chromatography, differential scanning calorimetry, steady-state fluorescence, and negative strained transmission electron microscopy techniques. MAP-12K aqueous solution showed some characteristics: (I) Vesicle aggregates were formed at very dilute concentration (1.2 mM). (II) The precipitate of a highly hydrophobic dimer of MAP, which was quaternary neutralized by potassium, was generated only in a certain dilute concentration region (2.7-200 mM) around the critical micelle concentration (cmc = 20 mM). (III) Vesicles spontaneously translate into micelles at the cmc. (IV) In the higher concentration above 200 mM, the solution becomes homogeneous micellar solution. All of these uncommon characteristics are thought to be caused by the generation of the dimer, which is much more hydrophobic than dissolved MAP derivatives, in the complicated chemical equilibria based on the weakly acidic character of MAP. MAP-12K aqueous solution behaves as if it is a binary mixed surfactant solution of hydrophobic dialkyl surfactant and hydrophilic monoalkyl surfactant in spite of a single component solution.

Determination of 14 monoalkyl phosphates, dialkyl phosphates and dialkyl thiophosphates by LC-MS/MS in human urinary samples

Human urine was analyzed for nine dialkyl (DAP) and five monoalkyl phosphates (MAP) by LC-MS/MS. Some phosphoric acid esters are industrial chemicals and other hydrolysis products of trialkyl or triaryl phosphates, used as pesticides, flame retardants or plasticizers. Five MAP and two DAP were detected here for the first time in human urine. Monobutyl, diethyl, diphenyl and diethylhexyl phosphate were determined with median concentrations in the μg/L-range. The total urinary concentration of the 14 DAP and MAP summed up to a median of 20 μg/L. Inclusion of MAP in future biomonitoring studies should provide a more comprehensive picture of the exposure of humans to organophosphorus compounds.

ChemInform Abstract: Effects of Monoalkyl Phosphate Surfactants Upon the Acid Hydrolysis of Dioxolanes.

The pseudophase ion-exchange (PPIE) model was tested in the presence and absence of buffer for the acid-catalyzed hydrolysis of 2-(p-methoxyphenyl)-1,3-dioxolane (p-MPD) and 2-(2,4-dimethoxyphenyl)-2-ethyl-1,3-dioxoloane (2,4-DPED) in the presence of sodium monoalkyl phosphate surfactants. The maximum increase in the observed rate constant was about 10-fold for both substrates

Synthesis of Amphoteric Phosphate Ester Surfactant by Polyphosphoric Acid and Its Application in Free-Chrome Collagen Fiber

In order to avoid using P2O5 as phosphorylation reagent in phosphorylation reaction, an amphoteric phosphate ester surfactant was synthesized by using polyphosphate acid as phosphorylation reagent. The phosphorylation reaction studies confirmed the best condition was molar ratio of hydroxyl and P2O5 of 3.0:1.0, reaction temperature of 80°C and reaction time of 5.5h. The content of monoalkyl phosphate (MAP) and the conversion rate reached to 89.3% and 97.2%, respectively. The production of MAP product was increased by 15% than that of obtained by P2O5 as phosphorylation reagent. The structure of the phosphate ester surfactant was characterized by FTIR. The surface tension of phosphate ester surfactant was better than that of dodecyl trimethyl ammonium bromide and sodium dodecyl sulfate. The application results indicated the leather oiled by the amphoteric phosphate surfactant was softer and than that treated by L-3 fatliquor.

Synthesis of High Purity Mono‐Alkyl Phosphate Using Cyclic Polyphosphoric Acid

The uniform design method was used to study the synthesis of high purity mono-alkyl phosphate (MAP) by cyclic polyphosphoric acid. The main factors influencing the content of mono-alkyl phosphate were investigated. The experimental results were analyzed by regression, and the optimum conditions were found to be as follows: mass pentoxide/mass 85 wt% phosphoric acid/mass octanol = 14.2/5.62/48.5, reaction temperature: 115°C, reaction time: 8 h. Under the optimized conditions, a high purity mono-alkyl phosphate with 98.6 wt% MAP yield was obtained.

Esterification of Phosphoric Acid with Equimolar Lauryl Alcohol Catalyzed by a Schiff Base Manganese Complex Anchored to a Keggin Heteropolyacid

Abstract Inorganic-organic hybrids were prepared by combining Schiff base complexes of manganese with silicotungstic acid (SiW). The composition and structure of the hybrid L1-Mn-SiW (L1: N,N′-disalicylidene-1,6-hexanediamine) were characterized by infrared spectroscopy and thermogravimetry. They were used as solid catalysts in the esterification of phosphoric acid with equimolar lauryl alcohol to monoalkyl phosphate ester (MAP). Over the L1-Mn-SiW catalyst, the yield and selectivity for MAP were 93% and > 98%, respectively, at the optimal reaction conditions. The catalyst exhibited excellent recoverability during a six-cycle test without any observable change of the catalyst structure. A base-catalyzed reaction route was proposed.

Potentially Prebiotic Passerini-Type Reactions of Phosphates

Monoalkyl phosphates can take the place of carboxylic acids in the Passerini reaction, but excesses of aldehyde and isonitriles are required, and transfer of the phosphate to the newly formed hydroxyl group does not take place. By rendering the phosphate addition intramolecular, the efficiency of the reaction is substantially increased. Phosphate transfer can take place when cyanovinyl phosphate is used rather than a monoalkyl phosphate.

Facile synthesis of simple mono-alkyl phosphates from phosphoric acid and alcohols

Simple aliphatic alcohols can be selectively converted into mono-alkyl phosphate esters at the laboratory scale using the acetic anhydride-mediated activation of inorganic phosphate.

Synthesis and properties of geminis with two alkyl and two phosphate headgroups

AbstractAmphipathic compounds having two phosphate groups and two long‐chain alkyl groups were prepared by a two‐step process: (a) preparation of monoalkyl phosphate from pyrophosphoric acid and dodecanol, (b) preparation of bis‐phosphoric acid from monoalkyl phosphate, (CH3)4NOH and 1,6‐dibromo hexane by using acetonitrile as solvent. The experimental results showed that a 5 : 10 : 2.5 molar ratio of reactants (alkyl phosphate/(CH3)4NOH/1,6‐dibromo hexane) and 3 h duration was the optimum for the reaction. The structure of the synthesized product was verified by analytical methods, viz. FT‐IR and 1H‐NMR. The surface‐active and performance properties like foaming, wetting and anionic content of the disodium salt of bis‐phosphoric acid were also evaluated. The synthesized anionic gemini surfactants possessed maximum anionic content, i.e. 73.4%, and showed better water solubility, foaming and wetting ability than conventional monoalkyl phosphates.

Preparation and characterization of mesoporous zirconium phosphates from alkyl phosphates

Abstract Zirconium alkyl phosphates (ZrAP) were prepared by the reaction of ZrOCl 2 · 8H 2 O with a mixture of aqueous phosphoric acid solution and monoalkyl phosphates (alkyl = decyl, stearyl) synthesized in the laboratory. All of the ZrAP samples showed X-ray diffraction peaks at diffraction angles below 2 θ = 8°. The calcined powders were mesoporous containing POH groups which were stable at high temperatures, and were crystallized into ZrP 2 O 7 by heating them at temperatures over 960 °C. The pores could be classified into wedge-shaped pores and spaces between parallel plates using small angle X-ray scattering and high-resolution transmission electron microscopy, and the specific surface area was found to be 130–308 m 2 /g by N 2 sorption measurements. A comparison of the materials synthesized under different conditions revealed that the ZrP layers supported by the neighboring particles maintained their layer structure during the calcination procedure performed to remove the alkyl chains.