Application of New Modified Poly(ethylene Oxide)-Block-Poly(propylene oxide)-Block-Poly(ethylene oxide) Copolymers as Demulsifier for Petroleum Crude Oil Emulsion

Water soluble nonionic amphiphilic block copolymers based on hydrophilic poly(ethylene glycol) (PEG) and hydrophobic poly(propylene glycol) (PPG) were prepared. Poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) copolymers, PEG-PPG-PEG, were prepared in the normal condition. The chemical composition and molecular weights of the prepared copolymers were determined from ¹H NMR and GPC techniques. The surface properties of the prepared surfactants were determined by measuring the surface tension at different temperatures. The prepared nonionic surfactants were evaluated as demulsifiers for water in crude-oil emulsions that were pronounced at different ratios of crude oil: water at 318 K and 333 K. The experimental results showed that the dehydration rate of the prepared demulsifiers reached 100% based on demulsifier chemical compositions and concentrations.     

Micellization and Thermogelation of Poly(ether urethane)s Comprising Poly(ethylene glycol) and Poly(propylene glycol)

A series of multiblock poly(ether urethane)s comprising poly(ethylene glycol) (PEG), and poly(propylene glycol) (PPG) segments were synthesized. Their aqueous solutions exhibited thermogelling behavior at critical gelation concentrations (CGC) ranging from 8 to 12 wt%. The composition and structural information of the copolymers were studied by GPC and ¹H NMR. The critical micellization concentration (CMC) and thermodynamic parameters for micelle formation were determined at different temperatures. The temperature response of the copolymer solutions were studied and found to be associated with the composition of the copolymers.     

Water-Based Oil Spill Dispersants Based on Rosin Formaldehyde Resins

Water-soluble surfactants based on rosin acids were synthesized from condensed rosin acid-formaldehyde. This was completed by esterification of series of rosin acid formaldehyde resins with poly(ethylene glycol) having different molecular weights to produce series of rosin esters. The structure of the produced resins was determined by infrared and ¹HNMR analysis. The molecular weight of the produced surfactants was determined by gel permeation chromatography (GPC) technique. The surface properties of the prepared surfactants were determined by measuring the surface tension at different temperatures. The surface tension, critical micelle concentration (CMC), and surface activities were determined at different temperatures. Surface parameters such as surface excess concentration (Γmax), the area per molecule at interface (A_min), and the effectiveness of surface tension reduction (πCMC) were determined from the adsorption isotherms of the prepared surfactants. Some thermodynamic data for the adsorption process were calculated and are discussed. The dispersion efficiency of the prepared surfactants as petroleum oil spill dispersants was determined and correlated with the surface activity, concentrations of the prepared surfactants and type of petroleum crude oil.     

Surface and Thermodynamic Properties of Nonionic Surfactants Based on Rosin-Maleic Anhydride and Acrylic Acid Adducts

Ester-adduct derivatives of rosin were synthesized by reacting rosin maleic anhydride (RMA) or rosin acrylic acid (RAA) adducts with polyethylene glycol 600 (PEG600), 1000 (PEG1000) or 2000 (PEG2000) and at elevated temperature. These derivatives were evaluated for acid number, FTIR spectroscopy, molecular weight (Mw) and polydispersity. The surface properties of the prepared surfactants were determined by measuring the surface tension at different temperatures. The surface tension, critical micelle concentration, and surface activities were determined at different temperatures. Surface parameters such as surface excess concentration (Γmax), the area per molecule at interface (Amin) and the effectiveness of surface tension reduction (πCMC) were determined from the adsorption isotherms of the prepared surfactants. Some thermodynamic data for the adsorption process were calculated and are discussed.     

Surface and Thermodynamic Parameters of Polymeric Surfactants from Recycled Poly(ethylene terephthalate)

Recycling of PET waste was carried out in presence of diethanolamine and manganese acetate as catalyst. The produced oligomers were reacted with stearic acid and polyethylene glycol, PEG, which have different molecular weights 400, 1,000, and 4,000 to produce nonionic polymeric surfactants having different hydrophilic‐hydrophobic balance (HLB). The surface tension, critical micelle concentration (CMC), and surface activities were determined at different temperatures. Surface parameters such as surface excess concentration Γ_max, the area per molecule at interface A_min and the effectiveness of surface tension reduction (Π_CMC) were determined from the adsorption isotherms of the prepared surfactants. From the adsorption isotherm, some thermodynamic data for the adsorption process are calculated and discussed.     

Micellization and Adsorption Parameters of Nonionic Polymeric Surfactants from Poly(ethylene terephthalate) Waste

Poly (ethylene terephthalate), PET, waste was recycled to oligomers in the presence of triethanolamine and manganese acetate as a catalyst. The produced oligomers were reacted with stearic acid and polyethylene glycol having different molecular weights 400, 1000, and 4000 to produce nonionic polymeric surfactants having different hydrophile‐hydrophobe balances (HLB). The surface tension, critical micelle concentration (CMC) and surface activities were determined at different temperatures. Surface parameters such as, surface excess concentration Γ_max, the area per molecule at interface A_min and the effectiveness of surface tension reduction (Π_CMC) were determined from the adsorption isotherms of the prepared surfactants. Some thermodynamic data for the adsorption process are calculated and discussed.     

Application of hydrophobically modified water‐soluble polyacrylamide conjugated with poly(oxyethylene)‐co‐poly(oxypropylene) surfactant as emulsifier

Hydrophobically modified polyacrylamide (PAAm) was prepared by grafting PAAm with block copolymer of poly(ethylene oxide) and poly(propylene oxide), PEO‐PPO‐PEO, by melt method in the presence of benzoyl peroxide as initiator. The chemical structure of the graft copolymer was determined by FTIR and ¹HNMR analyses. The surface tension, critical micelle concentration, and surface activities were determined at different temperatures. Surface parameters such as surface excess concentration (Γ_max), the area per molecule at interface (A_min), and the effectiveness of surface tension reduction (Π_CMC) were determined at different temperatures from the adsorption isotherms of the prepared surfactants. The prepared surfactant was tested as emulsifier for water with xylene, cyclohexane, or petroleum crude oil synthetic emulsions. Copyright © 2010 John Wiley & Sons, Ltd.     

Synthesis and Properties of Nonionic Surfactants from Rosin-Imides Maleic Anhydride Adduct

Ester-adduct derivatives of rosin were synthesized by reacting rosin with polyethylene glycol 600 (PEG 600) or 2000 (PEG2000) and maleic anhydride (MA) at elevated temperature. These derivatives were evaluated for acid number, FTIR spectroscopy, molecular weight (Mw), and polydispersity. The derivatives were soluble in organic solvents; aqueous solubility was pH dependent. Rosin-imides were synthesized from a rosin ester-maleic anhydride adducts. It was condensed with diaminobutane or triethylene tetramine to obtain rosinimides. This imide was etherified by reaction with PEG in the presence of β,β′-dichlorodiethyl ether as a linking agent and NaOH as a catalyst. The surface properties of the prepared surfactants were determined by measuring the surface tension at different temperatures. The surface tension, critical micelle concentration and surface activities were determined at different temperatures. Surface parameters such as surface excess concentration (Γmax), the area per molecule at interface (Amin), and the effectiveness of surface tension reduction (πCMC) were determined from the adsorption isotherms of the prepared surfactants. Some thermodynamic data for the adsorption process were calculated and are discussed.     

Synthesis,micellization properties,and cytotoxicity trends of N-hydroxyethyl-3-alkyloxypyridinium surfactants

N-hydroxyethyl-3-alkyloxypyridinium amphiphiles have been synthesized and characterized by various spectroscopic techniques. Self-assembling properties of these amphiphiles have been studied by surface tension, conductivity, and fluorescence measurements. Basic micellization parameters like critical micelle concentration (cmc), surface tension at the cmc (γ _cmc), adsorption efficiency (pC₂₀), effectiveness of surface tension reduction (Π _cmc), maximum surface excess concentration (Γ _max) and minimum surface area/molecule (A _min), and Gibbs free energy of the micellization (ΔG⁰ _mic) have also been determined. The micellization of these 3-alkyloxypyridinium halides in aqueous phase have been found to be exothermic and entropy-driven as assessed by conductivity measurements at different temperatures. Thermal degradation of these surfactants has also been assessed by thermal gravimetric analysis under nitrogen atmosphere. Further, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay of these surfactants on C6 glioma cells show them to be less toxic than conventional cationic surfactants.     

Surface Activity of Novel Polymerizable Anionic Polyoxyethylene 4-Nonyl-2-Prpylene-Phenyl Ether Ammonium Sulfate Succinate Surfactants

Novel polymerizable surface-active monomers were synthesized by successive treatment of polyoxyethylene 4-nonyl-2-prpylene-phenyl ether ammonium sulfate with maleic anhydride in the presence of hydroquinone at temperature of 180°C. The molecular structures of the polymerizable surfactants were confirmed by ¹H and ¹³C NMR spectroscopy. The surface tension isotherms on the air-water solution interface were obtained. The critical micelle concentrations (cmc) as well as the surface tension at the cmc were determined for these substances. The micellization and adsorption of the prepared anionic surfactants have been investigated by surface tension, and cloud point measurements. Surface parameters such as surface excess concentration (Γ _max), the area per molecule at interface (A _min) and the effectiveness of surface tension reduction (π_CMC) were determined from the adsorption isotherms of the prepared surfactants.      

Salt induced micellization of very hydrophilic PEO-PPO-PEO block copolymers in aqueous solutions

Symmetrical poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide), PEO-PPO-PEO, triblock copolymers with 80% polyethylene oxide (PEO, the hydrophilic end blocks) and polypropylene oxide (PPO, the hydrophobic middle block) usually remain as molecularly dissolved at ambient temperature even at fairly high-concentrations (2 wt.% or more). However, the micellization is induced at lower concentration/temperature in the presence of salts. The results on salt induced micellization from four such hydrophilic copolymers Pluronic^® F38, F68, F88 and F108 obtained from several independent techniques are described. FTIR and fluorescence results provide essentially identical critical micelle temperatures (CMTs) showing marked decrease with increase in PPO molecular weight and in the presence of salt. These copolymers were weakly surface active and did not show a clear break point in surface tension concentration plot typical of surfactants. While addition of salt decreases the cloud point, no significant micelle growth was observed even at temperature close to cloud point (CP). Marked increased in solubilization of an oil dye was observed in presence of KCl. Different methods showed good agreement in temperature/salt-induced micellization of these hydrophilic copolymers.     

Gemini表面活性剂烷烃尾链在吸附和聚集过程中的疏水协同效应(英文)

以表面张力法测定了系列Gemini表面活性剂m-6-m以及对应单体表面活性剂CmTABr的临界胶束浓度(cmc)和降低水表面张力20mN·m-1需要的浓度(pC20).比较这些参数表明m-6-m胶束化和在界面吸附的能力均强于CmTABr,这被归结为Gemini表面活性剂烷烃尾链间的疏水协同效应.与不对称Gemini表面活性剂12-6-m比较,对称的Gemini结构更有利于表面活性剂的聚集和吸附.     

Surface activity and thermodynamic of micellization and adsorption for isooctylphenol ethoxylates, phosphate esters and their mixtures with N-diethoxylated perfluorooctanamide

Three nonionic surfactants; p-isooctylphenol ethoxylates p-[i-OPE10], p-[i-OPE15], and p-[i-OPE20], were phosphorylated to produce three anionic phosphate ester surfactants. In addition, N-diethoxylated perfluorooctanamide (N-DEFOA) was also prepared. The surface and thermodynamic properties of the three types of surfactants and mixtures of the fluorocarbon surfactant (FC) with the hydrocarbon surfactants (HC) have been investigated. Surface tension as a function of concentration of the surfactant in aqueous solution was measured at 30, 40, 50 and 60°C, using the spinning drop technique. From these measurements the critical micelle concentration (CMC), the surface tension at the CMC (γ_CMC), the maximum surface excess concentration (Γ_max), the minimum area per molecule at the aqueous solution/air interface (A_min), and the effectiveness of surface tension reduction (π_CMC), were calculated. The thermodynamic parameters of micellization (ΔG_mic, ΔH_mic, ΔS_mic) and of adsorption (ΔG_ad, ΔH_ad, ΔS_ad) for these surfactants and their mixtures were also calculated. Structural effects on micellization, adsorption and effectiveness of surface tension reduction are discussed in terms of these parameters. The results show that the FC surfactant and its mixtures with HC surfactants enhance the efficiency in surface tension reduction and adsorption in the mixed monolayer at the aqueous solution/air interface, and also, reduce γ_CMC and the tendency towards micellization.     

The effect of amino acids on the surface and thermodynamic properties of poly[oxyethylene(10)] lauryl ether in aqueous solution

The interfacial and thermodynamic properties of a non-ionic surfactant, poly[oxyethylene(10)] lauryl ether, [C₁₂H₂₅(OCH₂CH₂)₁₀OH], in aqueous solution in the presence of amino acids have been investigated. Critical micelle concentrations (cmcs) were determined by surface tension measurements at different additive concentrations and temperatures using a du Nouy tensiometer. From the surface tension data, the surface excess concentration (F), the minimum area per molecule (A_min), and the surface pressure at the cmc(?_cmc) were evaluated. Thermodynamic parameters of adsorption and micellization were evaluated and discussed. The other solution properties of this surfactant like the cloud point viscosity, and foaming have been determined in the presence of different concentrations of alanine and glycine.     

N-酰基-L-丝氨酸钠表面活性剂的合成和胶束化热力学性质

以L-丝氨酸和长链酰氯为原料,合成了3种不同碳链长度（n=8,12,14）的N-酰基-L-丝氨酸。 并以1H NMR、ESI-MS和元素分析对3种目标产物进行了表征。 采用表面张力法研究了N-酰基-L-丝氨酸钠在298、308、318和328 K时水溶液中的聚集行为,确定了临界胶束浓度（cmc）、临界胶束浓度下的最低表面张力（γcmc）、表面饱和吸附量Γmax。 由cmc和温度的关系,应用相分离模型计算了胶束化热力学参数ΔGom、ΔHom和ΔSom。 结果表明,ΔGom＜0,ΔHom的绝对值比-TΔSom绝对值小的多,说明胶束化过程为熵驱动过程,随着温度的升高,胶束化过程是熵-焓补偿的过程。     

Surface activity and thermodynamic properties of water‐soluble polyester surfactants based on 1,3‐dicarboxymethoxybenzene used for enhanced oil recovery

The surface activity and thermodynamic properties for eight low molecular weight nonionic co‐polyester (PE) surfactants have been investigated. Surface and interfacial tensions (IFT) of surfactants in aqueous solutions were measured using the spinning drop technique. From these measurements, the critical micelle concentration (CMC), the surface pressure at CMC (Y_CMC), the maximum surface concentration (Γ_max), the minimum area/molecule at the aqueous solution/air interface (A_min), the effectiveness of surface tension reduction (Π_CMC), the alkane carbon number (n_min) and the IFT at n_min (Y_min) were determined. The thermodynamic parameters of micellization (ΔG_mic, ΔH_mic and ΔS_mic) and of adsorption (ΔG_ad, ΔH_ad and ΔS_ad) for these polymeric surfactants were also calculated. Structural effects on micellization and adsorption are discussed in terms of these parameters. The results show that the ΔG_ad values were more negative than ΔG_mic values for these compounds, so that they favored adsorption before the micellization process. They exhibited IFT in the order of 10⁻³ to 10⁻⁴ mN/m against the thin alkane carbon number range 6–9. This range seemed to be prefered for enhanced oil recovery. Copyright © 2000 John Wiley & Sons, Ltd.     

Synthesis and Surface Properties of N-Alkyl-N-methylgluconamides and N-Alkyl-N-methyllactobionamides

Three series of nonionic N-alkylaldonamides, N-alkyl-N-methylgluconamides (Cn-MGA, Cn: n-C(10)H(21), n-C(12)H(25), n-C(14)H(29), n-C(16)H(33), and n-C(18)H(37)), N-alkyl-N-methyllactobionamides (Cn-MLA, alkyl as above-mentioned), and N-oleyl-N-methylglucon/lactobionamide, were synthesized in the reaction of an appropriate N-alkyl-N-methylamine with delta-D-glucolactone and lactobionic acid, respectively. Krafft temperatures of aqueous solutions and surface properties of these surfactants at 20 degrees C, i.e., surface excess concentration, Gamma(cmc), surface area demand per molecule, A(min), efficiency in surface tension reduction, pC(20), effectiveness in surface tension reduction, Pi(cmc), critical micelle concentration, CMC, and CMC/C(20) parameter as well as standard free energies of adsorption, DeltaG degrees (ads), and of micellization, DeltaG degrees (mic), were determined. It was shown that introduction of the methyl group to the amide nitrogen increased the solubility of the surfactants, which was confirmed by their Krafft temperatures. Lactobionamides are more water soluble than gluconamides. On the other hand, the Cn-MGA surfactants are more surface active than the respective Cn-MLA ones. This observation is based on the determined adsorption and micellization parameters. The presence of one double bond in a hydrocarbon chain as in oleyl-amides increases their hydrophilic character compared with that of saturated C18 derivatives. No distinct differences were observed between the A(min) values obtained for both series studied, although they differ markedly in the size of the hydrophilic groups. Copyright 2001 Academic Press.     

Thermodynamics of Adsorption and Micellization of Triblock Copolymers of Oxyethylene and Oxybutylene in Aqueous Medium Using Surface Tensiometry

The aqueous solutions of three triblock copolymers based on polyoxyethylene and polyoxybutylene of the type E_mB₁₀E_m have been analyzed by surface tension measurements. Surface activity of these triblock copolymers was studied by measuring surface parameters, like surface excess concentration, Γ₂, area per molecule of polymer and standard Gibb's free energy of adsorption, Δ^oG_ads, at various temperatures in the range of 20 to 50°C. The Effect of block length of hydrophilic portion of triblock copolymers on surface activity was investigated in this work. Miceller behavior of these triblock copolymers was also investigated using above technique. Critical micelle concentration (CMC) was determined from the plot of surface tension versus log of concentration in the range of temperature of 20–50°C. Thermodynamic parameters, standard free energy of micellization, Δ^oG_mic, standard enthalpy of micellization, Δ^oH_mic, and standard entropy of micellization, Δ^oS_mic were calculated from CMC value using closed association model in this range of temperature. Self assembly behavior of triblock copolymer E₂₀B₁₀E₂₀ was compared with E₃₀B₁₀E₃₀ and E₄₈B₁₀E₄₈ triblock copolymer. Effect of temperature on surface and miceller properties of the triblock copolymers was also studied.     

Synthesis and Surface Properties of Novel N-Alkyl Quinoline-Based Cationic Gemini Surfactants

Two series of cationic dimeric (gemini) surfactants are prepared with respect to key surfactants properties, such as surface activity and solubilization. The influence of both the dimerization and the spacer group is examined in order to establish structure-property relationships. The surface tension and critical micelle concentration can be markedly reduced compared to the monomeric surfactants in the pure state. The critical micelle concentration (cmc) of each series has been determined using equilibrium surface tension measurements. Furthermore, air/water interface parameters including effectiveness (π_cmc), efficiency (P_C20), maximum surface excess (Γ _max ), and minimum surface area (A _min ) have been also derived using Gibb's adsorption equation at 25°C. Standard free energies of micellization and adsorption were calculated. Solubilization behaviors of the synthesized surfactants were measured towards paraffin oil as solubilized material using light transmission technique.     

Aggregation behavior of silicone surfactants in ethylammonium nitrate ionic liquid

The aggregation behavior of two silicone surfactants (monomeric and Gemini) was studied by surface tension measurements in a room temperature ionic liquid, ethylammonium nitrate (EAN), at various temperatures. A series of parameters, including critical micelle concentration (CMC), surface tension at the CMC (γ _CMC), adsorption efficiency (pC ₂₀), and effectiveness of surface tension reduction (Π _CMC), were obtained. By comparing the silicone surfactants with traditional surfactants, we deduced that the surface activity of the silicone surfactants in EAN was superior to the activity of other surfactants. In addition, from the CMC values and their temperature dependence, we estimated the thermodynamic parameters of the micelle formation, $ \Delta G_m^0 $ , $ \Delta H_m^0 $ , and $ \Delta S_m^0 $ . It was revealed that the micellization of the silicone surfactants is entropy driven at low temperature and enthalpy driven at high temperature. Isothermal titration calorimetry measurements were also carried out to study the micellization of Gemini silicone surfactant. ¹H NMR was performed to study the silicone surfactant micelle formation mechanism in EAN.