Synthesis and Characterization of Zirconia Nanocrystallites by Cationic Surfactant and Anionic Surfactant

Study on nanomaterials has attracted great interests in recent years. In this article, zirconia nanocrystallites of different structures have been successfully synthesized via hydrothermal methods with cationic surfactant （CTAB） and anionic surfactant （SDS）, respectively. Differential Scanning Calorimeter （DSC-TG）, X-ray Diffractometer （XRD）, Transmission Electron Microscope （TEM）, Ultraviolet-Visible （UV-vis） and N2 adsorption-desorption analyses are used for their structure characteristics. The results show that the cationic surfactant has a distinctive direction effect on the formation of zirconia nanocrystallites, while the anionic surfactant has a self-assembly synergistic effect on them. The sample synthesized with the cationic surfactant presents good dispersion with the main phase of tetragonal zirconia, and the average nanocrystal size is around 15 nm after calcination at 500 ℃. While the sample synthesized with the anionic surfactant exhibits a worm-like mesoporous structure with pure tetragonal phase after calcination at 500 ℃ and with good thermal stability.

Synthesis of Silica Hollow Spheres with Diameter Around 50 nm by Anionic Surfactant

Silica hollow spheres（SHSs） have attracted great attention because of their low toxicity, low density, large surface area, high chemical and thermal stability, and surface permeability. They can be widely applied in storage^[l], catalysis^[2], drug deli- very^[3,4], low-dielectric-constant materials^[5], low-refractive materials^[6-8], and so on. Up to now, there have been various methods to produce SHSs. Inorganic^[9] or organic particles^[10], such as polystyrene or calcium carbonate, were used as hard templates to create hollow cavities, However, the multistep synthetic process and the lack of structural robustness of the shells upon template removal process weaken their applica- tion. Soft templates, including oil-in-water emulsions^[11,12], vesicles^[13], micelle^[14,15] and gas bubbles^[16], are applied widely.

Improved Ti-containing Mesoporous Silica Catalyst Synthesized by Using Anionic Surfactant as Co-template

Ti-containing mesoporous silica materials(Ti-MSs) with isolated tetrahedrally coordinated Ti species have been widely applied in bulk molecular catalysis. Herein, Ti-MSs were synthesized using anionic surfactant SDS as the co-template. The SDS molecular assembled structures can interact with silica species through the interface hydrogen bonds leading to the formation of mesoporous silica structure with compact Ti-O bonds, lower hydrophilicity and low template cost. The influence of adding SDS as the co-template on the oxidation of styrene with aqueous H_2O_2 as the oxidant was investigated. Ti-MSs using SDS as the co-template showed better catalytic performance as compared with mesoporous titanium silicate synthesized with CTAB serving as the sole template. Moreover, the Ti-MSs synthesized at a Ti/Si ratio of 0.005 demonstrated an optimized performance for styrene oxidation with styrene conversion improved by 14.8%, benzaldehyde selectivity improved by 13.7% and styrene oxide selectivity improved by 9.2% when the reaction time was 6 h.

Effect of an Anionic Surfactant on Hydraulic Conductivities of Sodium- and Calcium-Saturated Soils

The effect of sodium dodecylbenzenesulfonate (SDBS), an anionic surfactant used widely in household products and industrial processes, on saturated hydraulic conductivities (Ksat) of an Anthrosol saturated with sodium (Na-soil) or calcium (Ca-soil) was analyzed in a laboratory experiment using the constant head method, and adsorption and dispersion experiments were also conducted to infer the possible mechanisms of Ksat fluctuations. The results showed that SDBS was more intensely adsorbed in the Ca-soil than in the Na-soil. With an increase in the SDBS concentration, the stability of the Na-soil suspensions decreased when the SDBS concentration was less than 1.2 mmol L-1 and then above this concentration, increased markedly, while the stability of the Ca-soil suspensions increased gradually at all SDBS concentrations studied. With an increase in the SDBS concentration, the Ksat of the Na-soil increased, which resulted mainly from the increase of water channels in the soil because of the coagulation of the soil particles, while the Ksat of Ca-soil decreased mainly on account of the clogging of partial water channels by precipitated Ca(DBS)2 and the fine soil particles generated.

Phase Separation and Microstructure of Mixed Surfactants Solution Containing Cationic Geminis and Traditional Anionic Surfactant

The properties of aqueous two-phase system (ATPS) of mixed solution containing gemini cationic surfactant trimethylene-1,3-bis(dodecyldimethyl ammonium) bromide (12-3-12, 2Br-) and traditional anionic surfactant sodium dodecyl sulfate (SDS) with or without added salt have been studied. An ATPS is formed in a narrow region of the ternary phase diagram different from that of traditional aqueous cationic-anionic surfactant systems. In ATPS region, the lowest total concentration of surfactants varies with the mixing ratio of geminis to SDS. Photographs obtained from freeze-etching, negative-staining and transmission electron microscopy show that the microstructures of two phases are different from each other. Micelles and vesicles can coexist in a single phase. The addition of salts can change the phase diagram of ATPS. Furthermore, the added salts promote the aggregation of rod-like micelles to form coarse network structure that increase the viscosity of solutions. The negative ions of the added salts are the determining factor.

Theoretical and Experimental Studies on Interactions of Cationic-Anionic Surfactants

Typical cationic and anionic surfactants were chosen and their interactions were calculated by quantum chemical method. Interaction energies are -0.2378 kJ·mol-1, -3.3394kJ·mol-1 and 0.1204kJ·mol-1 for the molecular pairs with fluocarbon and hydrocarbon chain: C4H10/C5H12, C4F10/C5H12, and C4F10 /C5F12, respectively. When hydrophilic group with cationic and anionicions is introduced, interaction energies are -287.40kJ·mol-1, -311.18kJ·mol-1 and -345.83kJ·mol-1. The results show that there is strong static interaction between cationic and anionic surfactants. It has been predicted that mixed monolayer may be formed and surface activity is enhanced favorably, especially for mixtures of cationic and anionic surfactants with fluocarbon and hydrocarbon chains. The anionic surfactants, sodium octadecylbenzenesulfonate perfluopolyetherbenzenesulonate(ANF-I) was synthesized, mixture effects of ANF-I with sodium octadecylbenzenesulfonate or dodecyldimethyl benzylammonium bromide were studied. The results indicate that the efficiency of mixing increased and the theoretical prediction was testified. These results can provide useful information for the design of new surfactants.

Development and Prospect of China’s Anionic Surfactant Industry

The development process of anionic surfactants in China was reviewed.The current status of anionic surfactants in China was analyzed.The overall situation of sulfonation equipment was introduced,and the development trend of anionic surfactant industry in China was prospected.

Anionic Surfactants Levels in M’Koa Lake Water (Jacqueville, Cote d’Ivoire)

In this study, anionic surfactants concentrations and other physico-chemical parameters of surface water quality were assessed in the water of M’Koa Lake in the city of Jacqueville (C?te d’Ivoire). Three sampling campaigns were conducted at different seasons at six (6) sampling stations, identified in M’koa Lake by taking into account potential sources of pollution. The analyses of physico-chemical parameters were carried out using both the French AFNOR standard and the methods described by Rodier. The anionic surfactants concentrations were performed by using the methylene blue colorimetric method. The average concentrations of anionic surfactants in the water of M’koa Lake ranged from 0.23 ± 0.04 mg·L-1 to 1.43 ± 0.68 mg·L-1. They are high compared to both population density and socio-economic activities of Jacqueville’s town. These values can be explained by the characteristics of the studied Lake that do not allow enough dilution of the discharged effluent. The results indicate that M’koa Lake is subjected to harmful pollution by anionic surfactants. And among the physicochemical parameters studied, only turbidity and transparency values show water quality deterioration, favoured by wastewater discharge and direct human activities around the Lake.

Surface Activity Interactions in Aqueous Solution of Anionic Surfactants with a Water Treatment Protein from <i>Moringa oleifera</i>Seeds

The interaction of anionic surfactants sodium dodecylbenzenesulphonate (SDBS) and sodium bis (2-ethyl-1-hexylsulfosuccinate) (AOT) with the water treatment protein extracted from Moringa oleifera seeds has been investigated by surface tension measurements. The results were compared with previously reported studies using surface tension and zeta potential measurements of the same protein with an anionic surfactant sodium dodecylsulphate. There is a strong electrostatic interaction between the protein and the surfactants characterized by a local maximum at intermediate surfactant concentration. This surfactant concentration depends on the protein concentration and corresponds to the surfactant concentration at the point of charge reversal (zeta potential = 0 mV). The number of surfactant molecules required to neutralize the positive charges on the protein was found to be 8 per protein molecule.

Synergistic anionic/zwitterionic mixed surfactant system with high emulsification efficiency for enhanced oil recovery in low permeability reservoirs

Emulsification is one of the important mechanisms of surfactant flooding. To improve oil recovery for low permeability reservoirs, a highly efficient emulsification oil flooding system consisting of anionic surfactant sodium alkyl glucosyl hydroxypropyl sulfonate(APGSHS) and zwitterionic surfactant octadecyl betaine(BS-18) is proposed. The performance of APGSHS/BS-18 mixed surfactant system was evaluated in terms of interfacial tension, emulsification capability, emulsion size and distribution, wettability alteration, temperature-resistance and salt-resistance. The emulsification speed was used to evaluate the emulsification ability of surfactant systems, and the results show that mixed surfactant systems can completely emulsify the crude oil into emulsions droplets even under low energy conditions. Meanwhile,the system exhibits good temperature and salt resistance. Finally, the best oil recovery of 25.45% is achieved for low permeability core by the mixed surfactant system with a total concentration of 0.3 wt%while the molar ratio of APGSHS:BS-18 is 4:6. The current study indicates that the anionic/zwitterionic mixed surfactant system can improve the oil flooding efficiency and is potential candidate for application in low permeability reservoirs.

Synthesis of silica particles with lamellar and wormhole-like bi-modal mesopores using anionic surfactant as the template

Silica particles with lamellar and wormhole-like bi-modal mesopores have been synthesized using anionic surfactant (N-lauroylsarcosine sodium) as the template. The particles with diameters of 300―500 nm possess bi-modal mesopores with pore sizes of 3 nm and 12 nm, which were ascribed to the disordered wormhole-like mesophase and lamellar mesophase, respectively. The BET surface area of the particles was 536 m2/g and the pore volume was 0.83 cm3/g. The lamellar mesophase and cylindrical mesophase were formed due to the co-assembly of the anionic surfactant and its protonized polar oil.

Evaluation of reusing alum sludge for the coagulation of industrial wastewater containing mixed anionic surfactants

A coagulation-flocculation process is typically employed to treat the industrial wastewater generated by the consumer products industry manufacturing detergents, soaps, and others. The expenditure of chemicals including coagulants and chemicals for pH adjustment is costly for treating this wastewater. The objective of this study was to evaluate the feasibility of reusing the aluminum sulfate （alum） sludge as a coagulant or as a coagulation aid so that the fresh alum dosage can be minimized or the removal efficiency can be enhanced. The experiments were conducted in a jar-test apparatus simulating the coagulation-flocculation process for simultaneous removals of organic matters, anionic surfactants, suspended solids, and turbidity. At the optimum initial pH value of 10 and the fresh alum concentration of 400 mg/L, the total suspended solids （TSS）, total chemical oxygen demand （TCOD）, total anionic surfactants, and turbidity removal efficiencies were 71.5%, 76.4%, 95.4%, and 98.2%, respectively. The addition of alum sludge as a coagulant alone without any fresh alum addition could significantly remove the turbidity, TCOD, and anionic surfactants. The TSS was left in the supernatants after the settling period, but would subsequently be removed by adding the fresh alum. The TSS, TCOD, and turbidity removal efficiencies were also enhanced when both the alum sludge and the fresh alum were employed. The TCOD removal efficiency over 80% has been accomplished, which has never fulfilled by using the fresh alum alone. It is concluded that the alum sludge could be reused for the treatment of industrial wastewater generated by the consumer products industry.

Determination of trace inorganic anions in anionic surfactants by single-pump column-switching ion chromatography

An ion chromatography method has been proposed for the determination of three common inorganic anions（chloride,nitrate and sulfate） in anionic surfactants using a single pump system.The new system consists of an ion exclusion column,a concentrator column,and an anion exchange column connected in series via two 6-ports valves in a Dionex ICS-2000 ion chromatograph.The valves were switched several times for removing surfactants,concentrating and separating the three anions.The chromatographic conditions were optimized.Detection limits（S/N = 3） were in the range of 0.10-0.68μg/L.The relative standard deviations（RSDs） of peak area were less than 4.6%.The recoveries were in the range of 84.1-112.6%.

Differences in Adsorption of Anionic Surfactant AOT by Calcium Oxalate： Effect of Crystal Size and Crystalline Phase

The adsorption of anionic surfactant sodium diisooctyl sulfosuccinate（AOT） onto calcium oxalate mono- hydrate（COM） and dihydrate（COD） with sizes of 50, 100 nm, 1, 3 and 10 μm was comparatively studied to simulate the interaction between urinary crystallites and urine components. The adsorption quantity of different concentrations of AOT onto COD and COM with different sizes was detected using a UV-Vis spectrophotometer. The crystalline phase transition of COM and COD before and after adsorption was analyzed by X-ray powder diffraction and Fourier transform infrared spectrometry. The zeta potential of the crystal surface after adsorption of different concentrations of AOT was measured using a zeta potential analyzer. The adsorption quantity of AOT on COM and COD with different sizes was ranked in the following order： 50 nm〉100 nm〉1μm〉3 μm〉10 μm. The adsorption quantity of COM was greater than that of COD with the same size because the density of the positive charges on the COM surface was higher than that on COD surface. With the increase of AOT concentration, the adsorption curves of the large-sized COM and COD（3 and 10μm） were S-type, whereas the adsorption curves of the small-sized COM and COD（50 nm, 100 nm and 1μm） were linear. The adsorption capacities of small-sized COM and COD were much greater than those of the 3 and 10μm crystals. On the basis of the above results, we proposed a molecular model to summarize the absorption of AOT onto COM and COD crystals. Small crystals exhibit a large specific surface area and high surface energy. Thus, the adsorption capacities of them are stronger than those of large crystals. Overall, this study implies that small crystals can easily absorb anionic molecules in urine and may easily adhere to a negatively charged cell surface, thereby increasing the severity of cell injury.

High Selective Determination of Anionic Surfactant Using Its Parallel Catalytic Hydrogen Wave

A faradaic response of anionic surfactants (AS),such as linear alkylbenzene sulfonate (LAS),dodecyl benzene sulfonate and dodecyl sulfate,was observed in weak acidic medium. The faradaic response of AS includes (1) a catalytic hydrogen wave of AS in HAc/NaAc buffer that was attributed to the reduction of proton associated with the sulfo-group of AS,and (2) a parallel catalytic hydrogen wave of AS in the presence of hydrogen peroxide,which was due to the catalysis of the catalytic hydrogen wave of AS by hydroxyl radical ·OH electrogenerated in the reduction of hydrogen peroxide. The parallel catalytic hydrogen wave is about 50 times as sensitive as the catalytic hydrogen wave. Based on the parallel catalytic hydrogen wave,a high selective method for the determination of AS was developed. In 0.1 mol/L HAc/NaAc (pH=6.2±0.1)/1.0×10 -3 mol/L H_2O_2 supporting electrolyte,the second-order derivative peak current of the parallel catalytic hydrogen wave located at -1.33 V (vs. SCE) was rectilinear to AS concentration in the range of 3.0×10 -6 —2.5×10 -4 mol/L,without the interference of other surfactants. The proposed method was evaluated by quantitative analysis of AS in environmental wastewater.

Partitioning of biomaterials in aqueous two-phase systems of mixed cationic-anionic surfactants

In a previous paper, we have showed that, when aqueous solutions of cationicand anionic surfactants at certain concentrations were mixed, the solution separatedspontaneously into two immiscible phases (aqueous two-phases), one phase was rich,and the other was poor in the mixed surfactants. A clear interfacial boundary existsbetween two phases.

Cloud point phenomenon in aqueous mixtures of cationic-anionic surfactants

It used to be held that the cloud point phenomenon was only a characteris-tic of nonionic surfactants alone. Such phenomenon is rarely observed in ionicsurfactants. The present study shows that the mixture of cationic-anionic surfac-tants not only has a krafft point which is the characteristic of an ionic surfactant,but also exhibits the cloud point phenomenon obviously at certain concentrations.

IR与ESI/MS结合鉴定复杂表面活性剂结构

复杂表面活性剂的结构鉴定往往是比较困难的,尤其在有许多副产物共存时,尝试应用红外光谱、质谱以及电喷雾质谱相结合的方法鉴定复杂表面活性剂及其副产物的结构.

SPECTROPHOTOMETRIC DETERMINATION OF URANIUM (Ⅵ) WITH 2-(3.5-DIBROMO-2-PYRIDYLAZO)-5-DIETHYLAMINOPHENOL IN THE PRESENCE OF ANIONIC SURFACTANT

We have studied some color reactions using pyridylazo compounds as chromogenic agents in the presence of anionic surfactant, and established the spectrophotometric methods with high sensitivity and selectivity for silver, copper, cobalt, nickel and palladium based on this kind of reaction. Continuing the previous study of

Application of anionic surfactant\engineered water hybrid EOR in carbonate formations:An experimental analysis

A hybrid enhanced oil recovery(EOR)method by combining low salinity water(LSW)and low salinity surfactant(LSS)flooding techniques was designed.Different experiments were done to screen the Caspian seawater(SW)with altered ionic composition and surfactant,for the optimized performance in Kazakhstani carbonate oil fields.Changing to a more water-wet state and creating the middle phase were studied as the main criteria to select the best-engineered brine and anionic surfactant.The largest alteration towards the water-wet condition was recorded at 10 times dilution of the SW with 3-and 6-times spiked calcium and sulfate ions,respectively(10xSW-6SO4,Mg,3Ca).This combination of anionic surfactants with carbonate formations is considered as a new approach in hybrid EOR methods.Among the anionic surfactants screened,Soloterra-113H(alkyl benzenesulfonic acid)showed the best solubilization ratio,aqueous stability and Winsor type 3 microemulsions.The wettability alteration by the combination of optimized brine and screened surfactant was greater compared to the standalone LSW,which was confirmed by the 10difference in contact angle measurement.The microemulsion phase constituted nearly 40%of the total height of the oil/brine column by the hybrid method.The recovery factor after injecting formation water was 52%,and it increased to 61%after optimized LSW injection.After switching to the engineered brine/surfactant,the recovery factor reached 70%,which proves the effectiveness of the hybrid method.The proposed combined method works better than either standalone EOR method due to the higher alteration in capillary number by changing wettability and reducing IFT,which leads to higher oil recovery.