Table of Content

22 December 2019, Volume 49 Issue 12 Previous Issue    Next Issue

Basic research

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Influence of alkali metal counterions on the complexation of polyvinylpyrrolidone with dodecyl sulfates CHEN Miao-miao,FENG Rui-qin,FANG Yun 2019, 49 (12):  769-773.  doi: 10.3969/j.issn.1001-1803.2019.12.001 Abstract ( 256 )   HTML ( 119 )   PDF (1666KB) ( 376 )   The complexation between polyvinylpyrrolidone（PVP）and dodecyl sulfates with different alkali metal counterions（Li +, Na + and K +）was studied by tensiometry, conductometry and capillary electrophoresis（CE）. The effects of these alkali metal counterions with different hydration radii on the pseudo-polyelectrolyte types and electrolyte strength of PVP-dodecyl sulfate complexes were also investigated. The experimental results of tensiometry and conductometry showed that, the association between PVP and dodecyl sulfates and the bridging degree of counterions both increase with the decrease of hydration radii of alkali metal counterions（Li +>Na +>K +）. The CE results showed that, the complexation between PVP and dodecyl sulfates has formed pseudo-polyanions no matter what alkali metal counterion is, but the polyanion properties become strong with the decreasing hydration radii of alkali metal counterions. Figures and Tables | References | Related Articles | Metrics

Lecture of science and technology

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Interactions between surfactants and nanoparticles and the construction of smart systems（VI）Interactions between like-charged nanoparticles and surfactants（ii）Stabilization mechanism and intelligentialization of the novel emulsions ZHANG Wan-qing,XU Mao-dong,JIANG Jian-zhong,CUI Zheng-gang 2019, 49 (12):  774-782.  doi: 10.3969/j.issn.1001-1803.2019.12.002 Abstract ( 320 )   HTML ( 12 )   PDF (3691KB) ( 308 )   Ionic surfactants and same-charged inorganic nanoparticles can co-stabilize novel O/W emulsions both at extremely low concentration, in which trace amount of the ionic surfactants adsorb at the oil/water interface to endow droplets with surface charge whereas the charged nanoparticles disperse in the aqueous lamellae（continuous phase）which increases the distance between droplets and thus significantly reduces the wan der Waals attraction between droplets. There is a critical Zeta potential for both particles and droplets, above which stable emulsions can be obtained. For nanoparticles the critical Zeta potential is approximately ±18 mV, whereas for droplets it still needs to be determined. Switchable novel emulsion can be obtained by using a CO2/N2switchable surfactant DDMA in combination with positively charged alumina nanoparticles. By bubbling N2 into the emulsion, the DDMA is transformed from cationic to neutral form, and the surface activity of DDMA and the Zeta potential of droplets are eliminated, leading to demulsification. In contrast, by bubbling CO2 into the system to turn DDMA back to cationic form, the Zeta potential of droplets is recovered and the emulsion is re-stabilized. For the novel emulsions co-stabilized by conventional ionic surfactants and same-charged nanoparticles, they can be made stimuli-responsive. By adding an ionic surfactant charged oppositely to the ionic surfactant already present in the emulsion, ionic pairs are formed to eliminate the Zeta potential of droplets, leading to demulsification, whereas by further addition of extra original ionic surfactant, the Zeta potential of droplets is recovered and the emulsion is re-stabilized. This lecture will discuss the most recent research progress relevant. Figures and Tables | References | Related Articles | Metrics

Development and application

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Study of the performance of mixed whey protein-rhamnolipid bioemulsifier ZHANG Guo-rui,SONG Yong-ting,BAO Mu-tai,WANG Wei-dong,LI Xi-ming 2019, 49 (12):  783-789.  doi: 10.3969/j.issn.1001-1803.2019.12.003 Abstract ( 257 )   HTML ( 6 )   PDF (2126KB) ( 344 )   The mixed systems of whey protein and rhamnolipid at different ratios were prepared, and their emulsifying properties（0 # diesel as a substrate hydrocarbon）were studied. The results showed that, at the same mass concentration, the mixture showed better emulsifying activity than pure whey protein or rhamnolipid, indicative of good emulsification synergism. The increase of rhamnolipid component therein can also effectively reduce the mean particle size of the emulsion. The emulsifying activity of the mixture under different conditions was studied, which showed that the mixture has significantly improved emulsifying activity under neutral and alkaline conditions; the mixtures of whey protein and rhamnolipid with mass ratio of 2∶1 and 1∶1 also show significantly improved emulsifying activity at 1.5% and 2.5% NaCl contents; Moreover, the mixture is effective in the emulsification of three different substrate hydrocarbons. The Zeta potential and interfacial properties are investigated. It was found that the negative Zeta potential of the mixed micelle particles is weakened compared with the individual components, and the addition of a small amount of rhamnolipid significantly increases the interfacial activity and wettability of the mixture. Figures and Tables | References | Related Articles | Metrics

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Study on the migration of ASP flooding system in long core BI Yan-chang,SUN Ling-hui,XIAO Han-min,GU Zhao-bin,ZHAO Hong-yun,YUE Qing 2019, 49 (12):  790-794.  doi: 10.3969/j.issn.1001-1803.2019.12.004 Abstract ( 248 )   HTML ( 5 )   PDF (1713KB) ( 295 )   To study the migration of ASP（alkali/surfactant/polymer）flooding system in the formation in Daqing Oilfield, a sand filling tube model with a permeability of 479 mD and a length of 6 m was prepared, according to the practical formula applied in oilfield, isothermal displacement was carried out at 45 ℃. The concentration, viscosity and interfacial tension of the produced fluid were analyzed. The results showed that in the ternary flooding stage, the higher the injection degree was, the lower the water content and the higher the recovery factor would be; the flooding effect of the system completely failed after ASP started 1.5 PV. The loss degrees of chemical agent concentration and viscosity in the system were as follows: viscosity（6 times） > surfactant（4 times） > polymer（3 times）> alkali（2 times）. Because of the excessive loss of viscosity, the system lost the function of controlling the fluidity ratio in the latter 1/12 well spacing. Because of the presence of alkali, ultralow interfacial tension（0.001 mN/m）could be maintained for the first 1/2 well spacing, while low interfacial tension（0.01 mN/m）could be maintained for the rear 1/2 well spacing. Figures and Tables | References | Related Articles | Metrics

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Study on removal of pesticide residues by microemulsion fruit and vegetable detergents LIU Dong,ZHANG Yun,SHANG Meng,NI Xin-jiong,CAO Yu-hua 2019, 49 (12):  795-800.  doi: 10.3969/j.issn.1001-1803.2019.12.005 Abstract ( 318 )   HTML ( 6 )   PDF (1832KB) ( 573 )   The removal effect of microemulusion fruit and vegetable detergents on pesticide residue on vegetable surface was studied. The mixed pesticides containing acephate, omethoate, trichlorfon and cyhalothrin were sprayed on the surface of green vegetables. Then, the vegetables were collected on the 3rd, 7th, 14th, and 21th days after spraying, and washed with the microemulsion detergent, commercially available vegetable and fruit detergent for removing pesticide residue and tap water, respectively. The residues of four pesticides in green vegetable samples were determined. The removal effects of the three cleaning agents on different pesticides and pesticides at different harvest time were evaluated. It is found that with the extension of the harvest time of spraying pesticide, the four pesticide residues in green vegetables decreased to varying degrees, but the cleaning efficiency decreased significantly. Microemulsion fruit and vegetable detergent have good removal effect on all of the four pesticides. The average removal rate of four pesticides in vegetables harvested on the 21st day after spraying is 63.90%, while the average removal rate of commercial vegetable and fruit detergent and tap water is only 44.88% and 20.76%, respectively. Owing to highly hydrophobic solubility and penetrability, the microemulsion detergent was suitable for removal of the highly hydrophobic pesticides and those penetrated into the organic outermost cuticle layer. In view of the good solubilization and permeability of the microemulsion fruit and vegetable detergents, it is suitable for the removal of hydrophobic pesticide residues in the surface of vegetables and fruits. Figures and Tables | References | Related Articles | Metrics

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Pickering emulsion stabilized by modified SOD nanoparticles and its antioxidation property LI Fei,PENG Zhi,WANG Wei-hao,SUN He-jia,GUO Ting,MENG Tao 2019, 49 (12):  801-804.  doi: 10.3969/j.issn.1001-1803.2019.12.006 Abstract ( 339 )   HTML ( 13 )   PDF (3334KB) ( 288 )   The SOD（superoxide dismutase） nanoparticles with good particle size and wettability were prepared by modification with glutaraldehyde. The modified SOD nanoparticles were characterized by scanning electron microscopy（SEM）, contact angle, emulsion stability and enzyme activity. The results show that the modified SOD nanoparticles exhibit uniform particle size, regular morphology and good wettability. The Pickering emulsion stabilized by the modified SOD nanoparticles has high stability and antioxidation property. Figures and Tables | References | Related Articles | Metrics

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Effects of sodium chloride on the multiple emulsion encapsulating Vitamin C CHEN Kai-li,LIU Dong,ZHANG Yun,NI Xin-jiong,CAO Yu-hua,CAO Guang-qun 2019, 49 (12):  805-810.  doi: 10.3969/j.issn.1001-1803.2019.12.007 Abstract ( 383 )   HTML ( 13 )   PDF (2205KB) ( 453 )   Water-in-oil-in-water（W1/O/W2）multiple emulsion was prepared by two-step method with caprylic/capric triglyceride as oil phase, lauryl PEG-9 polydimethylsiloxyethyl dimethicone as oleophilic emulsifier and the amphiphilic random copolymer as hydrophilic emulsifier. The multiple emulsion was used to encapsulate Vitamin C in internal aqueous phase（W1）. Sodium chloride（NaCl）regulated the osmotic pressure between the internal and external aqueous phases to improve the stability of the multiple emulsion. The effects of the amount of NaCl on the interfacial tension, droplet size of emulsion and viscosity were investigated. The stability of the multiple emulsion was evaluated by optical microscope and emulsion appearance. The results show that, the addition of NaCl in W1 lead to significant decrease of W1/O interfacial tension, smaller size of the emulsion droplets, and higher viscosity of the emulsion. The interfacial tension at O/W2 interface would be obviously increased if the content of NaCl in W2 is higher than 0.2%. In contrast to NaCl, the addition of Vitamin C merely slightly decrease the interfacial tension between W1/O interface. Thus, in this work the amount of NaCl is kept at 0.2% both in internal and external aqueous phases of W1/O/W2, and the effects of Vitamin C concentration in W1 on the microscopic states and appearance of the multiple emulsion are investigated. A homogeneous and stable multiple emulsion could be obtained with the encapsulation of Vitamin C at 0.75%. Figures and Tables | References | Related Articles | Metrics

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Microencapsulation of beeswax as a phase change material in polyurea by interfacial polymerization NI Zhuo,CHEN Shu-tian,ZHU Jin-pu 2019, 49 (12):  811-816.  doi: 10.3969/j.issn.1001-1803.2019.12.008 Abstract ( 433 )   HTML ( 7 )   PDF (3441KB) ( 292 )   Polyurea microcapsules containing beeswax as the core material were prepared by interfacial polymerization. Toluene diisocyanate （TDI） and ethylene diamine （EDA） were used as monomers and octylphenol polyoxyethylene （10） ether （OP-10） was used as emulsifier. The effects of emulsifier dosage, molar ratio of monomers and reaction temperature on polyurea/beeswax phase change microcapsules were studied. The effectiveness of microencapsulation was also analyzed. The results showed that when the emulsifier mass fraction is 2.40%, n（TDI）∶n（EDA） is 1.2∶1.0 and the reaction temperature is 70 ℃, the average particle size of polyurea/beeswax microcapsules prepared under such condition is 70.3 μm, while the heat-resistance temperature, phase change temperature and latent heat of phase change are 210 ℃, 41 ℃, and 59.55 J/g, respectively. Figures and Tables | References | Related Articles | Metrics

Reviews

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Progress in the formation of lyotropic liquid crystals in non-aqueous solvent XI Qi,YAN Yong-li,ZHANG Yang 2019, 49 (12):  817-823.  doi: 10.3969/j.issn.1001-1803.2019.12.009 Abstract ( 627 )   HTML ( 14 )   PDF (2868KB) ( 680 )   With wide applications of lyotropic liquid crystals in the fields of bionics, functional materials, chemical industry, medicine, petroleum industry, daily cosmetics, etc., the research of constructing non-aqueous phase liquid crystals attracts more attention recently. Based on the basic theory of the formation of the lyotropic liquid crystals of surfactant aggregates, the formation, characterization and application of the lyotropic liquid crystals of surfactants in non-aqueous solvents such as straight chain alcohols （glycerin, ethylene glycol, etc.）, organic amines （formamide, N-methylformamide, etc.）, ionic liquids, etc. are reviewed, and the development trend in this field is prospected. Figures and Tables | References | Related Articles | Metrics

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An overview of skin penetration test methods for cosmetics SONG Yan-qing,PAN Yao,ZHAO Hua 2019, 49 (12):  824-829.  doi: 10.3969/j.issn.1001-1803.2019.12.010 Abstract ( 1711 )   HTML ( 93 )   PDF (1895KB) ( 2694 )   The approaches and theories of skin penetration of cosmetics were summarized. The in vitro and in vivo of transdermal absorption, such as diffusion cell methods, tape stripping and spectroscopy were introduced. A new idea for evaluating the transdermal absorption capacity of cosmetics was provided and the development trend of the cosmetics skin penetration evaluation methods was proposed. Figures and Tables | References | Related Articles | Metrics

Analytical methods and testing

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Analysis of fatty alcohol ethoxylates in the serial products of fatty alcohol ethoxylate derived surfactants by HPLC ZHANG Jun,YANG Xiu-quan,ZHOU Yuan 2019, 49 (12):  830-834.  doi: 10.3969/j.issn.1001-1803.2019.12.011 Abstract ( 541 )   HTML ( 10 )   PDF (1663KB) ( 490 )   A uniform HPLC method was established for the determination of the fatty alcohol ethoxylates in the products of surfactants derived thereof. The surfactant products under investigation were alcohol ether sulfate, alkylethoxyglucoside, alcohol ether carboxylate, and fatty alcohol ether citrate monoester salt. The column was C18 column and the gradient elution was performed with methanol-water solvent. The chromatographic peaks of fatty alcohol ethoxylates were separated from interference peaks by adding modification agent in the mobile phase. Evaporative light scattering detection (ELSD) was used. The results showed that the coefficients of the regression equations of fatty alcohol ethoxylates with the same alkyl group were close. The method showed good precision with the R 2 being greater than 0.999; the method also showed good accuracy with the average recovery rate of each product being more than 95%. The method showed good adaptability for the samples with 0.5%-30% fatty alcohol ethoxylates. The method was also applicable to mixed products with different contents of fatty alcohol ethoxylates. Figures and Tables | References | Related Articles | Metrics

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HPLC determination of psoralen, lsopsoralen, neobavaisoflavone and bavachin in cosmetics FAN Fei,LI Jing-jing,LU Bang-mei 2019, 49 (12):  835-838.  doi: 10.3969/j.issn.1001-1803.2019.12.012 Abstract ( 318 )   HTML ( 7 )   PDF (1610KB) ( 372 )   An analytical method for the simultaneous determination of psoralen, lsopsoralen, neobavaisoflavone and bavachin in cosmetics by HPLC were developed. The linear relationships are good in the ranges of 0.109 1-21.814 4 mg/L, 0.106 7-21.332 8 mg/L, 0.108 6-21.712 8 mg/L and 0.112 3-22.464 4 mg/L for the four components, respectively. The average recoveries are 94.78%-104.74% with the RSD less than 5%. Figures and Tables | References | Related Articles | Metrics