Table of Content

20 May 2018, Volume 48 Issue 5 Previous Issue    Next Issue

Basic research

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Molecular dynamics simulation of OPEO surfactants at oil-water interface HOU Meng-die, LI Hui-ping, HU Zi-zhao, SONG Hong-wei 2018, 48 (5):  243-246.  doi: 10.13218/j.cnki.csdc.2018.05.001 Abstract ( 341 )   PDF (2741KB) ( 399 )   Polyoxyethylene octylphenol ether (OPEO) is a commonly used nonionic surfactant that can significantly reduce the interfacial tension of oil-water systems.The vinyl acetate/water system was chosen as the oil-water system.Molecular dynamics (MD) simulation methods in MS7.0 software was used.By changing the number of oxyethylene groups in OPEO,the interface formation energy,interface thickness and other parameters for the oil/surfactant/water system were measured at normal temperature and pressure.Results show that when the number of oxyethylene groups is 12,the interface formation energy of OPEO is relatively high,and its ability to reduce the interfacial tension of vinyl acetate/water system is relatively good. References | Related Articles | Metrics

Lecture of science and technology

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Efficacy evaluation of cosmetics (Ⅴ) Scientific support for soothing skin efficacy claims WANG Huan, PAN Yao 2018, 48 (5):  247-254.  doi: 10.13218/j.cnki.csdc.2018.05.002 Abstract ( 1329 )   PDF (762KB) ( 1205 )   The performance and formation mechanism of sensitive skin were summarized.Various evaluation methods for soothing skin cosmetics such as physical and chemical methods,biochemical methods,cell biological methods,three dimensional recombinant skin model substitution method,animal experiment method,subjective evaluation,semi subjective evaluation and objective instrument evaluation method were introduced.The new idea of soothing efficacy evaluation was proposed and put forward the development direction of it. References | Related Articles | Metrics

Development and application

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Preparation and application of Pickering emulsion stabilized by modified waxy maize starch QIAN Xin, LIANG Rong, YANG Cheng, CAO Guang-qun 2018, 48 (5):  255-259.  doi: 10.13218/j.cnki.csdc.2018.05.003 Abstract ( 339 )   PDF (2907KB) ( 324 )   The waxy maize starch (WS) was hydrophobically modified by octenyl succinic anhydride (OSA) to prepare the modified waxy maize starch (OSA-WS).Stable Pickering emulsions were prepared by using OSA-WS with different degree of substitution (DS).The DS,reaction efficiency (RE) and three-phase contact angle of OSA-WS were measured.The OSA-WS was characterized by FT-IR,XRD and SEM.The results show that,by reacting with the hydroxyl groups on the surface of starch,OSA has been successfully grafted without changing the granule of starch.The emulsifying ability of OSA-WS becomes stronger with larger DS,thus the storage stability of Pickering emulsion is also increased with DS.The Pickering emulsion emulsified by OSA-WS was then applied in the transdermal transport of coenzyme Q10.Compared with the oil solution of coenzyme Q10,the Pickering emulsion containing coenzyme Q10 is more favorable for transdermal transport of coenzyme Q10. References | Related Articles | Metrics

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Study on the modification of chitosan and its CO2/N2-switchable emulsification REN Dong-yin, SHANG Zhi-xin, WANG Qi-bao 2018, 48 (5):  260-265.  doi: 10.13218/j.cnki.csdc.2018.05.004 Abstract ( 240 )   PDF (1997KB) ( 287 )   2-(Dimethylamino) ethyl methacrylate (DMAEMA) was grafted onto the molecular structure of chitosan by chemical reaction.FT-IR and 1H NMR were used to characterize the structure of the modified product (CTS-g-DMAEMA).The appearance,conductivity and transmittance of the dispersion of CTS-g-DMAEMA aggregates are repeatedly changed in the stimulation of CO2 and N2,which shows the CO2/N2-switchable behavior of CTS-g-DMAEMA.The emulsification experiment of water-liquid paraffin illustrates that the CTS-g-DMAEMA shows better emulsification capability than the raw chitosan.Moreover,under the action of CO2/N2,the emulsion prepared by CTS-g-DMAEMA can be demulsified and re-emulsified circularly. References | Related Articles | Metrics

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Interfacial properties of compounded system of alkali and bio-oil sulfonate synthesized from waste cooking oil LONG Yun-qian, HUANG Xiao-he, WANG Yong-zheng, WANG Yong, SONG Xing-xing, SONG Fu-quan 2018, 48 (5):  266-271.  doi: 10.13218/j.cnki.csdc.2018.05.005 Abstract ( 229 )   PDF (790KB) ( 358 )   A bio-oil sulfonate was synthesized by sulfonation of waste cooking oil.A compounded system of bio-oil sulfonate and sodium carbonate was prepared.The interfacial activity,dynamic interfacial tension,interfacial tension stability and partition property of the blended system were measured.Results show that the bio-oil sulfonate is water soluble and its average molecular weight is 393.The blended system of bio-oil sulfonate and sodium carbonate has a wide range of interfacial activity and relatively good interfacial tension stability.The interfacial tension between oil and water can be reduced to 10-3 mN/m when sodium carbonate is in the mass fraction range of 0.4%-0.8%.The minimum interfacial tension between crude oil and compounded solution decreases first and then increases with the increase of mass fraction of sodium carbonate.The optimum mass fraction of sodium carbonate is 0.6%.The minimum interfacial tension is still maintained at 10-3 mN/m after 90 d.For a given mass fraction of sodium carbonate,the oil/water partition coefficient of bio-oil sulfonate is decreased as the mass fraction of bio-oil sulfonate increases.The decline of partition coefficient becomes smaller when the mass fraction of bio-oil sulfonate is greater than 0.25%.For a given mass fraction of bio-oil sulfonate,the oil/water partition coefficient of bio-oil sulfonate has a small increase with the increase of mass fraction of sodium carbonate. References | Related Articles | Metrics

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Preparation of anti-corrosion superhydrophobic/superoleophilic stainless steel mesh and its application in oil/water separation DING Peng, TAI Xiu-mei, DU Zhi-ping 2018, 48 (5):  272-277.  doi: 10.13218/j.cnki.csdc.2018.05.006 Abstract ( 280 )   PDF (3369KB) ( 494 )   Using stainless steel mesh as substrate,a superhydrophobic/superoleophilic stainless steel mesh with micro/nano hierarchical structure was prepared.The surface with micron-sized roughness was obtained through chemical etching and was then coated with hydrophobic/oleophilic nano-SiO2 (the nano-SiO2 was obtained by stöber method) through one step immersing method.The surface morphology,chemical composition and wettability of the superhydrophobic/superoleophilic stainless steel mesh were characterized by scanning electron microscopy (SEM),fourier transform infrared spectroscopy (FT-IR) and contact angle measurement (CA).The mesh was used in oil/water separation process.Results show that hydrophobic/oleophilic nano-SiO2 was coated on the surface of chemical etched stainless steel mesh.The surface of the prepared mesh exhibited superhydrophobicity and superoleophilicity with a water contact angle of 151° and kerosene contact angle of 0°.The prepared mesh could efficiently separate not only the mixtures of water and different kinds of oil but also the mixtures of oil and corrosive aqueous solutions (containing strong acid or alkali).The anti-corrosion ability could meet the requirements of oil/water separation in complex environments. References | Related Articles | Metrics

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Synthesis and characterization of 10-undecenoic acid tetrafluoropropyl ester GUO Rui, HAN Shuang, ZHANG Yao, WANG Ning 2018, 48 (5):  278-282.  doi: 10.13218/j.cnki.csdc.2018.05.007 Abstract ( 203 )   PDF (1637KB) ( 319 )   10-Undecenoic acid tetrafluoropropyl ester (UATE) was synthesized from 2,2,3,3-tetrafluoro-1-propanol and 10-undecenoic acid by direct esterification.The UATE was characterized by FT-IR and 1H NMR.The effects of the reaction temperature,the amounts of tetrafluoropropanol,catalyst and toluene and the reaction time on the yield of UATE were studied.The synthesis process of UATE was optimized through the response surface experimental design.Thus the optimal conditions of synthesis are determined:n (2,2,3,3-tetrafluoro-1-propanol)∶n (10-undecenoic acid) = 3∶1;the amount of concentrated sulfuric acid is 0.5%;the amount of toluene is 7.6 mL;the reaction time is 10 h;the reaction temperature is 138 ℃.Under such condition,the maximum yield of UATE is 78.6%. References | Related Articles | Metrics

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Surface modification of rutile titania-silica nanocomposites by ammonium fluoride ZHAO Shu-fang, HOU Lei-xin, LIU Dan-dan, FANG Li, CHENG Fang-qin 2018, 48 (5):  283-287.  doi: 10.13218/j.cnki.csdc.2018.05.008 Abstract ( 240 )   PDF (4208KB) ( 417 )   Rutile-TiO2-SiO2 nanocomposites were synthesized by an improved hydrolysis-coprecipitation method using sodium metasilicate and titanium oxysulfate as precursors.Using hydrothermal method,the obtained nanocomposites were further modified by ammonium fluoride (NH4F) in different solvents.The effects of solvents on modification were studied by characterization of the modified nanocomposites by X-ray diffraction,fourier transform infrared spectra,scanning electron microscopy,atomic force microscope and contact angle (CA) measurements.Results show that,the rutile-TiO2-SiO2 modified by NH4F in isopropanol exhibits large specific surface area and has good surface properties,due to the cooperative factors happening at the surface,such as the formation of Si-F bonds,the micro/nano hierarchical rough structure and the self-assembly of isopropanol.Its specific surface area is 332 m2/g,and the contact angles of water and diiodomethane are 147.1° and 147.2°,respectively. References | Related Articles | Metrics

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A preliminary study on in vitro skin sensitization test based on skin model and THP-1 cell co-culture CHAN Jian, KE Yi-hui, TAN Wei-jun 2018, 48 (5):  288-292.  doi: 10.13218/j.cnki.csdc.2018.05.009 Abstract ( 382 )   PDF (717KB) ( 344 )   An in vitro skin sensitization test based on skin model and THP-1 cell co-culture was established,and used to evaluate the sensitizing potency of petrochemicals.Skin model was treated with different concentrations of samples for 15 min,then removing the samples and was incubated for another 6 h.Skin tissue activity was measured by MTT assay,while cell viability and cell surface markers (CD54,CD86) expression levels of THP-1 cells were detected by flow cytometry.The skin sensitization potential of test substances was determined by statistically analyzing the above parameters and reaching a dose-response relationship.The results of SLS,cinnamaldehyde and citral show that this co-culture method can correctly distinguish irritants and sensitizers.The results of 4 unknown lubricant additives show that HVI60,Cuvan826 and ATM PAN are predicted to be non-sensitizers,while Irgamet30 is predicted to be a sensitizer,which at higher concentration can decrease the skin tissue activity and THP-1 cell viability,and specifically increase the expression of surface markers. References | Related Articles | Metrics

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Study on the mechanism of inhibition of melanin by phenethyl resorcinol HAO Mi-mi, WANG Yan, LIU Yuan-yuan, BAO Yan, LI Hong-yan, ZHENG Lin 2018, 48 (5):  293-298.  doi: 10.13218/j.cnki.csdc.2018.05.010 Abstract ( 546 )   PDF (1486KB) ( 428 )   Using the drug substitution method,the two stages in the process of melanin formation (i.e.enzyme catalysis and nonenzymatic catalysis) were blocked,in order to explore the mechanism of inhibition of melanin formation by phenethyl resorcinol.Using L-tyrosine and L-DOPA as substrates,after the reaction at 37 ℃ in the phosphate buffer solution of pH=6.8,the absorbance was measured at 475 nm.The effect of phenethyl resorcinol on the catalytic reaction of tyrosinase was studied,and the inhibition kinetic parameters were calculated;The mechanism of inhibition of tyrosinase by phenethyl resorcinol was explored by molecular docking analysis.Results show that phenethyl resorcinol is a tyrosinase inhibitor which can inhibit the enzymic catalytic reaction in the process of melanin formation,while it has no effect on nonenzymatic catalysis;phenethyl resorcinol can efficiently inhibit the activities of monophenolase and diphenolase of tyrosinase,with 50% inhibiting concentrations being 0.28 and 31 μmol/L,respectively;it is found that the inhibition of diphenolase is noncompetitive,and the inhibition constant is Km=1.1;molecular docking results show that phenethyl resorcinol forms hydrogen bonds with tyrosinase MET A:280,accompanied by hydrophobic interaction. References | Related Articles | Metrics

Analytical methods and testing

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Determination of ten fluorescent whitening agents in masks by HPLC- FLD/DAD with series double-detector LIU Ying, WANG Xiao-bing, LI Qi-yan, YU Hai-ying, XU Li-hua 2018, 48 (5):  299-302.  doi: 10.13218/j.cnki.csdc.2018.05.011 Abstract ( 327 )   PDF (702KB) ( 295 )   To establish a new HPLC-FLD/DAD with series double-detector method for the determination of ten fluorescent whitening agents in masks.The sample was separated by Welch Ultimate LP C18(4.6 mm×250 mm,3.5 μm) column with the gradient elution of methanol-0.05 mol/L ammonium dihydrogen phosphate solution as mobile phase at the flow rate of 1.0 mL/min.The column temperature was set at 35.0 ℃.The excitation wavelength and emission wavelength of fluorescence detector (FLD) were 360 and 430 nm,and the wavelength of diode array detector (DAD) was 360 nm.Results indicate that ten fluorescent whitening agents have good linear relationship in their linear range,with correlation coefficient greater than 0.999 5.At the three spiked levels,the average recoveries of ten fluorescent whitening agents are in the range of 87.6%-114.2% with the relative standard deviations (RSD,n=6) less than 5.0%.The detection limits of these ten fluorescent whitening agents are 0.026-0.40 mg/kg for FLD and 0.50-2.7 mg/kg for DAD. References | Related Articles | Metrics