Table of Content

20 June 2018, Volume 48 Issue 6 Previous Issue    Next Issue

Basic research

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Dynamic surface tension and adsorption behavior of vanillin-based nonionic surfactants at gas-liquid interface ZHAI Gong-xun, DING Feng-mei, XING Zhi-qi, ZHOU Xiang 2018, 48 (6):  303-307.  doi: 10.13218/j.cnki.csdc.2018.06.001 Abstract ( 259 )   PDF (957KB) ( 516 )   The dynamic surface tension of vanillin-based polyoxyethylene ethers (VAEO) was measured by the maximum bubble pressure method.The adsorption mechanism of surfactants at gas-liquid interface was studied by using Word-Tordai equation.The results show that when the mass concentration of VAEO is below critical micelle concentration (cmc),the adsorption of VAEO obeys the mechanisms of diffusion controlled adsorption and mixed diffusion-kinetic controlled adsorption,respectively,at the early stage and the later stage of adsorption.When the mass concentration is above cmc,the adsorption mechanism is mixed diffusion-kinetic controlled adsorption,where the micelles do not affect the adsorption behavior.The magnitude of diffusion coefficients of VAEO10 and VAEO20 are 10-11 m2/s,which are lower than the NPEO9s reported in literature. References | Related Articles | Metrics

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Effects of sodium salicylate on the self-assembly behavior of DTAB/PAM mixed system CHEN Yu-jia, LIU Jia-xi, ZHU Qian-qian, HU Song-qing, SUN Shuang-qing, WANG Xiu-min 2018, 48 (6):  308-313.  doi: 10.13218/j.cnki.csdc.2018.06.002 Abstract ( 303 )   PDF (2291KB) ( 523 )   The effects of sodium salicylate (NaSal) on the self-assembly behavior of the mixed system of polyacrylamide (PAM) and dodecyltrimethylammonium bromide (DTAB) were studied by coarse-grained molecular dynamics simulation.The results indicate that,with the increase of NaSal concentration,the aggregates of DTAB/PAM undergo a shape transition from sphere to rod then to sphere,and the number of DTAB molecules adsorbed onto HPAM chains first increases and then decreases.As for the DTAB/PAM aggregate,the PAM chain is located at the interface between the hydrophobic core and the hydrophilic layer of the DTAB micelle,and the Sal- ions are inserted into the interior of the micelle.The variations with time of the polymer chains Rg and the number of surfactant molecules in the aggregate can be both divided into three stages.The formation of larger DTAB/PAM aggregates needs longer time. References | Related Articles | Metrics

Lecture of science and technology

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Efficacy evaluation of cosmetics (Ⅵ) Experimental design of cosmetics human efficacy evaluation PAN Yao, ZHAO Hua 2018, 48 (6):  314-321.  doi: 10.13218/j.cnki.csdc.2018.06.003 Abstract ( 623 )   PDF (858KB) ( 1164 )   The concept,basic elements,and basic principles of experimental design of cosmetics human efficacy evaluation were summarized.The commonly used types and key points of experimental design were introduced.The new idea of the design of cosmetics human efficacy evaluation protocol was proposed,in order to improve the ability of researchers to make a reliable experiment protocol. References | Related Articles | Metrics

Development and application

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Study on the acid and alkali resistance of oleic acid methyl ester ethoxylate ZHANG Yong, SUN Yong-qiang, DING Li-rong, ZHOU Jing-jie, SUN Jin-yuan, LIANG Hui-bin 2018, 48 (6):  322-325.  doi: 10.13218/j.cnki.csdc.2018.06.004 Abstract ( 324 )   PDF (1031KB) ( 571 )   Oleic acid methyl ester ethoxylate (OMEE) was characterized by FT-IR.The acid and alkali resistance of fatty acid methyl ester ethoxylate (FMEE) and OMEE were measured qualitatively and quantitatively by national standard method and mass method,respectively.The experimental results show that,the structure of OMEE is different from that of conventional saturated FMEE because of the presence of carbon-carbon double bond.The national standard method is not suitable for the determination of acid or alkali resistance of FMEE.The hydrolysis rate of OMEE is always higher than that of FMEE at any pH.The hydrolysis of both FMEE and OMEE are the fastest at pH 13,and OMEE has been hydrolyzed completely at 170 h.At pH 2~9,the hydrolysis rate of FMEE is still less than 20% during the period of 500 h.In additon,the hydrolysis rate of OMEE has been little affected by either pH or time when the pH is less than 13. References | Related Articles | Metrics

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Study on the effect of essential oil from fruit kernel of Wampee against UV-induced skin photoaging in mice PENG Zhi-hong, WU Ke-feng, HUANG Yan-xia, LIAO Xue-hua, OUYANG Pei-pei, LI Wen-de 2018, 48 (6):  326-329.  doi: 10.13218/j.cnki.csdc.2018.06.005 Abstract ( 318 )   PDF (1972KB) ( 428 )   The essential oil from fruit kernel of Wampee was extracted by steam distillation and separated by frozen crystallization.Then the essential oil was applied to the back of hairless KM mice.Score of skin clinical observation and histopathological examination were performed to evaluate the anti-photoaging effects after UVA/UVB combined irradiation.Results show that 1.9% Vitamin E as the positive control plays a significant role in anti-photoaging,The essential oil from fruit kernel of Wampee at the dose of 2.5%,5% and 10% can play a role in resisting UV-induced dermis lesions ,and can improve UV-induced epidermal lesions like epidermal thickening and wrinkle formation at 5% and 10%. References | Related Articles | Metrics

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Study on extraction of unsaponifiable matter in camellia oil and its antioxidant activity ZHOU Zhen-yu, YANG Cheng, CAI Chun-hui 2018, 48 (6):  330-335.  doi: 10.13218/j.cnki.csdc.2018.06.006 Abstract ( 292 )   PDF (946KB) ( 333 )   Camellia oil was used as raw material to extract unsaponifiable matter (USM) by saponification-hexane extraction method.The compositions of USM in camellia oil were analyzed by gas chromatography-mass spectrometry (GC-MS),and DPPH radical-scavenging assay,ferric reducing-antioxidant power (FRAP) test and cellular antioxidant activity assay (CAA) were applied to determine their antioxidant activity in comparison with α-tocopherol.Results indicate that the compositions of USM in camellia oil obtained by saponification-hexane extraction are mainly hydrocarbon,triterpene alcohol and phytosterol.The DPPH free radical scavenging rate of USM in camellia oil is 95%,and the EC50 is 1.9 g/L.USM in camellia oil has certain ability to reduce Fe3+,and the FRAP value is 170 at the mass concentration of 5 g/L.USM in camellia can enter the HSF cells and inhibit the ABAP-induced intracellular reactive oxygen species formation.The CAA value is up to 36.6,when the mass concentration of USM is 100 mg/L. References | Related Articles | Metrics

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Preparation of macroporous aluminium oxide by using mono-dispersed PMMA microspheres as templates ZHANG Yong, KONG Qing-lan, LIU Zhi-ping, YAN Shan-shan, YU Feng 2018, 48 (6):  336-340.  doi: 10.13218/j.cnki.csdc.2018.06.007 Abstract ( 318 )   PDF (2263KB) ( 470 )   Mono-dispersed polymethyl methacrylate (PMMA) latex microspheres were prepared by emulsion polymerization using ammonium persulfate as initiator,sodium dodecyl sulfate as emulsifier and methyl methacrylate as monomer.The results show that the particle size of the as-synthesized PMMA microspheres can be effectively controlled and adjusted by changing the content of emulsifier.The PMMA microspheres with diameter distribution of 200~300 nm were obtained.The self-assembly of PMMA microspheres was accelerated by demulsification sedimentation method so as to obtain a tightly packed PMMA microsphere colloidal template.The solution of aluminum isopropoxide dissolved in ethanol (acidified by hydrochloric acid) was filled into the interspaces of the PMMA colloidal template.The macroporous material of alumina was then obtained by roasting the template.γ-Al2O3 three-dimensionally ordered macroporous material (3DOM) was obtained by calcination at 950 ℃ for 3 h.The results of SEM and TEM show that the material is 3DOM which has many porous channels. References | Related Articles | Metrics

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Effects of benzyl-grafted alginate derivative on the dispersion stability of TiO2 nanoparticles FENG Mei-xi, YAN Hui-qiong, CHEN Xiu-qiong, LIN Liang-quan, YANG Zheng, LIN Qiang 2018, 48 (6):  341-347.  doi: 10.13218/j.cnki.csdc.2018.06.008 Abstract ( 190 )   PDF (1759KB) ( 295 )   Benzyl-grafted alginate derivative (BAD) was prepared by bimolecular nucleophilic substitution reaction (SN2) using benzyl bromide as a hydrophobic modifier.The effects of BAD on the dispersion stability of aqueous suspension of TiO2 nanoparticles at different pH and ionic strength were investigated by dynamic light scattering.Additionally,the functional groups and morphology of BAD/TiO2 nanoparticle composite were measured by fourier transform infrared spectroscopy and scanning electron microscopy.The experimental results show that the colloidal BAD is successfully synthesized by SN2 reaction.The average hydrodynamic size (dH) of BAD micelles is 423.4 nm and the Zeta potential is-27.4 mV,which exhibits good colloidal properties.At different pH,the adsorption of BAD can enhance the chargeability of TiO2 nanoparticles,which makes their Zeta potential to be lower than -30 mV and their dH to be significantly lower than that of single TiO2 nanoparticles.At different ionic strength,BAD can obviously weaken the electrostatic shielding effect of counterions on TiO2 nanoparticles,which makes the agglomeration behavior of TiO2 nanoparticles to be greatly reduced and their dH to be significantly decreased.The molecular chain of BAD can not only enhance the electrostatic repulsion among TiO2 particles,but also provide effective steric hindrance,which improves the dispersion stability of TiO2 nanoparticles at different pH and ionic strength.The results of infrared spectroscopy and scanning electron microscopy indicate that the adsorption of BAD on TiO2 nanoparticles is achieved mainly through the hydrogen bonding between BAD and TiO2 nanoparticles,which has enhanced the steric hindrance among TiO2 nanoparticles and thus makes them dispersed stably. References | Related Articles | Metrics

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Determination of quercetin in Ginkgo leaves tablets by micellar SDS enhanced fluorimetry CHEN Jin-e, ZHANG Hai-rong 2018, 48 (6):  348-351.  doi: 10.13218/j.cnki.csdc.2018.06.009 Abstract ( 287 )   PDF (812KB) ( 331 )   A new method for the determination of quercetin in Ginkgo leaves tablets was established by sodium dodecyl sulfate (SDS) enhanced fluorimetry.The effects of external conditions,such as the type and amount of surfactant and pH on the fluorescence intensity of quercetin were investigated.Results show that among the four kinds of ordered media,i.e.,SDS,CTMAB,Triton X-100 and β-CD,the fluorescence intensity of quercetin is greatly enhanced in SDS solution under alkaline condition (pH=9.12) with a strong fluorescence emission peak at λex/λem=464/542 nm.Under the optimal experimental conditions of pH=9.12 and SDS concentration of 1.5×10-2 mol/L the linear relationship between fluorescence intensity and concentration of quercetin is kept in the range of 2-14 μg/mL with the detection limit of 0.16 μg/L and RSD of 1.56%.The method has been applied to the determination of quercetin in four kinds of Ginkgo leaves tablets with satisfactory results. References | Related Articles | Metrics

Analytical methods and testing

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Determination of methanol in polyvinyl alcohol used in cosmetics by gas chromatography YANG Ming, ZHANG Li-hua, HU Dan, WANG Chen-lei, REN Cheng-fang 2018, 48 (6):  352-355.  doi: 10.13218/j.cnki.csdc.2018.06.010 Abstract ( 320 )   PDF (846KB) ( 307 )   A gas chromatography method was established for the determination of methanol in polyvinyl alcohol used in cosmetics.It is found that headspace method is more suitable than distillation method and direct dilution method to determine the methanol in polyvinyl alcohol used in cosmetics.The factors of solvent and salting-out agent were investigated and the appropriate conditions are 10 mL water and 0.5 g sodium chloride,respectively.Results indicate that the linear relationship of methanol in the range of 10-1 000 mg/L is good,with correlation coefficient of 0.999 5.The recoveries are ranged from 92.6% to 104.8%,while the relative standard deviations are ranged from 1.2% to 6.5% and the detection limit is 5 mg/L.The results prove that this method is suitable for the determination of methanol in polyvinyl alcohol used in cosmetics. References | Related Articles | Metrics

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Simultaneous determination of polycyclic aromatic hydrocarbons and phthalic acid esters in cosmetics by GC-MS with solid-phase extraction ZHANG Rui-rui, WANG Chen-xia, LI Xiu-ying, DU Wei-feng, GUO Xin-dong 2018, 48 (6):  356-362.  doi: 10.13218/j.cnki.csdc.2018.06.011 Abstract ( 249 )   PDF (889KB) ( 294 )   A sensitive method for the simultaneous determination of 16 polycyclic aromatic hydrocarbons (PAHs) and 17 phthalic acid esters (PAEs) in cosmetics by gas chromatography-mass spectrometry (GC-MS) coupled with solid-phase extraction (SPE) was established.Samples were ultrasonically extracted with acetonitrile,purified using PSA/Slica Glass SPE column,separated using Agilent Select PAH chromatographic column and detected by GC-MS with selected ion monitoring (SIM).Results indicate that the linear relationship of 16 PAHs and 17 PAEs in the range of 0.5-200 μg/L is good,with correlation coefficient greater than 0.99.The limits of detection and quantification of the method for PAHs are in the range of 0.6-1.0 and 1.9-3.3 μg/kg,respectively,the average recoveries of negative samples at three spiked levels are between 86.4% and 112.2%.The limits of detection and quantification of the method for PAEs are in the range of 0.4-2.3 and 1.5-7.6 μg/kg,respectively,the average recoveries of negative samples at three spiked levels are between 82.2% and 114.1%,and the relative standard deviation (RSD,n=6) is less than 10%. References | Related Articles | Metrics