Optimization of Conditions for Extracting Luteolin from Ternate Grape Fern Herb by an Orthogonal Experiment

[Objectives] This study was conducted to optimize the extraction process of luteolin, a natural product of Ternate Grape Fern Herb, so as to provide a theoretical research basis for the chemical composition, pharmacological research and preparation development of Ternate Grape Fern Herb. [Methods] The effects of four factors including ultrasonic extraction time, liquid-to-material ratio, ultrasonic extraction temperature and ethanol concentration on extraction yield of luteolin from Ternate Grape Fern Herb were investigated by the ultrasonic-assisted extraction technology, through a single-factor experiment and an orthogonal experiment based on the single-factor experiment, and the experimental data was subjected to variance analysis and SSR analysis of the significance of differences between groups by SPSS20.0 software to select the optimal extraction process conditions. [Results] The optimal extraction process conditions were as follows: ultrasonic extraction time 25 min, liquid-to-material ratio 25∶1 ml/g, ethanol volume fraction 60%, ultrasonic extraction temperature 85 ℃. [Conclusions] The results were verified, and it was determined that the ultrasonic-assisted extraction process established in this study is reasonable and reliable, and can be used for the extraction of luteolin.

LDHs-MoO3复合粉体的制备及对聚氯乙烯阻燃抑烟性能的影响

通过高速球磨法制备了不同配比的三氧化钼(MoO3)和钙铝水滑石(LDHs)复合粉体。考察不同配比复合粉体对聚氯乙烯(PVC)体系热稳定性能、阻燃抑烟性能和力学性能的影响。结果表明,高能振磨使LDHs与MoO3分子间产生了化学键合,部分MoO42-进入LDHs片层结构,可以抑制MoO3纳米片之间容易团聚的问题;当LDHs∶MoO3质量比为10∶1时,MoO3在LDHs片层中分散效果最佳;当添加6 phr时PVC烟密度较纯PVC降低了29%,极限氧指数(LOI)提高了28%,对力学性能影响不明显;LDHs-MoO3/PVC(质量比10∶1)的热分解活化能(Ea)由纯PVC的129.1 kJ/mol提高至136.2 kJ/mol;根据Kissinger分解动力学原理分析,复合材料补偿参数(Sp*)基本恒定,说明其未改变PVC降解机理。

动态硫化法制备结构性耐候聚苯乙烯/乙烯-辛烯共聚物高韧合金

利用Friedel-Crafts烷基化反应制备50/50(质量比,下同)聚苯乙烯/乙烯-辛烯共聚物(PS/POE)增容母料,研究了POE-PS增容母料用量和动态硫化对PS/POE(70/30)性能的影响。结果表明,在增容母料中,PS接枝率为29.2%,凝胶含量为0%;当添加40 phr增容母料取代PS/POE(70/30)共混物中部分PS和POE,共混物的冲击强度比纯PS和相同配比简单共混物分别提高了300%和91.2%;在此基础上,添加过氧化二异丙苯(DCP)和三烯丙基异氰脲酸酯(TAIC)各0.2 phr进行动态硫化,其冲击强度和拉伸强度较未动态硫化的PS/POE/PS-POE增容母料(50/10/40)提高了12.4%和6.5%;扫描电镜、动态流变性能和动态力学热分析的测试结果表明,采用增容母料和动态硫化有助于提高POE与PS两相之间的相容性。

Optimization of Extraction Process of Quercetin from Flos Sophorae Immaturus Using Orthogonal Design

[Objectives]This study aimed to optimize the ultrasonic-assisted extraction process of quercetin from Flos Sophorae Immaturus.[Methods]The natural product quercetin in Flos Sophorae Immaturus was extracted by ultrasonic-assisted method,and the content of quercetin in the extract was determined by ultraviolet spectrophotometry.The effect of ethanol concentration,solid/liquid ratio,temperature,time and ultrasonic power on the yield of quercetin in Flos Sophorae Immaturus was investigated by using single-factor experiments.Based on the results of single-factor experiments,an orthogonal experiment was designed to optimize the extraction process.The experimental data obtained were subjected to range analysis,analysis of variance and SSR test using SPSS 20.0 software to obtain the optimal extraction process.The results concluded were verified.[Results]The optimal ultrasonic-assisted extraction process for quercetin in Flos Sophorae Immaturus was as follows:temperature of 85℃,time of 30 min,solid/liquid ratio of 1∶20 g/mL,ethanol concentration of 50%.Under the optimal extraction conditions,the yield of quercetin in Flos Sophorae Immaturus was the highest.[Conclusions]This study provides a theoretical basis for the application of quercetin in Flos Sophorae Immaturus.

Study on the Technological Conditions of Ultrasound-assisted Extraction of Polysaccharides from Ajuga ciliata Bunge (Fujian)

[Objectives]To determine the optimum technological conditions of ultrasound-assisted extraction of polysaccharides from Ajuga ciliata Bunge.[Methods]In this study,Ajuga ciliata Bunge was used as raw material,and an orthogonal experiment was designed based on the single factor experiment to investigate the effects of ultrasonic time,solid-liquid ratio,ultrasonic temperature and ultrasonic power on the extraction rate of polysaccharides from A.ciliata Bunge(Fujian).Range analysis,variance analysis and SSR test of significant differences between groups were carried out with SPSS 20.0,and the test results were verified.[Results]Under the conditions of ultrasonic temperature of 85℃,ultrasonic time of 80 min,solid-liquid ratio of 1∶15 g/mL and ultrasonic power of 500 W,the yield of polysaccharides from A.ciliata Bunge(Fujian)was the best.[Conclusions]This study can provide theoretical basis for the application of A.ciliata Bunge(Fujian).

Highly elastic wrinkled structures for stable and low volume-expansion lithium-metal anodes

Lithium(Li)metal is promising for high energy density batteries due to its low electrochemical redox potential and high specific capacity.However,the formation of dendrites and its tendency for large volume expansion during plating/stripping restrict the application of Li metal in practical scenarios.In this work,we developed reduced graphene oxide-graphitic carbon nitride(rGO-C3N4,GCN)with highly elastic and wrinkled structure as the current collector.Lithiophilic site C3N4 in GCN could reduce the nucleation overpotential.In addition,this material effectively inhibited electrode expansion during cycling.At the same time,due to its high elasticity,GCN could release the stress induced by Li deposition to maintain structural integrity of the electrode.Limetal anodes with GCN exhibited small volume expansion,high Coulombic efficiency(CE)of 98.6%within 300 cycles and long cycling life of more than 1700 h.This work described and demonstrated a new approach to construct flexible current collectors for stable lithium-metal anodes.