Traditional solvent recovery in the extraction step of edible oil processing is distillation,which consumes large amounts of energy.If the distillation is replaced by membrane process,the energy consumption can be red...Traditional solvent recovery in the extraction step of edible oil processing is distillation,which consumes large amounts of energy.If the distillation is replaced by membrane process,the energy consumption can be reduced greatly.In this work,two kinds of membrane,PDMS(polydimethylsiloxane) composite membrane and Zeolite filled PDMS membrane were prepared,in which asymmetric microporous PVDF(polyvinylidenefluoride) membrane prepared with phase inversion method was functioned as the microporous supporting layer in the flat-plate composite membrane.The different function compositions of the PDMS/PVDF composite membranes were characterized by reflection Fourier transform infrared(FTIR) spectroscopy.The surface and section of PDMS/PVDF composite membranes were investigated by scanning electron microscope(SEM).The PDMS NF(nanofiltration) membranes were then applied in the recovery of hexane from soybean oil/hexane miscellas(1:3,mass ratio).The effects of pressure(0.5-1.5 MPa),cross-linking temperature and PDMS layer thickness on membrane performances were investigated.The results indicated that both two kinds of NF membranes were promising for solvent recovery,and zeolite filled in PDMS NF membrane could enhance the separation performance.展开更多
Polydimethylsiloxane (PDMS) is inactive to electric fields, but when combined with ferroelectric cyanoethyl sucrose (CR-U), it becomes an electrically active actuator material. The PDMS/CR-U composites were prepared b...Polydimethylsiloxane (PDMS) is inactive to electric fields, but when combined with ferroelectric cyanoethyl sucrose (CR-U), it becomes an electrically active actuator material. The PDMS/CR-U composites were prepared by casting method using tetrahydrofuran (THF) and acetone (ACT) as solvents. The effect of a mixed solvent composition was investigated. The viscosity of the PDMS/CR-U/solvent solution decreased as the THF composition increased. The composite film obtained by evaporation of the solvent and cross-linkage of PDMS showed a phase-separated structure. Spherical CR-U dispersed in the PDMS matrix with a skin layer on one surface side. Electrical resistance, dielectric constant, space-charge distribution, and electrically induced bending deformation behavior were investigated for these composite films. The composite films prepared from a THF-rich solvent exhibited lower surface resistivity than those prepared from a THF-poor solvent. Applying an electric field to the composite film resulted in an asymmetric space-charge distribution with charge accumulation in the skin layer. THF content decreased the viscosity of the solution, meaning the decrease of the apparent size of PDMS chain aggregates. It allows the dispersion of CR-U in the PDMS matrix and also results in the decline of resistivity, the increase of permittivity, and the increase of charge injection. The results explained the structure formation of the composite film and the electric field response as an actuator. A casting solvent of THF content of 87.5 wt% or more is essential for the function of the PDMS/CR-U composite.展开更多
The novel method for preparing the polymer composite particles has been developed. It was tried to prepare polymer composite particles composed of polystyrene and carbon black with the phase separation method followed...The novel method for preparing the polymer composite particles has been developed. It was tried to prepare polymer composite particles composed of polystyrene and carbon black with the phase separation method followed by suspension polymerization. In order to prepare the polymer composite particles with the more uniform diameter, the styrene monomer droplets containing carbon black were formed with phase separation emulsification in which ethyl alcohol and water were used as the good solvent and the poor solvent for styrene monomer, respectively. In the experiment, the surfactant species and their concentrations, the pouring velocity of water and the weight ratio of carbon black to styrene monomer were mainly changed. Water was poured at the given pouring velocity into ethyl alcohol in which styrene monomer and an initiator were dissolved and carbon black was dispersed beforehand. The spherical polymer composite particles containing carbon black were prepared with Tween 20 and Tween 80 of nonionic surfactants and the irregular polymer composite particles were prepared with PVA, SDS and Kotamine. The diameters of polymer composite particles increased with the pouring velocity of water and with the weight ratio of carbon black to styrene monomer.展开更多
Objective: To analyse the phytochemical contents of leaf, stem bark and root of Jatropha curcas(J. curcas) in four solvent extracts and their proximate and mineral compositions. Methods: Standard analytical procedures...Objective: To analyse the phytochemical contents of leaf, stem bark and root of Jatropha curcas(J. curcas) in four solvent extracts and their proximate and mineral compositions. Methods: Standard analytical procedures were used for the determination of phytochemicals, proximate and mineral compositions of the leaf, stem bark and root extracts of J. curcas. Results: Results of the analysis showed the presence of polyphenols, flavonoids, alkaloids, cardiac glycosides, coumarins, saponins, terpenoids, steroids, triterpenoid saponins, carotenoids, phlobatannins and tannins in the leaf, stem bark and root of all the solvent extracts. Flavonoids were present in the highest amount in the ethyl acetate extracts of the leaf(7.35% ± 0.02%), stem bark(4.12% ± 0.01%) and root(3.35% ± 0.02%) followed by polyphenols in the methanol extracts of leaf(4.62% ± 0.02%), stem bark(2.77% ± 0.05%) and root(2.49% ± 0.02%). Poly-acetylated compounds were absent in all the solvent extracts of the leaf, stem bark and root. However, some anti-nutritional agents such as oxalates, phytates and cyanates were present in all the solvent extracts of the leaf, stem bark and root except the ethyl acetate. Phytates were high in the aqueous solvent of the leaf(6.12% ± 0.00%) but low in the stem bark(1.00% ± 0.05%) and root(0.89% ± 0.03%). Proximate composition showed appreciable amounts of total carbohydrate(36.33% ± 0.72%), crude protein(26.00% ± 0.47%) and reducing sugars(5.87% ± 0.14%) in the leaf, while crude fat was more in the stem bark(16.70% ± 0.30%). There was corresponding substantial energy in the leaf [(1 514.77 ± 20.87) kJ /100 g] and stem bark [(907.00 ± 8.52) kJ /100 g]. Moisture and ash contents of the leaf, stem bark and root were within acceptable limits for the use in drugs formulation. The mineral composition showed substantial amounts of important elements such as Fe, Ca, Na, Mg and Zn. Others were P, K and Se. Conclusions: The outcome of this study suggests that the leaf, stem bark and root of J. curcas have very good medicinal potentials, meet the standard requirements for drug formulation and serve as good sources of energy and nutrients except for the presence of some anti-nutritional elements predominant in the leaf.展开更多
目的采用加速溶剂萃取方法构建快速高效的小米多酚提取方法,并探究小米多酚类化合物的组成及滋味成分。方法采用加速溶剂萃取方法,以小米粉为原料,基于加速溶剂萃取仪,分析乙醇体积分数、萃取温度和萃取时间对提取的小米多酚含量的影响...目的采用加速溶剂萃取方法构建快速高效的小米多酚提取方法,并探究小米多酚类化合物的组成及滋味成分。方法采用加速溶剂萃取方法,以小米粉为原料,基于加速溶剂萃取仪,分析乙醇体积分数、萃取温度和萃取时间对提取的小米多酚含量的影响,并对提取工艺参数进行响应面优化,通过超高效液相色谱三重四极杆/线性离子阱质谱法(ultra performance liquid chromatography-triple quadrupole/linear ion trap mass spectrometry,UPLC-QTRAP-MS/MS)对所得小米多酚的组成及滋味成分进行分析。结果加速溶剂萃取法提取小米多酚的最优工艺参数为:乙醇体积分数为59%、萃取时间10 min、萃取温度60℃,此条件下小米多酚含量达(2.90±0.01)mg/g。UPLC-QTRAP-MS/MS从小米中共鉴定出822种多酚类化合物,其中黄酮类化合物最多,占总多酚类化合物的47.20%;其次为酚酸类化合物,占42.09%。将822种多酚类化合物与滋味库进行对比,发现其中能够呈现滋味的有16种,分别是2-甲氧基-4-甲基苯酚、水杨酸、苯甲酸、苯甲酰胺、芥子酸、熊果苷、咖啡酸、没食子酸、苯醋酸乙酯、查尔酮、水飞蓟素、白杨素、杨梅素、槲皮素、6-甲基香豆素、双香豆素。结论以加速溶剂萃取法结合响应面分析提取小米多酚的方法是可行的,该方法简便省时,是小米提取多酚的有效途径。本研究系统地定性了小米多酚的组成成分及其种类,明确了部分多酚类化合物的滋味,为小米多酚的组成及小米滋味的研究提供一定的理论依据。展开更多
基金Supported by the State Key Development Program for Basic Research of China （2009CB623404） the National Natural Science Foundation of China （20736003 20906056） the National High Technology Research and Development Program of China （2007AA06Z317 2008EG111021）
文摘Traditional solvent recovery in the extraction step of edible oil processing is distillation,which consumes large amounts of energy.If the distillation is replaced by membrane process,the energy consumption can be reduced greatly.In this work,two kinds of membrane,PDMS(polydimethylsiloxane) composite membrane and Zeolite filled PDMS membrane were prepared,in which asymmetric microporous PVDF(polyvinylidenefluoride) membrane prepared with phase inversion method was functioned as the microporous supporting layer in the flat-plate composite membrane.The different function compositions of the PDMS/PVDF composite membranes were characterized by reflection Fourier transform infrared(FTIR) spectroscopy.The surface and section of PDMS/PVDF composite membranes were investigated by scanning electron microscope(SEM).The PDMS NF(nanofiltration) membranes were then applied in the recovery of hexane from soybean oil/hexane miscellas(1:3,mass ratio).The effects of pressure(0.5-1.5 MPa),cross-linking temperature and PDMS layer thickness on membrane performances were investigated.The results indicated that both two kinds of NF membranes were promising for solvent recovery,and zeolite filled in PDMS NF membrane could enhance the separation performance.
文摘Polydimethylsiloxane (PDMS) is inactive to electric fields, but when combined with ferroelectric cyanoethyl sucrose (CR-U), it becomes an electrically active actuator material. The PDMS/CR-U composites were prepared by casting method using tetrahydrofuran (THF) and acetone (ACT) as solvents. The effect of a mixed solvent composition was investigated. The viscosity of the PDMS/CR-U/solvent solution decreased as the THF composition increased. The composite film obtained by evaporation of the solvent and cross-linkage of PDMS showed a phase-separated structure. Spherical CR-U dispersed in the PDMS matrix with a skin layer on one surface side. Electrical resistance, dielectric constant, space-charge distribution, and electrically induced bending deformation behavior were investigated for these composite films. The composite films prepared from a THF-rich solvent exhibited lower surface resistivity than those prepared from a THF-poor solvent. Applying an electric field to the composite film resulted in an asymmetric space-charge distribution with charge accumulation in the skin layer. THF content decreased the viscosity of the solution, meaning the decrease of the apparent size of PDMS chain aggregates. It allows the dispersion of CR-U in the PDMS matrix and also results in the decline of resistivity, the increase of permittivity, and the increase of charge injection. The results explained the structure formation of the composite film and the electric field response as an actuator. A casting solvent of THF content of 87.5 wt% or more is essential for the function of the PDMS/CR-U composite.
文摘The novel method for preparing the polymer composite particles has been developed. It was tried to prepare polymer composite particles composed of polystyrene and carbon black with the phase separation method followed by suspension polymerization. In order to prepare the polymer composite particles with the more uniform diameter, the styrene monomer droplets containing carbon black were formed with phase separation emulsification in which ethyl alcohol and water were used as the good solvent and the poor solvent for styrene monomer, respectively. In the experiment, the surfactant species and their concentrations, the pouring velocity of water and the weight ratio of carbon black to styrene monomer were mainly changed. Water was poured at the given pouring velocity into ethyl alcohol in which styrene monomer and an initiator were dissolved and carbon black was dispersed beforehand. The spherical polymer composite particles containing carbon black were prepared with Tween 20 and Tween 80 of nonionic surfactants and the irregular polymer composite particles were prepared with PVA, SDS and Kotamine. The diameters of polymer composite particles increased with the pouring velocity of water and with the weight ratio of carbon black to styrene monomer.
文摘Objective: To analyse the phytochemical contents of leaf, stem bark and root of Jatropha curcas(J. curcas) in four solvent extracts and their proximate and mineral compositions. Methods: Standard analytical procedures were used for the determination of phytochemicals, proximate and mineral compositions of the leaf, stem bark and root extracts of J. curcas. Results: Results of the analysis showed the presence of polyphenols, flavonoids, alkaloids, cardiac glycosides, coumarins, saponins, terpenoids, steroids, triterpenoid saponins, carotenoids, phlobatannins and tannins in the leaf, stem bark and root of all the solvent extracts. Flavonoids were present in the highest amount in the ethyl acetate extracts of the leaf(7.35% ± 0.02%), stem bark(4.12% ± 0.01%) and root(3.35% ± 0.02%) followed by polyphenols in the methanol extracts of leaf(4.62% ± 0.02%), stem bark(2.77% ± 0.05%) and root(2.49% ± 0.02%). Poly-acetylated compounds were absent in all the solvent extracts of the leaf, stem bark and root. However, some anti-nutritional agents such as oxalates, phytates and cyanates were present in all the solvent extracts of the leaf, stem bark and root except the ethyl acetate. Phytates were high in the aqueous solvent of the leaf(6.12% ± 0.00%) but low in the stem bark(1.00% ± 0.05%) and root(0.89% ± 0.03%). Proximate composition showed appreciable amounts of total carbohydrate(36.33% ± 0.72%), crude protein(26.00% ± 0.47%) and reducing sugars(5.87% ± 0.14%) in the leaf, while crude fat was more in the stem bark(16.70% ± 0.30%). There was corresponding substantial energy in the leaf [(1 514.77 ± 20.87) kJ /100 g] and stem bark [(907.00 ± 8.52) kJ /100 g]. Moisture and ash contents of the leaf, stem bark and root were within acceptable limits for the use in drugs formulation. The mineral composition showed substantial amounts of important elements such as Fe, Ca, Na, Mg and Zn. Others were P, K and Se. Conclusions: The outcome of this study suggests that the leaf, stem bark and root of J. curcas have very good medicinal potentials, meet the standard requirements for drug formulation and serve as good sources of energy and nutrients except for the presence of some anti-nutritional elements predominant in the leaf.
文摘目的采用加速溶剂萃取方法构建快速高效的小米多酚提取方法,并探究小米多酚类化合物的组成及滋味成分。方法采用加速溶剂萃取方法,以小米粉为原料,基于加速溶剂萃取仪,分析乙醇体积分数、萃取温度和萃取时间对提取的小米多酚含量的影响,并对提取工艺参数进行响应面优化,通过超高效液相色谱三重四极杆/线性离子阱质谱法(ultra performance liquid chromatography-triple quadrupole/linear ion trap mass spectrometry,UPLC-QTRAP-MS/MS)对所得小米多酚的组成及滋味成分进行分析。结果加速溶剂萃取法提取小米多酚的最优工艺参数为:乙醇体积分数为59%、萃取时间10 min、萃取温度60℃,此条件下小米多酚含量达(2.90±0.01)mg/g。UPLC-QTRAP-MS/MS从小米中共鉴定出822种多酚类化合物,其中黄酮类化合物最多,占总多酚类化合物的47.20%;其次为酚酸类化合物,占42.09%。将822种多酚类化合物与滋味库进行对比,发现其中能够呈现滋味的有16种,分别是2-甲氧基-4-甲基苯酚、水杨酸、苯甲酸、苯甲酰胺、芥子酸、熊果苷、咖啡酸、没食子酸、苯醋酸乙酯、查尔酮、水飞蓟素、白杨素、杨梅素、槲皮素、6-甲基香豆素、双香豆素。结论以加速溶剂萃取法结合响应面分析提取小米多酚的方法是可行的,该方法简便省时,是小米提取多酚的有效途径。本研究系统地定性了小米多酚的组成成分及其种类,明确了部分多酚类化合物的滋味,为小米多酚的组成及小米滋味的研究提供一定的理论依据。
