The electrokinetic properties and flotation of diaspore, kaolinite, pyrophyllite and illite with quaternary ammonium salts collectors were studied. The results of flotation tests show that the collecting ability of qu...The electrokinetic properties and flotation of diaspore, kaolinite, pyrophyllite and illite with quaternary ammonium salts collectors were studied. The results of flotation tests show that the collecting ability of quaternary ammonium salts for the four minerals is in the order（from strong to weak） ofoctadecyl dimethyl benzyl ammonium chloride（ODBA）, cetyl trimethyl ammonium bromide（CTAB）, dodecyl trimethyl ammonium chloride（DTAC）. Under the condition of alkalescence, it is possible to separate the diaspore from the silicate minerals such as kaolinite, illite and pyrophyllite using quaternary ammonium salts as collector. Isoelectric points （IEP） of diaspore, kaolinite, pyrophyllite and illite are pH=6.0, 3.4, 2.3 and 3.2, respectively. Quaternary ammonium salts can change ζ-potential of the aluminosilicate minerals obviously. The flotation mechanisms were explained by ζ-potential and Fourier transform infrared spectrum （FT-IR） measurements. The results demonstrate that only electrostatic interaction takes place between aluminosilicate minerals （diaspore, kaolinite, pyrophyllite and illite） and quaternary ammonium salts.展开更多
The unsaturated quaternary ammonium salt diethyldiallylammonium chloride(DEDAAC) was synthesized in a two-step synthetic method. The influences of the adding method of raw materials and temperature on the yields of di...The unsaturated quaternary ammonium salt diethyldiallylammonium chloride(DEDAAC) was synthesized in a two-step synthetic method. The influences of the adding method of raw materials and temperature on the yields of diethylallylamine (DEAA), and drying and temperature on the synthesis of DEDAAC were investigated. The content of in-process product DEAA was determined by non-aqueous titration. The structure of product DEDAAC was identified with IR, 1 H NMR and elemental analysis. The results show that adding allyl chloride and sodium hydroxide alternately can increase the yield of DEAA and decrease by-products. In further synthesizing of DEDAAC from DEAA, the step of drying DEAA is very necessary. When DEAA is dried by solid sodium hydroxide, good columnar crystals with a high purity(mp 199.5-201.0 ℃) are obtained; when DEAA is undried or the content of water in DEAA is above 20%, only platelets with bad quality are obtained even without crystals. The suitable synthesis conditions for DEAA and DEDAAC are 35 ℃, 6 h and 40 ℃, 36 h, respectively, and their yields are 69.7% and 67.3%, respectively.展开更多
A spiro-type quaternary ammonium salt, spiro-(1,1′)-bipyrrolidinium tetrafluoroborate(SBP-BF4) was successfully prepared by an economical and efficient three-step process comprising the cyclization reaction of 1,4-di...A spiro-type quaternary ammonium salt, spiro-(1,1′)-bipyrrolidinium tetrafluoroborate(SBP-BF4) was successfully prepared by an economical and efficient three-step process comprising the cyclization reaction of 1,4-dibromobutane and pyrrolidine, and subsequent ion exchange pathway with KOH followed by neutralization reaction via HBF4 in the system of ethanol solution. 1H NMR, 13 C NMR, FI-IR and XPS analyses showed the structure of SBP-BF4. The as-obtained SBP-BF4 was dissolved in AN and used as the electrolyte for supercapacitor. Electrochemical measurements demonstrate that, compared with commercial electrolyte TEMA-BF4/AN, SBP-BF4/AN exhibits high ionic conductivity, lower resistance and improved cycling performance, which is due to its smaller ion size and stable symmetry structure.展开更多
以壳聚糖季铵盐(HACC)为功能单体,丙烯酸、丙烯酸丁酯、丙烯酸异辛酯为软单体,甲基丙烯酸甲酯为硬单体,采用半连续种子预乳液法,制备了壳聚糖季铵盐基丙烯酸酯无氟防油剂(HACC-A)。将HACC-A与烷基烯酮二聚体(AKD)复配涂布构建了防水防油...以壳聚糖季铵盐(HACC)为功能单体,丙烯酸、丙烯酸丁酯、丙烯酸异辛酯为软单体,甲基丙烯酸甲酯为硬单体,采用半连续种子预乳液法,制备了壳聚糖季铵盐基丙烯酸酯无氟防油剂(HACC-A)。将HACC-A与烷基烯酮二聚体(AKD)复配涂布构建了防水防油AKD-HACC-A涂布纸。考察了反应条件对HACC-A粒径分布和贮存稳定性的影响,探讨了HACC-A涂布量、m(HACC-A)∶m(AKD)对涂布纸的60 s Cobb值、Kit防油等级的影响。采用FTIR、TGA、SEM、EDS对样品进行了表征,并测试了纸张性能。结果表明,在质量分数5%(以单体总质量计,下同)的OP-10为乳化剂、反应温度70℃、过硫酸铵(APS)用量0.8%(以单体总质量计,下同)、反应时间2 h的最优条件下,制备的HACC-A乳液粒径为200~400 nm,分布较窄,蓝光明显,可长时间(60 d)稳定储存;当HACC用量为5 g、HACC-A涂布量为6 g/m^(2)时,HACC-A涂布后的纸张60 s Cobb值为54 g/m^(2),Kit防油等级为6级,满足食品包装标准;当m(HACC-A)∶m(AKD)=1∶1、涂布量为6 g/m^(2)时,AKD-HACC-A涂布纸60 s Cobb值为30 g/m^(2),Kit防油等级为10级,对常见油脂(常温和105℃的食用油及辣椒油)、有机溶剂(乙醇和丙酮)和碱性溶液(盐酸和NaOH溶液)表现出良好的阻隔性能,防油性能优于聚乙烯淋膜纸,接近含氟防油纸的防油性能。展开更多
基金Project(2005CB623701) supported by the National Key Fundamental Research and Development Program of China
文摘The electrokinetic properties and flotation of diaspore, kaolinite, pyrophyllite and illite with quaternary ammonium salts collectors were studied. The results of flotation tests show that the collecting ability of quaternary ammonium salts for the four minerals is in the order（from strong to weak） ofoctadecyl dimethyl benzyl ammonium chloride（ODBA）, cetyl trimethyl ammonium bromide（CTAB）, dodecyl trimethyl ammonium chloride（DTAC）. Under the condition of alkalescence, it is possible to separate the diaspore from the silicate minerals such as kaolinite, illite and pyrophyllite using quaternary ammonium salts as collector. Isoelectric points （IEP） of diaspore, kaolinite, pyrophyllite and illite are pH=6.0, 3.4, 2.3 and 3.2, respectively. Quaternary ammonium salts can change ζ-potential of the aluminosilicate minerals obviously. The flotation mechanisms were explained by ζ-potential and Fourier transform infrared spectrum （FT-IR） measurements. The results demonstrate that only electrostatic interaction takes place between aluminosilicate minerals （diaspore, kaolinite, pyrophyllite and illite） and quaternary ammonium salts.
文摘The unsaturated quaternary ammonium salt diethyldiallylammonium chloride(DEDAAC) was synthesized in a two-step synthetic method. The influences of the adding method of raw materials and temperature on the yields of diethylallylamine (DEAA), and drying and temperature on the synthesis of DEDAAC were investigated. The content of in-process product DEAA was determined by non-aqueous titration. The structure of product DEDAAC was identified with IR, 1 H NMR and elemental analysis. The results show that adding allyl chloride and sodium hydroxide alternately can increase the yield of DEAA and decrease by-products. In further synthesizing of DEDAAC from DEAA, the step of drying DEAA is very necessary. When DEAA is dried by solid sodium hydroxide, good columnar crystals with a high purity(mp 199.5-201.0 ℃) are obtained; when DEAA is undried or the content of water in DEAA is above 20%, only platelets with bad quality are obtained even without crystals. The suitable synthesis conditions for DEAA and DEDAAC are 35 ℃, 6 h and 40 ℃, 36 h, respectively, and their yields are 69.7% and 67.3%, respectively.
基金Project(51371198)supported by the National Natural Science Foundation of China
文摘A spiro-type quaternary ammonium salt, spiro-(1,1′)-bipyrrolidinium tetrafluoroborate(SBP-BF4) was successfully prepared by an economical and efficient three-step process comprising the cyclization reaction of 1,4-dibromobutane and pyrrolidine, and subsequent ion exchange pathway with KOH followed by neutralization reaction via HBF4 in the system of ethanol solution. 1H NMR, 13 C NMR, FI-IR and XPS analyses showed the structure of SBP-BF4. The as-obtained SBP-BF4 was dissolved in AN and used as the electrolyte for supercapacitor. Electrochemical measurements demonstrate that, compared with commercial electrolyte TEMA-BF4/AN, SBP-BF4/AN exhibits high ionic conductivity, lower resistance and improved cycling performance, which is due to its smaller ion size and stable symmetry structure.
文摘以壳聚糖季铵盐(HACC)为功能单体,丙烯酸、丙烯酸丁酯、丙烯酸异辛酯为软单体,甲基丙烯酸甲酯为硬单体,采用半连续种子预乳液法,制备了壳聚糖季铵盐基丙烯酸酯无氟防油剂(HACC-A)。将HACC-A与烷基烯酮二聚体(AKD)复配涂布构建了防水防油AKD-HACC-A涂布纸。考察了反应条件对HACC-A粒径分布和贮存稳定性的影响,探讨了HACC-A涂布量、m(HACC-A)∶m(AKD)对涂布纸的60 s Cobb值、Kit防油等级的影响。采用FTIR、TGA、SEM、EDS对样品进行了表征,并测试了纸张性能。结果表明,在质量分数5%(以单体总质量计,下同)的OP-10为乳化剂、反应温度70℃、过硫酸铵(APS)用量0.8%(以单体总质量计,下同)、反应时间2 h的最优条件下,制备的HACC-A乳液粒径为200~400 nm,分布较窄,蓝光明显,可长时间(60 d)稳定储存;当HACC用量为5 g、HACC-A涂布量为6 g/m^(2)时,HACC-A涂布后的纸张60 s Cobb值为54 g/m^(2),Kit防油等级为6级,满足食品包装标准;当m(HACC-A)∶m(AKD)=1∶1、涂布量为6 g/m^(2)时,AKD-HACC-A涂布纸60 s Cobb值为30 g/m^(2),Kit防油等级为10级,对常见油脂(常温和105℃的食用油及辣椒油)、有机溶剂(乙醇和丙酮)和碱性溶液(盐酸和NaOH溶液)表现出良好的阻隔性能,防油性能优于聚乙烯淋膜纸,接近含氟防油纸的防油性能。
