Carbonated hydroxyapatites(CHA) were rapidly and continuously synthesized in supercritical water by using a tubular reactor. The effects of reaction time and the ratio of PO43-/CO32-on the apatite structure were inves...Carbonated hydroxyapatites(CHA) were rapidly and continuously synthesized in supercritical water by using a tubular reactor. The effects of reaction time and the ratio of PO43-/CO32-on the apatite structure were investigated by using XRD, FTIR and TEM. Results showed that 30 seconds were enough to produce fully crystalline CHA nano-rods, ca. 20×70 nm in size, at 380 ℃ and 24 MPa. When the ratio of PO43-/CO32-was not less than 1, the CO32-ions mainly substituted for PO43-in apatite structure; but CO32-ions could react with Ca2+ to form CaCO3 phase when the ratio of PO43-/CO32-was less than 1.展开更多
首次研究了一种添加剂——过氧化苯甲酰(BPO)对高密度聚乙烯在超临界水中降解行为的影响。对使用添加剂和未使用添加剂的实验产物采取多种方式检测对比,得到结论:在降解反应的前30 m in内,聚乙烯降解效率最高;温度是影响降解反应的重要...首次研究了一种添加剂——过氧化苯甲酰(BPO)对高密度聚乙烯在超临界水中降解行为的影响。对使用添加剂和未使用添加剂的实验产物采取多种方式检测对比,得到结论:在降解反应的前30 m in内,聚乙烯降解效率最高;温度是影响降解反应的重要因素;在反应温度较低和反应时间较短的情况下,添加BPO可以有效促进聚乙烯的降解,达到与未添加BPO实验中高温和长时间反应相比拟的效果。同时本文讨论了聚乙烯在超临界水中降解反应机理,对BPO在反应中的促进作用也进行了分析。展开更多
文摘Carbonated hydroxyapatites(CHA) were rapidly and continuously synthesized in supercritical water by using a tubular reactor. The effects of reaction time and the ratio of PO43-/CO32-on the apatite structure were investigated by using XRD, FTIR and TEM. Results showed that 30 seconds were enough to produce fully crystalline CHA nano-rods, ca. 20×70 nm in size, at 380 ℃ and 24 MPa. When the ratio of PO43-/CO32-was not less than 1, the CO32-ions mainly substituted for PO43-in apatite structure; but CO32-ions could react with Ca2+ to form CaCO3 phase when the ratio of PO43-/CO32-was less than 1.
文摘首次研究了一种添加剂——过氧化苯甲酰(BPO)对高密度聚乙烯在超临界水中降解行为的影响。对使用添加剂和未使用添加剂的实验产物采取多种方式检测对比,得到结论:在降解反应的前30 m in内,聚乙烯降解效率最高;温度是影响降解反应的重要因素;在反应温度较低和反应时间较短的情况下,添加BPO可以有效促进聚乙烯的降解,达到与未添加BPO实验中高温和长时间反应相比拟的效果。同时本文讨论了聚乙烯在超临界水中降解反应机理,对BPO在反应中的促进作用也进行了分析。
