1.Introduction Biodegradable polymeric biomaterials have been fabricated into various biomedical implants such as drug delivery nanoparticles,tissue engineering scaffolds and orthopedic devices.Using biodegradable pol...1.Introduction Biodegradable polymeric biomaterials have been fabricated into various biomedical implants such as drug delivery nanoparticles,tissue engineering scaffolds and orthopedic devices.Using biodegradable polymers as implant materials is beneficial as the implants are degraded and cleared by the body once their missions are complete,leaving no foreign materials in the body.Driven by the versatile needs in biomedical engineering,searching for ideal functional biodegradable polymers has been an endless effort in the past decades.Among biodegradable polymers,citrate-based biodegradable elastomeric(CABE)polymers have recently received increasing attention because their compliance under force can closely resemble the elastic展开更多
Dispersion behavior of ultra fine BaTiO3 particles in the aqueous solution of ammonium citrate （NH4-CA） or citric acid lanthanum chelate （NH4-La-CA） was investigated. The dispersion property was characterized with...Dispersion behavior of ultra fine BaTiO3 particles in the aqueous solution of ammonium citrate （NH4-CA） or citric acid lanthanum chelate （NH4-La-CA） was investigated. The dispersion property was characterized with sedimentation value. It is easier to obtain well dispersed slurry with NH4La-CA than NH4-CA. In an attempt to better understand the role of citric acid radical, simulation of the dispersant adsorption on BaTiO3 particle was performed with universal force field （UFF）. It is demonstrated that the interaction between citric acid radical and BaTiO3 particle surface is a weak chemical adsorption. Trivalent citric acid radical is adsorbed on BaTiO3 particle surface with maximal adsorption energy. And, larger molecules of NH4-La-CA formed by adding La^3＋ lead to better dispersion property than NHn-CA.展开更多
采用超声辅助提取的方法,以小龙虾壳和柠檬酸、苹果酸为原料,设计单因素试验和正交试验,对果酸钙的提取工艺进行优化,在最佳提取工艺下提取果酸钙并测定钙离子浓度,从而计算出果酸钙得率。结果表明,在超声时间50 min,超声温度60℃,加水...采用超声辅助提取的方法,以小龙虾壳和柠檬酸、苹果酸为原料,设计单因素试验和正交试验,对果酸钙的提取工艺进行优化,在最佳提取工艺下提取果酸钙并测定钙离子浓度,从而计算出果酸钙得率。结果表明,在超声时间50 min,超声温度60℃,加水量100 m L条件下钙得率为25.12%。在最佳工艺条件下制备果酸钙,其溶解度为1.2108 g/100 m L,大于不同摩尔比的果酸钙溶解度,说明苹果酸与柠檬酸比为3∶2形成的果酸钙溶解度较高。研究显示,小龙虾壳中钙得率可充分被回收利用,对环境问题的解决和突破具有重要意义。展开更多
基金supported in part by a NSF CAREER award(1313553)a NIH R01 award (EB012575)+2 种基金a NSF collaborative research award(1266116)a CPRIT High Impact/High Risk Research Award(RP110412)a research award from National Natural Sciences Foundation of China(31228007)
文摘1.Introduction Biodegradable polymeric biomaterials have been fabricated into various biomedical implants such as drug delivery nanoparticles,tissue engineering scaffolds and orthopedic devices.Using biodegradable polymers as implant materials is beneficial as the implants are degraded and cleared by the body once their missions are complete,leaving no foreign materials in the body.Driven by the versatile needs in biomedical engineering,searching for ideal functional biodegradable polymers has been an endless effort in the past decades.Among biodegradable polymers,citrate-based biodegradable elastomeric(CABE)polymers have recently received increasing attention because their compliance under force can closely resemble the elastic
基金Project(020951) supported by Natural Science Fundation of Guangdong Province, China
文摘Dispersion behavior of ultra fine BaTiO3 particles in the aqueous solution of ammonium citrate （NH4-CA） or citric acid lanthanum chelate （NH4-La-CA） was investigated. The dispersion property was characterized with sedimentation value. It is easier to obtain well dispersed slurry with NH4La-CA than NH4-CA. In an attempt to better understand the role of citric acid radical, simulation of the dispersant adsorption on BaTiO3 particle was performed with universal force field （UFF）. It is demonstrated that the interaction between citric acid radical and BaTiO3 particle surface is a weak chemical adsorption. Trivalent citric acid radical is adsorbed on BaTiO3 particle surface with maximal adsorption energy. And, larger molecules of NH4-La-CA formed by adding La^3＋ lead to better dispersion property than NHn-CA.
文摘采用超声辅助提取的方法,以小龙虾壳和柠檬酸、苹果酸为原料,设计单因素试验和正交试验,对果酸钙的提取工艺进行优化,在最佳提取工艺下提取果酸钙并测定钙离子浓度,从而计算出果酸钙得率。结果表明,在超声时间50 min,超声温度60℃,加水量100 m L条件下钙得率为25.12%。在最佳工艺条件下制备果酸钙,其溶解度为1.2108 g/100 m L,大于不同摩尔比的果酸钙溶解度,说明苹果酸与柠檬酸比为3∶2形成的果酸钙溶解度较高。研究显示,小龙虾壳中钙得率可充分被回收利用,对环境问题的解决和突破具有重要意义。
