Synchrotron radiation based combined technique can provide multiple structural information simultaneously,which is an important development direction of structural detection.In this study,a novel small-angle X-ray sca...Synchrotron radiation based combined technique can provide multiple structural information simultaneously,which is an important development direction of structural detection.In this study,a novel small-angle X-ray scattering/X-ray diffraction/X-ray absorption fine structure(SAXS/XRD/XAFS)combined setup was constructed,where an area detector,a curved detector,and a point detector are,respectively,used for the measurements of SAXS,XRD,and XAFS signals.A detailed description about the combined setup was given.A minitype diamond detector coupled to a SAXS beamstop was used to record the transmitted X-ray intensity,making the scattering(SAXS and XRD)signal measurement compatible with the absorption(XAFS)signal measurement,avoiding mechanical switching.The two-way sampling strategy was used to acquire XAFS signals,shortening the non-counting time.The two-way and one-way sampling strategies were discussed.High-frequency sampling scheme was used to collect experimental signals,improving the measurement efficiency and signal-to-noise ratio.A detailed description and discussion about the high-frequency scheme were also given in this paper.Except the rotation of monochromator,there is no mechanical movement in measurements,time resolution may reach the level of seconds.Using this SAXS/XRD/XAFS combined setup,SAXS,XRD,and XAFS signals can be acquired simultaneously.With some in-situ sample environment system,the newlydeveloped combined technique can be used to track the structure evolution in complex fluids.During the formation processes of(BiO)2CO3 and ZnAPO-34 particles,the changes of in-situ experimental data with reaction time demonstrate that SAXS/XRD/XAFS combined technique is feasible to track the dynamic process.展开更多
许多材料研究中,都需要采用X射线吸收精细结构谱学(X-ray Absorption Fine Structure,XAFS)和X射线衍射(X-ray Diffraction,XRD)技术测量材料的短程和长程有序结构信息,而如何同时快速地测量是开展原位动态研究的一个关键。本文提出了...许多材料研究中,都需要采用X射线吸收精细结构谱学(X-ray Absorption Fine Structure,XAFS)和X射线衍射(X-ray Diffraction,XRD)技术测量材料的短程和长程有序结构信息,而如何同时快速地测量是开展原位动态研究的一个关键。本文提出了一种结合能量色散X射线吸收精细结构谱(Energy-dispersive X-ray Absorption Fine Structure,EDXAFS)和能量色散X射线衍射(Energy-dispersive X-ray Diffraction,EDXRD)的测试方案,该方案利用同步辐射白光,理论上可以提供微秒量级的表征速度和时间分辨能力,为真实环境下材料结构的原位实时表征提供了一种可能方法。展开更多
选择固体脂质山榆酸甘油酯(Compritol ATO 888)和液态油三辛酸甘油酯制备雷公藤内酯醇新型固体脂质纳米粒(SLN)载体系统,运用常温、低温差示量热分析(DSC)、X射线衍射(XRD)、小角X射线衍射(SAXS)和核磁共振(NMR)等多种分析测试手段对新...选择固体脂质山榆酸甘油酯(Compritol ATO 888)和液态油三辛酸甘油酯制备雷公藤内酯醇新型固体脂质纳米粒(SLN)载体系统,运用常温、低温差示量热分析(DSC)、X射线衍射(XRD)、小角X射线衍射(SAXS)和核磁共振(NMR)等多种分析测试手段对新型SLN性能和微观结构进行研究。结果显示,新型SLN纳米体系熔点从70.8℃降低到61.4℃,纳米化后熔融焓大大降低,于-17.7℃发生油相熔融吸热行为;无论是否载药,制备的纳米分散体系(新型SLN和传统SLN)都是由α相和少量β′相组成,所载药物雷公藤内酯醇对载体结晶性能基本无影响;新型SLN中分子运动自由度介于Compritol ATO 888基材和其制备的传统SLN二者之间,其长程结构相对于传统SLN和基材的结构只偏移0.1 nm,表明中链甘油酯液态油分子不可能插入片间和2个或3个链长结构间。两种物理状态不同的甘油酯在新型SLN中仍以两种状态存在:液态油和固态脂质,因其有各自的熔融性状(低温和常温DSC研究)和分子运动状态(NMR检测),推测本实验室制备新型SLN的微观结构应是液态油分子,没有插入到固体脂质层状结构之间,而是形成了更加微细的纳米油室,周围包被着固体脂质,整个球形颗粒还处于纳米尺度。展开更多
基金This work was supported by the National Key Research and Development Program of China(Nos.2017YFA0403000 and 2017YFA0403100).
文摘Synchrotron radiation based combined technique can provide multiple structural information simultaneously,which is an important development direction of structural detection.In this study,a novel small-angle X-ray scattering/X-ray diffraction/X-ray absorption fine structure(SAXS/XRD/XAFS)combined setup was constructed,where an area detector,a curved detector,and a point detector are,respectively,used for the measurements of SAXS,XRD,and XAFS signals.A detailed description about the combined setup was given.A minitype diamond detector coupled to a SAXS beamstop was used to record the transmitted X-ray intensity,making the scattering(SAXS and XRD)signal measurement compatible with the absorption(XAFS)signal measurement,avoiding mechanical switching.The two-way sampling strategy was used to acquire XAFS signals,shortening the non-counting time.The two-way and one-way sampling strategies were discussed.High-frequency sampling scheme was used to collect experimental signals,improving the measurement efficiency and signal-to-noise ratio.A detailed description and discussion about the high-frequency scheme were also given in this paper.Except the rotation of monochromator,there is no mechanical movement in measurements,time resolution may reach the level of seconds.Using this SAXS/XRD/XAFS combined setup,SAXS,XRD,and XAFS signals can be acquired simultaneously.With some in-situ sample environment system,the newlydeveloped combined technique can be used to track the structure evolution in complex fluids.During the formation processes of(BiO)2CO3 and ZnAPO-34 particles,the changes of in-situ experimental data with reaction time demonstrate that SAXS/XRD/XAFS combined technique is feasible to track the dynamic process.
文摘选择固体脂质山榆酸甘油酯(Compritol ATO 888)和液态油三辛酸甘油酯制备雷公藤内酯醇新型固体脂质纳米粒(SLN)载体系统,运用常温、低温差示量热分析(DSC)、X射线衍射(XRD)、小角X射线衍射(SAXS)和核磁共振(NMR)等多种分析测试手段对新型SLN性能和微观结构进行研究。结果显示,新型SLN纳米体系熔点从70.8℃降低到61.4℃,纳米化后熔融焓大大降低,于-17.7℃发生油相熔融吸热行为;无论是否载药,制备的纳米分散体系(新型SLN和传统SLN)都是由α相和少量β′相组成,所载药物雷公藤内酯醇对载体结晶性能基本无影响;新型SLN中分子运动自由度介于Compritol ATO 888基材和其制备的传统SLN二者之间,其长程结构相对于传统SLN和基材的结构只偏移0.1 nm,表明中链甘油酯液态油分子不可能插入片间和2个或3个链长结构间。两种物理状态不同的甘油酯在新型SLN中仍以两种状态存在:液态油和固态脂质,因其有各自的熔融性状(低温和常温DSC研究)和分子运动状态(NMR检测),推测本实验室制备新型SLN的微观结构应是液态油分子,没有插入到固体脂质层状结构之间,而是形成了更加微细的纳米油室,周围包被着固体脂质,整个球形颗粒还处于纳米尺度。
