Research on storage process of high-pressure fluid into nano-structures of minerals

目前应用于高压流体储存的候选材料是碳纳米管。首先，我们测试了碳纳米管的机械强度，以了解其储存高压流体的能力。在此基础上，利用同步辐射产生的X射线与金刚石压腔(DAC)相结合，进行了高压下的原位X射线衍射实验。在52 Gpa的压缩压力下，没有观察到像sp^3杂化这样的层间相互作用导致在石墨中形成六方金刚石。此外，尽管有非静力压缩的历史，但电子显微镜观察显示，结构仍为嵌套管状。这种可逆性表明，纳米管在极端压力下的非静压压缩中具有很强的耐久性。接下来，我们尝试在压力下对纳米管进行气体加载实验。预先建立了气体加载系统，用于控制将气体加载到DAC中的压力。在…之后在放置纳米管样品的样品室中装入更多的Ar，压力高达6 Gpa。用CO_2激光器将样品加热到1000K。加热后的样品在环境条件下回收，然后用配备EDAX检测器的扫描电子显微镜进行分析。检测到了极少量的Ar。然而，由于激光加热的温度梯度，所检测的药液是不均匀的。因此，我们将实验从激光加热DAC改为热等静压(HIP)装置。该装置可在800~1000℃、300 Mpa的Ar压力下，保持大批量样品10小时。在相同的条件下，在该装置上处理了几个样品，包括开端和闭端的多壁纳米管、束状单壁纳米管和富勒烯。回收的样品用分析透射式电子显微镜(ATEM和STEM)仔细检查。根据样品中Ar的EDX图谱，仅在束状单壁碳纳米管中检测到大量的Ar。因此，我们可以得出结论，Ar可以被捕获在束状单壁纳米管的间隙位置。较少

The present candidates for the storage application of high pressure fluid are carbon nanotubes. First of all, we examined the mechanical strength of carbon nanotubes to know a capability for storage of high-pressure fluids. Then, we conducted in-situ X-ray diffraction experiments under high pressure using a diamond anvil cell (DAC) combined with x-ray from synchrotron radiation. No interlayer interaction such as sp^3 hybridization that could lead to hexagonal diamond in graphite was observed under compression up to 52 GPa. Furthermore, despite the history of non-hydrostatic compression, electron microscopic observation revealed that the structure remained nested tubular. This reversibility suggests the nanotubes have strong durability on non-hydrostatic compression under extreme pressures.Next, we tried to make experiments of gas loading to the nanotubes under pressure. In advance, a gas loading system was built for the purpose of controlling the pressure in loading gas into DAC. After … More loading argon into the sample chamber, where nanotubes sample was placed, the pressure applied up to 6 GPa. The sample was heated to 1000 K by a CO_2 laser. The heated sample was recovered at ambient condition, and then analyzed by a scanning electron microscope equipped with EDAX detector. A very small amount of argon was detected. However, the detected potion was inhomogeneous due to temperature gradient by the laser heating. Thus we change the experiments from the laser heated DAC to the hot isostatic pressing (HIP) apparatus. A large amount of sample can be kept at the 800-1000 deg C under 300 MPa argon pressure for 10 hrs in this apparatus. Several samples of open and closed end multi-walled nanotubes, bundled single-walled nanotubes, and fullerene are treated in this apparatus at the same condition. The recovered samples are carefully examined by analytical transmitted electron microscopes (ATEM and STEM). According to the EDX mapping of argon in the samples, a large amount of argon are only detected from the bundled single walled carbon nanotubes. Hence, we can conclude that argon can be trapped in an interstitial position of bundled single-walled nanotubes. Less