...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >Effects of Confinement and Pressure on the Vibrational Behavior of Nano-Confined Propane
【24h】

Effects of Confinement and Pressure on the Vibrational Behavior of Nano-Confined Propane

机译：限制与压力对纳米局限性丙烷振动行为的影响

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Fluids confined in nanopores exhibit significant deviations in their structure and dynamics from the bulk behavior. Although phase, structural, and diffusive behaviors of confined fluids have been investigated and reported extensively, confinement effects on the vibrational properties are less understood. We study the vibrational behavior of propane confined in 1.5 nm nanopores of MCM-41-S using inelastic neutron scattering (INS) and molecular dynamics (MD) simulations. Vibrational spectra have been obtained from INS data as functions of temperature and pressure. At ambient pressure, a strong quasielastic signal observed in the INS spectrum at 80 K suggests that confined propane remains liquid below the bulk phase melting point of 85 K. The quasielastic signal is heavily suppressed when either the pressure is increased to 1 kbar or the temperature is lowered to 30 K, indicating solidification of pore-confined propane. Confinement in MCM-41-S pores results in a glass-like state of propane that exhibits a relatively featureless low-energy vibrational spectrum compared to that of the bulk crystalline propane. Increasing the pressure to 3 kbar results in hardening of the intermolecular and methyl torsional modes. The INS data are used for estimating the isochoric specific heat of confined propane, which is compared with the specific heat of bulk propane reported in literature. Data from MD simulations are used to calculate the vibrational power spectra that agree qualitatively with the experimental data. Simulation data also suggest a reduction of the structural ordering (positional, orientational, and intramolecular) of propane under confinement.
机译：限制在纳米孔中的流体表现出它们的结构和动力学中的显着偏差。虽然已经研究了狭窄的液体的相位，结构和扩散行为，并广泛地报道了对振动性质的限制效应。我们研究了使用无弹性中子散射（INS）和分子动力学（MD）模拟的MCM-41-S中1.5nm纳米孔局限于1.5nm纳米孔的振动行为。从INS数据中获得振动光谱作为温度和压力的功能。在环境压力下，在80k的INS光谱中观察到的强矩形信号表明，限制丙烷在85k的体相熔点以下的液体中保持液体。当压力增加到1 kbar或温度时，准弹性信号受到严重抑制降低至30 k，表明孔限制丙烷的凝固。 MCM-41-S孔的限制导致诸如散装晶丙烷的玻璃状丙烷的丙烷状态，其表现出相对不佳的低能量振动谱。将压力增加到3kbar导致分子间和甲基扭转模式的硬化。 INS数据用于估计被限制丙烷的异形特异性热量，其与文献中报告的散装丙烷的特定热量进行比较。 MD模拟的数据用于计算与实验数据定性同意的振动功率谱。仿真数据还提出了在限制下减少丙烷的结构排序（位置，取向和分子内）。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号