Capture of Hyperthermal CO2 by Amorphous Water Ice via Molecular Embedding.
Capture of Hyperthermal CO2 by Amorphous Water Ice via Molecular Embedding.
复制标题
通过分子嵌入非晶水冰捕获高温二氧化碳。
DOI：
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发表时间：
2015
影响因子：
2.9
通讯作者：
S. Sibener
中科院分区：
文献类型：
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作者：
Grant G. Langlois;Wenxin Li;K. Gibson;S. Sibener
我们提出的第一项研究详细描述了超高真空条件下，在125 K，近无定形/结晶转变的无定形固体水（ASW）的超高温CO2分子的捕获和聚集。使用时间分辨原位反射吸收红外光谱（RAIRS），观察到平移能量高于3.0 eV的CO2分子直接嵌入真空-固体界面下方，尽管在125 K下无法吸附，但在冰膜内被吸收;结晶膜没有观察到这种行为。嵌入后，在125 K的无定形冰和它的分子间相互作用的强度内的流动性的CO2的结果在其分离成团内的冰膜。跟踪动力学的CO2嵌入事件在不同的能量条件下允许阐明的基本动力学，我们绘制与其他弹丸，我们已经研究，以促进广义结论的经验预测弹丸的嵌入概率方面的比较。通过应用一个经典模型的入口障碍的弹丸碰撞无定形冰，我们提供了直接的证据嵌入概率和弹丸动量之间的统一连接，所有嵌入数据的帐户由我们的小组跟踪一个统一的障碍模型。这项工作突出了在高速气流中与冰碰撞时平移能和动量调节之间的相互作用。
We present the first study detailing the capture and aggregation of hyperthermal CO2 molecules by amorphous solid water (ASW) under ultra-high vacuum conditions at 125 K, near the amorphous/crystalline transition. Using time-resolved in situ reflection-absorption infrared spectroscopy (RAIRS), CO2 molecules with translational energies above 3.0 eV are observed to directly embed underneath the vacuum-solid interface to become absorbed within the ice films despite an inability to adsorb at 125 K; this behavior is not observed for crystalline films. Upon embedding, the mobility of CO2 within 125 K amorphous ice and the strength of its intermolecular interactions result in its segregation into clusters within the ice films. Tracing the kinetics of CO2 embedding events under different energetic conditions allows for elucidation of the underlying dynamics, and we draw comparison with other projectiles we have studied to promote generalized conclusions in regard to empirical prediction of a projectile's embedding probability. Through application of a classical model of the entrance barrier for projectiles colliding with amorphous ice, we provide direct evidence for a unified connection between embedding probability and projectile momentum; an account of all embedding data measured by our group traces a unified barrier model. This work highlights the interplay between translational energy and momentum accommodation during collisions with ice in high speed gas flows.