Effect of physically adsorbed water molecules on the H_2-selective perforemance of a silica membrane prepared with dimethoxydiohenylsilane and its regeneration
Effect of physically adsorbed water molecules on the H_2-selective perforemance of a silica membrane prepared with dimethoxydiohenylsilane and its regeneration
复制标题
物理吸附水分子对二甲氧基二苯基硅烷二氧化硅膜H_2选择性的影响及其再生
DOI：
10.1016/j.memsci.2011.12.007
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
et al
中科院分区：
文献类型：
--
作者：
T.Saito;et al
研究了在室温下暴露于潮湿条件下对二甲氧基二苯基硅烷（DMDPS）衍生的二氧化硅膜的H2-选择性性能的影响。暴露于相对湿度为20%的空气中后，H2和N2的渗透率立即急剧下降，然后保持恒定值，SF6的渗透率也略有下降。这种降低被认为是由于水分子在膜表面上或在膜中的孔表面的内部上的物理吸附，这导致用于气体渗透的有效孔径减小。此外，膜的再生程序进行了研究。当在573 K下处理膜时，在一侧加压H2流动，而另一侧减压，每种气体的渗透率都有相当大的恢复。这是因为物理吸附的水分子在再生过程中分离。然而，N2渗透的恢复不是那么出色，可能是因为即使在再生后，在N2最初可以渗透的孔内仍残留有少量的吸附水分子，这大大减小了N2渗透的有效孔径。
The effect of exposure to humid conditions at room temperature on the H2-selective performance of a dimethoxydiphenylsilane (DMDPS)-derived silica membrane was studied. Immediately after exposure to air with 20% relative humidity, the permeances of H2and N2decreased drastically and then kept constant values, and that of SF6also decreased slightly. This decrease was considered to result from the physical adsorption of water molecules on the membrane surface or on the inside of the pore surfaces in the membrane, which resulted in a decrease of effective pore size for gas permeation. In addition, a regeneration procedure of the membrane was investigated. When the membrane was treated at 573K with pressurized H2streaming in one side while depressurizing the other side, the permeance of each gas recovered considerably. This is because the physically adsorbed water molecules detached during the regeneration process. However, the recovery of N2permeance was not so excellent, probably because a slight amount of adsorbed water molecules was remained even after the regeneration inside the pores where N2can originally permeate, which greatly reduced the effective pore size for N2permeation.