Efficient Gas Adsorption Using Superamphiphobic Porous Monoliths as the under-Liquid Gas-Conductive Circuits

The gas–liquid
membrane contactor forms a gas–solid–liquid
interface and has a high potential for the applications in gas adsorption,
catalysis, energy exchange, and so on. Porous superhydrophobic membranes
show a great gas separation/adsorption ability. However, the complicated
device architecture and the durability issue are normally concerned
especially for the continuous circulation of gas and liquid. In this
work, we present a free-standing gas-conductive circuit simply formed
by connecting the superamphiphobic porous monoliths (SAPMs) to achieve
an efficient under-liquid gas adsorption. The porous worm-like SAPM
is prepared with low-temperature expandable graphite and polyvinylidenefluoride,
exhibiting superamphiphobicity and superaerophilicity after fluoridation.
The as-made SAPM circuits can be used as a reliable gas conductor
under numerous liquids, such as water, alkaline, acidic, and oily
solutions. In this work, the CO2 adsorption capacities
of the SAPM circuits are evaluated under NaOH and methyldiethanolamine
solutions and the mass transfer rate can reach up to 9.61 mmol m–2 s–1. Moreover, the effective human
blood oxygenation process is also demonstrated using SAPM circuits.
Thus, the reported SAPM provides an alternative gas–liquid
exchanging method and the simplified process could be of great benefit
to the cost-effectively large-scale CO2 capture or gas
exchanging applications.

气液膜接触器（gas–liquid membrane contactor）可构建气-固-液三相界面，在气体吸附、催化、能量交换等领域具备极高的应用潜力。多孔超疏水膜展现出优异的气体分离与吸附性能。然而，其复杂的装置结构以及耐用性问题始终受到广泛关注，尤其在气液连续循环的工况中。本研究提出一种简易自立式导气回路，仅通过连接超两疏多孔整体材料（superamphiphobic porous monoliths，SAPMs）即可实现高效的液下气体吸附。该蠕虫状多孔SAPM以低温可膨胀石墨与聚偏氟乙烯（polyvinylidenefluoride）为原料制备，经氟化处理后同时具备超两疏性与超亲气性。所制备的SAPM回路可在多种液体（如水、碱性溶液、酸性溶液及油相溶液）中作为可靠的导气介质。本研究评估了SAPM回路在氢氧化钠与甲基二乙醇胺（methyldiethanolamine）溶液中的二氧化碳（CO₂）吸附性能，其传质速率可达9.61 mmol·m⁻²·s⁻¹。此外，本研究还利用SAPM回路演示了有效的人体血液氧合过程。综上，本研究报道的SAPM为气液交换提供了一种全新方案，其简化的工艺有望为规模化二氧化碳捕集或气体交换应用带来显著的成本效益优势。