CO2 Adhesion on Hydrated Mineral Surfaces

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• 作者：Shibo Wang ; Zhiyuan Tao ; Sara M. Persily ; Andres F. Clarens
• 刊名：Environmental Science & Technology
• 出版年：2013
• 出版时间：October 15, 2013
• 年：2013
• 卷：47
• 期：20
• 页码：11858-11865
• 全文大小：324K
• 年卷期：v.47,no.20(October 15, 2013)
• ISSN：1520-5851

文摘

Hydrated mineral surfaces in the environment are generally hydrophilic but in certain cases can strongly adhere CO₂, which is largely nonpolar. This adhesion can significantly alter the wettability characteristics of the mineral surface and consequently influence capillary/residual trapping and other multiphase flow processes in porous media. Here, the conditions influencing adhesion between CO₂ and homogeneous mineral surfaces were studied using static pendant contact angle measurements and captive advancing/receding tests. The prevalence of adhesion was sensitive to both surface roughness and aqueous chemistry. Adhesion was most widely observed on phlogopite mica, silica, and calcite surfaces with roughness on the order of 10 nm. The incidence of adhesion increased with ionic strength and CO₂ partial pressure. Adhesion was very rarely observed on surfaces equilibrated with brines containing strong acid or base. In advancing/receding contact angle measurements, adhesion could increase the contact angle by a factor of 3. These results support an emerging understanding of adhesion of, nonpolar nonaqueous phase fluids on mineral surfaces influenced by the properties of the electrical double layer in the aqueous phase film and surface functional groups between the mineral and CO₂.