Waterborne Fluorine‐Free Superhydrophobic Surfaces Exhibiting Simultaneous CO2 and Humidity Sorption

Recent progress in the field of superhydrophobic materials has proven their potential to solve many problems of the contemporary society. However, the use of such materials to capture moisture and CO2 from air, to help reduce the impact of global climate change is not explored. In addition, most of the time, fabrication of these materials needs organic solvents and fluorinated molecules involving multiple steps that hinder the use of nonwettable materials in everyday life. Herein, a waterborne, fluorine‐free, robust superhydrophobic material synthesized at room temperature through a one‐step chemical‐modification process is reported, which exhibits moisture and CO2 capturing capability. While covalently grafted low surface energy hydrocarbon molecules control the bulk superhydrophobicity, the incorporated amine functionalities facilitate moisture and CO2 adsorption as these molecules (H2O and CO2) can easily diffuse through hydrocarbon assemblies. Being polar, H2O molecules are observed to readily interact with amine groups and favor the adsorption process. Synthesized material shows an approximate CO2 adsorption of 480 ppm (10.90 mmol L−1) in ambient conditions having 75% humidity. Multifunctionality along with durability of this material will help expand the applications of superhydrophobic materials. A waterborne, fluorine‐free, robust superhydrophobic material is developed from hydrophilic clay particles that capture moisture and CO2 simultaneously. Chemically, adsorption of moisture and CO2 needs polar surfaces and superhydrophobicity/water‐repellency requires apolar/nonpolar surfaces. Both of these properties are controlled here by molecular functionalities of different dimensions.