Superhydrophobic surfaces with dual-scale roughness and water vapor-barrier property for sustainable liquid packaging applications

Abstract There has been continuous global unmet need to manufacture new sustainable liquid packaging materials, without plastic film or aluminum foil. A proposed research direction is based on superhydrophobic coating technologies to develop more sustainable packaging materials. In this study, the underlying engineering principle, including but not limited to the substrates and engineering properties, of superhydrophobic surfaces proposed for liquid packaging application is investigated. Specifically, in order to improve the engineering performance of superhydrophobic paper designed for packaging, the possibilities to utilize the barrier property of nano-platy-shaped montmorillonite (MMT) and the superhydrophobic property of nano-rolling-pin-shaped precipitated calcium carbonate (PCC) to form multifunctional coating layers are investigated. Then, the subtle differences in morphological structures of the as-prepared superhydrophobic paper samples are characterized by water droplet evaporation experiment to verify the promising roughness structure for packaging applications. Furthermore, paperboard, which is widely utilized in packaging, is chosen as the substrate to study the challenges of fabricating superhydrophobic paperboard designed for packaging. The research findings of this study provide the engineering principles of promoting sustainable paper-based materials with dual-scale roughness structure and barrier properties in liquid packaging applications.