Practical Elaboration of Carnauba Wax -PVA Nanocomposite Emulsion Using Modified SMA Copolymer and Carbon Nanotubes for Coating and Filtering Applications

In this study, we present a novel approach for emulsifying Carnauba wax (CW) by incorporating a modified styrene–maleic anhydride copolymer (m–SMA) with tallow amine as an emulsifying agent, with the aim of fabricating hydrophobic membranes or surface coating via electrospinning and brush-coating techniques. Functionalized carbon nanotubes (CNTs) were introduced to improve emulsion stability and enhance its mechanical and barrier properties. CW was blended with mineral oil and turpentine and subsequently dispersed in an aqueous polyvinyl alcohol solution containing N,N–dimethylformamide, in the presence of m-SMA and functionalized CNTs. Electrospinning produced porous fibrous membranes, while brush-coating generated continuous thin films on polyester fabric substrates. These materials were evaluated for potential applications, such as oil–water separation and fruit preservation. The performance of the brush coated films on bananas was monitored through mechanical firmness testing over time as an indicator of ripening. Overall, this study demonstrates that m-SMA and CNTs stabilize the CW emulsion, enabling processing via brushing and electrospinning techniques. The resulting nanocomposite coating enhances crystallinity and hydrophobicity, effectively extending the shelf life of the coated bananas and functioning as an effective oil filtration medium, offering a versatile strategy for protective packaging and filtration applications.