Filling of Chitosan Film with Wax/Halloysite Microparticles for Absorption of Hydrocarbon Vapors

The effect of the preparation protocol of chitosan (CHI) based films filled with wax microparticles stabilized by halloysite nanotubes (HNTs) in Pickering emulsions (PE) is investigated. The obtained results show that the addition of acetic acid (before or after the preparation of wax/HNT microspheres) affects the properties of the composite films as well as the colloidal stability of PE. The colloidal behavior of CHI/HNT/wax PE by optical microscopy and sedimentation tests are studied. On the other hand, the corresponding composite films (prepared by solvent casting method) are characterized through several techniques, including Scanning Electron Microscopy, UV-vis spectrometer, water permeability, and contact angle measurements. Dynamic Mechanical Analysis allows this to estimate the effect of wax microparticles on the tensile performances of CHI-based films. As a general consideration, the filling of the CHI matrix with wax/HNT improves the physicochemical properties of the films. Finally, the efficacy of the films as adsorbents of n-dodecane vapors is explored. Due to the presence of hydrophobic domains (wax embedded in CHI), the composite films possess higher adsorption efficiencies compared to pristine CHI. Accordingly, it can be stated that the combination of CHI with wax/HNT microparticles is promising to obtain biocompatible composite films useful for remediation purposes. Chitosan films filled with hydrophobic microparticles are successfully prepared by solvent casting of wax/halloysite Pickering emulsions. The addition of wax microparticles within chitosan generated the surface hydrophobization of the film. Due to hydrophobic attractions, the presence of microwax improved the absorption capacity toward n-dodecane vapors. The filled film is promising as a sustainable material for capturing organic pollutants, such as hydrocarbons. image