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

Abstract

We investigate the effect of the preparation protocol of chitosan (CHI) based films filled with wax microparticles stabilized by halloysite nanotubes (HNTs) in Pickering emulsions. 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 Pickering emulsions. We study the colloidal behaviour of CHI/HNT/wax Pickering emulsions by optical microscopy and sedimentation tests. On the other hand, we characterize the corresponding composite films (prepared by solvent casting method) through several techniques, including Scanning Electron Microscopy, UV-Vis spectrometer, water permeability and contact angle measurements. Dynamic Mechanical Analysis allows us to estimate the effect of wax microparticles on the tensile performances of CHI based films. As a general consideration, the filling of CHI matrix with wax/HNT improves the physico-chemical properties of the films. Finally, we explore the efficacy of the films as adsorbents of n-dodecane vapours. Due to the presence of hydrophobic domains (wax embedded in CHI), the composite films possess higher adsorption efficiencies compared to pristine CHI. Accordingly, we can state that the combination of CHI with wax/HNT microparticles is promising to obtain biocompatible composite films useful for remediation purposes.