Adsorption of Janus-Type Amphiphilic Cellulose Nanofibrils onto Microspheres of Semicrystalline Polymers

Cellulose nanofibrils (CNFs), which are attracting increasing attention as sustainable biomass nano-objects, are believed to be hydrophilic. Recently, aqueous counter collision (ACC) has been used to produce Janus-type amphiphilic cellulose nanofibrils (ACC-CNFs) from various cellulosic raw materials. In the current study, ACC-CNFs were preferentially adsorbed onto hydrophobic isotactic polypropylene (i-PP) microparticles and linear low-density polyethylene (LLDPE), which demonstrated their characteristic amphiphilicity. This was achieved by simply mixing the constituents together in aqueous media. The products were visualized by confocal laser microscopy (CLMS). Thermodynamic measurements obtained by differential scanning calorimetry revealed that the melting points of i-PP/ACC-CNFs and LLDPE/ACC-CNFs were lower than those of the untreated polymers, which indicates interactions between the ACC-CNFs and the polymer surfaces. Coating the polymer particles with the ACC-CNFs - as confirmed by CLMS - appeared to reduce their melting points. This finding demonstrates the possibility of a novel fusion between synthetic polymeric materials and biomass nano-objects.