Effects of Surface Functional Groups on the Adhesion of SiO₂ Nanospheres to Bio-Based Materials

The interactions between nanoparticles and materials must be considered when preparing functional materials. Although researchers have studied the interactions between nanoparticles and inorganic materials, little attention has been paid to those between nanoparticles and bio-based protein materials, like leather. In this study, organically modified silica nanospheres (SiO₂ nanospheres) loaded with rose fragrance were prepared using (3-aminopropyl) triethoxysilane (APTES), (3-mercaptopropyl) triethoxysilane (MPTES), or 3-(2, 3-epoxypropyloxy) propyl triethoxysilane (GPTES) using the sol-gel method. To study the interactions between the modified SiO₂ nanospheres and leather, a non-cross-linking adsorption experiment was conducted. According to the Dubinin-Radushkevich isotherm calculation, we found that the adsorption process of leather fiber and organically modified silica nanospheres is physical. The average adhesion energies of APTES-, MPTES-, and GPTES-modified SiO₂ nanospheres on the leather are 1.34016, 0.97289, and 2.09326 kJ/mol, respectively. The weight gain, adsorption capacity, and average adhesion energy show that the modified SiO₂ nanospheres can be adsorbed on leather in large quantities. The sensory evaluation confirmed that GPTES-modified SiO₂ nanospheres endowed the leather with an obvious rose aroma.