Preparation and characterization of boronic acid- functionalized halloysite nanotube/poly(vinyl alcohol) nanocomposites

Organic-inorganic nanocomposite films consisting of surface functionalized halloysite nanotube (HNT) and poly (vinyl alcohol) (PVA) with improved mechanical and thermal properties were prepared. The surface of HNT was modified with boronic acid by two different methods. In the first method, a boronic acid group bearing a triethoxysilane was synthesized and used to modify HNT directly. In the second method, HNT was modified by 3-aminopropyltriethoxysilane (APTES) and 4-formylphenylboronic acid sequentially. The surface-modified HNT was characterized by ζ-potential, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The nanocomposite films were prepared by solvent casting, followed by compression molding. The molecular aggregation structure and physicochemical properties were investigated by UV–Vis spectrophotometry, differential scanning calorimetry, wide-angle X-ray diffraction, tensile test, and dynamic mechanical analysis. [Display omitted]