Use of nanocomposite coatings and chemical treatments to improve mechanical performance of bio-composite materials

The building industry demonstrated a growing interest in recently developed biocomposite materials for structural strengthening based on natural fibers as an alternative to synthetic fibers. In the last years, research activities were focused on investigating the mechanical properties of different types of natural fibers, e.g. hemp, sisal, kenaf, Spanish Broom fibers. Despite the numerous advantages associated with the use of these natural resources towards sustainability, their performance is affected by shortcomings given by their morphology, mechanical behavior, and durability. These factors can compromise the interaction between matrix and fibers, resulting in poor structural performance. Indeed, when natural fibers are embedded in mortar-based matrices, cracks of the mortar can occur at early load stage before the natural fibers begin to fulfill their reinforcing role. This work investigates the use of bio-based coatings and treatments for natural fibers to improve the fibers mechanical properties. Treatments based on sodium hydroxide are investigated to eliminate non-cellulosic components, resulting in an compatibility with mortar. Graphene-based coatings are employed to improve the mechanical behavior of vegetal fibers in terms of resistance.