Boron Nitride-Modified Hemp Nanofiber Reinforced Slag-Based Geopolymer Composites: Mechanical, Microstructural and...

Area of Science:

• Materials Science
• Civil Engineering
• Nanotechnology

Background:

• Geopolymer composites offer sustainable alternatives to traditional concrete.
• Enhancing mechanical and thermal properties of geopolymers is crucial for advanced applications.
• Nanofiber reinforcement presents a promising strategy for material improvement.

Purpose of the Study:

• To investigate the impact of boron nitride (BN)-modified hemp nanofibers on the properties of ground granulated blast furnace slag (GGBFS)-based geopolymer composites.
• To evaluate the mechanical performance, high-temperature resistance, and microstructural characteristics of these novel composites.
• To determine the optimal content of BN-modified hemp nanofibers for enhanced material properties.

Main Methods:

• Synthesis of BN-modified hemp nanofibers (PVA-mBN/Hemp) via electrospinning.
• Incorporation of nanofibers into GGBFS-geopolymer mixtures at varying concentrations (0-4 wt%).
• Characterization using mechanical testing, ultrasonic pulse velocity (UPV), SEM-EDS, FTIR, and XRD, with thermal exposure up to 1200 °C.

Main Results:

• Optimal flexural strength improvement (up to 15%) observed with 0.5-1 wt% nanofiber addition; slight decrease in compressive strength due to porosity.
• Enhanced residual strength in nanofiber-reinforced composites at elevated temperatures compared to control.
• Microstructural analysis revealed improved fiber-matrix interaction, reduced crack propagation, and enhanced thermal stability due to BN modification.

Conclusions:

• Incorporating 0.5-1 wt% BN-modified hemp nanofibers offers a balanced enhancement of mechanical properties and high-temperature resistance in GGBFS-geopolymer composites.
• These composites demonstrate potential for sustainable and fire-resistant construction materials.
• The study aligns with UN SDGs 9, 11, and 12, promoting innovation, sustainable cities, and responsible production.