Silicified Wood with Dual Fire Retardancy and Thermal Management Functionalities.

Area of Science:

• Materials Science
• Sustainable Construction
• Fire Safety Engineering

Background:

• Natural wood is a common building material with inherent limitations in fire retardancy and thermal management.
• Energy-efficient and fire-safe buildings require advanced materials that address these dual functionalities.
• Current wood treatments often compromise structural integrity or environmental sustainability.

Purpose of the Study:

• To develop a novel wood-based material with enhanced fire retardancy and improved thermal management properties.
• To investigate the effects of silicification on the physical and thermal characteristics of wood.
• To assess the potential of silicified wood as a sustainable building material for fire-safe and energy-efficient applications.

Main Methods:

• Fabrication of silicified wood through multi-cycle infiltration of SiO2 into native wood lumens.
• Evaluation of fire retardancy using Limiting Oxygen Index (LOI) and ignition delay tests.
• Measurement of thermal conductivity and surface temperature under heat exposure.
• Assessment of mechanical properties, including ultimate tensile stress and toughness.

Main Results:

• Silicified wood exhibited a significant increase in LOI (from 21.9% to 36.0%) and delayed ignition (from 15s to 50s).
• The material demonstrated low thermal conductivity (0.074 W·m⁻¹·K⁻¹) and enhanced emissivity, leading to improved thermal management.
• Surface temperature of silicified wood rose slower than native wood when heated, indicating better insulation.
• Mechanical tests showed that ultimate tensile stress remained largely unchanged, while toughness was significantly improved.

Conclusions:

• Silicification is an effective method to impart fire retardancy and enhance thermal management in wood.
• Silicified wood offers a promising sustainable alternative for fire-safe, energy-efficient building applications.
• The improved properties of silicified wood contribute to passive cooling and reduced thermal conduction, optimizing building performance.