Smart Graphite-Cement Composites with Low Percolation Threshold

Area of Science:

• Materials Science
• Nanotechnology
• Civil Engineering

Background:

• Developing cost-effective conductive cement composites is crucial for smart infrastructure.
• Traditional conductive additives often increase composite cost and can compromise mechanical integrity.
• Exfoliated graphite presents a promising alternative due to its unique properties.

Purpose of the Study:

• To create cement composites with significantly reduced percolation thresholds using exfoliated graphite.
• To evaluate the impact of exfoliated graphite on the electrical and mechanical performance of cement mortars.
• To explore the practical applicability of these novel composites in smart systems.

Main Methods:

• Exfoliation of expanded graphite using ultrasonic irradiation in an aqueous surfactant solution.
• Incorporation of exfoliated graphite and residual surfactant into the cement matrix for uniform dispersion.
• Characterization of electrical conductivity to determine the percolation threshold.
• Assessment of flexural and compressive strength to evaluate mechanical properties.
• Investigation of piezoresistive, temperature-resistivity, and thermoelectric characteristics.

Main Results:

• Achieved a remarkably low percolation threshold of 0.96% (by volume) for the cement composites.
• Demonstrated satisfactory mechanical properties suitable for practical engineering applications.
• Confirmed good piezoresistive, temperature-resistivity, and thermoelectric properties, indicating suitability for smart composite functions.

Conclusions:

• The use of exfoliated graphite with surfactant is an effective strategy for developing low-cost, high-performance conductive cement composites.
• The resulting composites exhibit a low percolation threshold and robust mechanical integrity.
• These advanced cement composites hold significant potential for facilitating the widespread practical use of smart materials in various applications.