Development of carbon nanotube modified cement paste with microencapsulated phase-change material for...

Area of Science:

• Materials Science
• Civil Engineering
• Sustainable Building Materials

Background:

• Microencapsulated phase-change materials (MPCM) offer thermal energy storage in cementitious composites.
• MPCM incorporation often compromises the mechanical integrity of cement-based materials.
• There is a need to enhance the mechanical properties of MPCM-integrated cement paste.

Purpose of the Study:

• To evaluate the impact of carbon nanotubes (CNTs) on the properties of MPCM-enhanced cement paste.
• To determine the optimal dosage of CNTs for improving both mechanical and thermal performance.
• To assess the potential of CNTs in mitigating the negative effects of MPCM on cement paste.

Main Methods:

• Preparation of cement paste incorporating varying dosages of MPCM and CNTs.
• Mechanical testing (flexural and compressive strength) at 28 days.
• Scanning Electron Microscopy (SEM) for microstructural analysis.
• Thermal performance evaluation of cement paste panels.

Main Results:

• CNTs incorporation accelerated cement hydration and improved mechanical strength (up to 41% flexural, 5% compressive).
• SEM confirmed strong bonding between CNTs and cement hydration products.
• The optimal CNT dosage was determined to be 0.5 wt%.
• MPCM-containing panels reduced room center temperature by up to 4.6 °C, showing an inverse relationship with MPCM dosage.

Conclusions:

• CNTs effectively enhance the mechanical properties of MPCM-modified cement paste.
• The optimal CNT dosage of 0.5 wt% balances mechanical enhancement and MPCM's thermal storage function.
• MPCM-integrated cement paste demonstrates significant potential for passive thermal regulation in buildings.