Biopolymer-Based Hybrids as Effective Admixtures for Cement Composites

Area of Science:

• Materials Science
• Civil Engineering
• Sustainable Materials

Background:

• Development of novel admixtures for cement composites is crucial for improving material properties.
• Hybrid materials offer unique characteristics by combining different components.
• Silica and lignin are abundant and potentially sustainable resources.

Purpose of the Study:

• To design, obtain, and characterize silica-lignin hybrid materials.
• To evaluate these hybrid materials as admixtures in cement pastes.
• To determine the optimal ratio of silica to lignin for cement composite performance.

Main Methods:

• High-energy mechanical grinding for homogeneous hybrid material synthesis.
• Fourier transform infrared spectroscopy (FTIR) for interaction analysis.
• Characterization of porous structure and colorimetric data.
• Incorporation of silica-lignin admixtures (0.5-1 wt.%) into cement pastes.
• Evaluation of rheological and mechanical properties (compressive strength, plasticity).

Main Results:

• Silica-lignin hybrid materials exhibited weak physical interactions, classified as Class I.
• Increasing lignin content improved paste rheology but decreased mechanical properties.
• Higher silica content showed an inverse effect on rheology and mechanics.
• A silica-lignin ratio of 5:1 wt./wt. yielded the most favorable results.
• Significant increase in compressive strength with satisfactory paste plasticity was achieved at the 5:1 ratio.

Conclusions:

• Silica-lignin hybrid materials can be effectively produced using mechanical grinding.
• The 5:1 wt./wt. silica-lignin admixture optimizes cement paste properties, enhancing strength and plasticity.
• These findings suggest potential for sustainable and high-performance cement composites.