Conference proceeding
Enhancing Enzyme-Induced Calcium Carbonate Precipitation (EICP) for Self-healing Applications: The Role of Bio-Based Hydrogel as a Nucleation Promoter
Bio-Based Building Materials - Proceedings of ICBBM 2025, pp 302-312
2025
Abstract
Microbial-induced calcium carbonate precipitation (MICCP) is a promising technique for self-healing concrete applications. Microbes, through different metabolic pathways, produce carbonate ions which then react with calcium ions (Ca2+) present in the surrounding environment and result in calcium carbonate (CaCO3) precipitation. The presence of bacterial cells with negatively charged cell walls provides nucleation sites that bind with positively charged Ca+2, allowing crystal growth and stabilization. However, this process heavily depends on bacterial viability and growth. Subsequently, direct use of the enzyme responsible for this activity known as EICP (Enzyme-induced carbonate precipitation) has emerged. This more controlled reaction allows for faster CaCO3 production. However, the absence of cell walls leads to the lack of nucleation sites necessary for growth and binding of crystals. To resolve this issue, the present research aims to use gelatin, a negatively charged biological hydrogel, to provide nucleation sites that enhance EICP. Different concentrations of Gelatin type B (isoelectric point: 4.7–5.3) were mixed with the enzyme urease (extracted from bean meal), urea and calcium acetate, and incubated for 24 hours at room temperature The resulting precipitates were characterized by X-ray diffraction and scanning electron microscopy to identify the mineral phases. The results indicate that an increase in the concentration of hydrogel leads to an increase in the formation of various polymorphs of calcium carbonate (i.e. vaterite, calcite, and aragonite) and interestingly, a decrease in the total amorphous phase. This implies that incorporating the hydrogel promotes crystalline phase production which can be beneficial for achieving more stability in self-healing applications.
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Details
- Title
- Enhancing Enzyme-Induced Calcium Carbonate Precipitation (EICP) for Self-healing Applications: The Role of Bio-Based Hydrogel as a Nucleation Promoter
- Creators
- Irene Verdú - Drexel UniversityParsa Namakiaraghi - Drexel UniversityErica Alston - Drexel UniversityYaghoob Farnam - Drexel UniversityChristopher M. Sales - Drexel University
- Publication Details
- Bio-Based Building Materials - Proceedings of ICBBM 2025, pp 302-312
- Series
- RILEM Bookseries
- Publisher
- Springer Nature ; Cham
- Resource Type
- Conference proceeding
- Language
- English
- Academic Unit
- C. and J. Nyheim Plasma Institute; Civil, Architectural, and Environmental Engineering
- Scopus ID
- 2-s2.0-105008783801
- Other Identifier
- 991022056999504721