Self-Healing Properties of Bioinspired Amorphous CaCO3/Polyphosphate-Supplemented Cement

Molecules

Xiaohong Wang¹  Emad Tolba¹  HeinzC. Schröder¹  Meik Neufurth¹  WernerE. G. Müller¹  Shunfeng Wang¹  Maximilian Ackermann²  Rafael Muñoz-Espí³  BothainaM. Abd El-Hady⁴ 

[1] ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, 55128 Mainz, Germany;Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg University, Johann Joachim Becher Weg 13, 55099 Mainz, Germany;Institute of Materials Science (ICMUV), Universitat de València, C/Catedràtic José Beltrán 2, 46980 Paterna, València, Spain;Polymers and Pigments Department, National Research Center, Dokki, Giza 12622, Egypt;

关键词: polyphosphate;    amorphous calcium carbonate;    calcite;    Portland cement;    microcrack formation;    self-healing;   

DOI  :  10.3390/molecules25102360

来源: DOAJ

【 摘 要 】

There is a strong interest in cement additives that are able to prevent or mitigate the adverse effects of cracks in concrete that cause corrosion of the reinforcement. Inorganic polyphosphate (polyP), a natural polymer that is synthesized by bacteria, even those on cement/concrete, can increase the resistance of concrete to progressive damage from micro-cracking. Here we use a novel bioinspired strategy based on polyP-stabilized amorphous calcium carbonate (ACC) to give this material self-healing properties. Portland cement was supplemented with ACC nanoparticles which were stabilized with 10% (w/w) Na–polyP. Embedding these particles in the hydrated cement resulted in the formation of calcite crystals after a hardening time of 10 days, which were not seen in controls, indicating that the particles dissolve and then transform into calcite. While there was no significant repair in the controls without ACC, almost complete closure of the cracks was observed after a 10 days healing period in the ACC-supplemented samples. Nanoindentation measurements on the self-healed crack surfaces showed a similar or slightly higher elasticity at a lower hardness compared to non-cracked surfaces. Our results demonstrate that bioinspired approaches, like the use of polyP-stabilized ACC shown here, can significantly improve the repair capacity of Portland cement.

【 授权许可】

Unknown