Smart self-healing materials

Skorbab, E.V., Andreeva, D.V. Layer-by-layer approaches for formation of smart self-healing materials. Polym. Chem. 4, 4834 845 (2013)... 

Self-healing materials form another emerging class of smart materials. Such materials have the ability to recover from damage, such as cracks and holes, by repairing ( healing ) themselves [62]. Some examples of repair mechanism are as... 

Why there is an growing interest in a covalent mechanochemistry (CMC) [16-18]. Mostly because of the potential use of such smart materials in applications that range from drug delivery to camouflage systems and self-healing materials [19, 20]. At this moment it is hard to overestimate the potential and importance of mechanochemistry as it has a great impact in different fields such as synthetic chemistry and materials science [21]. 

Recently, encapsulation of benzotriazole [283], a corrosion inhibitor in silica-zirconia anticorrosion film on aluminum alloy substrates, has been reported. The benzotriazole could be slowly released from the hybrid film deposit on the substrate and provide long-term corrosion protection. This approach is especially attractive because the dissolution and redeposition of the benzotriazole is pH dependent and increases when local corrosion takes place. This type of self-healing material is likely to play an increasing role in futuristic active smart materials or corrosion protection as well as other applications. 

Nji, J. and Li, G. (2010) A self-healing 3D woven fabric reinforced shape memory polymer composite fm impact mitigation. Smart Materials and Structures, 19, paper 035(X)7 (9 pages). 

Venna, R. (2011) Self Healing Composite Materials The Smart Technology for Future Aerospace, ISBN-13 978-3-844-30942-3, LAP LAMBERT Academic PubUshing. 

Kousourakis, A. and Mouritzl A.P. (2010) The effect of self-healing hollow fibres on the mechanical properties of polymer composites. Smart Materials and Structures, 19, 085021. 

Shojaei, A., Li, G., and Voyiadjis, G.Z. (2013) Cyclic viscoplastic-viscodamage analysis of shape memory polymer fibers with application to self-healing smart materials. ASME Journal of Applied Mechanics, 80, paper... 

For some applications, it is necessary to maintain a hydrophobic surface. If the surface is damaged then the recovery or restructuring is beneficial and is called self-healing. In this sense, PDMS is a smart material, in that it responds constructively to a change in the environment. 

Self-healing, which is the ability of a system or material to autonomously and spontaneously heal or repair itself, or more specifically repair surface or internal damage, has received considerable attention as a function of smart materials... 

On the other hand, smart PHA materials with properties of shape memory, selective gas permeability, selective liquid permeability, temperature and/or pH responsibility, self-healing, controllable degradation and/or controllable porosity will be developed. These properties will add values to the microbial PHA, they should have a small but b mai n market. 

A prototypical autonomous biological device is a Vibrio cholerae bacterium that packs the ability to move, sense, target, adapt, and release active substances into just a few cubic centimeters. An example of a smart biological material, muscle, which is composed of autonomous systems, is hierarchically assembled from microscopic subunits, has the ability to exehange information with the enviromnent via electrical and mechanical stimuli, and incorporates energy-conversion modules and self-healing abilities. 

In addition, composite systems can be manufactured with smart materials to identify damage and lead to self-healing or even self-cleaning mechanisms [8]. Composite applicahons are not limited to new structures, as they can be utilized to rehabilitate or upgrade existing structures for safety or to increase load-carrying capacity. A few of these aspects are briefly described in the sections given later. 

---