Nanoencapsulation-Driven Microbial Hydrogel Spray

Concrete microcracking causes three negative effects which are
decreased durability, increased permeability, and higher
maintenance costs. The researchers created a sprayable hydrogel
system through nanoengineering which uses Bacillus subtilis spores
and urease-loaded nanogels and mesoporous silica nanoparticles to
achieve autonomous crack healing. The researchers created a
protective system for spores which used chitosan–alginate nanoshells
with six to ten layers to protect against ultraviolet light and drying
and alkaline environments while maintaining over 80 percent
germination capacity. The system used urease which was
immobilized in alginate nanogels to produce rapid calcium carbonate
precipitation while silica nanoparticles functioned as both urea
storage and nucleation sites. The dual-phase spray system provides
two functions which are effective material delivery and on-site
mineralization.