Aerogels are light-weight supplies with intensive microscale pores, which may very well be utilized in thermal insulation, vitality units, aerospace constructions, in addition to rising applied sciences of versatile electronics. Nevertheless, conventional aerogels based mostly on ceramics are usually brittle, which limits their efficiency in load-bearing constructions. As a result of restrictions posed by their constructing blocks, lately developed lessons of polymeric aerogels can solely obtain excessive mechanical power by sacrificing their structural porosity or light-weight traits.
A analysis staff led by Dr Lizhi Xu and Dr Yuan Lin from the Division of Mechanical Engineering of the School of Engineering of the College of Hong Kong (HKU), has developed a brand new sort of polymer aerogel supplies with huge applicational values for numerous purposeful units.
On this research, a brand new sort of aerogels was efficiently created utilizing a self-assembled nanofiber community involving aramids, or Kevlar, a polymer materials utilized in bullet-proof vests and helmets. As an alternative of utilizing millimetre-scale Kevlar fibres, the analysis staff used a solution-processing methodology to disperse the aramids into nanoscale fibrils. The interactions between the nanofibers and polyvinyl alcohol, one other mushy and “gluey” polymer, generated a 3D fibrillar community with excessive nodal connectivity and powerful bonding between the nanofibers. “It is like a microscopic 3D truss community, and we managed to weld the trusses firmly collectively, leading to a really sturdy and hard materials that may face up to intensive mechanical hundreds, outperforming different aerogel supplies,” stated Dr Xu.
The staff has additionally used theoretical simulations to clarify the excellent mechanical efficiency of the developed aerogels. “We constructed a wide range of 3D community fashions in laptop, which captured the important traits of nanofibrillar aerogels,” stated Dr Lin, who led the theoretical simulations of the analysis. “The nodal mechanics of fibrillar networks are important to their total mechanical behaviours. Our simulations revealed that the nodal connectivity and the bonding power between the fibres influenced the mechanical power of the community by many orders of magnitudes even with the identical stable content material,” stated Dr Lin.
“The outcomes are very thrilling. We not solely developed a brand new sort of polymer aerogels with glorious mechanical properties but additionally supplied insights for the design of assorted nanofibrous supplies,” stated Dr Xu, including, “the straightforward fabrication processes for these aerogels additionally enable them for use in numerous purposeful units, similar to wearable electronics, thermal stealth, filtration membranes, and different programs,”