Models of aerogel networks from pyrolysis of proteins

Covalent networks and nanoporous scaffolds composed of graphene sheets and carbon nanofiber with hierarchical porosity have attracted interest for a wide range of applications, including energy storage and water purification. It has been recently show that such structures can be obtained by pyrolysis subsequent to freezing of aggregating proteins. The final material displays a hierarchical porosity on the nano and on the micro scale, depending on the type of protein used (e.g. Egg white proteins, bovine serum albumin, collagen).

(a) Pyrolysis of an amyloid simulated with a reactive force field. (b) Simulation of water (in light blue) desalinization. Ions (colored balls) are trapped in the fibers, as shown by the distribution functions (plots).

In order to clarify the origin of these differences, we simulated the pyrolytic process by means of atomistic molecular dynamics with reactive force fields (Fig, panel a). We observed the formation of fibers or extended sheets (with nanopores) depending on the boundary conditions imposed to the system, mimicking the application of anisotropic or isotropic tension occurring in the real system as an effect of the release of the pyrolysis volatile products. In any case the result is a structure with nanopores and nanochannels. We tested these structures vs their water desalinization capability (panel b), showing that ions are trapped into the nano-cavities of the structures. These materials, also obtainable by food waste, might be a great resource for environmental applications.

Outreach & Media coverage

Featured in the Carbon News section of Materials Today Simple ingredient is egg-actly right for ultralight aerogels

NANO web site Ultra-light aerogels derived from egg white

PeopleValentina Tozzini
KeywordsAmyloid aggregates, graphene-like structures, porous materials, water desalinization
Methods, techniquesMolecular Dynamics, reactive force fields (ReaxFF)
CollaborationsThis research is performed in collaboration with Susanna Monti (ICCOM-CNR), and with University of Trento (prof Nicola Pugno) and Princeton University (Craig Arnold, Sehmus Ozden)
PublicationsS Ozden, S Monti, V Tozzini, NS Dutta, S Gili, N Caggiano, AJ Link, N Pugno, J Higgins, R Priestley, C Arnold Egg protein derived ultralightweight hybrid monolithic aerogel for water purification Materials Today (2022)