Figure 1.
(a) Photograph showing a HEPF standing on a dandelion, demonstrating its lightweight property. SEM images showing the hierarchical pore structure from (b) the surface and (c–e) the cross section of the HEPF.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.