Accession Number:

AD1026374

Title:

Energy Absorbing Media Based Upon Nanocrystals of Complex Shape and Topology

Descriptive Note:

Technical Report,15 Apr 2007,30 Nov 2009

Corporate Author:

University of California, Berkeley Berkely United States

Personal Author(s):

• Alivisatos, P. A.
• Merkle,Maxwell G.
• Park,Jungwon
• Wittenberg,Joshua S.
• Drugan-Kamp,Noelle M.

Report Date:

2010-05-26

Pagination or Media Count:

18.0

Abstract:

Hollow CoS, CoO, and iron oxide particles have all been synthesized by exploiting the nanoscale Kirkendal effect. Yolk-shell type particles havebeen synthesized by coating an inert seed particle with a reactive metal intermediate. Anion exchange of ZnO nanoparticls through heteroepitaxialanion exchange was shown to preserve single-crystallinity and parent-particle shape. Silver nanoparticles have been shown to undergo a reversible, noncubic distortion under pressure. Diffraction peaks from Ag nanoparticles inside hollow CoO and Fe304 nanoshells were used to monitor their internal pressure. The mechanical properties and fracturing of hollow nanoparticles were studied with an in-situ TEM indenter. The single-particle fracturing and deformation events were correlated to their individual stress-strain maps in this way. The ftrst-order phase transition of CdSe nanoparticles, deformation of gold spheres, and the absorption of energy by breaking hollow nanoshells have been demonstrated under shock compression.

Descriptors:

• materials science
• composite materials
• mechanical properties
• nanoparticles
• high pressure
• nanocrystals
• nanotechnology
• polymeric films
• polymers
• shock waves
• electron microscopes
• anion exchange
• iron oxides
• x ray diffraction
• transmission electron microscopy
• topology

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE