Dataset Information

The interplay of crack hopping, delamination and interface failure in drying nanoparticle films.

ABSTRACT: Films formed through the drying of nanoparticle suspensions release the build-up of strain through a variety of different mechanisms including shear banding, crack formation and delamination. Here we show that important connections exist between these different phenomena: delamination depends on the dynamics of crack hopping, which in turn is influenced by the presence of shear bands. We also show that delamination does not occur uniformly across the film. As cracks hop they locally initiate the delamination of the film which warps with a timescale much longer than that associated with the hopping of cracks. The motion of a small region of the delamination front, where the shear component of interfacial crack propagation is believed to be enhanced, results in the deposition of a complex zig-zag pattern on the supporting substrate.

SUBMITTER: Yang B

PROVIDER: S-EPMC4997629 | biostudies-literature | 2016 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

The interplay of crack hopping, delamination and interface failure in drying nanoparticle films.

Yang Bin B Sharp James S JS Smith Mike I MI

Scientific reports 20160825

Films formed through the drying of nanoparticle suspensions release the build-up of strain through a variety of different mechanisms including shear banding, crack formation and delamination. Here we show that important connections exist between these different phenomena: delamination depends on the dynamics of crack hopping, which in turn is influenced by the presence of shear bands. We also show that delamination does not occur uniformly across the film. As cracks hop they locally initiate the ...[more]

PMID: 27558989

Similar Datasets

Project description:We have investigated photoinduced hole hopping in a Pseudomonas aeruginosa azurin mutant Re126WWCuI, where two adjacent tryptophan residues (W124 and W122) are inserted between the CuI center and a Re photosensitizer coordinated to a H126 imidazole (Re = ReI(H126)(CO)3(dmp)+, dmp = 4,7-dimethyl-1,10-phenanthroline). Optical excitation of this mutant in aqueous media (≤40 μM) triggers 70 ns electron transport over 23 Å, yielding a long-lived (120 μs) ReI(H126)(CO)3(dmp•-)WWCuII product. The Re126FWCuI mutant (F124, W122) is not redox-active under these conditions. Upon increasing the concentration to 0.2-2 mM, {Re126WWCuI}2 and {Re126FWCuI}2 are formed with the dmp ligand of the Re photooxidant of one molecule in close contact (3.8 Å) with the W122' indole on the neighboring chain. In addition, {Re126WWCuI}2 contains an interfacial tryptophan quadruplex of four indoles (3.3-3.7 Å apart). In both mutants, dimerization opens an intermolecular W122' → //*Re ET channel (// denotes the protein interface, *Re is the optically excited sensitizer). Excited-state relaxation and ET occur together in two steps (time constants of ∼600 ps and ∼8 ns) that lead to a charge-separated state containing a Re(H126)(CO)3(dmp•-)//(W122•+)' unit; then (CuI)' is oxidized intramolecularly (60-90 ns) by (W122•+)', forming ReI(H126)(CO)3(dmp•-)WWCuI//(CuII)'. The photocycle is closed by ∼1.6 μs ReI(H126)(CO)3(dmp•-) → //(CuII)' back ET that occurs over 12 Å, in contrast to the 23 Å, 120 μs step in Re126WWCuI. Importantly, dimerization makes Re126FWCuI photoreactive and, as in the case of {Re126WWCuI}2, channels the photoproduced "hole" to the molecule that was not initially photoexcited, thereby shortening the lifetime of ReI(H126)(CO)3(dmp•-)//CuII. Although two adjacent W124 and W122 indoles dramatically enhance CuI → *Re intramolecular multistep ET, the tryptophan quadruplex in {Re126WWCuI}2 does not accelerate intermolecular electron transport; instead, it acts as a hole storage and crossover unit between inter- and intramolecular ET pathways. Irradiation of {Re126WWCuII}2 or {Re126FWCuII}2 also triggers intermolecular W122' → //*Re ET, and the Re(H126)(CO)3(dmp•-)//(W122•+)' charge-separated state decays to the ground state by ∼50 ns ReI(H126)(CO)3(dmp•-)+ → //(W122•+)' intermolecular charge recombination. Our findings shed light on the factors that control interfacial hole/electron hopping in protein complexes and on the role of aromatic amino acids in accelerating long-range electron transport.

Dataset Information

The interplay of crack hopping, delamination and interface failure in drying nanoparticle films.

Publications

The interplay of crack hopping, delamination and interface failure in drying nanoparticle films.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets