Silver Nanocube and Nanobar Growth via Anisotropic Monomer Addition and Particle Attachment Processes
Understanding the growth mechanism of noble metal nanocrystals during solution synthesis is of significant importance for shape and property control. However, much remains unknown about the growth pathways of metal nanoparticles due to the lack of direct observation. Using an in situ transmission electron microscopy technique, we directly observed Ag nanocube and nanobar growth in an aqueous solution through both classical monomer-by-monomer addition and nonclassical particle attachment processes. During the particle attachment process, Ag nanocubes and nanobars were formed via both oriented and nonoriented attachment. Our calculations, along with the dynamics of the observed attachment, showed that the van der Waals force overcomes hydrodynamic and friction forces and drives the particles toward each other at separations of 10–100 nm in our experiments. During classical growth, anisotropic growth was also revealed, and the resulting unsymmetrical shape constituted an intermediate state for Ag nanocube gr...
Dongdong Xiao; Zhigang Wu; Miao Song; Jaehun Chun; Gregory K. Schenter; Dongsheng Li
We recently generalized the formerly alignment-dependent multivariate image analysis applied to quantitative structure–activity relationships (MIA-QSAR) method through the application of the discrete Fourier transform (DFT), allowing for its application to noncongruent and structurally dive ... more
Poly-ADP-ribosylation (PARylation) is a protein posttranslational modification (PTM) that is critically involved in many biological processes that are linked to cell stress responses. It is catalyzed by a class of enzymes known as poly-ADP-ribose polymerases (PARPs). In particular, PARP1 is ... more
This review focuses on the type A cytochrome c oxidases (CcO), which are found in all mitochondria and also in several aerobic bacteria. CcO catalyzes the respiratory reduction of dioxygen (O2) to water by an intriguing mechanism, the details of which are fairly well understood today as a r ... more
Rohm and Haas Powder Coatings is delighted to announce that its Reading, Pennsylvania, facility is the first site in the world to receive the RCMS® Site Certification awarded by the American Chemical Council (ACC).
When Raj Gupta, Chairman and CEO of Rohm and Haas Company, became Chairman ... more