The analysis of realistic numerical simulations of a gel-forming irreversible aggregation process provides information on the role of cluster diffusion in controlling the late stages of the aggregation kinetics. Interestingly, the crossover from chemically controlled to diffusion-controlled aggregation takes place well beyond percolation, after most of the particles have aggregated in the spann...

In this paper, the transformation process from Au8 to Au25 nanoclusters (NCs) is investigated with steady state fluorescence spectroscopy and time-resolved fluorescence spectroscopy at various reaction temperatures and solvent diffusivities. Results demonstrate that Au8 NCs, protected by bovine serum albumin, transform into Au25 NCs under controlled pH values through an endothermic reaction wit...

The reaction of fly ash with a KOH solution was used to synthesize Linde F(K) zeolite, following which Fourier transform infrared spectroscopy were used to characterize the crystalline material. The competitive adsorption of Cu, Ni, Pb, and Cd onto this zeolite was subsequently studied in quaternary solution systems. The results show that the metal removal rates gradually increase with incr...

Within the framework of a realistic atomistic lattice-gas model, we present the theoretical formulation and simulation procedures for precise analysis of the chemical diffusion flux of highly mobile CO within a nonuniform interacting mixed CO + O adlayer on a Pd(100) surface. The approach applies in both regimes of relatively immobile unequilibrated and fairly mobile near-equilibrated O adlayer...

Solid state diffusion in a binary system, such as lithiation into crystalline silicon, often involves two symbiotic processes, namely, interfacial chemical reaction and bulk diffusion. Building upon our earlier work (Cui et al., 2012b, J. Mech. Phys. Solids, 60 (7), 1280–1295), we develop a mathematical framework in this study to investigate the interaction between bulk diffusion and interfacia...

In a diffusion-controlled interaction, the Kirkendall plane, as marked by inert particles placed at the original contact surface of a reaction couple, need not be unique. Multiple planes can develop, and sometimes the Kirkendall plane does not exist at all. A phenomenological approach is introduced to rationalize the Kirkendall-effect-mediated migration of macroscopic inclusions inside a diffus...

A mathematical reaction-diffusion model is defined to describe the gradual decomposition of polymer microspheres composed of poly(D,L-lactic-co-glycolic acid) (PLGA) that are used for pharmaceutical drug delivery over extended periods of time. The partial differential equation (PDE) model treats simultaneous first-order generation due to chemical reaction and diffusion of reaction products in s...

Abstract Crystal growth is often described as either interface-controlled or diffusion-controlled. Here, we study crystal in an intermediate scenario where reaction rates at the crystal-melt interface are similar to of diffusive transport ions through melt advancing surface. To this end, experimentally investigated euhedral plagioclase shapes dry mafic (basaltic) and hydrous silicic (haplodacit...

Feedstock diffusion and decomposition in the root growth of aligned carbon nanotube (CNT) arrays is discussed. A nondimensional modulus is proposed to differentiate catalystpoisoning controlled growth deceleration from one which is diffusion controlled. It is found that, at current stage, aligned multi-walled carbon nanotube (MWNT) arrays are usually free of feedstock diffusion resistance. Howe...