Early Onset of Kinetic Roughening due to a Finite Step Width in Hematin Crystallization

Abstract

The structure of the interface of a growing crystal with its nutrient phase largely determines the growth dynamics. We demonstrate that hematin crystals, crucial for the survival of malaria parasites, transition from faceted to rough growth interfaces at increasing thermodynamic supersaturation Δμ. Contrary to theoretical predictions and previous observations, this transition occurs at moderate values of Δμ. Moreover, surface roughness varies nonmonotonically with Δμ, and the rate constant for rough growth is slower than that resulting from nucleation and spreading of layers. We attribute these unexpected behaviors to the dynamics of step growth dominated by surface diffusion and the loss of identity of nuclei separated by less than the step width w. We put forth a general criterion for the onset of kinetic roughening using w as a critical length scale.

One-Dimensional Segregated Single Au Sites on Step-Rich ZnO Ladder for Ultrasensitive NO2 Sensors

“…This is according to the classical nucleation growth mechanism, which involves a layer-bylayer evolution in a supersaturated condition. [29][30][31][32] Meanwhile, no obvious distortion points were found on the flat ZnO ladder surface in both TEM and SEM images in Figures S4 and S5. Moreover, an optimal precursor dosage m 0 is crucial, since ZnO ladders with larger sizes of approximately 250 nm (Figures 2F, S6, and S7) and 400 nm (Figures 2G and S10) are observed when the precursors are 1.5 and 2.5 times (1.5m 0 and 2.5m 0 ) referring to the initial concentration.…”

Synthesis of centimeter-size free-standing perovskite nanosheets from single-crystal lead bromide for optoelectronic devices

“…It is expected that growth occurs by burst nucleation because the NSs become detectable after a very short time 27,28 . The nucleation phase is still unclear in our study limited by the resolution of the optical microscope 29 . Figure 2a shows the real-time growth evolution of NSs observed with an optical microscope, where we can observe the nucleation and growth of an individual NS identified by the white dotted circle.…”

Solvent Structure and Dynamics near the Surfaces of β-Hematin Crystals

“…Importantly, our findings demonstrate that solvent structuring may be upheld by bonds distinct from the hydrogen bonds, as on the apolar (010) face, and may be a general feature of all solvents in contact with periodic crystal surfaces. The slow solvent dynamics in the vicinity of the crystal faces retards the diffusion of hematin molecules along the surface en route to their incorporation sites ,, and suggests a pathway to control hematin crystallization using additives that disrupt or reinforce solvent structures.…”

“…The synthetic analogue of hemozoin is known as β-hematin (Figure c). To explore the crystallization of β-hematin, the mixture of neutral lipids found in the parasite’s digestive vacuole is typically replaced with normal 1-octanol, which saturates with water at about 5 wt %. ,,,, Despite many years of research on hemozoin and β-hematin crystallization ,,− ,,,,− ,, and the activity of antimalarial drugs, ,,− ,,− ,,,,− fundamental understanding of the structures and dynamics at both the crystal–solution interface and in the solution bulk, and on their correlation to the crystallization mechanism and the activity of the antimalarials, remains elusive.…”

“…We explore the properties of a 5 wt % water–octanol mixture; owing to the lower molecular weight of water, the number of water molecules in this mixture is ∼28% of the total number of molecules. This solvent composition was chosen to model the majority components in the solution used to precipitate β-hematin in recent experiments. ,,,,− …”