ESRF Highlights 2022

S C

IE N

T IF

IC H

IG H

LI G

H T

S C

O M

P L

E X

S Y

S T

E M

S A

N D

B IO

M E

D IC

A L

S C

IE N

C E

5 5 I H I G H L I G H T S 2 0 2 2

PRINCIPAL PUBLICATION AND AUTHORS

Persistent Nucleation and Size Dependent Attachment Kinetics Produce Monodisperse PbS Nanocrystals, B. Abécassis (c), M.W Greenberg (a), V. Bal (b), B.M. McMurtry (a), M.P. Campos (a), L. Guillemeney (c), B. Mahler (e), S. Prevost (f), L. Sharpnack (g), M.P. Hendricks (a,d), D. DeRosha (a), E. Bennett (a), N. Saenz (a), B. Peters (b), J.S. Owen (a), Chem. Sci. 13 (17), 4977-4983 (2022); https:/doi.org/10.1039/D1SC06134H (a) Department of Chemistry, Columbia University, New York (USA) (b) Department of Chemical Engineering, University of Illinois (USA) (c) Laboratoire de Chimie, ENS de Lyon, CNRS, Université Claude Bernard Lyon 1 (France) (d) Department of Chemistry, Whitman College, Washington (USA) (e) Univ. Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, Villeurbanne (France) (f) Institut Laue-Langevin, Grenoble (France) (g) Department of Earth Science, University of California, Santa Barbara (USA)

REFERENCES

[1] V.K. LaMer & R.H. Dinegar, J. Am. Chem. Soc. 72 (11), 4847- 4854 (1950). [2] M.P. Hendricks et al., Science 348 (6240), 1226-1230 (2015).

Interplay between the self-assembly and dynamics of colloidal ellipsoids

Stimuli-responsive self-assembly of (an)isotropic colloids has resulted in a plethora of self-assembled structures with potential applications in smart materials. X-ray photon correlation spectroscopy unveils the interplay between the field-driven self-assembled structures and the corresponding collective dynamics at the nearest-neighbour length scale.

Positioned between the microscopic and the atomic world, colloids have often been employed as model systems to mimic general phenomena that occur at the atomic and molecular length scales. Other than this academic pursuit, stimuli-responsive self-assembly of anisotropic colloids have paved the way towards the development of smart materials with potential applications in many different fields. However, without detailed knowledge of the interplay between the self-assembled structures and dynamics of anisotropic building blocks, it is not possible to exploit the full potential of self-assembly-

reproduce the data for three different thioureas of different reactivities using a single growth rate constant.

Interestingly, the magnitude of the growth rate constant and the lack of solvent viscosity-dependence indicates that the rate-limiting step is slower than diffusion through the solvent. This radius-dependent growth kinetics must be explained by some other microscopic

attachment mechanism that is size-dependent: e.g., ligand penetration, surface binding, migration, and/or facet nucleation. The results suggest a model where the attachment is limited by penetration of the monomer through the ligand shell around the nanoparticle. This model accurately predicts the experimental data using a single adjustable parameter corresponding to the penetration probability.

Fig. 44: a) In-situ SAXS patterns and corresponding modelling results including (b) radius and (c) polydispersity. d) Simultaneous in-situ WAXS data and corresponding modelling results including (e) intensity and (f) polydispersity.