Controlling crystallization and its absence: proteins, colloids and patchy models

Abstract

The ability to control the crystallization behaviour (including its absence) of particles, be they biomolecules such as globular proteins, inorganic colloids, nanoparticles, or metal atoms in an alloy, is of both fundamental and technological importance. Much can be learnt from the exquisite control that biological systems exert over the behaviour of proteins, where protein crystallization and aggregation are generally suppressed, but where in particular instances complex crystalline assemblies can be formed that have a functional purpose. We also explore the insights that can be obtained from computational modelling, focussing on the subtle interplay between the interparticle interactions, the preferred local order and the resulting crystallization kinetics. In particular, we highlight the role played by "frustration", where there is an incompatibility between the preferred local order and the global crystalline order, using examples from atomic glass formers and model anisotropic particles.

Fabrication, Assembly, and Application of Patchy Particles

“…Many other models have been developed to describe patchy particle interactions and the main approaches are reviewed in the following section. There are four different categories of models to distinguish based on how the patchy interactions are incorporated in the simulations: i) patchy particle models, involving a pair potential function that depends on the distance and orientation of particles, [108][109][110][111][112][113][114][115][116][117] ii) particle models with distinguishable ''atoms'' belonging to the patch and the core particle, [36,41,42,[118][119][120][121][122] iii) models for interactions between proteins, [123][124][125][126][127][128][129][130] and, iv) a density functional theory (DFT) approach incorporating anisotropic interactions between particles. [38,40] Note that the various theoretical studies involving patchy interactions reviewed in the following are categorized based on the approach and the model involved to address the patchy interactions between particles rather than the type of method used in the simulations.…”

Computing the free energy of molecular solids by the Einstein molecule approach: Ices XIII and XIV, hard-dumbbells and a patchy model of proteins

“…65,66,67 This model consists of a repulsive core with some attractive sites (patches) on its surface. In particular, we studied model particles with six patches in an octahedral arrangement.…”

Predicting patchy particle crystals: Variable box shape simulations and evolutionary algorithms

“…We consider a patchy particle model first introduced in Ref. 34. In the model, the repulsion between two particles is given by an isotropic Lennard-Jones repulsive core, while the directional patchpatch attraction is specified by a Lennard-Jones attraction of depth , modulated via a Gaussian-shaped angular decay.…”