Chemistry in Motion: Tiny Synthetic Motors

Abstract

In this Account, we describe how synthetic motors that operate by self-diffusiophoresis make use of a self-generated concentration gradient to drive motor motion. A description of propulsion by self-diffusiophoresis is presented for Janus particle motors comprising catalytic and noncatalytic faces. The properties of the dynamics of chemically powered motors are illustrated by presenting the results of particle-based simulations of sphere-dimer motors constructed from linked catalytic and noncatalytic spheres. The geometries of both Janus and sphere-dimer motors with asymmetric catalytic activity support the formation of concentration gradients around the motors. Because directed motion can occur only when the system is not in equilibrium, the nature of the environment and the role it plays in motor dynamics are described. Rotational Brownian motion also acts to limit directed motion, and it has especially strong effects for very small motors. We address the following question: how small can motors be and still exhibit effects due to propulsion, even if only to enhance diffusion? Synthetic motors have the potential to transform the manner in which chemical dynamical processes are carried out for a wide range of applications.

arXiv comment12 pages, 8 figures

References in corpus (15)

• Self-motile colloidal particles: from directed propulsion to random walk
• Dynamical clustering and phase separation in suspensions of self-propelled colloidal particles
• Propulsion of a molecular machine by asymmetric distribution of reaction--products
• Dynamic clustering in active colloidal suspensions with chemical signaling
• Designing phoretic micro- and nano-swimmers
• Self-assembly of catalytically active colloidal molecules: Tailoring activity through surface chemistry
• Electrokinetic Effects in Catalytic Pt-Insulator Janus Swimmers
• Phoretic self-propulsion at finite Péclet numbers
• A Classical Density-Functional Theory for Describing Water Interfaces
• Generic theory of colloidal transport
• Pulling and Pushing a Cargo With a Catalytically Active Carrier
• Phoretic self-propulsion: a mesoscopic description of reaction dynamics that powers motion
• Three-body Baryonic anti-B -->Lambda anti-p pi Decays and Such
• Ångström-scale chemically powered motors
• Probing the CP nature of the Higgs bosons by top-pair production at photon linear colliders

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• Simulating a Chemically-Fueled Molecular Motor with Nonequilibrium Molecular Dynamics
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• Efficiency of isothermal active matter engines: Strong driving beats weak driving
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• Molecular theory of Langevin dynamics for active self-diffusiophoretic colloids
• Nanoconfined catalytic Ångström-size motors
• Clustering of chemically propelled nanomotors in chemically active environments
• Self-organization of active colloids mediated by chemical interactions
• The stress tensor of dilute active colloidal suspensions
• The non-equilibrium thermodynamics of active suspensions