Linking catalyst-coated isotropic colloids into ``active'' flexible chains enhances their diffusivity

TitleLinking catalyst-coated isotropic colloids into ``active'' flexible chains enhances their diffusivity
Publication TypeJournal Article
Year of Publication2017
AuthorsBiswas, B, Manna, RKumar, Laskar, A, Kumar, PBSunil, Adhikari, R, Kumaraswamy, G
JournalACS Nano
Volume11
Issue10
Pagination10025-10031
Date PublishedOCT
Type of ArticleArticle
ISSN1936-0851
Keywordsactive matter, Brownian motion, colloidal assembly, diffusivity, ice templating
AbstractActive colloids are not constrained by equilibrium: ballistic propulsion, superdiffusive behavior, or enhanced diffusivities have been reported for active Janus particles. At high concentrations, interactions between active colloids give rise to complex emergent behavior. Their collective dynamics result in the formation of several hundred particle-strong flocks or swarms. Here, we demonstrate significant diffusivity enhancement for colloidal objects that neither have a Janus architecture nor are at high concentrations. We employ uniformly catalyst-coated, viz. chemo-mechanically, isotropic colloids and link them into a chain to enforce proximity. Activity arises from hydrodynamic interactions between enchained colloidal beads due to reaction-induced phoretic flows catalyzed by platinum nanoparticles on the colloid surface. This results in diffusivity enhancements of up to 60% for individual chains in dilute solution. Chains with increasing flexibility exhibit higher diffusivities. Simulations accounting for hydrodynamic interactions between enchained colloids due to active phoretic flows accurately capture the experimental diffusivity. These simulations reveal that the enhancement in diffusivity can be attributed to the interplay between chain conformational fluctuations and activity. Our results show that activity can be used to systematically modulate the mobility of soft slender bodies.
DOI10.1021/acsnano.7b04265
Type of Journal (Indian or Foreign)Foreign
Impact Factor (IF)13.942
Divison category: 
Polymer Science & Engineering

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