Title: Directed nanoparticle motion on an interfacial free energy gradient
Authors : Walder, Robert
Honciuc, Andrei
Schwartz, Daniel K.
Published in : Langmuir
Volume(Issue) : 26
Issue : 3
Pages : 1501
Pages to: 1503
Publisher / Ed. Institution : American Chemical Society
Issue Date: 2010
License (according to publishing contract) : Licence according to publishing contract
Type of review: Peer review (publication)
Language : English
Subject (DDC) : 540: Chemistry
Abstract: Using total internal reflection fluorescence microscopy (TIRFM), we have observed the directed motion of 20 nm probe particles on specific regions of surfaces that exhibited strong gradients of hydrophobicity. Patterned surfaces were prepared by selective photodegradation (using a contact photomask) of a hydrophobically modified fused silica surface. The lateral distribution of hydrophobicity was characterized in situ using the selective affinity of amphiphilic probes (i.e., hydrophobic interaction microscopy). Probe particles were observed to move unidirectionally from regions of lower to higher to hydrophobicity over distances of approximately 1 microm when the hydrophobicity gradient was greater than d(cos theta)/dx = 0.05 +/- 0.02 microm(-1), where theta is the water contact angle on the bare surface. Only adsorption events were observed on energetically homogeneous surface regions.
Departement: Life Sciences and Facility Management
Organisational Unit: Institute of Chemistry and Biotechnology (ICBT)
Publication type: Article in scientific journal
DOI : 10.1021/la903753z
ISSN: 0743-7463
1520-5827
URI: https://digitalcollection.zhaw.ch/handle/11475/14579
Appears in Collections:Publikationen Life Sciences und Facility Management

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