Adhesion force studies of Janus nanoparticles

Janus nanoparticles represent a unique nanoscale analogue to the conventional surfactant molecules, exhibiting hydrophobic characters on one side and hydrophilic characters on the other. Yet, direct visualization of the asymmetric surface structures of the particles remains a challenge. In this pape...

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Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1992. - 23(2007), 16 vom: 31. Juli, Seite 8544-8
1. Verfasser: Xu, Li-Ping (VerfasserIn)
Weitere Verfasser: Pradhan, Sulolit, Chen, Shaowei
Format: Aufsatz
Sprache:English
Veröffentlicht: 2007
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article
Beschreibung
Zusammenfassung:Janus nanoparticles represent a unique nanoscale analogue to the conventional surfactant molecules, exhibiting hydrophobic characters on one side and hydrophilic characters on the other. Yet, direct visualization of the asymmetric surface structures of the particles remains a challenge. In this paper, we used a simple technique based on AFM adhesion force measurements to examine the two distinctly different hemispheres of the Janus particles at the molecular level. Experimentally, the Janus nanoparticles were prepared by ligand exchange reactions at the air-water interface. The particles were then immobilized onto a substrate surface with the particle orientation controlled by the chemical functionalization of the substrate surface, and an AFM adhesion force was employed to measure the interactions between the tip of a bare silicon probe and the Janus nanoparticles. It was found that when the hydrophilic side of the particles was exposed, the adhesion force was substantially greater than that with the hydrophobic side exposed, as the silicon probes typically exhibit hydrophilic properties. These studies provide further confirmation of the amphiphilic nature of the Janus nanoparticles
Beschreibung:Date Completed 02.10.2007
Date Revised 24.07.2007
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1520-5827