Structure and frictional properties of Langmuir-Blodgett films of Cu nanoparticles modified by dialkyldithiophosphate

TL;DR

This study investigates the structure and frictional properties of Langmuir-Blodgett films made from dialkyldithiophosphate-modified copper nanoparticles, revealing their core-shell structure, orderly arrangement, low friction, and minimal adhesion.

Contribution

It demonstrates the formation of well-ordered LB films of modified Cu nanoparticles with favorable frictional and adhesion properties, highlighting their potential for surface coating applications.

Findings

Modified Cu nanoparticles have a core-shell structure.

LB films show lower friction and orderly nanoparticle arrangement.

Modified nanoparticles exhibit very small adhesive forces.

Abstract

Langmuir-Blodgett (LB) films of dialkyldithiophosphate (DDP) modified Cu nanoparticles were prepared. The structure, microfrictional behaviors and adhesion of the LB films were investigated by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and atomic/friction force microscopy (AFM/FFM). Our results showed that the modified Cu nanoparticles have a typical core-shell structure and fine film-forming ability. The images of AFM/FFM showed that LB films of modified Cu nanoparticles were composed of many nanoparticles arranged closely and orderly and the nanoparticles had favorable behaviors of lower friction. The friction loop of the films indicated that the friction force was affected prominently by the surface slope of the Cu nanoparticles and the microfrictional behaviors showed obvious "ratchet effect". The adhesion experiment showed that the modified Cu nanoparticle had a very small adhesive force. (c) 2006 Elsevier B.V. All rights reserved.