Magnetic tubules

TL;DR

This study investigates how magnetic nanoparticles influence the formation, stability, and magnetic properties of diacetylenic phospholipid tubules in aqueous dispersions, revealing electrostatic interactions and magnetic response behaviors.

Contribution

It provides new insights into the magnetic response and electrostatic interactions of phospholipid tubules with magnetic nanoparticles, including effects on transition temperature and surface charge.

Findings

Magnetic nanoparticles decrease the tubule-vesicle transition temperature.

Tubules exhibit a negative apparent surface charge.

System shows variable magnetic permeability depending on conditions.

Abstract

Dispersion of tubules made of diacetylenic phospholipids (DC 8,9 PC), in aqueous colloidal dispersions of magnetic nanoparticles is studied as a function of the sign of particles surface charges. In every case the tubule-vesicle transition temperature is decreased by the presence of the magnetic nanoparticles. Electrophoresis experiments on the tubules in pure water permits to conclude on a negative apparent surface charge. We study the magnetic response of the system to a static or stationary rotating field and to a magnetic field gradient. These experiments reveal an excess or a lack of magnetic permeability between tubules and the surrounding medium. Electron microscopy confirms these results showing an electrostatic interaction between the phospholipidic bilayer and the magnetic particles.