Solvent-free surface modification of milled carbon fiber using resonant acoustic mixing

Resonant Acoustic Mixing (RAM) is used to rapidly modify the surface of milled carbon fiber using diazonium salts in solvent free conditions. This novel method allows tuning of the surface properties of this material and reduces the environmental footprint usually associated with surface modification of carbon fiber (discontinuous or otherwise). As a proof of concept, fluorine-containing diazonium salts were successfully grafted as determined by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy with energy dispersive X-ray spec-troscopy (SEM-EDX) and an increase in water contact angle (WCA) of the milled carbon fiber samples (+15 degrees). Atomic Force Microscopy (AFM) together with SEM revealed the surface structure and integrity of the milled carbon fibers could be maintained despite vigorous mixing conditions. Using RAM proved more efficient than positive controls produced under thermal conditions in solvent.

Automated summary

Resonant Acoustic Mixing (RAM) is used to modify the surface of milled carbon fiber quickly and without solvents, allowing for tuning of surface properties and reducing environmental impact. Fluorine-containing diazonium salts were successfully grafted onto the carbon fiber, maintaining surface integrity and increasing water contact angle. RAM proved more efficient than thermal treatment in solvent.