Bouncing of Hydroxylated Silica Nanoparticles: an Atomistic Study Based on REAX Potentials

Area of Science:

• Materials Science
• Surface Chemistry
• Computational Chemistry

Background:

• Clean silica surfaces exhibit high surface energy, leading to nanoparticle adhesion over a broad velocity range.
• Adsorbates like water can passivate silica surfaces, lowering surface energy and influencing particle interactions.

Purpose of the Study:

• To investigate the impact of surface hydroxylation on silica nanoparticle collision dynamics.
• To quantify the effect of reduced surface energy on nanoparticle bouncing behavior.

Main Methods:

• Atomistic simulations were employed to model silica nanoparticle collisions.
• The REAX potential was utilized, enabling bond breaking and formation during simulations.

Main Results:

• Surface hydroxylation dramatically reduces the critical bouncing velocity for silica nanoparticles.
• The bouncing velocity was observed to decrease by over an order of magnitude compared to clean silica nanoparticles.

Conclusions:

• Hydroxylation is a key factor in modifying silica nanoparticle collision outcomes.
• Understanding these surface effects is vital for controlling nanoparticle assembly and behavior in various applications.