Surface Modification

In order to partially hydrophobize the particles and enable their adsorption to a gas-liquid interface, their surface needs to be modified. Particle hydrophobization is achieved through the adsorption of amphiphiles exhibiting a functional group that efficiently anchors on the particle surface and a short hydrophobic tail which remains in contact with the aqueous phase. Depending on the surface chemistry of the particles (a), the anchoring group of the amphiphile has to be deliberately tuned (b) to allow adsorption onto the particle surface. Short-chain carboxylic acids, alkyl gallates and alkyl amines were used as amphiphiles that can in-situ hydrophobize the surface of different oxide and non-oxide particles (c).