Abstract:

Non-aqueous foams are widely used in fields such as oilfield development, functional materials, food industry and daily chemicals. The regulation of the properties of non-aqueous foams plays an important role in the development of related industries. Due to the low interfacial tension and low dielectric constant of non-aqueous solvents, foaming is difficult. Therefore, in this work, to solve the problems in non-aqueous solvent foaming, CaCO₃ nanocrystals were prepared. The crystal particles were characterized by TEM, FT-IR and XRD. 1H, 1H, 2H, 2H-perfluorodecyl triethoxy silane was used to regulate the wettability of CaCO₃ nanocrystals. The effects of CaCO₃ nanocrystals on the foaming performance of non-aqueous solvents were studied. It was found that, with the increase of mass fraction of CaCO₃ nanocrystals, the foam volume produced by CaCO₃ nanocrystals with different contact angles first increased and then decreased. When the crystal mass fraction was 5%, the foaming performance of non-aqueous solvent was the best, and the foam volume could reach 120 mL. The stability of the non-aqueous foam first increased and then decreased with the increase of the contact angle of CaCO₃ nanocrystals. When the contact angle was in the range from 47.5° to 73.9°, the stability of the non-aqueous foam was the best, and the draining half-life was up to 100 h.

Key words: foam, CaCO₃ nanocrystal, wettability, foaming performance