纳米TiO₂颗粒制备刺激–响应性Pickering泡沫

Stimuli-Responsive Pickering Foams Stabilized by the TiO₂ Nanoparticles

摘要: 本文探究了无机纳米TiO2颗粒和表面活性剂十六烷基三甲基溴化铵(CTAB)共同作用形成稳定的Pickering泡沫以及泡沫获得刺激–响应性的可能性。结果表明：原始的TiO2颗粒表面活性较差，不能获得Pickering泡沫。和CTAB混合之后，被原位疏水化，在CTAB浓度为0.06 mM时，就能形成稳定的Pickering泡沫。随着CTAB浓度的增加，泡沫体积越来越多，稳泡性能也有所提高。向稳定的泡沫体系中，加入等摩尔的阴离子型表面活性剂SDS，振荡摇晃之后，泡沫消失；再向其中加入和初始浓度相同的游离CTAB，震荡后又能形成稳定的泡沫，如此可以进行5次循环，得到刺激–响应性Pickering泡沫，而重新稳定的泡沫体积与初始泡沫的体积基本相同。

Abstract: This paper explores the possibility of Pickering foams stabilized by inorganic TiO2 nanoparticles to-gether with surfactant cetyltrimethylammonium bromide (CTAB) and stimuli-responsive foams are obtained by certain trigger mechanisms. The results show that TiO2 nanoparticles have less surface activity so they cannot stabilize Pickering foams alone. After mixing with CTAB, the system under-goes in-situ hydrophobization. A stable Pickering foam can be formed at a CTAB concentration of 0.06 mM. With the increasing CTAB concentration, the foam volume increases, and the foam stabil-ity improves. Upon adding an equal amount of anionic surfactant SDS to the stable foam system and agitating it, the foam disappears. However, when the same concentration of free CTAB is added to the system and agitated, a stable foam is formed again. This cycle can be repeated five times, re-sulting in a stimulus-responsive Pickering foam. The volume of the re-stabilized foam is similar to the initial foam volume.