二氧化硅颗粒表面硅烷化对其润湿性能的影响

Effect of Surface Silanization on Wettability of Silica Particles

采用3-氨丙基三乙氧基硅烷（APTES）接枝改性二氧化硅颗粒表面,通过调节APTES的接枝密度（颗粒表面每平方纳米接枝硅烷偶联剂分子的个数）定量控制二氧化硅颗粒在石蜡/水界面上的接触角。结果表明：随着APTES在二氧化硅颗粒表面接枝密度的增加,颗粒由超亲水转变为疏水,在油水界面的接触角从15°增加到116°;改性颗粒在石蜡/水界面形成固态膜,当石蜡低温固化后,改性颗粒在石蜡相中的部分被掩盖;相比于未改性颗粒,改性后的颗粒在石蜡表面形成的包裹层更加紧密有序。

The surface of silica particles were modified by（3-aminopropyl）-triethoxysilane（APTES）. The contact angle of silica particles in the wax-water（W） interface was quantitatively controlled by tuning the APTES grafting density. The modified particles（APTES @ SiO2） were used to prepare the wax/W Pickering emulsions. The results show that the particles are changed from superhydrophilic to hydrophobic as APTES graft density increases, and the contact angle of wax/W interface increases from 15° to 116°. The modified particles formed the solid film in the Wax/W interface, and the part of the modified particles is shielded after wax solidifying. Compared to the bare particles, the modified particles pack more closely and in a more ordered fashion on the wax surface.