反相气相色谱法探究镁铁水滑石及其改性材料的表面性质

Surface Properties of Magnesium-iron Hydrotalcite and Its Modified Products by Inverse Gas Chromatography

采用反相气相色谱法(IGC)探究司班20(Span-20)、吐温-80(Tween-80)、曲拉通X-100(Triton X-100)分别与十二烷基苯磺酸钠(SDBS)复合改性镁铁水滑石材料(即SDBS/Span-LDHs、SDBS/Tween-LDHs、SDBS/Triton-LDHs)的表面性质,通过表面吸附自由能(–ΔG0)、表面能色散组分(γsd)及酸碱作用自由能(–ΔGsp)这三个参数探讨材料改性前后的变化。结果表明,水滑石经改性后的–ΔG0值均比未改性材料的值小,其中SDBS/Triton-LDHs的–ΔG0值最小,说明SDBS/Triton-LDHs材料的稳定性最好,且水滑石材料改性后碱性减弱,其中SDBS/Triton-LDHs材料的碱性最弱。此外,各类水滑石的γsd值均随着温度的升高而减小,因此,在制备聚合物/水滑石类材料时,可提高温度来改善其与聚合物的相容性。

The magnesium-iron hydrotalcite was modified by three nonionic surfactants（Span-20, Tween-80, Triton X-100） combined with sodium dodecyl benzene sulfonate（SDBS）, respectively, and surface characterizations of modified hydrotalcites were investigated using inverse gas chromatography（IGC）. The free energy of adsorption（–ΔG0）, dispersive component of the surface energy（γsd） and acid-basic action free energy（–ΔGsp） were determined to explore the changes between Mg Fe-LDHs and modified hydrotalcites. The results show that the –ΔG0 of the modified hydrotalcites are lower than that of Mg Fe-LDHs, among which the –ΔG0 of the SDBS/Triton-LDHs is the lowest, indicating the best stability. The alkalinity of modifed hydrotalcites is weakened and the alkalinity of SDBS/Triton-LDHs is the weakest. In addition, the γsd decreases with temperature increase. Therefore, the compatibility with polymer can be improved by increasing the temperature in preparation of polymer/hydrotalcite materials.