利用接触角测试仪对喷雾干燥所得到的氧化石墨烯粉体对于水/乙二醇液体的接触角进行测量。 展示了不同GO粉体样品的水接触角（WCA）和乙二醇接触角(EGCA)。随着进料浓度的增加，两者均相应降低，表明低卷曲程度均有利于增强粉体与溶剂（水、乙二醇）的相互作用，并且在相同进料浓度下EGCA通常小于WCA。

在此基础上，采用Owens，Wendt，Rabel和Kaelble模型（OWRK模型）对固体GO粉体的表面张力（σ_s）进行计算，计算出的GO粉体的固体表面张力主要由两部分组成：色散分量和极性分量，分别由范德华力和氢键控制。

The contact Angle of the spray dried graphene oxide powder to water/glycol liquid was measured by a contact Angle tester. The water contact Angle (WCA) and glycol contact Angle (EGCA) of different GO powder samples are shown. With the increase of feed concentration, both of them decrease correspondingly, indicating that the low crimp degree is conducive to enhancing the interaction between the powder and the solvent (water, ethylene glycol), and EGCA is generally smaller than WCA at the same feed concentration.

On this basis, the Owens, Wendt, Rabel and Kaelble model (OWRK model) was used to calculate the surface tension (σs) of the solid GO powder. The calculated surface tension of the solid GO powder mainly consists of two components: the dispersion component and the polarity component, which are controlled by the van der Waals force and the hydrogen bond respectively.