For the apolar compounds, the derivatization was not necessary.

对于非极性化合物，不一定这样的衍化。

Moreover, the results of IR spectrum and apolar component of surface free energy showed that the alkyl chains of OTS tilted on the surface of PTW after the modification.

IR析和量测定表明，改性后OTS的烷基链倾斜在PTW表面。