Surface modification of polyester nonwoven fabrics by Al₂O₃ sol–gel coating

Nonwoven polyester (PET) fabrics have been extensively studied for various applications. However, the nonwoven PET fabrics have poor wettability. In this work, nonwoven PET fabrics were impregnated in a stable and transparent alumina sol that was prepared by the hydrolysis of aluminium isopropoxide using the sol–gel technique. The Al₂O₃ particles were coated on nonwoven PET fabrics after the rolling-drying process. The surface morphology of modified nonwoven PET fabrics was characterized by scanning electronic microscopy (SEM) and atomic force microscopy (AFM). The SEM and AFM observations revealed the formation of the Al₂O₃ particles on the fiber surface. The Al₂O₃ coating was also confirmed by Fourier transform infrared (FTIR). The mechanical properties of the coated nonwoven PET fabrics were investigated using a tensile strength test, and the results showed that the mechanical properties were improved after surface sol–gel coating. The effect of Al₂O₃ on the wetting behavior of the fabric was also significantly improved.