In this study, surfaces of multiwalled carbon nanotubes (CNTs) were functionalized with poly(hexafluorobutyl acrylate) (PHFBA) thin film using a rotating-bed plasma-enhanced chemical vapor deposition (PECVD) method without imparting any defects on their surfaces. Polyacrylonitrile (PAN) electrospun polymer fiber mats and composite fiber mats with CNTs and functionalized CNTs (f-CNTs) were prepared. The wettability and chemical and morphological properties of the synthesized fiber mats were investigated, and the dispersion of CNTs and f-CNTs in the polymer matrix was compared according to the contact angle results of electrospun polymer mats. According to the chemical and morphological characterization results, PHFBA-coated CNTs were dispersed more uniformly in the polymer matrix than the uncoated CNTs. The f-CNTs/PAN composite fiber mat exhibits a lower surface energy than the pristine CNTs/PAN fiber mat. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47768.