The Role of Zn2+-Doping on the Surface Chemistry of Poly(vinylidene difluoride) Thin Films
Angela Thach, Satu Kristiina Heiskanen, Brett L. Lucht, William B. Euler, Surfaces & Interfaces, 2021, 23, 101005
Abstract
Thin films of poly(vinylidene difluoride) (PVDF) doped with zinc nitrate spin-cast onto silicon substrates were studied by optical profilometry, infrared and x-ray photoelectron spectroscopy (XPS). The spin-cast films were found to be significantly nonuniform having variations on the order of hundreds of nanometers across tens of microns for films with low zinc ion content and with pores that extend through the entire film thickness. As the Zn2+ content increases both the porosity and the amount of β-phase of the PVDF in the bulk of the films increase. The depth of some of the pores allowed investigation of both the polymer/air and polymer/substrate interface. The increased porosity of the doped films is tentatively attributed to Marangoni effects.
