Open Access Received: 23 July 2026   |   Accepted: 03 September 2026   |   Published: 07 September 2026

SURFACE MORPHOLOGY AND STRUCTURAL CHARACTERIZATION OF ION-IRRADIATED PET FILMS AFTER ALKALINE ETCHING

Asilbek D. Yorbekov, Abdumutolib A. Atakhanov

Institute of Polymer Chemistry and Physics, Academy of Science of the Republic Uzbekistan, Abdulla Kadiriy Street 7b, 700011 Tashkent, Uzbekistan

---

Abstract. This study reports the fabrication and structural characterization of track-etched membranes based on a 12 μm-thick, locally produced polyethylene terephthalate (PET) film. PET films were irradiated with krypton (Kr) ions (2.0 MeV/nucleon, fluence 10⁹ cm⁻²) and subsequently etched in a 2.2 M NaOH solution at 82–85°C to convert the latent ion tracks into open, cylindrical micropores. X-ray diffraction (XRD) revealed a shift and broadening of the principal PET reflection after etching, indicating a reorganization of the crystalline domains rather than a simple increase or decrease in crystallinity. Fourier-transform infrared (FTIR) spectroscopy confirmed that all characteristic PET absorption bands were retained after etching, showing that the polymer's chemical backbone remained intact. Scanning electron microscopy (SEM) revealed a clear, etching-time-dependent evolution of the surface and pore morphology, with roughness and pore density increasing progressively between 150 and 180 s of etching. Considered jointly, the three techniques converge on a single mechanistic picture in which etching selectively removes radiation-damaged, amorphous-like PET while preserving the core polyester chemistry and reorganizing the surviving crystalline framework. These results demonstrate that structurally well-defined track-etched membranes can be produced from locally available PET film, supporting their practical and economic potential as a domestic alternative to imported membranes for gas and liquid separation, medicine, and biotechnology. Surface wettability and membrane transport behavior were not measured in the present work and are identified as directions for follow-up study.

---

Key words. PET; ion-track etching; XRD; FTIR; SEM; cylindrical pores.


DOI: 10.66640/UJP-2026-5-00020

*Corresponding author: Asilbek D. Yorbekov, Institute of Polymer Chemistry and Physics, Academy of Science of the Republic Uzbekistan, Abdulla Kadiriy Street 7b, 700011 Tashkent, Uzbekistan

Citation: Asilbek D. Yorbekov, Abdumutolib A. Atakhanov, SURFACE MORPHOLOGY AND STRUCTURAL CHARACTERIZATION OF ION-IRRADIATED PET FILMS AFTER ALKALINE ETCHING. Uzbekistan Journal of Polymers, Vol. 5(3) 2026: pp.127-137. DOI: 10.66640/UJP-2026-5-00020

©2026 Uzbekistan Journal of Polymers