2.3. Radiation-Induced Synthesis of Copper Nanoclusters (NCs)

PET-g-PAA TeMs obtained in Section 2.2 were used as templates for the formation of NCs. Sorption of Cu(II) ions was accomplished by passing a saturated solution of copper sulfate (37%, w/v) for at least 48 h through the pores of the PAA-grafted membranes using a LOIP peristaltic pump (JSC «Laboratory Equipment and Instruments»б Saint-Petersburg, Russia). The waiting time of the samples in saturated CuSO₄ solution without using a pump was at least 15 days. Irradiation was carried out using ILU-10 accelerator (JSC “Park of Nuclear Technologies”, Kurchatov). Each membrane was immersed into glass vials containing 0.01 M CuSO₄ in 10% EtOH, bubbled with argon, and irradiated by e-beam or γ-rays. For e-beam irradiation, beam current, conveyor speed, and electron energy was 6.84 mA, 7.0 m/min and 3.8 MeV, respectively. The samples were irradiated till different total absorbed doses of 100, 128.3, 185, and 231.2 kGy. γ-rays treatment was carried out in gamma mode using a tantalum bremsstrahlung converter manufactured by the INP named after Budker SB RAS at the ILU-10 accelerator. During irradiation with gamma quanta, a dose range of 100–200 kGy was employed, since destruction of the PET polymer template occurred at radiation doses exceeding 200 kGy.

The amount of copper deposited was determined gravimetrically with an accuracy of 0.1 mg (AS 220.R2, Radwag, Radom, Poland) and expressed in mg/cm² based on the difference in the weights of the PAA-grafted membranes before and after e-beam and γ-rays treatments.