## 2 Materials and Methods
### Characterization of Methods
Differential scanning calorimetry (DSC) thermograms were performed with the use of a Netzsch 204 calorimeter (Netzsch, Gunzbung, Germany). All DSC measurements were obtained in the aluminum pans with pierced lids with a sample mass of \(\sim\)5-10 mg in the nitrogen atmosphere (30 mL \(\times\) min\({}^{-1}\)). Dynamic scans were performed at a heating rate of 10 K \(\times\) min\({}^{-1}\) in the temperature range of 20-500 \({}^{\circ}\)C.  
Thermal analysis was carried out on a [PERSON], STA 449 Jupiter F1 (Selb, Germany). The samples were heated from 30 to 800 \({}^{\circ}\)C at a rate of 10 \({}^{\circ}\)C \(\times\) min\({}^{-1}\) in the dynamic atmosphere of helium (25 mL \(\times\) min\({}^{-1}\)). The sensor thermocouple type S TG-DSC was used with the empty Al\({}_{2}\)O\({}_{3}\) crucible as the reference. The loss mass temperatures (T\({}_{5\%,\,10\%,\,50\%}\)), peak maximum decomposition temperatures (T\({}_{\rm max1,\,max2}\)), and residual mass at 800 \({}^{\circ}\)C (RM) were determined. The carbonization process took place in an electric furnace. The temperature during the process was 400 \({}^{\circ}\)C. The process was carried out for 0.5 h. Crucibles with the polymer material in an amount of about 2 g were placed in a quartz tube. The carbonization process was carried out in a continuous flow of nitrogen. The remains of the polymeric sample were divided into five portions (ca. 4.5 g) and each of them was treated with a different activating agent. The aqueous solutions of 85% phosphoric acid (diluted 1:1 v/v (P2) and undiluted (P1)), 95% sulphuric acid (diluted 1:1 v/v (S)), 65% nitric acid (diluted 1:1 v/v (N)), and silver nitrate (9% (Ag)) were used as surface activators. The polymer samples were soaked in the solutions for 24 h and then dried in the air at 40-50 \({}^{\circ}\)C. The thoroughly dried samples were weighed (2-2.5 g) into crucibles and placed in the electric furnace. As previously, the carbonization process was conducted in the nitrogen atmosphere for 30 min at 400 \({}^{\circ}\)C. In the names of the prepared materials the type of activator was marked with the symbol of the characteristic atom. The specific surface area of the microspheres was determined from the low-temperature nitrogen adsorption data (automatic sorption analyzer ASAP 2420, Micrometrics, (Norcross, GA, USA). Prior to the measurements all samples were degassed at 120 \({}^{\circ}\)C (for 2 h). The value of the Brunauer-Emmett-Teller (BET) specific surface area was calculated automatically by the equipment. All the pore volumes and pore size distributions were determined by the Barrett-Joyner-Halenda (BJH) method. All chromatographic analyses were performed by a gas chromatograph (GC) with an FID detector (GC-2010, Shimadzu, Japan). Potential sorption properties of the studied materials after carbonization were examined. The extent of the decrease of the tested substance (acetylsalicylic acid) concentration in the solution above the sorbent compared to that of the starting solution was taken as a measure of carbonization sorption capacity. At the beginning, 0.2 g of selected polymeric material was weighed for a vial. Each vial was flooded with the 1.5 mL standard solution of ASA (the initial concentration of ASA in methanol was 500 ug/mL). The vials were capped and shaken for 30 min. The next step was centrifugation (2500 rpm for 3 min). Supernatants were filtered through a syringe filter (0.45 um). Twenty uL of caffeine solution (as an internal standard) was added to the filtrate. Gas chromatography analyses were conducted. The ASA concentration in the blank sample (without any sorbent) was also determined. The measurement procedure was applied three times for each sorbent. The average value and standard deviation were calculated for each sample.