2.1. Materials

Gelatin (porcine type A with 250 bloom) was purchased from Gelita, Eberbach, Germany. Methacrylic anhydride (MA, 94%), 2,2′-Azobis(2-methylpropionamidine) dihydrochloride (AMPA V50, 97%), N,N′-methylene-bis(acrylamide) (BIS, 99%), hexadecyltrimethylammonium bromide (CTAB, 99%), and deuterium oxide (D₂O, 99.9%) were purchased from Sigma-Aldrich, Zwijndrecht, The Netherlands. N-isopropylacrylamide (NIPAM, 98%) was purchased from TCI, Zwijndrecht, Belgium. N-(3-aminopropyl)methacrylamide hydrochloride (APMA, 98%), and methacryloxyethyl thiocarbamoyl rhodamine B (MRB, 95%) were purchased from Polysciences, Bergstrasse, Germany. Lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP, 95%) was purchased from Allevi, Inc., PA, USA. Hydrogen chloride (HCl), sodium bicarbonate (NaHCO₃), and sodium hydroxide (NaOH) were purchased from Merck, Darmstadt, Germany. All chemicals were used as received, without any further purification. Ultrapure water (18.2 MΩ, Arium 611 DI water purification system; Sartorius AG, Göttingen, Germany) was used in all experiments.