2.3. Preparation of Poly(N-Isopropylacrylamide-Co-Dopamine Methacrylamide) Copolymer

The copolymer based on N-isopropylacrylamide and dopamine methacrylamide was synthesized using a Schlenk tube under a nitrogen atmosphere. For that purpose, the N-isopropylacrylamide (0.0663 mol), dopamine methacrylamide (0.0046 mol), and AIBN initiator (7 × 10⁻⁵ mol) were added inside the Schlenk tube. Then, 10 mL DMF was injected in the tube, keeping the inert conditions. The Schlenk tube was located inside of a thermostatic bath at 70 °C where the reaction took place for 48 h. After, the reaction was stopped using nitrogen liquid, the copolymer was precipitated in diethyl ether.

The final polymer was washed and purified several times through precipitation, dried under vacuum and, finally, it was stored at room temperature. The details about the synthetic procedure and reaction schemes can be found in previous works reported by the authors [31,33]. The yield of the reaction obtained was around 68%.