Ethanol etoh

PCL, average molecular weight 80 000 Da (Mw/Mn <2), was obtained from Sigma Aldrich (Spain). Microspheres of Elvacite 2043 (a mixture of low molecular weight poly (ethyl methacrylate) (PEMA) and poly (methyl methacrylate) (PMMA)) with diameters ranging from 120 to 200 µm were purchased from Lucite International (USA). We will call them porogen microspheres hereafter. 1,4 Dioxane from Sigma Aldrich (Spain) was used as solvent for PCL, and ethanol (EtOH) (99% pure) from Scharlab (Spain) was used to dissolve the Dioxane and PEMA/PMMA in the freeze extraction and particle leaching process. Poly(vinyl alcohol), average Mw 130 000 Da, 99+ % hydrolyzed was purchased from Sigma Aldrich (Spain). All the chemicals were used as received and with no further modification.

All reagents used were of analytical-reagent grade. Ultrapure water obtained from a Milli-Q water purifier (Millipore, Bedford, MA, USA) was used for the preparation of all solutions. Britton Robinson (BR) buffer solutions, containing 0.04 M phosphoric acid (Panreac, Barcelona, Spain), 0.04 M acetic acid (VWR Chemical, Fontenay, France) and 0.04 M boric acid (Panreac, Barcelona, Spain), were used as supporting electrolyte for the electrochemical measurements. 1 M NaOH (Ercros, Barcelona, Spain) solutions were used to adjust the pH value of the buffer solutions.
Stock standard solutions of 4-ethylphenol (Alfa Aesar, Haverhill, Massachusetts, USA) were prepared by dissolving the adequate amount in Milli-Q water. Pyrrole and LiClO 4 , used to modify the working electrode surface, were purchased from Sigma-Aldrich (Steinheim, Germany) and Panreac (Barcelona, Spain), respectively. Ethanol (EtOH), used to remove the template molecules, was purchased from Scharlau (Barcelona, Spain).