SPEEK/PVA Polymer Films

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Catherine Stokes
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1 Supporting Information Photogeneration of H 2 O 2 in Water-Swollen SPEEK/PVA Polymer Films PaviElle Lockhart, 1 Brian K. Little, 1, B. L. Slaten 2 and G. Mills* 1 Department of Chemistry and Biochemistry, Department of Consumer and Design Sciences, Auburn University, Alabama, 36849, United States 1: Department of Chemistry and Biochemistry, Auburn University 2: Department of Consumer and Design Sciences, Auburn University Supporting Information Available: Figure S1 is an image of an irradiation vessel made from borosilicate glass. The overall length of the photoreactor (from base to top of glass opening) amounts to 140 mm with a width at the base of 55 mm. Fitted on top of the vessel is an Ace-Thread glass adaptor # 25 with an outer diameter of 31.5 mm, which includes a nylon bushing cap (inner diameter = 26 mm). Screwing this cap serves to secure inside the photoreactor a glass tube (outer diameter = 25 mm, length = 100 mm) with the aid of an o-ring. The top of the glass tube was terminated in a small S1

2 opening. A side arm with an Ace-Thread glass adaptor # 7, equipped with a cap possessing a small opening sealed with a rubber septum, serve to retrieve aliquots of the solutions. SPEEK/PVA films were placed between the inner surface of the vessel and the outer surface of the vertically secured glass tube. Presented on the left panel of Figure S2 is a top view representation of the film position inside the photochemical reactor. In this way the films were held in a fully extended, stress-free position without applying excessive pressure on them. The films were subsequently swollen (1 h) with aqueous solutions to ensure their equilibrium volume was reached. This procedure avoided extensive manipulation of the somewhat fragile swollen films. The photochemical reactor was closed prior to illumination and the pressure was equilibrated against air by means of needle punctured through the septum located top opening. Small aliquots of the photolyzed solutions were retrieved during illumination through the side arm using gas-tight syringes (Hamilton) for subsequent H 2 O 2 analysis. Shown on the right panel of Figure S2 is an image of a vessel with a film immersed in a methylene blue (MB) solution. The light blue region on the photoreactor top identifies the film location since the path length there is smaller than below the tube held vertically inside the vessel. Tests with MB solutions were performed to determine the time needed for the dye to diffuse into swollen SPEEK/PVA films under stirring. Injection of a small volume of a 1 μm MB solution through the side arm turned the swollen films blue in about 3 s, showing that diffusion of the dye into SPEEK/PVA films was completed in that period of time. Obviously, migration of photogenerated H 2 O 2 from the swollen films into solution is anticipated to occur in the same time range. Given that retrieval of aliquots from the photoreactor took about 0.5 min, the MB results ensured that any H 2 O 2 photogenerated inside the swollen films was able to diffuse into the solution present in the photochemical vessel. S2

3 Summarized in Table S1 are the results obtained from the different analytical methods, including the theoretical compositions for the sodium salt of the hydrate SPEEK 2H 2 O. S3

4 Figure S1. Typical illumination vessel of borosilicate glass with a side arm for retrieval of samples. S4

Figure S2. Left panel: top view representation of the film location in the illumination vessel, where the glass tube served as boundary between the two regions of solution.

5 Figure S2. Left panel: top view representation of the film location in the illumination vessel, where the glass tube served as boundary between the two regions of solution. Right panel: image of the photoreactor containing a solution of methylene blue. Films were located in the light-blue region beneath the top screw cap that is confined by the two meniscuses. S5

6 Table S1 Elementary Compositions and Degree of Sulfonation of SPEEK Samples Sample Days of Sulfonation Carbon % Hydrogen % Sulfur % D.S. 1 H NMR D.S. Elemen. Analysis PEEK SPEEK 2H 2 O* *Theoretical values S6

Pressure Vessel Assembly Instructions

Pressure Vessel Assembly Instructions 1) Measure aluminum tube outer diameter 2) Machine both end caps and only drill pilot holes for all hoes shown 3) Weld both end caps onto the aluminum tube and be