TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The standard electrolyte comprises at least one of: iodine, alkali metal and alkaline earth metal iodides, iodides of quaternary ammonium compounds or of N-heterocyclic cations (including 1,2-dimethyl-3-propylimidazolium iodide), preferably lithium iodide, sodium iodide, potassium iodide, cesium iodide, calcium(II) iodide, or 1,2-dimethyl-3-propyl-imidazolium iodide. In the process, the iodides are present at 0.05-1 M, and the iodine is at a concentration of 0.01-0.3 M.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The photoelectrochemical comprises at least one photovoltaic cell. The photovoltaic cell is a dye sensitized solar cell.    TECHNOLOGY FOCUS - POLYMERS - Preparation (Claimed): Preparation of (I) comprises: reacting a copolymer of formula (II) optionally in presence of standard electrolytes with a monoalkylating halide of formula (R2-Hal),Hal = leaving group comprising Cl, Br or I (preferred). Preferred Definitions:    R1 = methyl, butyl, trifluoroethyl, -CH2CF3, -CH2CF2CF3, or -CH2CH2CF3;    R2 = methyl, n-propyl or trifluoropropyl; and    Y1- = Cl-, Br-, I-, CF3COO-, CF3SO3- or (CF3SO2)2N-.    EXAMPLE - Methyl methacrylate (6.25 g) and 4-vinyl pyridine (0.82 g) were placed in a 50 ml flask. Then azobisisobutyronitrile (64 mg) dissolved in (previously de-aerated) toluene (17 ml) were added to the mixture of monomers de-aerated using a flow of dry nitrogen. The solution was heated under stirring to 65-70 degrees C for 48 hours. After returning the reaction mixture to ambient temperature, the copolymer was precipitated out by pouring the toluene solution slowly into methanol (150-200 ml) which was kept stirred. The suspension containing the precipitate was filtered and the precipitate was further washed with methanol and dried under vacuum at 40 degrees C/21 mbar, to give 4-vinyl pyridine-methyl methacrylate copolymer (P1). The copolymer (P1) (1.8 g) was dissolved in the solvent mixture based on 3-methoxypropionitrile/N-methyl oxazolidinone (5 g, 1/1 (wt./wt.)). 1,2-dimethyl-3-propyl imidazolium iodide (0.77 g), iodine (122 mg) and methyl iodide (0.41 g) were added to the resulting mixture aerated with flow of dry nitrogen. The resulting mixture was kept stirred at 70 degrees C for 20 hours in a nitrogen atmosphere to give quaternized 4-vinyl pyridine-methyl methacrylate copolymer.