K+-selective PVC membrane electrodes based on 12 alkanedioyl, polymethylene, and a,a'-dihydroxypolymethylene bis-crown ethers (I, I, III, n = 3-8) with 2-nitrophenyl octyl ether as plasticizer were prepared and their characteristics were investigated. Response performance of these electrodes indicated that polymethylene bis(4'-benzo-15-crown-5) and alkanedioyl (4-benzo-15-crown-5) with longer carbon chain (n ?) are feasible for the neutral carrier of K+-selective electrode. At 25癈, in pure KCl solution, the linear response ranges of these electrodes are from 2 ?10-5 to 10-1 mol.dm-3, KK+,Na+pot ? ?10-4 and KK+,Ca+pot ~10-2. The response performance of the electrodes based on a,a'-dihydroxypolymethylene and alkanedioyl with shorter carbon chain bis-crown ethers decreased with the lowering of the temperature of solution, the slopes are less than 50 mV/pK+ at 15癈.

Key words: ALKANE, CROWN ETHER COMPOUNDS, ION SELECTIVE ELECTRODE, POLYVINYL CHLORIDE, BENZENE P, MEMBRANE ELECTRODES, POTASSIUM ION, ALCOHOL, KETONE, ELECTRODE LIFE TIME