HEAT-INDUCED VOLTAGE GENERATION IN HEXADECYL MEROCYANINE DYE-PROBED PLANAR LIPID-MEMBRANES

A hexadecyl merocyanine dye was used as a heat driven proton gate, by incorporating it in a planar lipid membrane which is a good model for biological membranes. Being hydrophobic in nature, it prevents charge recombination, and transmembrane voltages of high magnitude (similar t o 310 mV) were obtained upon heating. The process was reversible and t he whole cycle took about 20 h, suggesting that the system could be us ed as a heat driven storage cell. Comparison of the X-ray diffraction patterns of the thin films of the dye at 30 degrees C showed a heat-in duced conformational change in the crystalline structure of the dye. F rom differential thermal analysis three reversible phase transitions w ere observed, at 39.2 degrees C, 53.7 degrees C and 62.1 degrees C, an d the associated enthalpy changes were calculated The results indicate that the heat-induced conformational change of the dye molecule is re sponsible for the observed thermovoltage generation.