Assessing the molecular weight of a conducting polymer by grazing emissionXRF

A spray coated thin film of all-E-poly[(3-methoxy-2,5-thiophenediyl- 1'',2' '-ethenediyl)(4''-methoxy-2",5"-thiophenediyl-1", 2"-ethenediyl)], a conduc ting polymer, was analyzed by grazing emission X-ray fluorescence spectrome try, Measuring the S/Cl ratio in this sulfur-containing polymer with one te rminal chlorine allowed us to determine the chain length and, hence, the mo lecular weight. The result was in acceptable agreement with that of a well- established method for the determination of the molecular weight of polymer ic materials.