Stabilisation de la microstructure des couches actives OPV par réticulation

Date du colloque : 10/2013</p

Stabilization of polymer-fullerene bulk-heterojuntion morphology

International audienc

Carbazole-based \u3c0-conjugated polyazomethines: Effects of catenation and comonomer insertion on optoelectronic features

A series of carbazole-based polyazomethines have been synthesized under micro-wave irradiation and without transition-metal based catalyst. The impact of both the catenation brought by the carbazole subunits and the insertion of a co-monomer, i.e. 3,4 ethylene dioxythiophene (EDOT), on the optical and electrochemical properties have been studied. Among the different polyazomethines synthesized, the best in terms of optical and electrochemical properties has been found to be the one with the azomethine function linked in positions 2,7 of carbazole subunits. Upon the insertion of the EDOT comonomer, an increase of the molecular weight and a red-shift in the absorption spectra has been observed, corresponding to a diminution of the electronic gap

Simultaneous monitoring of single cell and of micro-organ activity by PEDOT:PSS covered multi-electrode arrays

© 2017 Continuous and long-term monitoring of cellular and micro-organ activity is required for new insights into physiology and novel technologies such as Organs-on-Chip. Moreover, recent advances in stem cell technology and especially in the field of diabetes call for non-invasive approaches in quality testing of the large quantities of surrogate pancreatic islets to be generated. Electrical activity of such a micro-organ results in single cell action potentials (APs) of high frequency and in low frequency changes in local field potentials (slow potentials or SPs), reflecting coupled cell activity and overall organ physiology. Each of them is indicative of different physiological stages in islet activation. Action potentials in islets are of small amplitude and very difficult to detect. The use of PEDOT:PSS to coat metal electrodes i s expected to reduce noise and results in a frequency-dependent change in impedance, as shown here. Whereas detection of high-frequency APs improves, low frequency SPs are less well detected which is, however, an acceptable trade off in view of the strong amplitude of SPs. Using a dedicated software, recorded APs and SPs can be automatically diagnosed and analyzed. Concomitant capture of the two signals will considerably increase the diagnostic power of monitoring islets and islet surrogates in fundamental research as well as drug screening or the use of islets as biosensors

Self-assembly of Si-containing block copolymers with high-segregation strength: toward sub-10nm features in directed self-assembly

International audienc