Viscoelastic Characterization of Poly(3-hexylthiophene): Determination of Young’s Modulus
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Materials Science↗
Engineering topics
Stefan, Mihaela C.
Publications and source records attributed to Stefan, Mihaela C..
Improved Self-Assembly of P3HT with Pyrene-Functionalized Methacrylates
A block copolymer with discotic liquid crystalline behavior was synthesized using Grignard metathesis polymerization (GRIM) and initiators for continuous activator regeneration atom transfer radical polymerization (ICAR-ATRP). A novel discotic liquid crystalline mesogen, 6-(pyren-1-yloxy)hexyl methacrylate (PyMA), comprises a block that is attached to regioregular poly(3- hexylthiophene) (rr-P 3 HT) generated by GRIM and subjected to end-group modification. Due to the continuous regeneration of Cu + in the reaction mixture in ICAR-ATRP compared to conventional methods, the synthesis was successfully performed with less catalyst. The purity and yield of the final product are increased by eliminating rigorous post-synthesis purification. Stacked pyrene units have contributed to the enhanced long-range π-π interactions and aligning of the P 3 HT block as observed in thin-film X-ray diffraction (XRD). Furthermore, field-effect mobilities in the order of 10 -2 cm 2 V -1 s -1 in bottom-gate, top-contact organic field-effect transistors (OFETs) suggest an enhancement in charge transport due to the discotic electron-rich pyrene units that help mitigate the insulating effect of the methacrylate backbone. The formation of uniform microdomains of P 3 HT-bpoly(PyMA) observed with tapping mode atomic force microscopy (TMAFM) on the channel regions of OFETs indicates the unique packing of the block copolymer in comparison to pristine P 3 HT. Thermotropic properties of the novel discotic mesogen in the presence and absence of P3HT were observed with both the poly(3-hexylthiophene)-b-poly(6-(pyren-1-yloxy)hexyl methacrylate) (P3HT-b-poly(PyMA)) block copolymer and poly(6-(pyren-1-yloxy)hexyl methacrylate) (poly(PyMA)) homopolymer using polarized optical microscopy (POM) and differential scanning calorimetry (DSC).
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Peroxide-Templated Assembly of a Trimetal Neodymium Complex Single-Molecule Magnet
In this study, we present a tri-metal neodymium complex with two notable qualities. Firstly, the assembly of the complex is templated by peroxide derived from atmospheric oxygen. Secondly, the bulk material behaves as a super-paramagnet, implying that the individual complexes are molecular magnets. The peroxide-templated assembly is possible due to the confluence of the high oxophilicity of neodymium along with the use of an azeotropic distillation synthesis method, which excludes water but admits oxygen. SQUID magnetometer measurements show an extremely high magnetic susceptibility as well as a lack of remanence.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗