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The X-ray structure of TEA-(TCNQ)2 has been measured at 110, 173, 234 and 345 K, which, in addition to data in the literature, enables a detailed description of the structural evolution of the compound with temperature. The charge transfer estimated from bond lengths indicates a partial localization (0.6 and 0.4e) of the charges, on the two independent TCNQ molecules, in the temperature range considered. The unit-cell thermal expansion has been measured in the range 156 to 367 K. An anomaly at 200-220 K was found and the related structural changes are described. Since electricalconductivity anomalies at 200-220 K have already been reported and sometimes attributed to a metalinsulator phase transition, an attempt is thus made to interpret the temperature dependence of the stacking distances in the TCNQ columns in terms of Peierls-like lattice distortions -namely dimerization and tetramerization.

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Fabricating novel materials for biomedical applications mostly require the use of biodegradable materials. In this work biodegradable materials like polylactic acid (PLA) and chitosan (CHS) were used for designing electrospun mats. This work reports the physical and chemical characterization of the PLA-CHS composite, prepared by the electrospinning technique using a mixed solvent system. The addition of chitosan into PLA, offered decrease in fiber diameter in the composites with uniformity in the distribution of fibers with an optimum at 0.4wt% CHS. The fiber formation and the reduction in fiber diameter were confirmed by the SEM micrograph. The inverse gas chromatography and contact angle measurements supported the increase of hydrophobicity of the composite membrane with increase of filler concentration. The weak interaction between PLA and chitosan was confirmed by Fourier transform infrared spectroscopy and thermal analysis. The stability of the composite was established by zeta potential measurements. Cytotoxicity studies of the membranes were also carried out and found that up to 0.6% CHS the composite material was noncytotoxic. The current findings are very important for the design and development of new materials based on polylactic acid-chitosan composites for environmental and biomedical applications.