Two-step direct heteroarylation reaction towards 2,5-bis(alkoxy)benzene polymer for organic field-effect transistors processed with tetrahydrofuran

A 2,5-bis(alkoxy)benzene polymer POB-TNT has been newly designed and synthesized via very convenient two-step direct heteroarylation reaction. Its physicochemical properties have been investigated. POB-TNT demonstrates typical [Formula: see text]-type carrier transport characteristic in unencapsulated bottom-gate and top-contact organic field-effect transistors (OFETs) processed with relatively green tetrahydrofuran solvent. The results highlight a readily accessible and low-cost-oriented polymer semiconductor for non-halogenated solvent-processed OFET application.

Circularly polarized luminescence from oriented polymer films doped with a tetraphenylethylene-based conjugated oligomer

Circularly polarized luminescence (CPL) materials have attracted increasing interest due to their wide potential applications. However, achieving CPL-active materials with both large dissymmetry factor (glum) and high quantum yield (F)...

Strong anisotropic hydrogels with ion transport capability via reswelling contrast of two oriented polymer networks

The reswelling disparity of two polymer components with contrasting persistence lengths leads to the formation of anisotropic hydrogels with soft/stiff hybridized structures, resulting in high mechanical strength and ion transport capability.

Исследование электрофизических свойств композиционных волокон на основе хитозана и полипиррола для тканевой инженерии

Composite fibers based on chitosan, coated with a conducting polymer, polypyrrole (PPyr), have been obtained. Their morphology was studied by scanning electron microscopy. The electrical conductivity of the fibers in a dry state and in a liquid culture medium simulating tissue fluid has been estimated. The values of resistivity, ro, and conductivity, sigma , of the investigated fibers are determined depending on the number of PPyr layers, the degree of drawing (orientation) of the fibers in dry and in liquid media. It was found that with an increase in the amount of drawing from 0 to 100%, ro of fibers decreases both in a dry state and in a liquid culture medium. In this case, the maximum drop ro of fibers upon immersion in a liquid culture medium was observed for undrawn fibers with two layers of PPyr. It was shown that after an initial drop in ro of oriented chitosan fibers with 1 and 2 layers of PPyr ro changes weakly in a liquid culture medium for 2 hours. The investigated oriented polymer fibers of chitosan coated with 1 and 2 layers of PPyr are promising for use in the field of tissue engineering and regenerative medicine.

Quadratic Non-Linear Optical Properties of the poly(2,5-bis(but-2-ynyloxy) Benzoate Containing the 2-(ethyl(4-((4-nitrophenyl)buta-1,3-diynyl)phenyl)amino)ethanol) Chromophore

Excellent quadratic non-linear optical (ONL-2) properties of the poly(2,5-bis(but-2-ynyloxy) benzoate, containing a polar diacetylene as a chromophore, were found. According with the Maker fringes method, oriented polymer films showing an order parameter of ∼0.23 can display outstanding and stable Second Harmonic Generation (SHG) effects under off-resonant conditions (SHG-532 nm). Also, the macroscopic non-linear optical (NLO)-coefficients were evaluated under the rod-like molecular approximation, obtaining: χzzz(2) and χzxx(2) in the order of 280 ± 10 and 100 ± 10 pm V−1, respectively. The mechanical and chemical properties, in addition to the large ONL-2 coefficients exhibited by this polymer, make it a promising organic material in the development of optoelectronic/photonic devices.

Method and Mathematical Modeling of Formation of Gradually and Homogeneously Oriented Linear Polymers

Previously, we developed several technical solutions for the conversion of isotropic polymers into materials of a new type—gradually oriented polymers with a gradient of physical and mechanical properties, thereby materializing for the first time the unused possibilities inherent in the polymeric nature of the substance. The scientific basis of these developments is the concept of a new structural state of linear polymers—a gradually oriented (stretched) state (GOS), the essence of which is set out briefly. An algorithm and a mathematical model for controlling the process of uniaxial, zonal stretching of linear polymers are proposed, which allow the formation of gradually or homogeneously oriented polymers (polymer composites). At the same time, specified values of quantitative parameters are ensured, in particular, the selected profile of distribution of the relative elongation (linear, sinusoidal, etc.) along the length of the gradually oriented polymer sample and the specified constant relative elongation along the length of the homogeneously oriented polymer. Mathematical expressions for calculating the conditions to obtain gradually oriented polymers with given geometric dimensions (length, width) and with a given distribution of relative elongation along the length of the resulting sample were also derived. The description of method and principles of operation of the appropriate device is given. Experimental data illustrating the possibilities of the proposed method and the efficiency of mathematical modeling are presented. The issues of creating functionally graded materials with a gradient of microstructure (gradient of degree of orientation/relative elongation) or chemical composition (volume fraction of functional fillers), respectively, based on thermoplastic polymer/copolymer or polymer composite (containing functional fillers) by method of uniaxial, zonal graded stretching are discussed.