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In this paper, the synthesis and characterisation of photoluminescent graft copolymers of poly(p-phenyleneethynylene) (PPE) with grafted poly(n-butyl acrylate) (PnBA) side chains is presented. The grafted copolymer exhibited the desired intrinsic physical properties of the grafted side chain polymer while preserving the optical properties of PPE. Grafting from the conjugated macroinitiator was conducted utilising activators regenerated by an electron transfer (ARGET) atom transfer radical polymerisation (ATRP) technique. The novel physical and optical properties of the grafted copolymer are reported and the enhancement of the quantum yield both in the solid and solution state can be attributed to the prevention of interchain interactions of the PPE chains. The enhancement of the photophysical properties observed upon grafting is greater than that seen in a similar PPV system.

In this study, we have demonstrated a suitable methodology towards tailoring the optical and physical properties of poly(phenylene vinylene)s (PPVs) by grafting poly(n-butyl acrylate) side chains to yield highly processable PPVs with the physical characteristics of the grafted polymer. Grafting from the PPV macroinitiators was conducted using activators regenerated by electron transfer (ARGET) atom transfer radical polymerisation (ATRP) technique. The resulting graft copolymers showed significant enhancement of photoluminescence quantum yield in both solution and in the solid state while exhibiting lower glass transition temperature and dry adhesive properties compared to the ungrafted PPVs, thereby signifying the methodology as an attractive tool for fabricating functional conjugated polymers with desired physical characteristics.

This study is aimed at developing an effective and potentially industrially applicable methodology for dry adhesion enhancement of bioinspired adhesive materials. Recently developed Activator Re-Generation through Electron Transfer Atom Transfer Radical Polymerization (ARGET ATRP) was employed to graft poly(ethyl acrylate), poly(n-butyl acrylate) and poly(n-hexyl acrylate) polymer brushes on poly(dimethylsiloxane) (PDMS) substrates in presence of a structurally similar sacrificial initiator. Attenuated Total Reflection-Fourier Transformed Infrared spectroscopy (ATR-FTIR), Gel Permeation Chromatography (GPC), Nuclear Magnetic Resonance Spectroscopy (NMR), and ellipsometry were used to confirm the grafting and controlled growth of polymer chains on PDMS surfaces and in solution. A nanoindenter was used to measure adhesion on the PDMS samples at retraction rates of 10–50 nm/s and indentation depths of 100–500 nm. The polymer brushes were also grafted on PDMS micropillars of 20 μm in diameter with aspect ratio of 3, to test applicability of the developed method on bioinspired microstructured surfaces. A significant increase in adhesion was observed in all flat and micropatterned samples after the grafting resulting in achieving 20 kPa of adhesion strength in the flat samples. The study suggests that the investigated ARGET ATRP procedure can be used to produce cost effective dry adhesive surfaces.

Recent advances in organic electronic devices have reached new milestones in performance and function, and they are used in applications ranging from displays to sensory devices. However, they still present limitations in mechanical flexibility and electrical durability following the damage caused during their lifetime. Herein, we present a simple route to prepare conducting polymer composites that can address some of these issues through solvent vapour-induced healing of cracks formed within conducting polymer composites. Conducting polymer composites were prepared by solution blending of poly(3-hexylthiophene) (P3HT) and poly(dimethylsiloxane) (PDMS)-containing urea segmented copolymer. The bicomponent composites with various weight fractions of neutral P3HT were used to demonstrate their electroactivity whereas the electrical conductivity, mechanical and solvent vapour-induced self-healing studies were carried out with composites with various weight fractions of FeCl3-doped P3HT. A mechanically bisected free-standing film with 30 wt% of doped P3HT was observed to be readily healed through exposure to solvent vapour at room temperature, with a mechanical healing efficiency of 55 ± 24% and restoration of electrical conductivity up to 82 ± 1%.

Polymerizations of aniline were conducted in the mixtures of water and polar organic solvents (50 vol.%): acetone, acetonitrile, dimethylsulfoxide and ethanol, by using ammonium peroxydisulphate as an oxidant, without added acid. Course of reactions was followed by recording the temperature and pH changes of the reaction systems. The influence of the organic co-solvents and the reaction time on the molecular structure, molecular weights, morphology and properties of synthesized polyaniline (PANI) samples was studied by elemental analysis, laser desorption ionization mass spectrometry (LDI-MS), gelpermeation chromatography (GPC), FTIR, Raman and UV vis spectroscopies, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electrical conductivity measurements. The results were compared with those obtained for PANI prepared under the same reaction conditions in water without a co-solvent. Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3422]