The Poly(Chloro-P-Xylylene)-Ag Metal-Polymer Nanocomposites Obtained by Controlled Vapor-Phase Synthesis for SERS Effect Realisation

Substrates based on the metal-polymer nanocomposites 2,3-dichloro-p-xylylene-silver (PCPX-Ag) that realize the effect of surface-enhanced Raman scattering (SERS) were developed. To obtain nanocomposites, the vapor-phase polymerization method was used (VDP), which makes it possible to control the nanocomposite microstructure. In the process of self-assembly during VDP, nanocomposite films with inclusions of silver particles were formed on the polycore substrates. Silver content varied from 2.5 to 16% vol. The possibility of using such substrates for the detection of low-molecular substances, for example 5,5′-dithiobis- (2-nitrobenzoic acid) (DTNB) analyte, by the SERS method with an enhancement factor of up to 104, was demonstrated. The dependence of the SERS spectra enhancement on the microstructure of the nanocomposite and the silver content was determined. The optical and morphological properties of nanocomposites were also investigated and their dependence on the silver content was shown. It has been demonstrated that the nanocomposite is SERS selective since when working with complex solutions in the presence of high molecular weight substances, signal enhancement was only observed for low molecular weight substances.

Combining Electrospinning and Electrode Printing for the Fabrication of Stretchable Organic Electrochemical Transistors

Stretchable conductors and organic electrochemical transistors (OECT) were fabricated from PEDOT:Tos (poly (3,4-ethylenedioxythiophene):iron tosylate) nanofibers. The devices were prepared by a combination of electrospinning and electrode printing followed by vapor phase polymerization (VPP). The impact of both the processing time and the composition of three electrospinning mixtures on the electrospun fiber mats was evaluated by scanning electron microscopy and cyclic voltammetry. Fibrillar mats prepared from the different mixtures maintained their electrical properties and could be stretched up to 140% of their original length. Stretchable OECTs were fabricated by printing silver drain and source electrodes directly on the conductive spun fibers. The fabricated devices showed transistor behavior up to ∼50% strain.

V2O5/Carbon Nanotube/Polypyrrole Based Freestanding Negative Electrodes for High-Performance Supercapacitors

In this study, the vanadium pentoxide (V2O5), functionalized carbon nanotubes (f-CNT), and polypyrrole (PPy) based composites films have been prepared through a facile synthesis method and their electrochemical performance were evaluated as freestanding negative electrodes of supercapacitor. A hydrous V2O5 gel prepared by treating V2O5 powder with H2O2 was mixed with f-CNT to obtain V2O5/f-CNT composite film. V2O5/f-CNT composite was then coated with PPy through vapor phase polymerization method. The PPy deposited on the V2O5/f-CNT prevented the dissolution of V2O5 and thus resulted in an improved the capacitance and cycle life stability for V2O5/f-CNT/PPy composite electrode. V2O5/f-CNT/PPy freestanding negative electrode exhibited a high areal capacitance value (1266 mF cm−2 at a current density of 1 mA cm−2) and good cycling stability (83.0% capacitance retention after 10,000 charge-discharge cycles). The superior performance of the V2O5/f-CNT/PPy composite electrode can be attributed to the synergy between f-CNT with high conductivity and V2O5 and PPy with high-energy densities. Thus, V2O5/f-CNT/PPy composite based electrode can effectively mitigate the drawbacks of the low specific capacitance of CNTs and the poor cycling life of V2O5.

Spectroscopic Investigations of Electron and Hole Dynamics in MAPbBr3 Perovskite Film and Carrier Extraction to PEDOT Hole Transport Layer

Organometallic halide perovskite (MAPPbBr3), Rust-based Vapor Phase Polymerization (RVPP)-PEDOT hole transporting layers and (RVPP-PEDOT)/MAPPbBr3 dual-layer, deposited on fluorine doped tin oxide glass were studied at room temperature using steady-state absorption,...