Exploring Mixed Ionic-Electronic-Conducting PVA/PEDOT:PSS Hydrogels as Channel Materials for Organic Electrochemical Transistors.

Here, we report the preparation and evaluation of PVA/PEDOT:PSS-conducting hydrogels working as channel materials for OECT applications, focusing on the understanding of their charge transport and transfer properties. Our conducting hydrogels are based on crosslinked PVA with PEDOT:PSS interacting via hydrogen bonding and exhibit an excellent swelling ratio of ~180-200% /. Our electrochemical impedance studies indicate that the charge transport and transfer processes at the channel material based on conducting hydrogels are not trivial compared to conducting polymeric films.

On the Donor: Acceptor Features for Poly(3-hexylthiophene): TiO Quantum Dots Hybrid Materials Obtained via Water Vapor Flow Assisted Sol-Gel Growth.

Here, we present a novel methodology for the preparation of P3HT:TiO quantum dots hybrid materials via water vapor flow-assisted sol-gel growth focusing on the structural, optical and electrical property characterization complemented with first-principles calculations as a promising donor-acceptor system for polymer and hybrid solar cells. X-ray diffraction and UV-Vis spectroscopy analyses suggest that the increasing concentration of TiO quantum dots leads to the formation of higher amounts of amorphous regions while the crystalline regions exhibited interesting aspect ratio modifications for the P3HT polymer. Raman spectra evidenced the formation of charge carriers in the P3HT with increasing TiO quantum dots content and the P3HT:TiO 50:50 weight ratio resulted in the best composition for optimizing the bulk electronic conductivity, as evidenced by impedance spectroscopy studies.

Hybrid Organic-Inorganic Materials and Interfaces With Mixed Ionic-Electronic Transport Properties: Advances in Experimental and Theoretical Approaches.

The main goal of this mini-review is to provide an updated state-of-the-art of the hybrid organic-inorganic materials focusing mainly on interface phenomena involving ionic and electronic transport properties. First, we review the most relevant preparation techniques and the structural features of hybrid organic-inorganic materials prepared by solution-phase reaction of inorganic/organic precursor into organic/inorganic hosts and vapor-phase infiltration of the inorganic precursor into organic hosts and molecular layer deposition of organic precursor onto the inorganic surface. Particular emphasis is given to the advances in joint experimental and theoretical studies discussing diverse types of computational simulations for hybrid-organic materials and interfaces.

From Chain- to Graphene-like Hydroxyl-terminated (ZnO) Clusters with n≤6 Obtained via Zinc Dimethoxide Hydrolysis and Condensation: Ab initio Structural, Electronic, Vibrational and Optical Properties Calculations.

Recent reports are focusing on the structural evolution from the atomic-scale and also at the expenses of alkyl zinc alkoxide precursors towards (ZnO) clusters and nanostructures with different interesting motifs, but still not much is known about their electronic properties. In this manuscript, we present a theoretical study using DFT and TD-DFT methodologies on the hydrolysis and condensation of zinc dimethoxide precursor in its monomeric, dimeric and trimeric forms towards thermodynamically stable hydroxyl-terminated (ZnO) clusters with novel chain- and graphene-like fashions. For all cases, distinct vibrational and optical spectra features were assigned evidencing a global monotonic decrease in the opto-electronic gap with increasing oligomerization and cyclization stages.

Mini-Review: Mixed Ionic-Electronic Charge Carrier Localization and Transport in Hybrid Organic-Inorganic Nanomaterials.

In this mini-review, a comprehensive discussion on the state of the art of hybrid organic-inorganic mixed ionic-electronic conductors (-MIECs) is given, focusing on conducting polymer nanocomposites comprising inorganic nanoparticles ranging from ceramic-in-polymer to polymer-in-ceramic concentration regimes. First, a brief discussion on fundamental aspects of mixed ionic-electronic transport phenomena considering the charge carrier transport at bulk regions together with the effect of the organic-inorganic interphase of hybrid nanocomposites is presented. We also make a recount of updated instrumentation techniques to characterize structure, microstructure, chemical composition, and mixed ionic-electronic transport with special focus on those relevant for -MIECs.

Physico-chemical and antilisterial properties of nisin-incorporated chitosan/carboxymethyl chitosan films.

The objective of this work was to investigate the effect of the addition of carboxymethyl chitosan on the structural properties and antilisterial activity of nisin-incorporated chitosan films. Chitosan and carboxymethyl chitosan solutions were prepared with different mass ratios and bacteriocin nisin was added (0, 1000 and 6000 IU/ml). Filmogenic solutions were cast, dried and their physico-chemical and antimicrobial properties were investigated.

Extremely Large Magnetic-Field-Effects on the Impedance Response of TiO Quantum Dots.

Here, we report large magnetoresistance and magnetocapacitance response of undoped TiO quantum dots weighting the contribution of both grain and grain boundaries by means of impedance spectroscopy. We also performed a complete characterization of the TiO quantum dots (~5 nm) prepared by sol-gel via water vapor diffusion method, using X-ray diffraction, small angle X-ray scattering, transmission electron microscopy and Raman spectroscopy. In addition, we showed a complete theoretical study on the electronic properties of TiO surface and subsurface oxygen and titanium vacancies to shed some light in their electronic and magnetic properties.

Raman Microscopy Insights on the Out-of-Plane Electrical Transport of Carbon Nanotube-Doped PEDOT:PSS Electrodes for Solar Cell Applications.

In the present report, we focused on the study of the out-of-plane electrical transport of multiwalled carbon nanotube (MWCNT)-doped poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) composites (PEDOT:PSS-MWCNTs) as electrodes for solar cell applications. The out-of-plane direct current and alternating current electrical transport, rarely studied but not less relevant, was additionally supported with in-plane and out-of-plane confocal Raman microscopy and grazing incidence small-angle X-ray scattering characterizations. The main relevance of our study is the monitoring of the polymer structure all across the polymeric film by using confocal Raman spectroscopy and its correlation with electrical transport.