La invasión de los garbanzos

Congreso Universitario de Innovación Educativa En las Enseñanzas Técnicas, CUIEET (26º. 2018. Gijón

Acrylates Polymerization on Covalent Plasma-Assisted Functionalized Graphene: A Route to Synthesize Hybrid Functional Materials

[EN] The modification of the surface properties of graphene with polymers provides a method for expanding its scope into new applications as a hybrid material. Unfortunately, the chemical inertness of graphene hinders the covalent functionalization required to build them up. Developing new strategies to enhance the graphene chemical activity for efficient and stable functionalization, while preserving its electronic properties, is a major challenge. We here devise a covalent functionalization method that is clean, reproducible, scalable, and technologically relevant for the synthesis of a large-scale, substrate-supported graphene–polymer hybrid material. In a first step, hydrogen-assisted plasma activation of p-aminophenol (p-AP) linker molecules produces their stable and covalent attachment to large-area graphene. Second, an in situ radical polymerization reaction of 2-hydroxyethyl acrylate (HEA) is carried out on the functionalized surface, leading to a graphene–polymer hybrid functional material. The functionalization with a hydrophilic and soft polymer modifies the hydrophobicity of graphene and might enhance its biocompatibility. We have characterized these hybrid materials by atomic force microscopy (AFM), X-Ray photoelectron spectroscopy (XPS) and Raman spectroscopy and studied their electrical response, confirming that the graphene/p-AP/PHEA architecture is anchored covalently by the sp3 hybridization and controlled polymerization reaction on graphene, retaining its suitable electronic properties. Among all the possibilities, we assess the proof of concept of this graphene-based hybrid platform as a humidity sensor. An enhanced sensitivity is obtained in comparison with pristine graphene and related materials. This functional nanoarchitecture and the two-step strategy open up future potential applications in sensors, biomaterials, or biotechnology fields.Funding from the innovation program under grant agreement no. 881603 (Graphene Core3-Graphene-based disruptive technologies). We acknowledge a research contract Margarita Salas financial support from Spanish “Ministerio de Ciencia, Innovación y Universidades” financed with Next Generation funds from EU. This work was supported by the project references PID2020-113142RB-C21, PID2021-125309OA-100, TED2021-129999B-C31 and TED2021-129416A-I00 funded by MCIN/AEI/10.13039/501100011033.Peer reviewe

In-situ study of the gas-phase composition and temperature of an intermediate-temperature solid oxide fuel cell anode surface fed by reformate natural gas

An innovative experimental setup is used for in-depth and in-operando characterization of solid oxide fuel cell anodic processes. This work focuses on the heterogeneous reactions taking place on a 121 cm2anode-supported cell (ASC) running with a H2, CH4, CO2, CO and steam gas mixture as a fuel, using an operating temperature of 923 K. The results have been obtained by analyzing the gas composition and temperature profiles along the anode surface in different conditions: open circuit voltage (OCV) and under two different current densities, 165 mA cmâ2and 330 mA cmâ2, corresponding to 27% and 54% of fuel utilization, respectively. The gas composition and temperature analysis results are consistent, allowing to monitor the evolution of the principal chemical and electrochemical reactions along the anode surface. A possible competition between CO2and H2O in methane internal reforming is shown under OCV condition and low current density values, leading to two different types of methane reforming: Steam Reforming and Dry Reforming. Under a current load of 40 A, the dominance of exothermic reactions leads to a more marked increase of temperature in the portion of the cell close to the inlet revealing that current density is not uniform along the anode surface