Pencil graphite electrodes for in-situ spectroelectrochemical sensing of reaction intermediates and products in organic solvents.

Background: Spectroelectrochemistry (SEC) is a valuable analytical tool providing insights to reaction mechanisms and the structure of species involved in charge transfer reactions. Most of commercial SEC setups are based on platinum working electrodes where the adsorption of species involved in reactions often complicates their analysis.

Results: In this work, we employ an array of pencil graphite rods as an optically transparent working electrode in a custom-made air-tight thin-layer cell suitable for the SEC analysis performed here in acetonitrile as a representative non-aqueous solvent.

3D Printed Platform for Impedimetric Sensing of Liquids and Microfluidic Channels.

Fused deposition modeling 3D printing (FDM-3DP) employing electrically conductive filaments has recently been recognized as an exceptionally attractive tool for the manufacture of sensing devices. However, capabilities of 3DP electrodes to measure electric properties of materials have not yet been explored. To bridge this gap, we employ bimaterial FDM-3DP combining electrically conductive and insulating filaments to build an integrated platform for sensing conductivity and permittivity of liquids by impedance measurements.

Electric conductivity measurements employing 3D printed electrodes and cells.

The electric conductivity is one the most routinely inspected characteristics of aqueous media, being employed in monitoring drinking water quality and determining thermodynamic properties of electrolytes. In this work, we utilize fused deposition modelling 3D printing (3DP) to manufacture a platform composed of supporting cells and sensing electrodes for electric conductivity measurements of aqueous solutions. For the first time, the electric conductivity of liquid electrolytes is sensed by 3DP electrodes, employing a direct electrode/electrolyte contact.

Non-Arrhenius kinetics and slowed-diffusion mechanism of molecular aggregation of a rhodamine dye on colloidal particles.

The non-covalent association is important for many fields of science, including processes in living systems. This work elucidates the mechanism of rhodamine 123 molecular aggregation in dispersions of a layered silicate and explains the mystery of the slow kinetics of this process. Chemometric analysis of thousands of spectra recorded by stopped-flow visible spectroscopy identified two parallel diffusion processes described by a two-phase exponential function.

The development of a fully integrated 3D printed electrochemical platform and its application to investigate the chemical reaction between carbon dioxide and hydrazine.

The combination of computer assisted design and 3D printing has recently enabled fast and inexpensive manufacture of customized 'reactionware' for broad range of electrochemical applications. In this work bi-material fused deposition modeling 3D printing is utilized to construct an integrated platform based on a polyamide electrochemical cell and electrodes manufactured from a polylactic acid-carbon nanotube conductive composite. The cell contains separated compartments for the reference and counter electrode and enables reactants to be introduced and inspected under oxygen-free conditions.