BIABooster: Online DNA Concentration and Size Profiling with a Limit of Detection of 10 fg/μL and Application to High-Sensitivity Characterization of Circulating Cell-Free DNA.

We describe a technology to perform sizing and concentration analysis of double stranded DNA with a sensitivity of 10 fg/μL in an operating time of 20 min. The technology is operated automatically on a commercial capillary electrophoresis instrument using electro-hydrodynamic actuation. It relies on a new capillary device that achieves online concentration of DNA at the junction between two capillaries of different diameters, thanks to viscoelastic lift forces.

Pulsed lasers versus continuous light sources in capillary electrophoresis and fluorescence detection studies: Photodegradation pathways and models.

Pulsed lasers are widely used in capillary electrophoresis (CE) studies to provide laser induced fluorescence (LIF) detection. Unfortunately pulsed lasers do not give linear calibration curves over a wide range of concentrations. While this does not prevent their use in CE/LIF studies, the non-linear behavior must be understood.

New Method for Super Hydrophobic Treatment of Gas Diffusion Layers for Proton Exchange Membrane Fuel Cells Using Electrochemical Reduction of Diazonium Salts.

The purpose of this article is to report a new method for the surface functionalization of commercially available gas diffusion layers (GDLs) by the electrochemical reduction of diazonium salt containing hydrophobic functional groups. The method results in superhydrophobic GDLs, over a large area, without pore blocking. An X-ray photoelectron spectroscopy study based on core level spectra and chemical mapping has demonstrated the successful grafting route, resulting in a homogeneous distribution of the covalently bonded hydrophobic molecules on the surface of the GDL fibers.

Submicrometer 3D Structural Evidence of Fuel Cell Membrane Heterogeneous Degradation.

Polymer membranes used in the proton exchange membrane fuel cell (PEMFC) technology are subject to severe chemical and physical degradations during operation. A microscopic diagnosis of the effects of aging on the microstructure of benchmark perfluorinated sulfonic acid (PFSA) membranes is crucial to developing long-lasting devices. We report here the first μSAXS study of membranes aged for 2500 h in a stack.

In-situ measurement of electroosmotic drag coefficient in Nafion membrane for the PEMFC.

A new method based on hydrogen pump has been developed to measure the electroosmotic drag coefficient in representative PEMFC operating conditions. It allows eliminating the back-flow of water which leads to some errors in the calculation of this coefficient with previously reported electrochemical methods. Measurements have been performed on 50 μm thick Nafion membranes both extruded and recast.

The kinetics of water sorption in Nafion membranes: a small-angle neutron scattering study.

The optimization of the water management in proton exchange membrane fuel cells is a major issue for the large-scale development of this technology. In addition to the operating conditions, the membrane water sorption and transport processes obviously control the water management. The main objective of this work is to provide new experimental evidence based on the use of the small-angle neutron scattering (SANS) technique in order to allow a better understanding of water sorption processes.