An automatic method that fully compensates the quantitative phase measurements in off-axis digital holographic microscopy (DHM) is presented. The two main perturbations of the quantitative phase measurements in off-axis DHM are automatically removed. While the curvature phase flaw introduced by the microscope objective is avoided by the use of an optimized telecentric imaging system for the recording of the holograms, the remaining phase perturbation due to the tilt of the reference wave is removed by the automatic computation of a digital compensating reference wave. The method has been tested on both nonbiological and biological samples with and improving on the quality of the recovered phase maps.
Lately, the field
of redox flow batteries is flourishing because of the emergence of
new redox chemistries, including organic compounds, new electrolytes,
and innovative designs. Recently, we reported an original membrane-free
battery concept based on the mutual immiscibility of an aqueous catholyte
containing hydroquinone and an ionic liquid anolyte containing para-benzoquinone as redox species. Here, we investigate
the versatility of this concept exploring the electrochemical performance
of 10 redox electrolytes based on different solvents, such as propylene
carbonate, 2-butanone, or neutral-pH media, and containing different
redox organic molecules, such as 2,2,6,6-tetramethylpiperidine-1-oxyl,
4-hydroxy-2,2,6,6-tetramethylpiperidine1-oxyl (OH-TEMPO), or substituted
anthraquinones. The most representative electrolytes were paired and
used as immiscible anolyte–catholyte in 5 different membrane-free
batteries. Those batteries with substituted anthraquinones in the
anolyte exhibited up to 50% improved open-circuit voltage (2.1 V),
an operating voltage of 1.75 V, and 62% higher power density compared
with our previous work. On the other hand, the partition coefficient
of redox molecules between the two immiscible phases and the inherent
self-discharge occurring at the interphase are revealed as intrinsic
features affecting the performance of this type of membrane-free battery.
It was successfully demonstrated that the functionalization of redox
molecules is an interesting strategy to tune the partition coefficients
mitigating the crossover that provokes low battery efficiency. As
a result, the cycling life of a battery having OH-TEMPO as active
species in the catholyte and containing propylene carbonate-based
anolyte was evaluated over 300 cycles, achieving 85% capacity retention.
These results demonstrated the huge versatility and countless possibilities
of this new membrane-free battery concept.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.