Understanding the mechanisms and energetics of ion solvation is critical in many scientific areas. Here, we present a methodlogy for studying ion solvation using differential mobility spectrometry (DMS) coupled to mass spectrometry. While in the DMS cell, ions experience electric fields established by a high frequency asymmetric waveform in the presence of a desired pressure of water vapor. By observing how a specific ion's behavior changes between the high- and low-field parts of the waveform, we gain knowledge about the aqueous microsolvation of that ion. In this study, we applied DMS to investigate the aqueous microsolvation of protonated quinoline-based drug candidates. Owing to their low binding energies with water, the clustering propensity of 8-substituted quinolinium ions was less than that of the 6- or 7-substituted analogues. We attribute these differences to the steric hinderance presented by subtituents in the 8-position. In addition, these experimental DMS results were complemented by extensive computational studies that determined cluster structures and relative thermodynamic stabilities.

The use of low-cost and widely available infrared lasers to pattern laser-induced graphene (LIG) into commercial polymers has incited intense research over the past few years due to its simplicity and ability to create various electrical and electrochemical devices. While the highest performing devices have been created by using costly synthetic polymers such as Kapton, the carbonization of one of the most common carbon precursors, the waste biomass-derived polymer poly(furfuryl alcohol) (PFA), has yet to be reported. As we demonstrate here, this is likely because PFA does not carbonize effectively via laser exposure. Instead, we show that the successful carbonization of PFA can be achieved by doping films with graphene oxide (GO) at loadings as low as 1 wt % GO. This enables the formation of highly conductive traces with sheet resistances as low as 13 Ω/sq. Supercapacitors built from microstructured PFA/GO composites result in specific areal capacitances as high as 16.0 mF/cm 2 at 0.05 mA/cm 2 , which is among the highest ever reported for micro-supercapacitors based on the LIG method, and retain 97% of their capacitance over 10000 cycles. This materials system provides a simpler, more versatile, higher performing, and greener platform for laser writing than previously reported polymers and composites.

Advancements in electrochemical energy storage devices such as batteries and supercapacitors are vital for a sustainable energy future. Significant progress has been made in developing novel materials for these devices, but less attention has focused on developments in electrode and device manufacturing. While electrodes are traditionally made through slurry casting of electrochemically active material, advanced manufacturing techniques enable patterning of novel electrode architectures and control of device geometries in real-time, which can potentially result in electrodes with increased loading, improved electrochemical performance, and added functionality, such as flexibility and wearability. These inexpensive methods are particularly suited for lab-scale research and start-up companies, as they enable rapid prototyping without a full device production line. The present review describes three main methods of advanced manufacturing (inkjet printing, direct ink writing, and laser-induced graphene techniques) and evaluates the performance of batteries and supercapacitors fabricated via these methods in comparison to traditionally manufactured devices.

The alignment and sorting of carbon nanotubes constitutes a challenging and industrially significant field of research. We have recently created a technique to simultaneously align and sort single-walled carbon nanotubes on a surface through the use of a specially designed organic thin film. This alignment relay technique can be intelligently altered to judiciously target key parameters of nanotube deposition including density, alignment, and length. Here, we demonstrate that by simply altering the nature of the liquid crystal used the average length of the nanotubes can be decreased by half while increasing the density 3-fold, with minimal impact on the diameter sorting.