Make it greener: Exploring novel biobased materials in photopolymerization processes

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Ionogel hybrid polymer electrolytes encompassing room-temperature ionic liquids for 4V-class Li-metal batteries operating at ambient temperature

In this study, we prepare ionogels composed of bisphenol A ethoxylate dimethacrylate, poly(ethylene glycol) methyl ether methacrylate, lithium bis(trifluoromethanesulfonyl)imide, and 1-butyl-1-methylpyrrolidinium bis(fluorosulfonyl)imide or 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide ionic liquids via rapid, scalable, solvent-free UV-induced polymerization.The various hybrid polymer electrolyte formulations are thoroughly characterized using acomprehensive set of physico-chemical and electrochemical methods, including gel content,FTIR, rheology, DTMA, TGA, SEM, cycling voltammetry, impedance spectroscopy, andgalvanostatic cycling in laboratory-scale Li-metal cells. We particularly focus on the influence ofusing two different ionic liquids as reaction medium on the properties of the resulting materialsand their electrochemical behaviors. Our results indicate that viscosity affects thepolymerization kinetics of the ionogels, which in turn might affect their thermal stability andgalvanostatic cycling behavior. In the purpose of promoting overall performance of solid-statebatteries, we also present the results of composite electrolytes obtained by introducingLi7La3Zr2O12(LLZO) into ionogels and followingin-situUV-polymerisation. The addition of LLZOceramic results in more porous solid networks, leading to enhanced charge/discharge stabilityat ambient temperature and higher C-rates featuring 4V-class NMC cathodes, enlightening thepromising prospects of the developed materials to be successfully implemented as stable,durable, and efficient electrolytes in next-generation Li-metal cells

Vanillin-Based Photocurable Anticorrosion Coatings Reinforced with Nanoclays

This study investigates the chemical-physical properties and anticorrosion effectiveness of UV-cured coatings produced using epoxidized vanillin (DGEVA) as biobased precursor, then reinforced by the addition of nanoclay. After optimizing the UV-curing parameters of three different formulations by Fourier transform infrared spectroscopy (FTIR), the thermo-mechanical properties of the coatings are assessed by differential scanning calorimetric analysis (DSC), dynamic thermal mechanical analysis (DTMA), and pencil hardness. The coatings are applied on mild steel substrates and then their barrier properties are investigated by electrochemical impedance spectroscopy measurements, immersing the samples in 3.5 wt% NaCl aerated solutions. The results show the good corrosion protective effectiveness of the biobased coatings. The nanoclay addition has a beneficial effect, as it hinders the diffusion of the aggressive ions from the electrolyte solution to the metal substrate. The reported findings demonstrate the possibility of using biobased precursors and UV-curing technology to reduce the environmental impact of the coating industry.A photocurable epoxy composite is realized using epoxidized vanillin (DGEVA) as a biobased precursor, and functionalized nanoclay as filler. The coating shows good thermo-mechanical properties, high chemical resistance, and satisfactory corrosion protection effectiveness in aggressive environments containing chlorides. imag

On the Role of Alfvenic Fluctuations as Mediators of Coherence within Interplanetary Coronal Mass Ejections: Investigation of Multi-Spacecraft Measurements at 1 au

Interplanetary coronal mass ejections (ICMEs) are defined as ''coherent'' if they are capable of responding to external perturbations in a collective manner. This implies that information must be able to propagate across ICME structures, and if this is not the case, single-point in-situ measurements cannot be considered as indicative of global ICME properties. Here, we investigate the role of Alfvenic fluctuations (AFs) as mediators of ICME coherence. We consider multi-point magnetic field and plasma measurements of 10 ICMEs observed by the ACE and Wind spacecraft at 1 au at longitudinal separations of 0.5{\deg}-0.7{\deg}. For each event, we analyze the Alfvenicity in terms of the residual energy and cross helicity of fluctuations, and the coherence in terms of the magnetic correlation between Wind and ACE. We find that ~65% and 90% of ICME sheaths and magnetic ejecta (MEs), respectively, present extended AFs covering at least 20% of the structure. Cross helicity suggests AFs of solar and interplanetary origin may co-exist in the ICME population at 1 au. AFs are mainly concentrated downstream of shocks and in the back of MEs. The magnetic field is poorly correlated within sheaths, while the correlation decreases from the front to the back of the MEs for most magnetic field components. AFs are also associated with lower magnetic field correlations. This suggests either that ICME coherence is not mediated by Alfven waves, implying that the coherence scale may be smaller than previously predicted, or that the magnetic field correlation is not a measure of coherence

Evolution of Interplanetary Coronal Mass Ejection Complexity: A Numerical Study through a Swarm of Simulated Spacecraft

In-situ measurements carried out by spacecraft in radial alignment are critical to advance our knowledge on the evolutionary behavior of coronal mass ejections (CMEs) and their magnetic structures during propagation through interplanetary space. Yet, the scarcity of radially aligned CME crossings restricts investigations on the evolution of CME magnetic structures to a few case studies, preventing a comprehensive understanding of CME complexity changes during propagation. In this Letter, we perform numerical simulations of CMEs interacting with different solar wind streams using the linear force-free spheromak CME model incorporated into the EUropean Heliospheric FORecasting Information Asset model. The novelty of our approach lies in the investigation of the evolution of CME complexity using a swarm of radially aligned, simulated spacecraft. Our scope is to determine under which conditions, and to what extent, CMEs exhibit variations of their magnetic structure and complexity during propagation, as measured by spacecraft that are radially aligned. Results indicate that the interaction with large-scale solar wind structures, and particularly with stream interaction regions, doubles the probability to detect an increase of the CME magnetic complexity between two spacecraft in radial alignment, compared to cases without such interactions. This work represents the first attempt to quantify the probability of detecting complexity changes in CME magnetic structures by spacecraft in radial alignment using numerical simulations, and it provides support to the interpretation of multi-point CME observations involving past, current (such as Parker Solar Probe and Solar Orbiter), and future missions

First Simultaneous In Situ Measurements of a Coronal Mass Ejection by Parker Solar Probe and STEREO-A

We present the first Parker Solar Probe mission (PSP)-observed coronal mass ejection (CME) that hits a second spacecraft before the end of the PSP encounter, providing an excellent opportunity to study short-term CME evolution. The CME was launched from the Sun on 2019 October 10 and was measured in situ at PSP on 2019 October 13 and at STEREO-A on 2019 October 14. The small, but not insignificant, radial (∼0.15 au) and longitudinal (∼8°) separation between PSP and STEREO-A at this time allows for both observations of short-term radial evolution as well as investigation of the global CME structure in longitude. Although initially a slow CME, magnetic field and plasma observations indicate that the CME drove a shock at STEREO-A and also exhibited an increasing speed profile through the CME (i.e., evidence for compression). We find that the presence of the shock and other compression signatures at 1 au are due to the CME having been overtaken and accelerated by a high speed solar wind stream (HSS). We estimate the minimum interaction time between the CME and the HSS to be ∼2.5 days, indicating the interaction started well before the CME arrival at PSP and STEREO-A. Despite alterations of the CME by the HSS, we find that the CME magnetic field structure is similar between the vantage points, with overall the same flux rope classification and the same field distortions present. These observations are consistent with the fact that coherence in the magnetic structure is needed for steady and continued acceleration of the CME

The Effect of Stream Interaction Regions on ICME Structures Observed in Longitudinal Conjunction

We study two interplanetary coronal mass ejections (ICMEs) observed at Mercury and at 1 au by spacecraft in longitudinal conjunction, investigating the question: what causes the drastic alterations observed in some ICMEs during propagation, while other ICMEs remain relatively unchanged? Of the two ICMEs, the first one propagated relatively self-similarly, while the second one underwent significant changes in its properties. We focus on the presence or absence of large-scale corotating structures in the ICME propagation space between Mercury and 1 au, which have been shown to influence the orientation of ICME magnetic structures and the properties of ICME sheaths. We determine the flux rope orientation at the two locations using force-free flux rope fits as well as the classification by Nieves-Chinchilla et al. We also use measurements of plasma properties at 1 au, the size evolution of the sheaths and magnetic ejecta with heliocentric distance, and identification of structures in the propagation space based on in situ data, remote-sensing observations, and simulations of the steady-state solar wind to complement our analysis. Results indicate that the changes observed in one ICME were likely caused by a stream interaction region, while the ICME exhibiting little change did not interact with any transients between Mercury and 1 au. This work provides an example of how interactions with corotating structures in the solar wind can induce fundamental changes in ICMEs. Our findings can help lay the foundation for improved predictions of ICME properties at 1 au