Proximity-independent acid–base synergy in a solid ZrOxHy catalyst for amine regeneration in post-combustion CO2 capture
Related Articles
Off-stoichiometry effect on the physical properties of epoxy resins
Amines generally tend to segregate at the interface of the epoxy resins cured with amines. To gain better insight into the aggregation states and physical properties at the adhesive interface, we examined the cross-linking structure and physical properties of the cured epoxy resins with an off-stoichiometric ratio of epoxy and amine. As the excess amine increased, the amine not only remained as unreacted monomers or low-molecular-weight isolated chains within the cross-linking structure but also formed dangling chain ends, increasing heterogeneity in the cured epoxy resin. As a result, the cross-linking density and mass density decreased, along with a reduction in the glass transition temperature. On the other hand, Young’s modulus increased with the excess amount of amine. Wide-angle X-ray scattering experiments, in conjunction with molecular dynamics simulations, revealed that the excess amine suppressed the widening of the distance between phenyl groups during the curing reaction, suggesting that this could act as steric resistance during deformation.
Improvement in the toughness and compatibility of poly(lactic acid)/starch acetoacetate through reactive melt-kneading with amine-modified silicone
Nonbiodegradable plastic pollution has taken centerstage because of its negative impacts on ecosystems, and poly(lactic acid) (PLA)/starch blends, which are biodegradable plastics, have attracted increased attention as sustainable materials. However, the poor compatibility between hydrophobic PLA and hydrophilic starch causes their composites to become brittle. In this study, to improve the compatibility between PLA and starch, the hydroxyl groups of starch were modified with acetoacetate, and amine-modified silicone was used as the compatibilizer. The acetoacetyl group readily reacts with primary amines under mild conditions to form enamines and is expected to react rapidly during the melt-kneading process. The amino groups also react with the decomposed PLA end groups via condensation. Therefore, amine-modified silicone is considered a suitable compatibilizer for PLA and starch acetoacetate (SAA). PLA/SAA/amine-modified silicone blends were prepared via melt-kneading. The toughness of PLA/SAA was improved by approximately 15 times when 3 wt% amine-modified silicone was added. Furthermore, in the SEM observation of the tensile fracture surface, it was found that the dispersibility of SAA in PLA was improved such that SAA and PLA were indistinguishable. This approach can contribute to the widespread use of biodegradable plastics in packaging materials and single-use plastics.
A scalable synergy-first backbone decomposition of higher-order structures in complex systems
In the last decade, there has been an explosion of interest in the field of multivariate information theory and the study of emergent, higher-order interactions. These “synergistic” dependencies reflect information that is in the “whole” but not any of the “parts.” Arguably the most successful framework for exploring synergies is the partial information decomposition (PID). Despite its considerable power, the PID has a number of limitations that restrict its general applicability. Subsequently, other heuristic measures, such as the O-information, have been introduced, although these measures typically only provide a summary statistic of redundancy/synergy dominance, rather than direct insight into the synergy itself. To address this issue, we present an alternative decomposition that is synergy-first, scales much more gracefully than the PID, and has a straightforward interpretation. We define synergy as that information encoded in the joint state of a set of elements that would be lost following the minimally invasive perturbation on any single element. By generalizing this idea to sets of elements, we construct a totally ordered “backbone” of partial synergy atoms that sweeps the system’s scale. This approach applies to the entropy, the Kullback-Leibler divergence, and by extension, to the total correlation and the single-target mutual information (thus recovering a “backbone” PID). Finally, we show that this approach can be used to decompose higher-order interactions beyond information theory by showing how synergistic combinations of edges in a graph support global integration via communicability. We conclude by discussing how this perspective on synergistic structure can deepen our understanding of part-whole relationships in complex systems.
Bank lending and environmental quality in Gulf Cooperation Council countries
To achieve economies with net-zero carbon emissions, it is essential to develop a robust green financial intermediary channel. This study seeks empirical evidence on how domestic bank lending to sovereign and private sectors in Gulf Cooperation Council (GCC) countries impacts carbon dioxide and greenhouse gas emissions. We employ PMG-ARDL model to panel data comprising six countries in GCC over twenty years for carbon dioxide emissions and nineteen years for greenhouse gas emissions. Our findings reveal a long-term positive impact of both bank lending variables on carbon dioxide and greenhouse gas emissions. In addition, lending to the government shows a negative short-term effect on greenhouse gas emissions. The cross-country results demonstrate the presence of a long-run effect of explanatory variables on both types of emissions, except for greenhouse gas in Saudi Arabia. The sort-term impact of the explanatory variables on carbon dioxide and greenhouse gas emissions is quite diverse. Not only do these effects differ across countries, but some variables have opposing effects on the two types of emissions within a single country. The findings of this study present a new perspective for GCC economies: neglecting total greenhouse gas emissions and concentrating solely on carbon dioxide emissions means missing critical information for devising effective strategies to combat threats of environmental degradation and achieve net-zero goals.
Combustion-assisted low-temperature ZrO2/SnO2 films for high-performance flexible thin film transistors
We developed high-performance flexible oxide thin-film transistors (TFTs) using SnO2 semiconductor and high-k ZrO2 dielectric, both formed through combustion-assisted sol-gel processes. This method involves the exothermic reaction of fuels and oxidizers to produce high-quality oxide films without extensive external heating. The combustion ZrO2 films were revealed to have an amorphous structure with a higher proportion of oxygen corresponding to the oxide network, which contributes to the low leakage current and frequency-independent dielectric properties. The ZrO2/SnO2 TFTs fabricated on flexible substrates using combustion synthesis exhibited excellent electrical characteristics, including a field-effect mobility of 26.16 cm2/Vs, a subthreshold swing of 0.125 V/dec, and an on/off current ratio of 1.13 × 106 at a low operating voltage of 3 V. Furthermore, we demonstrated flexible ZrO2/SnO2 TFTs with robust mechanical stability, capable of withstanding 5000 cycles of bending tests at a bending radius of 2.5 mm, achieved by scaling down the device dimensions.
Responses