A state-of-the-art review of Engaged Learning in Belgium, Finland, Germany, Italy, Spain and the United Kingdom

In this state of the art review, we explore the concept of Engaged Learning, and the development of this pedagogy globally, with a specific focus on each of the CaST Partner Countries of Belgium, Finland, Germany, Italy, Spain and the United Kingdom. We define Engaged Learning as the process where students apply the theory learned at Higher Education Institutions (HEI) to a context outside of HEI by addressing societal concerns, challenges or needs while producing knowledge in an equitable, mutually beneficial partnership

13C NMR assignments of regenerated cellulose from solid-state 2D NMR spectroscopy

From the assignment of the solid-state 13C NMR signals in the C4 region, distinct types of crystalline cellulose, cellulose at crystalline surfaces, and disordered cellulose can be identified and quantified. For regenerated cellulose, complete 13C assignments of the other carbon regions have not previously been attainable, due to signal overlap. In this study, two-dimensional (2D) NMR correlation methods were used to resolve and assign 13C signals for all carbon atoms in regenerated cellulose. 13C-enriched bacterial nanocellulose was biosynthesized, dissolved, and coagulated as highly crystalline cellulose II. Specifically, four distinct 13C signals were observed corresponding to conformationally different anhydroglucose units: two signals assigned to crystalline moieties and two signals assigned to non-crystalline species. The C1, C4 and C6 regions for cellulose II were fully examined by global spectral deconvolution, which yielded qualitative trends of the relative populations of the different cellulose moieties, as a function of wetting and drying treatments

Synthesis and structural properties of a 2D Zn(II) dodecahydroxy-closo-dodecaborate coordination polymer

In this work, we discuss the synthesis and characterization of a 2D coordination polymer composed of a dianionic perhydroxylated boron cluster, [B12(OH)122-], coordinated to Zn(II)—the first example of a transition metal-coordinated [B12(OH)12]2- compound. This material was synthesized via cation exchange from the starting cesium salt and then subjected to rigorous characterizion prior to and after thermal activation. Numerous techniques, including XRD, FTIR, SEM, TGA, and solid-state NMR revealed a 2D coordination polymer composed of sheets of Zn(II) ions intercalated between planes of boron clusters. The as-synthesized material was then evacuated of solvent via thermal treatment, and atomic-level changes from this transformation were elucidated through a combination of 1D and 2D solid-state NMR analyses of 11B and 1H nuclei, suggesting the full removal of coordinated solvent molecules. Evidence also suggested that [B12(OH)122-] can adjust its coordination to Zn(II) in the solid-state through hemilability of its numerous -OH ligands

Understanding and Promoting Molecular Interactions and Charge Transfer in Dye-Mediated Hybrid Photovoltaic Materials

The performances of hybrid organic–inorganic photovoltaics composed of conjugated polymers and metal oxides are generally limited by poor electronic coupling at hybrid interfaces. In this study, physicochemical interactions and bonding at the organic–inorganic interfaces are promoted by incorporating organoruthenium dye molecules into self-assembled mesostructured conjugated polymer–titania composites. These materials are synthesized from solution in the presence of surfactant structure-directing agents (SDA) that solubilize and direct the nanoscale compositions and structures of the conjugated polymer, dye, and inorganic precursor species. Judicious selection of the SDA and dye species, in particular, exploits interactions that direct the dye species to the inorganic–organic interfaces, leading to significantly enhanced electronic coupling, as well as increased photoabsorption efficiency. This is demonstrated for the hydrophilic organoruthenium dye N3, used in conjunction with alkyleneoxide triblock copolymer SDA, polythiophene conjugated polymer, and titania species, in which the N3 dye species are localized in molecular proximity to and interact strongly with the titania framework, as established by solid-state NMR spectroscopy. In contrast, a closely related but more hydrophobic organoruthenium dye, Z907, is shown to interact more weakly with the titania framework, yielding significantly lower photocurrent generation. The strong SDA-directed N3-TiO_<i>x</i> interactions result in a significant reduction of the lifetime of the photoexcited state and enhanced macroscopic photocurrent generation in photovoltaic devices. This study demonstrates that multicomponent self-assembly can be harnessed for the fabrication of hierarchical materials and devices with nanoscale control of chemical compositions and surface interactions to improve photovoltaic properties

Unifying charge generation, recombination, and extraction in low-offset non-fullerene acceptor organic solar cells

Even though significant breakthroughs with over 18% power conversion efficiencies (PCEs) in polymer:non-fullerene acceptor (NFA) bulk heterojunction organic solar cells (OSCs) have been achieved, not many studies have focused on acquiring a comprehensive understanding of the underlying mechanisms governing these systems. This is because it can be challenging to delineate device photophysics in polymer:NFA blends comprehensively, and even more complicated to trace the origins of the differences in device photophysics to the subtle differences in energetics and morphology. Here, a systematic study of a series of polymer:NFA blends is conducted to unify and correlate the cumulative effects of i) voltage losses, ii) charge generation efficiencies, iii) non-geminate recombination and extraction dynamics, and iv) nuanced morphological differences with device performances. Most importantly, a deconvolution of the major loss processes in polymer:NFA blends and their connections to the complex BHJ morphology and energetics are established. An extension to advanced morphological techniques, such as solid-state NMR (for atomic level insights on the local ordering and donor:acceptor pi-pi interactions) and resonant soft X-ray scattering (for donor and acceptor interfacial area and domain spacings), provide detailed insights on how efficient charge generation, transport, and extraction processes can outweigh increased voltage losses to yield high PCEs.Department of the Navy, Office of Naval Research AwardOffice of Naval Research [N00014-14-1-0580]; Schlumberger foundation; Alexandervon-Humboldt StiftungAlexander von Humboldt Foundation; DOE Office of Science User FacilityUnited States Department of Energy (DOE) [DE-AC02-05CH11231]; MRSEC Program of the NSF - NSF [DMR-170256]; U.S. Office of Naval Research (ONR)Office of Naval Research [N000141712204]; VEGAVedecka grantova agentura MSVVaS SR a SAV (VEGA) [2/0081/18]; Center for Advanced Material Application, SAS; Simons Foundation [601946