Self-assembly of block copolymers in ionic liquids: Ultrastretchable iono- elastomers with mechanoelectrical response

Self-assembly of amphiphilic block copolymers can impart desired discrete or continuous nanostructures, such as micelles utilized as drug delivery vehicles in aqueous solvents, or cross-linked micelles for stretchable electronics fabrications in ionic liquids. These appealing applications have motivated significant research efforts to understand the nano- and microstructure as well as the structure-property relationships underlying such self-assembled systems, with the ultimate goal being effective formulation. To take full advantage of the bottom-up self-assembly approach, a comprehensive understanding of the factors that govern the self-assembly behavior of dilute, concentrated and functionalized system of non-ionic block copolymers self-assembly in ionic liquids, as well as robust characterization methods for quantifying the microstructure and properties relationship must be reviewed. For each system, the most significant challenges are presented and discussed. In addition, current and potential applications of block copolymers/ionic liquid system are also discussed, such as iono-elastomers. The emerging technologies involving wearable electronics require new materials with high stretchability, resistance to high loads, and high conductivities. We report a facile synthetic strategy based on self-assembly of concentrated solutions of end-functionalized PEO106-PPO70-PEO106 triblock copolymer in ethylammonium nitrate into face-centered cubic micellar crystals, followed by micelle corona cross-linking to generate elastomeric ion gels (iono-elastomers). These materials exhibit an unprecedented combination of high stretchability, high ionic conductivity, and mechanoelectrical response. The latter consists of a remarkable and counterintuitive increase in ion conductivity with strain during uniaxial extension, which is reversible upon load release. Based on in situ SAXS measurements of reversible crystal structure transformations during deformation, we postulate that the origin of the conductivity increase is a reversible formation of ion nanochannels due to a novel microstructural rearrangement specific to this material

Remote control of apomorphine infusion rate in Parkinson's disease: Real-time dose variations according to the patients' motor state. A proof of concept.

Postprint (author's final draft

Amber and the Cretaceous Resinous Interval

Amber is fossilized resin that preserves biological remains in exceptional detail, study of which has revolutionized understanding of past terrestrial organisms and habitats from the Early Cretaceous to the present day. Cretaceous amber outcrops are more abundant in the Northern Hemisphere and during an interval of about 54 million years, from the Barremian to the Campanian. The extensive resin production that generated this remarkable amber record may be attributed to the biology of coniferous resin producers, the growth of resiniferous forests in proximity to transitional sedimentary environments, and the dynamics of climate during the Cretaceous. Here we discuss the set of interrelated abiotic and biotic factors potentially involved in resin production during that time. We name this period of mass resin production by conifers during the late Mesozoic, fundamental as an archive of terrestrial life, the `Cretaceous Resinous Interval (CREI).This work was supported by the Spanish Ministerio de Ciencia, Innovación y Universidades [research agreement CRE CGL2017-84419 AEI/FEDER, UE] and by the Consejería de Industria, Turismo, Innovación, Transporte y Comercio of the Gobierno de Cantabria through the public enterprise EL SOPLAO S.L. [research agreement #20963 with University of Barcelona and research contract Ref. VAPC 20225428 to CN-IGME CSIC, both 2022–2025]; the Conselho Nacional de Pesquisa (Brazil) [research grand PQ 304529/19–2]; National Geographic Global Exploration Fund Northern Europa [research agreement GEFNE 127-14]; Deutsche Forschungsgemeinschaft (DFG) [research agreement SO 894/6-1]; VolkswagenStiftung [research agreement 90946]; the Secretary of Universities and Research (Government of Catalonia) and by the Horizon 2020 program of research and innovation of the European Union under the Marie-Curie [research contract no. 801370, Beatriu de Pinós]; the Secretary of Universities and Research (Government of Catalonia) and the European Social Fund [research contract 2021FI_B2 00003]; this work is a contribution to the grant RYC2021-032907-I, funded by the MCIN/AEI/10.13039/501100011033 and by the European Union «NextGenerationEU»/PRTR; and the National Agency for Research and Development (ANID) Scholarship Program [BECAS CHILE 2020-Folio 72210321].Abstract Keywords 1. Introduction 2. Definition of the Cretaceous Resinous Interval 3. Conditional factors on resin production and preservation 3.1. Abiotic factors 3.1.1. Atmospheric gas composition, temperature, and wildfires 3.1.2. Volcanism and changes in sea level 3.1.3. Oceanic physicochemical properties and hurricanes 3.1.4. Climatic overview throughout the CREI 3.2. Biotic factors 4. Present limitations and future directions 5. Conclusions Funding Author contributions Declaration of Competing Interest Acknowledgements Appendix A. Supplementary data Data availability Reference

Iono-elastomer-based wearable strain sensor with real-time thermomechanical dual response

An ultrastretchable iono-elastomer with resistance sensitive to both elongation strain and temperature has been developed by hierarchical self-assembly of an end functionalized triblock copolymer in a protic ionic liquid (ethylammonium nitrate) followed by cross-linking. Small-angle X-ray scattering experiments in situ with uniaxial elongation reveal a nanoscale microstructural transition of the hierarchically self-assembled cross-linked micelles that is responsible for the material's remarkable mechanical and ionic conductivity responses. The results show that the intermicelle distance extends along the deformation direction while the micelles organize into a long-range ordered face-centered-cubic structure during the uniaxial elongation. Besides good cyclability and resistance to selected physical damage, the iono-elastomer simultaneously achieves an unprecedented combination of high stretchability (340%), highly linear resistance vs elongation strain ( R = 0.998), and large temperature gauge factor (Δ R/ R = 3.24%/°C@30 °C). Human subject testing demonstrates that the iono-elastomer-based wearable thermomechanical sensor is able to effectively and accurately register both body motion and skin temperature simultaneously

Long-Chain Branched Polypentenamer Rubber: Topological Impact On Tensile Properties, Chain Dynamics, and Strain-Induced Crystallization

In this work, the effect of long-chain branching (LCB) on the tensile properties of sulfur-cured, unfilled, polypentenamer rubber (PPR) was investigated. Branched PPR, prepared by ring-opening metathesis copolymerization of cyclopentene (CP) and dicyclopentadiene (DCPD), showed improved mechanical strength, demonstrating more than 3 times higher tensile stress at 500% strain compared to its linear counterpart (a homopolymer of CP). In situ wide-angle X-ray scattering showed that branching units caused significant changes in the strain-induced crystallization (SIC). At low temperatures, linear PPR underwent rapid SIC after a critical stretch was reached, while branched PPR crystallized more slowly. However, SIC is not the cause of the enhanced mechanical strength. Elevated temperature experiments confirmed that even in the absence of SIC, LCB PPR exhibits a stiffer stress–strain response. We propose that the stiffer behavior of branched PPR is caused by a reduction in the chain mobility. The origins of reduced chain mobility are likely from topological constraints imposed by the LCB architecture and also from an unintended nanofiller effect created by microphase separation of DCPD-rich domains. The work described here is the initial investigation of adding branching units to PPR to improve the elastomer performance