Semicrystalline polymers are solids that are supposed to flow only above their melting temperature. By using confinement within nanoscopic cylindrical pores, we show that a semicrystalline polymer can flow at temperatures below the melting point with a viscosity intermediate to the melt and crystal states. During this process, the capillary force is strong and drags the polymer chains in the pores without melting the crystal. The unexpected enhancement in flow, while preserving the polymer crystallites, is of importance in the design of polymer processing conditions applicable at low temperatures, e.g., cold drawn polymers such as polytetrafluoroethylene, self-healing, and in nanoconfined donor/acceptor polymers used in organic electronics.
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http://dx.doi.org/10.1126/sciadv.adg8865 | DOI Listing |
Sci Rep
January 2025
Centro de Física Teórica e Computacional, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal.
Three-dimensional (3D) simulations of the structure of liquid crystal (LC) torons, topologically protected distortions of the LC director field, under material flows are rare but essential in microfluidic applications. Here, we show that torons adopt a steady-state configuration at low flow velocity before disintegrating at higher velocities, in line with experimental results. Furthermore, we show that under partial slip conditions at the boundaries, the flow induces a reversible elongation of the torons, also consistent with the experimental observations.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
University of Limerick, Chemical Sciences, IRELAND.
Guest transport through discrete voids (closed pores) in crystalline solids is poorly understood. Herein, we report the gas sorption properties of a nonporous coordination network, [Co(bib)2Cl2]n·2MeOH (sql-bib-Co-Cl-α), featuring square lattice (sql) topology and the bent linker 1,3-bis(1H-imidazol-1-yl)benzene (bib). The as-synthesized sql-bib-Co-Cl-α has 11.
View Article and Find Full Text PDFMater Horiz
January 2025
Soft Matter Lab, Department of Chemical Engineering, Shiv Nadar Institution of Eminence Deemed to be University, Greater Noida, 201314, India.
This study focuses on fabricating photonic crystals (PCs) by surfactant-based particle capture at the gas-liquid interface of evaporating sessile droplets. The captured particles form interfacial films, resulting in ordered monolayer depositions manifesting iridescent structural colors. The particle dynamics behind the ordered arrangement is delineated.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Université de Caen Normandie, ENSICAEN, CNRS, LCS, Laboratoire Catalyse et Spectrochimie, Caen 14000, France.
The urgent need to mitigate carbon emissions has spurred research into small-pore zeolites as cost-effective options for CO capture by solid adsorbents, particularly in postcombustion and biogas separation applications. In this study we investigate levyne (LEV-type) zeolite, a largely unexplored material for CO adsorption, as a novel adsorbent for CO capture and gas separation. Using seed-assisted synthesis approaches and different synthesis conditions, nanosized and micron-sized LEV zeolites were synthesized and characterized in terms of synthesis pathways, morphology, crystal size, and chemical composition.
View Article and Find Full Text PDFSmall
January 2025
Department of Chemical Engineering, University of South Carolina, Columbia, SC, 29208, USA.
Precisely crafted hierarchical architectures found in naturally derived biomaterials underpin the exceptional performance and functionality showcased by the host organism. In particular, layered helical assemblies composed of cellulose, chitin, or collagen serve as the foundation for some of the most mechanically robust and visually striking natural materials. By utilizing structured materials in additive manufacturing techniques such as extrusion-based 3D printing, the intrinsic deformation process can be used to implement bottom-up design of printed constructs, offering the potential to create intricate macroscale geometries with embedded nanoscale functionality.
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