King Abdullah University of Science and Technology

About: King Abdullah University of Science and Technology is a education organization based out in Jeddah, Saudi Arabia. It is known for research contribution in the topics: Catalysis & Membrane. The organization has 6221 authors who have published 22019 publications receiving 625706 citations. The organization is also known as: KAUST.

Adhesive supramolecular polymeric materials constructed from macrocycle-based host–guest interactions

Abstract: Nature uses the power of non-covalent interactions as the basis for many kinds of adhesion phenomena. Inspired by nature, scientists have prepared various synthetic adhesive materials that rely on a number of non-covalent interactions at the interfaces. Commonly used non-covalent interactions include hydrogen bonding, π–π stacking, charge transfer interactions, electrostatic interactions, hydrophobic interactions, macrocycle-based host–guest interactions, among others. Within this context, macrocycle-based host–guest interactions are of particular interest. Often they give rise to distinct properties, such as multiple combined noncovalent interactions and a diversity of stimuli-based responsiveness. In this tutorial review, we will summarise recent advances in adhesive supramolecular polymeric materials that rely primarily on macrocycle-based host–guest interactions. An overview of future challenges and a perspective of this sub-field are also provided.

Ancestral genetic diversity associated with the rapid spread of stress-tolerant coral symbionts in response to Holocene climate change

Abstract: Coral communities in the Persian/Arabian Gulf (PAG) withstand unusually high salinity levels and regular summer temperature maxima of up to ∼35 °C that kill conspecifics elsewhere. Due to the recent formation of the PAG and its subsequent shift to a hot climate, these corals have had only 5,000 km of the PAG, the Gulf of Oman, and the Red Sea coastline, we show that S. thermophilum is a member of a highly diverse, ancient group of symbionts cryptically distributed outside the PAG. We argue that the adjustment to temperature extremes by PAG corals was facilitated by the positive selection of preadapted symbionts. Our findings suggest that maintaining the largest possible pool of potentially stress-tolerant genotypes by protecting existing biodiversity is crucial to promote rapid adaptation to present-day climate change, not only for coral reefs, but for ecosystems in general.

Crystal Phase and Architecture Engineering of Lotus-Thalamus-Shaped Pt-Ni Anisotropic Superstructures for Highly Efficient Electrochemical Hydrogen Evolution

Abstract: The rational design and synthesis of anisotropic 3D nanostructures with specific composition, morphology, surface structure, and crystal phase is of significant importance for their diverse applications. Here, the synthesis of well-crystalline lotus-thalamus-shaped Pt-Ni anisotropic superstructures (ASs) via a facile one-pot solvothermal method is reported. The Pt-Ni ASs with Pt-rich surface are composed of one Ni-rich "core" with face-centered cubic (fcc) phase, Ni-rich "arms" with hexagonal close-packed phase protruding from the core, and facet-selectively grown Pt-rich "lotus seeds" with fcc phase on the end surfaces of the "arms." Impressively, these unique Pt-Ni ASs exhibit superior electrocatalytic activity and stability toward the hydrogen evolution reaction under alkaline conditions compared to commercial Pt/C and previously reported electrocatalysts. The obtained overpotential is as low as 27.7 mV at current density of 10 mA cm-2 , and the turnover frequency reaches 18.63 H2 s-1 at the overpotential of 50 mV. This work provides a new strategy for the synthesis of highly anisotropic superstructures with a spatial heterogeneity to boost their promising application in catalytic reactions.

Universal Ferroelectric Switching Dynamics of Vinylidene Fluoride-trifluoroethylene Copolymer Films

Abstract: In this work, switching dynamics of poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] copolymer films are investigated over unprecedentedly wide ranges of temperature and electric field. Remarkably, domain switching of copolymer films obeys well the classical domain nucleation and growth model although the origin of ferroelectricity in organic ferroelectric materials inherently differs from the inorganic counterparts. A lower coercivity limit of 50 MV/m and 180° domain wall energy of 60 mJ/m2 are determined for P(VDF-TrFE) films. Furthermore, we discover in copolymer films an anomalous temperature-dependent crossover behavior between two power-law scaling regimes of frequency-dependent coercivity, which is attributed to the transition between flow and creep motions of domain walls. Our observations shed new light on the switching dynamics of semi-crystalline ferroelectric polymers and such understandings are critical for realizing their reliable applications.

Novel porous carbon materials with ultrahigh nitrogen contents for selective CO2 capture

Abstract: Nitrogen-doped carbon materials were prepared by a nanocasting route using tri-continuous mesoporous silica IBN-9 as a hard template. Rationally choosing carbon precursors and carefully controlling activation conditions result in an optimized material denoted as IBN9-NC1-A, which possesses a very high nitrogen doping concentration (∼13 wt%) and a large surface area of 890 m2 g−1 arising from micropores (<1 nm). It exhibits an excellent performance for CO2 adsorption over a wide range of CO2 pressures. Specifically, its equilibrium CO2 adsorption capacity at 25 °C reaches up to 4.50 mmol g−1 at 1 bar and 10.53 mmol g−1 at 8 bar. In particular, it shows a much higher CO2 uptake at low pressure (e.g. 1.75 mmol g−1 at 25 °C and 0.2 bar) than any reported carbon-based materials, owing to its unprecedented nitrogen doping level. The high nitrogen contents also give rise to significantly enhanced CO2/N2 selectivities (up to 42), which combined with the high adsorption capacities, make these new carbon materials promising sorbents for selective CO2 capture from power plant flue gas and other relevant applications.