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Nucleation effects of coccoliths in portland cement

Matter 2025年

作者： Beatty, Danielle N. Srubar, Wil V. Materials Science and Engineering Program University of Colorado Boulder 4001 Discovery Drive UCB 027 BoulderCO80303 United States Department of Civil Environmental and Architectural Engineering University of Colorado Boulder 1111 Engineering Drive ECOT 441 UCB 428 BoulderCO80309 United States

This work explores the use of photosynthesized coccoliths (intricate CaCO3 particles) as a nucleation agent or cement replacement in portland cement paste. First, coccoliths were produced and harvested from the marine microalgae Emiliania huxleyi and the particle size, morphology, and mineralogy were characterized. Then, the nucleation effects of E. huxleyi coccoliths as seeding agent (0.5, 1, 3, or 5 wt % additions) and limestone filler (5 and 15 wt % cement replacements) were studied using isothermal conduction calorimetry and compressive strength testing. The results were compared with five commercially available CaCO3 sources used as nucleation agents and fillers. While the high surface area of coccoliths (12.22 m2/g) enhanced water demand, it also enhanced nucleation during cement hydration without accelerating hydration, leading to enhanced early-age strength without detriments to 28-day strength. Results highlight a potential carbon reduction strategy, namely employing photosynthesis as a method of mineral admixture production, for the cement and concrete industry. © 2025 Elsevier Inc.

关键词： Portland cement

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Low voltage graphene interface engineered organic ferroelectric tunnel junction devices

arXiv

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arXiv 2025年

作者： Natani, S. Khajanji, P. Cheng, L. Eshraghi, K. Zhang, Z. Shipley, W. Tao, A. Bandaru, P.R. Department of Mechanical Engineering University of California San Diego La Jolla CA United States Program in Materials Science University of California San Diego La Jolla CA United States Applied Materials Santa ClaraCA United States

It has been indicated 1 that the path forward for the widespread usage of ferroelectric (FE) materials may be considerably facilitated through the reduction of programming voltages to on-chip logic compatible values o... 详细信息

关键词： Ferroelectric devices

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Optimized hydrogen production via dry methane reforming with Ni/Al2O3 catalysts modified by cobalt and Boron: A design of experiments approach for enhanced performance

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Journal of the Energy Institute 2025年 120卷

作者： Silva, Yuri K.R.O. Melo, Dulce M.A. Maziviero, Fernando V. Medeiros, Rodolfo L.B.A. Silva, Joyce C.A. Azevedo, Amanda L. Araújo, Tomaz R. Braga, Renata M. Graduate Program in Chemistry Federal University of Rio Grande do Norte Natal Brazil Graduate Program in Materials Science and Engineering Federal University of Rio Grande do Norte Natal Brazil Agricultural School of Jundiaí Federal University of Rio Grande do Norte RN Macaíba Brazil

In this study, seven catalysts were designed, synthesized, and evaluated using the Design of Experiments (DOE) approach. The catalysts included one nickel (Ni) catalyst as a standard, two Ni catalysts promoted with boron trioxide (B2O3), two bimetallic catalysts in Ni-Cobalt (Co) systems, and two bimetallic catalysts also promoted with B2O3, all supported on γ-alumina. The γ-alumina support was synthesized via the microwave-assisted combustion method, while the metals and non-metallic promoter were incorporated using incipient wetness impregnation. The catalysts were thoroughly characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Field-Emission Scanning Electron Microscopy (FE-SEM), physisorption of N2 and Temperature-programmed Reduction (TPR). Activation was performed at 700 °C for 1 h under hydrogen (H2) flow. Catalytic performance was tested in a fixed-bed quartz reactor coupled with a gas chromatograph over 12 h at a space velocity of 96 L g−1 h−1. Carbon formation was analyzed by XRD and Raman spectroscopy, revealing a lower degree of crystalline carbon with a disorder index of 1.29 in the sample containing the highest B2O3 content. Thermogravimetric analysis (TG) quantified the reduction in carbon production by up to 57.7 %, demonstrating that B2O3 significantly reduced coke deposition. The results indicate that the catalysts with all three components exhibited high stability, enhanced catalytic activity, and minimized coke formation. A cubic special predictive model, with an Fcalculated/Ftabulated ratio of 41.12, demonstrated high statistical significance as confirmed by the Fisher test. © 2025 The Energy Institute

关键词： Fourier transform infrared spectroscopy

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Synergetic effects of multiple junction and surface hydroxyl in Cu/CuO/Cu2O/TiO2 heterostructures towards highly efficient photocatalysts for hydrogen generation

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materials science for Energy Technologies 2025年 8卷 131-142页

作者： Subagyo, Riki Anindika, Garcelina Rizky Aufkani, Afif Akmal Zhang, Lei Ardhyananta, Hosta Burhan, R.Y. Perry Nugraheni, Zjahra Vianita Akhlus, Syafsir Bahruji, Hasliza Prasetyoko, Didik Wellia, Diana Vanda Ivansyah, Atthar Luqman Arramel Kusumawati, Yuly Department of Chemistry Faculty of Science and Analytic Data Institut Teknologi Sepuluh Nopember Surabaya60111 Indonesia Center of Excellence Applied Physics and Chemistry Nano Center Indonesia Jl PUSPIPTEK South Tangerang Banten15314 Indonesia Department of Physics National University of Singapore Singapore117551 Singapore Department of Materials and Metallurgical Engineering Faculty of Industrial Technology and Systems Engineering Institut Teknologi Sepuluh Nopember Surabaya60111 Indonesia Centre of Advanced Material and Energy Science Universiti Brunei Darussalam Jalan Tungku Link BE 1410 Brunei Department of Chemistry Faculty of Mathematics and Natural Sciences Universitas Andalas Padang25163 Indonesia Master Program in Computational Science Faculty of Mathematics and Natural Science Institut Teknologi Bandung Jalan Ganesha No. 10 Bandung40132 Indonesia Instrumentation and Computational Physics Research Group Department of Physics Faculty of Mathematics and Natural Sciences Institut Teknologi Bandung Jalan Ganesha No.10 West Java Bandung40132 Indonesia

The implementation of titanium dioxide (TiO2) as a photocatalyst material in hydrogen (H2) evolution reaction (HER) has embarked renewed interest in the past decade. Rapid electron-hole pairs recombination and wide band gap of a photo-sensitive material of TiO2 are detrimental toward the targeted catalytical reaction. In this study, we present the rational design, fabrication, photocatalytic performance of TiO2-Cu/CuO/Cu2O heterostructures (CuTi) using viable chemical reduction method. The Z-scheme and S-scheme are succesfully generated across the TiO2/CuO/Cu2O interfaces, while the Schottky junction arises on the Cu perimeters. This is evidenced from the blue shifted about 0.3 eV of Cu 2p core level determined by using X-ray photoemission spectroscopy (XPS), in combination with the formation of inverse V-shape of the Mott-Schottky plots. In addition, we find that Cu/CuO/Cu2O facilitates photon absorption range up to the visible region. The multiple heterojunction and the large number of OHsurface enhanced charge carrier transfer are associated to the suppression of photoluminescence (PL) intensity, high surface hydroxyl (OHsurface) density in CuTi probed by XPS, and fast electron transfer based on the electrochemical measurements. The presence of OHsurface inhibits the recombination of electron. A significant H2 photogeneration rate enhancement is achieved when an optimized 5 wt% Cu/CuO/Cu2O concentration is used on TiO2 to achieve 7,157.19 μmol·g−1 (1,789.30 μmol·g−1·h−1). Based on this finding, zero emission energy innitiative could be materialized under multiple heterojunctions in photocatalytic process is beneficial for enhancing the H2 production. © 2025 The Authors

关键词： Titanium dioxide

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Deep Insights into the Design of Next-Generation Water-Based Stimuli-Responsive Shape Memory Polymers: From Fundamentals to Nature-Inspired Innovations

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Applied materials Today 2025年 44卷

作者： Prathumrat, Peerawat Likitaporn, Chutiwat Rimdusit, Sarawut Nikzad, Mostafa Wongsalam, Tawan Tanalue, Nattapon Okhawilai, Manunya Department of Chemical Engineering Faculty of Engineering Chulalongkorn University Bangkok Pathumwan10330 Thailand Department of Mechanical and Product Design Engineering School of Engineering Swinburne University of Technology HawthornVIC3122 Australia Multidisciplinary Program in Petrochemistry and Polymer Science Faculty of Science Chulalongkorn University Bangkok Pathumwan10330 Thailand Center of Excellence on Polymeric Materials for Medical Devices Chulalongkorn University Bangkok Pathumwan10330 Thailand

The design of next-generation shape memory polymers (SMPs) is increasingly focused on water-based stimuli-responsive materials, which offers new possibilities in biomedical and industrial fields. These SMPs exhibit shape memory effects under ambient conditions, enhancing their utility across various fields. This review provides a significant overview of the fundamental mechanisms behind water-based responsiveness, with a special focus on dual- and multi-stimuli responses that broaden the functional versatility of these materials. Advanced characterisation techniques are explored, providing deep insights into the molecular dynamics and interactions that influence their water-based stimuli-responsive behaviour. Emerging innovations inspired by nature are highlighted, exhibiting their potential in cutting-edge industrial and engineering advancements. Furthermore, the review emphasises the essence of sustainability and biocompatibility in developing environmentally friendly and safe SMPs. By addressing these critical aspects, this work sheds light on the evolving landscape and future potential of water-based stimuli-responsive SMPs, guiding both research and real-world applications. © 2025

关键词： Biocompatibility

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Periodic phase diagrams in micromagnetics with an eigenvalue solver

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IEEE Transactions on Magnetics 2025年

作者： Ai, Fangzhou Lin, Zhuonan Duan, Jiawei Lomakin, Vitaliy University of California Department of Electrical and Computer Engineering San DiegoCA92093 United States University of California Center for Memory and Recording Research San DiegoCA92093 United States University of California Program in Materials Science and Engineering San Diego92093 United States

This work introduces an approach to compute periodic phase diagram of micromagnetic systems by solving a periodic linearized Landau-Lifshitz-Gilbert (LLG) equation using an eigenvalue solver with the Finite Element Method formalism. The linear operator in the eigenvalue problem is defined as a function of the periodic phase-shift wave vector. The dispersion diagrams are obtained by solving the eigenvalue problem for complex eigenfrequencies and corresponding eigenstates for a range of prescribed wave vectors. The presented approach incorporates a calculation of the periodic effective field, including the exchange and magnetostatic field components. The approach is general in that it allows 3D problems to be handled with any 1D, 2D, and 3D periodicities. The ability to calculate periodic diagrams provides insights into the spin wave propagation and localized resonances in complex micromagnetic structures. © 1965-2012 IEEE.

关键词： Spin waves

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Theoretical insights into metal-doped nanostructured hematite catalyst supported by graphene underlayer for photoelectrochemical water splitting applications

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Discover Catalysis 2025年第1期2卷 1-27页

作者： Bhattacharya, Labanya Caspary Toroker, Maytal Department of Materials Science and Engineering Technion-Israel Institute of Technology Haifa Israel The Nancy and Stephen Grand Technion Energy Program Technion-Israel Institute of Technology Haifa Israel Resnick Sustainability Center for Catalysis Technion-Israel Institute of Technology Haifa Israel

Catalysis is pivotal in the production of green hydrogen through water splitting to meet the goal of carbon neutrality. Hematite (Fe2O3) is an excellent catalyst and benchmarked photoanode materials in photoelectrochemical water splitting. Among the metal dopants, aluminum (Al) substitution in hematite is found intrinsically. In this study, we investigate Al doped nanostructured hematite as a photoanode material and a catalyst in water oxidation mechanism using density functional theory+ U methodology. We have found that Al doping in hematite monolayer leads to unfavorable increase in theoretical overpotential value by 0.19 V. To improve the efficiency of oxygen evolution reaction, we consider heterostructuring of Al doped nanostructured hematite with pristine graphene and nitrogen (N) doped graphene as an underlayer material. Nitrogen doped graphene underlayer leads to the lowest overpotential value of 0.54 V compared to Al doped hematite catalyst (0.96 V) and graphene-Al doped hematite catalyst (0.63 V). The work function is notably reduced after nitrogen doping by 1.41 eV and 1.12 eV as compared to graphene-Al doped hematite and Al doped hematite, respectively. Charge density difference and Bader charge analysis confirm that nitrogen doped graphene underlayer induces delocalized charge density and lowers the activity of the surface states in the *O intermediate. Nitrogen doped graphene-Al doped hematite heterostructure has nearly zero band gap and has the highest cumulative probability of charge transport at photoanode’s surface. Our theoretical study provides mechanistic insights into improving the catalytic efficiency of Al doped nanostructured hematite by heterostructuring with pristine and N doped graphene.

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Nonsolvent-induced phase separation polyimide/polymeric ionic liquid separators for high-performance and safe lithium metal-based batteries

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Journal of Membrane science 2025年 728卷

作者： Lin, Yi-Hsiang Huang, Wei-Ming Li, Jing-Yu Mohamed, Mohamed Gamal Tseng, Chi-Yung Chiu, Jian-Ming Hwang, Bing-Joe Kuo, Shiao-Wei Ye, Yun-Sheng Department of Materials and Optoelectronic Science Center of Crystal Research National Sun Yat-Sen University Kaohsiung80424 Taiwan Department of Chemical Engineering National Taiwan University of Science and Technology Taipei106335 Taiwan from the Featured Areas Research Center Program National Taiwan University of Science and Technology Taipei106335 Taiwan

Lithium-ion battery separator safety has grown significantly in recent years, and preventing or minimizing thermal runaway in Li-ion batteries, especially during rapid charging and discharging, is a crucial problem. Therefore, there is a pressing need to develop high-safety thermotolerant separators that can guarantee high ion transport while also enabling homogeneous Li+ fluxes for the inhibition of Li dendritic growth. The nonsolvent-induced phase separation (NIPS) technique is used here to create a novel kind of polyimide (PI)/polymeric ionic liquid (PIL) separator that can be used as a thermotolerant separator alternative to commercial polyolefin-based separators. Without encountering a problem with other types of thermotolerant separators, whether they have nanopores or micropores, the fabricated PI/PIL separator with homogenous and nanosized pores exhibits high electrolyte adsorption/retention, ionic conductivity, mobility, and electrochemical properties in addition to typical high mechanical and thermal properties. Moreover, the PI/PIL separator displays excellent resistance for dendrite growth, and when integrated into the NCM811/Li cell demonstrates excellent cycling stability and rate performance. This work offers a significant method for creating a thermotolerant separator that addresses the issues of Li metal batteries, such as the absence of a high-performance and high-safety separator. © 2025

关键词： Nanopores

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Machine Learning for Identifying Grain Boundaries in Scanning Electron Microscopy (SEM) Images of Nanoparticle Superlattices

arXiv

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arXiv 2025年

作者： Paruchuri, Aanish Thrasher, Carl Hart, A.J. Macfarlane, Robert Jayaraman, Arthi Science in Data Science Program University of Delaware NewarkDE19713 United States Department of Materials Science and Engineering Massachusetts Institute of Technology CambridgeMA02139 United States Department of Mechanical Engineering Massachusetts Institute of Technology CambridgeMA02139 United States Department of Chemical and Biomolecular Engineering University of Delaware 150 Academy St NewarkDE19713 United States Department of Materials Science and Engineering University of Delaware NewarkDE19713 United States Data Science Institute University of Delaware NewarkDE19713 United States

Nanoparticle superlattices consisting of ordered arrangements of nanoparticles exhibit unique optical, magnetic, and electronic properties arising from nanoparticle characteristics as well as their collective behaviors. Understanding how processing conditions influence the nanoscale arrangement and microstructure is critical for engineering materials with desired macroscopic properties. Microstructural features such as grain boundaries, lattice defects, and pores significantly affect these properties but are challenging to quantify using traditional manual analyses as they are labor-intensive and prone to errors. In this work, we present a machine learning workflow for automating grain segmentation in scanning electron microscopy (SEM) images of nanoparticle superlattices. This workflow integrates signal processing techniques, such as Radon transforms, with unsupervised learning methods like agglomerative hierarchical clustering to identify and segment grains without requiring manually annotated data. In the workflow we transform the raw pixel data into explainable numerical representation of superlattice orientations for clustering. Benchmarking results demonstrate the workflow's robustness against noisy images and edge cases, with a processing speed of four images per minute on standard computational hardware. This efficiency makes the workflow scalable to large datasets and makes it a valuable tool for integrating data-driven models into decision-making processes for material design and analysis. For example, one can use this workflow to quantify grain size distributions at varying processing conditions like temperature and pressure and using that knowledge adjust processing conditions to achieve desired superlattice orientations and grain sizes. © 2025, CC BY.

关键词： Grain boundaries

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Tribological Behaviors and Statistical Experimental Design of Sintered and Age-Hardened Aluminum–Copper Based Composites

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Lubricants 2025年第4期13卷 172-172页

作者： Popescu, Ileana Nicoleta Alhalaili, Badriyah Anghelina, Florina Violeta Nicolicescu, Claudiu Vidu, Ruxandra Faculty of Materials Engineering and Mechanics Valahia University of Targoviste Targoviste130004 Romania Valahia University of Targoviste Targoviste130004 Romania American Romanian Academy of Arts and Sciences Citrus HeightsCA95611 United States Nanotechnology and Advanced Materials Program Kuwait Institute for Scientific Research P.O. Box 24885 Safat 13109 Kuwait Department of Engineering and Management of the Technological Systems Faculty of Mechanics University of Craiova Drobeta-Turnu Severin220037 Romania Faculty of Materials Science and Engineering National University of Science and Technology POLITEHNICA Bucharest Bucharest060042 Romania

This paper reports on the influence of various processing parameters and different SiCp proportions on the outcome of mechanical, tribological, microstructural, and microcompositional investigations of Al-Cu based composites used as potential brake friction materials for eco-friendly vehicle parts. The composites were obtained by powder metallurgy, and then the sintered composite was treated at 515 ± 5 °C/6 h, quenched in water, and artificially aged at different temperatures and times. The microstructural and microcompositional investigations of the composites were made using an environmental scanning electron microscopy (ESEM), energy-dispersive X-ray spectroscopy (EDS). After analyzing the microstructures in correlation with the results of the hardness tests, the optimal proportion of SiCp and optimal heat treatment parameters were determined. The composite samples with the best properties were chosen for tribological investigation. The friction and wear tests of samples were made under dry sliding conditions using a "pin on disc" machine, at a contact pressure of 0.35 to 1.15 MPa, 2 to 4.5 m/s relative speed, and the prediction of tribological behavior was made using a linear factorial design approach. © 2025 by the authors.

关键词： Sintering

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