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17th Unified International Technical Conference on Refractories, UNITECR 2022

作者： Borges, O.H. Sardelli, J.A.P. Rocha, R.M. Neto, C. Pagliosa Pandolfelli, V.C. Federal University of Sao Carlos Graduate Program in Materials Science and Engineering SP Sao Carlos Brazil FIRE Associate Laboratory SP Sao Carlos Brazil RHI Magnesita Research and Development Center Praça Louis Ensch 240 MG Contagem32210-902 Brazil

Environmental and occupational issues regarding Cr6+ formation urge the replacement of chrome-containing refractories by greener alternatives. For the latest decades, magnesium-containing refractories have been investigated for this purpose, however, few studies evaluated the likelihood of using other chemical elements as inducers of spinel-like phase formation in refractory castables. In this work, the addition of zincite (ZnO) in alumina-based vibrated castables bonded with calcium aluminate cement (CAC) or hydratable alumina (HA) was evaluated and compared with its MgO counterpart. The formation of the Zn-based spinel (ZnAl2O4, gahnite) took place at a lower temperature (1100 ºC) than MgAl2O4 (1300 ºC), resulting in the anticipated strengthening of these compositions. Despite the challenges regarding using ZnO - as its volatilization under reduced atmosphere and fast reaction kinetics -, lower linear dimensional changes, comparable cold modulus of rupture and enhanced thermal shock damage resistance was detected. © 2022 Unified International Technical Conference on Refractories, UNITECR 2022 - Proceedings. All rights reserved.

关键词： Zinc oxide

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Vibrational entropies of oxygen vacancy formation in metal oxides

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Physical Review materials 2024年第5期8卷 055407-055407页

作者： Bianca Baldassarri Jiangang He Christopher Wolverton Graduate Program in Applied Physics Northwestern University Evanston Illinois 60208 USA Department of Materials Science and Engineering Northwestern University Evanston Illinois 60208 USA

Oxygen vacancies play a key role in many energy-related applications, and the investigation of the thermodynamic forces driving their formation across different materials can be tackled through the use of ab initio methods. In this context, however, computational studies targeting finite-temperature properties such as entropy remain scarce. Wider-ranging studies are of interest to deepen the understanding of the role of the entropy of oxygen vacancy formation and its different components in processes like the ones involved in solar thermochemical hydrogen (STCH) production, and to investigate the existence of common trends and differences between materials. In this work, we use density functional theory and harmonic phonon calculations to compute the vibrational entropy of oxygen vacancy formation (ΔSvib) for 10 different metal oxide compounds. The computation is carried out by taking the difference between the vibrational entropy of a vacancy-containing and a pristine structure, while the entropic contribution from the final gaseous state of the oxygen lost from the material is accounted for separately with a gas entropy term. We first examine the temperature dependence of ΔSvib and highlight the presence of an initial peak around room temperature, followed by a steady decrease resulting from the presence of an additional O atom (the one becoming vacant) in the defect-free structure. We then inspect the atomic contributions to ΔSvib, and highlight similarities and differences between compounds. Finally, we consider other significant sources of entropy, and find ΔSvib to provide a smaller, yet non-negligible, contribution to the total entropy of vacancy formation. We also compare the temperature dependence of ΔSvib to that of the gas entropy, and show that the two largely counterbalance each other at high temperatures.

关键词： Entropy Hydrogen production Density functional theory

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Microwave sinterability of pure and CuO doped ZnO macroporous ceramic foams with deposited zinc oxide nanoparticles produced by bioinspired replica technique 18

Microwave sinterability of pure and CuO doped ZnO macroporou...

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18th International Conference on Microwave and High Frequency Applications, AMPERE 2021

作者： Cardoso, A.L.F. Maestrelli, S.C. Perdomo, C.P.F. Kiminami, R.H.G.A. Gunnewiek, R.F.K. Federal University of São Carlos Post Graduate Program in Materials Science and Engineering rod. Washington Luiz km 235 SP São Carlos13565-905 Brazil km 533 MG Poços de Caldas 37715-400 Brazil

Macroporous open-celled ceramic foams finds applications in numerous technological fields, like particle filters, insulating coatings, porous support for catalyst and photocatalyst processes, and even photoelectrochemical applications. In latter two, a macroporous open cell structure favors photoelectrochemical and photocatalyst reactions, due to its higher surface area. Many methods are used for producing these types of ceramics, specially the replica technique. In this simple method, the samples are obtained by impregnating a highly porous polymeric foam with a high solid loading ceramic slurry. After thermal treatment, the macroporous ceramic presents the structure of the polymeric foam used as template. Exceptionally complex and regular geometries can also be found in nature, which is the case of the Luffa sp sponge, that can replace the use of synthetic polymeric foams. In this work, microwave sinterability of porous ceramics obtained by impregnation of high solid loading ceramic slurries of nanostructured zinc oxide in natural Luffa sp fibrous sponges. Carboxymethyl cellulose (CMC), xanthan gum (XG) and polyvinyl alcohol (PVA) were assessed as binder agents. Ceramic slurries were prepared by dispersing nanostructured zinc oxide in distilled water (70% wt. ratio) using ammonium polyacrilate (APA) as deflocculant, followed by mixing in a high shear mixer (IKA Ultra-Turrax T25) for 10 minutes. After homogenization, binders were added and mixed in mechanical mixer for 10 minutes. The sponges (with dimensions of 2x2x1 cm) were carefully immersed in the ceramic slurry, squeezed to remove excess and then left to dry 24h in air. The dried ceramic foams were microwave heated at 550 °C during 10 minutes with 100 °C/min heating rate, followed by microwave sintering at 1150 and 1200 °C during 15 minutes with a 100 °C/min heating rate. The microwave sintered samples were analyzed by optical and scanning electron microscopy, photocatalysis efficiency and density measurement

关键词： Microwave heating

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Intrinsic Raman signatures of pristine hybrid perovskite CH3NH3PbI3 and its multiple stages of structure transformation 44

Intrinsic Raman signatures of pristine hybrid perovskite CH3...

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44th IEEE Photovoltaic Specialist Conference, PVSC 2017

作者： Chen, Qiong Liu, Henan Kim, Hui-Seon Liu, Yucheng Yang, Mengjin Yue, Naili Ren, Gang Zhu, Kai Liu, Shengzhong Frank Park, Nam-Gyu Zhang, Yong Department of Electrical and Computer Engineering Korea Republic of Optical Science and Engineering Graduate Program University of North Carolina at Charlotte CharlotteNC28223 United States School of Chemical Engineering and Department of Energy Science Sungkyunkwan University Suwon440-746 Korea Republic of Key Laboratory of Applied Surface and Colloid Chemistry National Ministry of EducationInstitute for Advanced Energy Materials School of Materials Science and Engineering Shaanxi Normal University Xi'an710062 China Chemical and Materials Science Center National Renewable Energy Laboratory GoldenCO80401 United States Molecular Foundry Lawrence Berkeley National Laboratory BerkeleyCA94720 United States

ISBN: (纸本)9781509056057

By performing spatially resolved Raman and photoluminescence spectroscopy with different illumination conditions, we have achieved a unified understanding towards the spectroscopy signatures of the organic-inorganic hybrid perovskite, transforming from the pristine state (CH3NH3PbI3 or MAPbI3) to fully degraded state (i.e., PbI2), for samples with varying crystalline domain size from mesoscopic scale to macroscopic size, synthesized by three different techniques. © 2017 IEEE.

关键词： Perovskite

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Resonant plasmon-exciton coupling in zinc oxide quantum well-aluminum nanodisc heterostructure arrays

Resonant plasmon-exciton coupling in zinc oxide quantum well...

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作者： Lawrie, Benjamin Kim, Kyeong-Won Norton, David Mu, Richard Haglund, Richard Interdisciplinary Graduate Program in Materials Science Vanderbilt University Nashville TN 37235 United States Department of Materials Science and Engineering University of Florida Gainesville FL 32611 United States Department of Physics Fisk University Nashville TN 37208 United States Department of Physics and Astronomy Vanderbilt University Nashville TN 37235 United States

The emergence of Fano resonances in the extinction spectra of arrays of aluminum nanodiscs 30-200 nm in diameter deposited on [Zn, Mg]O quantum wells provide the first evidence of strong coupling in zinc oxide heteros... 详细信息

ISBN: (纸本)9781557529107

关键词： Semiconductor quantum wells

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Heteromorphic Hematite Pigments Obtained from Steel Scrap and Encapsulated in Amorphous Silica for Porcelainized Stoneware

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材料科学与工程（中英文版） 2010年第5期4卷 1-13页

作者： Viviana Possamai Della Janaina Accordi Junkes Antonio Pedro Novaes de Oliveira Dachamir Hotza Federal Institute of Espirito Santo-IFES Graduate Program on Metallurgical and Materials Engineering-PROPEMM Vitoria29040-780 ES Brazil Federal University of Santa Catarina-UFSC Gradttate Program on Materials Science and Engineering-PGMA T Florian6polis88040-900 SC Brazil

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Molecular recognition by stable dispersion of gold nanoparticles modified with heterobifunctional poly (ethylene glycol)

Molecular recognition by stable dispersion of gold nanoparti...

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Transactions - 7th World Biomaterials Congress

作者： Aboshi, F. Takahashi, T. Ishii, T. Nagasaki, Y. Otsuka, Hidenori Kataoka, K. Pre-venture Program JST 4-1-8 Hon-machi Kawaguchi Saitama 332-0012 Japan Department of Materials Science Tokyo University of Science 2641 Yamazaki Noda Chiba 278-8510 Japan Department of Matereals Science Graduate School of Engineering University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan

ISBN: (纸本)1877040193

The stability of gold nanoparticles modified with heterobifunctional poly (ethylene glycol) (PEG) were investigated. An effective method for preparing hetero-bifunctional PEG by anionic ring-opening polymerization was also developed. Streptavidin-PEG gold nanoparticle showed extremely high response with biotinylated surface plasmon resonance (SPR) sensors. PEG-modified gold nanoparticles showed remarkable stability in physiological conditions, such as the solution of high ionic strength.

关键词： Nanostructured materials

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PH dependence of polypseudorotaxane formation between cationic linear polyethylenimine and cyclodextrins

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Macromolecules 2004年第18期37卷 6705-6710页

作者： Choi, Hak Soo Ooya, Tooru Lee, Sang Cheon Sasaki, Shintaro Kurisawa, Motoichi Uyama, Hiroshi Yui, Nobuhiko School of Materials Science Japan Adv. Inst. Sci. and Technol. 1-1 Asahidai Tatsunokuchi Ishikawa 923-1292 Japan Inst. of Bioeng. and Nanotechnology Singapore Science Park II #01-01/10 The Aries 117586 Singapore Department of Materials Chemistry Graduate School of Engineering Osaka University Suita Osaka 565-0871 Japan 21st Century COE Program Japan Adv. Inst. Sci. and Technol. 1-1 Asahidai Tatsunokuchi Ishikawa 923-1292 Japan

A series of linear polyethylenimines (LPEIs) with various molecular weights were synthesized and used for pH-dependent polypseudorotaxane formation with α- or γ-cyclodextrins (α-, γ-CDs). The polypseudorotaxane formation was significantly dependent on the pH of the aqueous media. The maximum yield of the recovered polypseudorotaxane precipitates was observed at pH 11.0, whereas no complexation was observed in the pH range below 8.0 due to the protonation of secondary amine groups in LPEI backbones. This suggests that the ionization of the secondary amine groups leads to dethreading of CD molecules because PEI chains with cationic nature disfavor the hydrophobic cavities of CDs. The solid-state 13C CP/MAS NMR and X-ray diffraction measurements verified the successful formation of crystalline polypseudorotaxanes through the inclusion complexation. In addition, 1H NMR analysis showed that LPEI formed a 2:1 inclusion complex with α-CD ([EI]:[α-CD] = 2:1) and a 4:1 complex with γ-CD ([EI]:[γ-CD] = 4:1) as reported in the poly(ethylene glycol)-based polypseudorotaxane system. Such unique pH-controllable polypseudorotaxane formation may be useful in designing many building blocks for stimuli-responsive polyrotaxanes.

关键词： Polyethylenes

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Cementing the grain boundary defects in the strain relaxed mixed Sn-Pb perovskite solar cells

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Chemical engineering Journal 2025年 516卷

作者： Kumar, Abhishek Ansari, Zeeshan Alam Hanmandlu, Chintam Banerjee, Soumallya Chen, Yu-Te Yang, Po-Yu Musa, Ahmed Fouad You, Yun-Wen Pao, Chun-Wei Wei, Tzu-Chien Shyue, Jing-Jong Lu, Yu-Jung Chu, Chih-Wei Department of Physics National Taiwan University Sec. 4 Roosevelt Road Taipei106 Taiwan Research Center for Applied Sciences Academia Sinica 128 Academia Road Section 2 Taipei Nangang11529 Taiwan Nano-Science and Technology Program Taiwan International Graduate Program Academia Sinica Taipei106 Taiwan Department of Materials Science and Engineering National Yang Ming Chiao Tung University Hsinchu300 Taiwan Department of Chemical Engineering National Tsing Hua University 101 Section 2 Kuang-Fu Road Hsinchu City300044 Taiwan College of Engineering Center for Green Technology Chang Gung University Taoyuan City333002 Taiwan Department of Photonics National Yang Ming Chiao Tung University Hsinchu City30010 Taiwan Institute of Applied Mechanics National Taiwan University Sec. 4 Roosevelt Road Taipei106 Taiwan

Mixed Tin-lead (Sn-Pb) perovskite solar cells (PSCs) offer a promising avenue for achieving high power conversion efficiencies (PCEs) due to their narrow bandgaps and substantial optical absorption in the visible–near-infrared region. However, the disparated reaction kinetics of PbI2 and SnI2 with organic salts, resulting in an uneven spatial distribution of Sn2+ and Pb2+ within the perovskite lattice, inducing micro-strain in the film and a Sn-rich surface vulnerable to oxidation-Sn2+ to Sn4+, thereby elevating nonradiative recombination. Here, we report the incorporation of 2,5-Dibromo-3,4-pyridinediamine (DBPDA) as an additive in the mixed Sn-Pb perovskite precursor solution, designed to mitigate micro-strain formation, reduce defect density by suppressing Sn4+ formation, and enhance the passivation of undercoordinated Sn/Pb species through synergistic bonding interaction. The best performing PSCs achieved an impressive PCE of 21.24 % with a high open circuit voltage (Voc) of 0.85 V, alongside significantly improved long-term stability, retaining near 80 % of their initial PCE after 1,008 h in a nitrogen-filled glovebox without encapsulation. In contrast, the control devices retained only 18 % of their initial efficiency under identical conditions. Additionally, an enhanced field effect hole mobility, increasing from 0.18 cm2/V-s in the control film to 1.43 cm2/V-s in the target film, was achieved in mixed Sn-Pb perovskite thin film transistors (TFTs) using these films as active layers. These findings present a viable strategy for strain-relieved perovskite films, enabling stable and high-performance mixed Sn-Pb PSCs and TFTs. © 2025 Elsevier B.V.

关键词： Crystallization kinetics

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Ultrahigh zT from strong electron-phonon interactions and a low-dimensional Fermi surface

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Energy and Environmental science 2024年第5期17卷 1904-1915页

作者： Ranganayakulu, V.K. Wang, Te-Hsien Chen, Cheng-Lung Huang, Angus Ma, Ma-Hsuan Wu, Chun-Min Tsai, Wei-Han Hung, Tsu-Lien Ou, Min-Nan Jeng, Horng-Tay Lee, Chih-Hao Chen, Kuei-Hsien Li, Wen-Hsien Brod, Madison K. Snyder, G. Jeffrey Chen, Yang-Yuan Institute of Physics Academia Sinica Taipei11529 Taiwan Department of Engineering and System Science National Tsing Hua University Hsinchu30013 Taiwan Taiwan International Graduate Program Taipei11529 Taiwan Department of Physics National Chung Hsing University Taichung City40227 Taiwan Graduate School of Materials Science National Yunlin University of Science and Technology Yunlin64002 Taiwan Bachelor Program in Semiconductor Materials and Fabrication Ming Chi University of Technology New Taipei City243303 Taiwan Department of Physics National Tsing Hua University Hsinchu30013 Taiwan Center for Theory and Computation National Tsing Hua University Hsinchu30013 Taiwan Physics Division National Center for Theoretical Sciences Taipei10617 Taiwan Department of Physics National Central University Jhongli32001 Taiwan National Synchrotron Radiation Research Center Hsinchu Science Park Hsinchu30076 Taiwan Institute of Atomic and Molecular Sciences Academia Sinica Taipei10617 Taiwan Department of Materials Science and Engineering Northwestern University EvanstonIL60208 United States Graduate Institute of Applied Physics National Chengchi University Taipei11605 Taiwan

The outstanding thermoelectric performance of GeTe has attracted significant attention in the research community in recent years. However, many of the underlying physical mechanisms that contribute to GeTe's exceptionally high figure of merit (zT) remain not fully understood. In this study, an Sb-Bi codoped GeTe single crystal (Ge0.86Sb0.08Bi0.06)Te with an ultrahigh zT of 2.7 at 700 K and a record high device zT of 1.41 in the temperature range of 300-773 K was synthesized and investigated. The ultrahigh zT is attributed to the extremely low lattice thermal conductivity induced by strong electron-phonon (EP) interactions as revealed by the experimentally observed Kohn anomaly, through inelastic neutron scattering (INS) measurements. First-principles calculations further demonstrate that the remarkable EP interaction arises from the Fermi surface nesting featured in a one-dimensional (double-walled) topology. Our finding unravels the ultrahigh-zT mechanism in GeTe-based materials, serving as an inspiring guide toward high thermoelectric performance. © 2024 The Royal Society of Chemistry.

关键词： Neutron scattering

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