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SSRN 2024年

作者： Dos Santos, Leonardo Leandro Do Nascimento, Rubens Maribondo Castellã Pergher, Sibele berenice Department of Chemistry Federal University of Rio Grande do Norte Natal59078970 Brazil Postgraduate Program in Materials Science and Engineering Federal University of Rio Grande do Norte Natal59078970 Brazil

This study presents a novel approach to extract lithium from beta-spodumene and synthe- size LTA-type zeolite as a by-product, with no organic solvents or calcination. The process involves solubilization with sodium salts and the recycling of the mother liquor, with lithium content quantified via atomic absorption spectroscopy (AAS) from the supernatant. Syn- thesis conditions were carefully optimized to achieve the concurrent synthesis of LTA-type zeolite, denoted as LPM-15, characterized by cubic morphology and spherical facets. Com- putational simulations using density functional theory (DFT) were employed to investigate the impact of cation exchange processes (Na+/Al3+, NH4+/Al3+, and Ca2+/Al3+) on the stability of the LPM-15 structure and molecular diffusion within its zeolitic pores. Addi- tionally, the mobility of cations within the LPM-15 was assessed through cation exchange capacity (CEC) measurements. This comprehensive approach elucidates the fundamental mechanisms underlying LTA zeolite synthesis and provides valuable insights into potential applications, particularly in water purification. © 2024, The Authors. All rights reserved.

关键词： Density functional theory

Increased corrosion resistance of steel substrates coated with epoxy resin/ZnO/Fe 2 O 3 obtained from electric arc furnace dust recovery

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Journal of materials Research and Technology 2025年 36卷 9462-9472页

作者： Mário Andrean Macedo Castro Tanara Caroline Nunes Nicácio Antonio Carlos do Nascimento Santos José Eudes Lima Santos Luis David Loor-Urgilés Antonio Eduardo Martinelli Fabiana Villela da Motta Mauricio bomio LSQM–Laboratory of Chemical Synthesis of Materials Department of Materials Engineering Federal University of Rio Grande do Norte – UFRN P.O. Box 1524 Natal RN Brazil Institute of Chemistry Federal University of Rio Grande do Norte 59078-970 Natal RN Brazil Postgraduate Program in Materials Science and Engineering Federal University of Rio Grande do Norte 59078-900 Natal RN Brazil

The sustainable management of metal-rich industrial wastes, such as electric arc furnace dust (EAFD), remains a critical challenge for the steel industry. Although previous studies have investigated metal recovery routes and their application in functional materials, few have explored the reuse of these wastes as active components in anticorrosive coatings. This work proposes an innovative approach for valorizing EAFD, recovering iron (Fe 2 O 3 ) and zinc (ZnO) oxides through acid leaching, basic precipitation, and heat treatment. After recovery, mixed ZnO/Fe 2 O 3 oxides were prepared in different proportions and incorporated as nanofillers in an epoxy matrix, creating a hybrid coating aimed at protecting carbon steel against corrosion. The obtained materials were characterized by XRF, XRD, FTIR, SEM, and bET analysis, while the mechanical and anticorrosive properties were evaluated by Vickers hardness tests, Potentiodynamic Polarization and Electrochemical Impedance Spectroscopy. After 240 h of immersion in saline solution and 360 h of Salt-spray test, the coating with the highest Fe 2 O 3 content demonstrated superior performance, reducing the corrosion rate by up to 100 times and increasing the load transfer resistance by up to 80 times. The contribution of this study lies in both the proposal of a new cycle for reusing steel waste and in demonstrating a viable route for developing high-performance anticorrosive coatings with potential for industrial application in sectors such as oil and gas. The combination of waste recovery and functional improvement of the material positions this study as a technologically and environmentally relevant solution.

关键词： EAFD ZnO Fe 2 O 3 Epoxy resin Anti-corrosive coatings

Alkali-Aggregate Reaction and its Mineral Reactive Phases Contribution to the Microstructural Consolidation of Portland Cement and Geopolymeric Mortars with Metakaolin-based Precursors

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SSRN 2023年

作者： Valenga, Matheus Villian de Lima, Rubia Catarina Przybysz Pereira, Elias Pereira, Eduardo Farias, Marcelo Miranda Pianaro, Sidnei Antonio State University of Ponta Grossa Postgraduate Program in Engineering and Materials Science Carlos Cavalcanti Avenue 4748 Uvaranas Paraná Ponta GrossaCEP: 84030-900 Brazil

HIGHLIGHTS Metakaolin-based geopolymeric mortars are not negatively affected by *** aggregates contribute to geopolymer matrix consolidation and *** cement partial replacement by metakaolin reduces AAR effects in *** ... 详细信息

关键词： Mortar

Facile Synthesis, Structure and battery-Type behavior of Graphene Oxides

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SSRN 2023年

作者： Silva, Jullyani M.D. Fenandes, Filipe P.M. Silva, Mariana de O. Maraschin, Thuany G. Ferreira, Luciena S. Macedo, Daniel A. da Silva, Lucineide b. Fim, Fabiana de C. Materials Science and Engineering Postgraduate Program UFPB João Pessoa58051-900 Brazil Department of Materials Engineering UFPB Paraíba João Pessoa58051-900 Brazil RS Porto Alegre90619-900 Brazil

Graphene oxide (GO) is one of the main precursors for the production of graphene and other graphene-based materials. In this work, we report a simple, safe and fast synthesis method for obtaining graphene oxide as a functional material for battery-type electrodes. The method provides to obtain an aqueous solution of graphene oxide suitable for drying by freeze-drying (sample GO1). Washing and freeze-drying processes are performed to assess their effects on the exfoliation and removal of functional groups from the graphene sheets (sample GO2). GO1 sample consists of a stack of 10 oxidized graphene layers without any additional exfoliation process, while the GO2 sample has 8 stacked layers, after two washing and freeze-drying processes. FTIR results indicate that bulkier groups such as carboxylic acid are most likely to be found on the edges and surfaces of the graphene sheets of both samples. The presence of point defects such as vacancies was also observed in both samples, with the GO2 sample having a higher content of vacancies. The electrochemical performance of graphene oxide-based electrodes, classified as battery-type, indicate an improved specific capacity of 10.15 C g-1 for GO1 against 4.55 C g-1 for GO2 at a specific current of 0.5 A g-1. This superior battery-type behavior of the GO1 electrode, also confirmed by electrochemical impedance spectroscopy, is most likely due to a higher degree of oxygenated groups on its surface, as shown by EDS and FTIR studies. © 2023, The Authors. All rights reserved.

关键词： Washing

Thermo-optical properties of erbium-doped germanate-bismuth glasses

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Optical materials 2025年 166卷

作者： Silva, Adriano Almeida Lima, Lucas batista Silva da Silva, Isis Lee Garcia, Hans Anderson bell, Maria José Valenzuela Kassab, Luciana Reyes Pires Santos, Francisco Eroni Paz Postgraduate Program in Physics Federal University of Piauí PI 64049550 Brazil Department of Physics Federal University of Juiz de Fora MG Juiz de Fora36036-900 Brazil Faculdade de Tecnologia São Paulo CEETEPS SP São Paulo01124060 Brazil Postgraduate Program in Engineering and Materials Science Federal University of Teresina PI 64049550 Brazil

In this study, we investigate the thermo-optical properties of GeO2–bi2O3 glasses doped with different concentrations of rare earth ions by thermal lens technique;UV-VIS and photoluminescence (PL) spectroscopy, as well as measurements of thermal diffusivity, thermal conductivity and quantum efficiency, are presented aiming at potential photonic applications. High infrared fluorescence lifetimes around 4 ms and quantum efficiencies of ∼80 % for 1 % Er3+ concentration, determined via lifetime and thermal lens methods, enabled efficient laser operation. Positive ds/dT values confirmed the self-focusing nature beneficial for high-power systems. While quantum efficiencies decreased exponentially with rising Er3+ due to non-radiative relaxation from erbium-matrix interactions, reasonably high efficiencies above 74 % persisted at 1 % doping. The thermal diffusivity and conductivity exhibited little changes with varying Er3+ concentration and showed to be matrix dependent. © 2025 Elsevier b.V.

关键词： Quantum efficiency

Utilization of Pineapple Crown Fiber and Recycled Polypropylene for Production of Sustainable Composites

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Journal of Renewable materials 2020年第10期8卷 1327-1341页

作者： Alexandra Augusta Reichert Mariana Ribas de Sá Gabriela Escobar Hochmuller da Silva Cesar Augusto Gonçalves beatrice AndréRicardo Fajardo Amanda Dantas de Oliveira Postgraduate Program in Materials Science and Engineering(PPGCEM) Federal University of Pelotas(UFPel)Pelotas96075-630Brazil Technology Development Center(CDTec) Materials EngineeringFederal University of Pelotas(UFPel)Pelotas96075-630Brazil Postgraduate Program in Materials Science and Engineering(PPGCEM) Federal University of São Carlos(UFSCar)São Carlos13565-905Brazil Laboratory of Technology and Development of Composites and Polymeric Materials Federal University of Pelotas(UFPel)Pelotas96010-900Brazil

Nowadays,the production of consumer goods is based on the use of non-renewable raw materials,which in recent years has been performing as a problem for the *** the large number of available biofibers in nature,their use in the development of polymeric composites has inevitably emerged,it is also necessary to take into account the countless discarded plastics that still have the potential to be *** this work,fibers were extracted from pineapple crown residues and utilized to compose sustainable composites using recycled polypropylene from cups discarded in the trash as a ***,it is known that for good performance,it is necessary to achieve a good chemical interaction between the fiber and the *** order to improve this interaction,alkaline mercerization treatment was carried out on the surface of the fibers removing some components incompatible with the *** this work,the effect of the mercerization treatment on the properties of the fibers was studied,as well as their interaction with the *** effect of fiber concentration on the mechanical and thermal properties of composites was also *** of 5 and 7 wt%were used for both natural and mercerized fibers.A decrease in the number of degradation stages was observed through thermogravimetry analyses(from four in natural fiber to two in mercerized fibers),showing that the mercerization performed on the fibers was *** increase in the degree of crystallinity of mercerized fibers was also observed through the results of X-ray *** techniques indicate that amorphous compounds,such as hemicellulose and lignin,were partially *** the tensile test,it could be noted that all composites presented higher values of de elastic modulus than recycled polypropylene without added load;however,there were no differences in the elastic modulus between the different types of fibers and load ***,it is interesting to use fibers as r

关键词： Recycling composites polypropylene biofibers pineapple crown

Novel spent bleaching earth industrial waste as low-cost ceramic membranes material: elaboration and characterization

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materials Today: Proceedings 2023年 87卷 136-140页

作者： Rahma A. Elma M. Roil bilad M. Isnasyauqiah Rahman Wahid A. Sirajul Huda M. Resa Lamandau D. Doctoral Program of Environemntal Science Postgraduate Program Lambung Mangkurat University Jl Brigjen H. Hasan Basri Kayutangi South Kalimantan Banjarmasin 70123 Indonesia Materials and Membranes Research Group (M2ReG) Lambung Mangkurat University Jl A. Yani Km 36 South Kalimantan Banajrbaru 70714 Indonesia Chemical Engineering Department Engineering Faculty Lambung Mangkurat University Jl A. Yani Km 36 South Kalimantan Banajrbaru 70714 Indonesia Faculty of Integrated Technologies Universiti Brunei Darussalam Gedung BE1410 Brunei Darussalam

Ceramic membrane support derived from spent bleaching earth (SbE) become a novel study due to their low-cost, sustainable features, abundance material, and there is not yet applicated as membrane. In this study, flat disk ceramic membrane configuration was fabricated and characterized from solid waste of crude palm oil bleaching process by pressing method in different SbE loading mass (38–42 %wt.). The SbE as raw material was deoiled using n-hexane and acetone solvent, followed by fabricated it become flat disk SbE membranes. Afterward, the SbE flat disk membranes was characterized through fourier-transform infrared spectroscopy (FTIR) and X-ray fluorescence (XRF) analyzer. The result exhibits the flat disk SbE ceramic membrane has dimension of 41 and 6 mm for diameter and thickness, respectively. SbE membranes indicating have montmorillonite structure due to presence of silica as main component materials of SbE. besides that, the existence of siloxane vibration band in SbE membranes for the sample after regeneration with n-hexane and acetone were dominated over using raw SbE. It concludes the oil residue was removed and produced SbE membrane properties become robust with less organic contaminant. © 2023

关键词： Ceramic membrane CPO Pressing method SbE Support

Influence of Treatment Time on the Synthesis of Copper Oxide Films by Cathode Cage Plasma Deposition

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SSRN 2023年

作者： de Carvalho, Júlio F.S. Monção, Renan M. de Sousa, Ediones M. da Luz Lima, Cleânio Costa, Carla L.S.C. Garcia, Ramón R.P. Feitor, Michelle C. de Carvalho Costa, Thércio H. Libório, Maxwell S. de Sousa, Rômulo R.M. Federal University of Piauí Graduate Program in Materials Science and Engineering PI Teresina Brazil Federal University of Piauí Physics Postgraduate Program PI Teresina Brazil Federal university of Rio Grande do Norte Department of Materials Science and Engineering RN Natal Brazil Federal University of Rio Grande do Norte Department of Mechanical Engineering RN Natal Brazil Federal university of Rio Grande do Norte School of Science and Technology RN Natal Brazil

Copper oxide is a valuable p-type semiconductor for photovoltaic applications. In this work, plasma deposition with cathodic cage (CCPD) of copper oxide (CuO+Cu2O) films on glass was performed to evaluate the microstructural, morphological, chemical, and bandgap changes as a function of the treatment time variation (2, 3, 4, and 5 hours). The samples were analyzed by Scanning Electron Microscopy (SEM), Energy Dispersive System (EDS), X-ray Diffraction (XRD), and Raman Spectroscopy to identify morphologies, chemical composition, and crystalline phases of the deposited films, and the absorption spectrum optics was used to calculate the bandgap width. All films showed bandgap energies around 2.60 eV. However, the sample treated with a time of 3h presented a compact coating with 1.46 µm of thickness and bandgap energy equal to 2.57 eV, being the best result. © 2023, The Authors. All rights reserved.

关键词： Energy gap

Tecnological Tests of the Pegamites Residues Extraction at Alto Dois Irmãos/Pb in borborema Pegmatitic Province/bpp

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SSRN 2023年

作者： Silva, Gerson Ferreira de brum, Irineu Cordeiro, Vinícius becheleni, Emily Araújo, Defsson Federal University of Rio Grande do Sul – UFRGS Postgraduate Program in Mining Engineering Metallurgical and of Materials Brazil Federal University of Rio Grande do Sul – UFRGS Department of Metallurgical Engineering Postgraduate Program in Mining Engineering Metallurgical and Materials Brazil Federal University of Campina Grande – UFCG Academic Unity of Mining and Geology Brazil Federal University of Vales do Jequitinhonha e Mucuri – UFVJM Engineering Institute Science and Technology Brazil Federal University of Campina Grande – IFPB Federal Institute of Science Education and Technology of Paraíba Campus Picuí Brazil

The borborema Pegmatitic Province – bPP situated between Paraiba and Rio Grande do Norte states in brazilian northeast presents several pegmatites occurrences. In the region of the county of Pedra Lavrada – Pb, are observed various mineral occurrences where the pegmatites have been explored with prominence at Alto Dois Irmãos-Pb pegmatite, in what quartz, feldspar and mica are extracted. because an existence of a complex mineralogy of the pegmatites, the understanding about mineral constituent is fundamental to define its industrial employment and also to implement improvements in beneficiation process. The proposal of this research line is the detailed characterization and proof that part of the ore (quartz) considered sterile, presents low poisoning (Fe2O3) and high silica (SiO2) content, to enable its industrial use mainly to nobler purposes. Also will be fundamental to minimize the environmental impact and decrease the grinding energetic consume. besides that, the obtained results of this research will be used in a future work, as inputs in simulation stage, aiming to optimize the researched beneficiation unity grinding process. To the pegmatite characterization were done density determination tests, mineralogical identification by X-ray diffraction (XRD), chemical analysis by fluorescents X-rays and morphological analysis by scanning electron microscopy (SEM/EDS). Then were done tests to Work Index (WI) calculous. The sterile (quartz extraction) from pegmatite mining in Pedra Lavrada/Pb presented medium density of 2,66g/cm3, majority chemical composition of silicon and oxygen and quartz as the mainly mineralogical stage, through X-ray diffractograms and scanning electron microscopy images, what indicates that this material has high purity. The Work Index (WI) was 15,9 kwh/t, showing that this material presents in the pegmatite can be consider resistant to breaking in grinding process. © 2023, The Authors. All rights reserved.

关键词： Quartz

High fluorescent carbon dots/Ag as a sensitive sensor for tetracycline waste in aqueous solution 10

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High fluorescent carbon dots/Ag as a sensitive sensor for te...

10th International Seminar on New Paradigm and Innovation of Natural sciences and itsApplication, ISNPINSA 2020

作者： Alkian, I. Sutanto, H. Hadiyanto, H. Hidayanto, E. Hapsari, H.P. Wibowo, A.A. Syahida, A.N. Irianti, F.D.D. Master Program of Environmental Science School of Postgraduate Studies Diponegoro University Semarang Indonesia Departemen of Physics Faculty of Science and Mathematics Diponegoro University Semarang Indonesia Departemen of Chemical Engineering Faculty of Engineering Diponegoro University Semarang Indonesia Smart Materials Research Center Laboratory Diponegoro University Semarang Indonesia

Currently, antibiotics waste produced by hospitals and pharmacies is increasing, increasing demand and public consumption. Tetracyclines are a popular type of antibiotic that can pollute the environment even in low concentrations. This study aimed to detect tetracyclines in an aqueous environment using C-dots/Ag. C-dots material was synthesized by microwave radiation method with the addition of Ag 0-4 %. C-dots/Ag is produced in the form of a brown-black powder that glows green. FTIR testing shows that C-dots/Ag contains various functional groups O-H, N-H, C-H, C=O, and C=C. The surface morphology of the C-dots based on SEM testing is round and rough. Ag's addition causes C-dots' surface morphology to agglomerate, shifting the C-dots' absorbance peaks towards a larger wavelength and decreasing the energy bandgap. C-dots/Ag 2% has the best optical properties based on the intensity of the resulting fluency. In general, C-dots/Ag has excellent potential to be a susceptible, selective, and effective tetracycline detection agent. © Published under licence by IOP Publishing Ltd.

关键词： Surface morphology