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Kim SK, Koo YJ, Kim HS, Lee JK, Jeong K, Lee Y, Jung EY. Fabrication and Characterization of Al 2O 3-Siloxane Composite Thermal Pads for Thermal Interface Materials. MATERIALS (BASEL, SWITZERLAND) 2024; 17:914. [PMID: 38399165 PMCID: PMC10889976 DOI: 10.3390/ma17040914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 02/10/2024] [Accepted: 02/12/2024] [Indexed: 02/25/2024]
Abstract
In this study, Al2O3-siloxane composite thermal pads were fabricated using a tape-casting technique, and the thermal conductivity effect of the Al2O3 nanoparticle powder synthesized using a flame fusion process on siloxane composite thermal pads was investigated. Furthermore, various case studies were implemented, wherein the synthesized Al2O3 nanoparticle powder was subjected to different surface treatments, including dehydration, decarbonization, and silylation, to obtain Al2O3-siloxane composite thermal pads with high thermal conductivity. The experimental results confirmed that the thermal conductivity of the Al2O3-siloxane composite pads improved when fabricated using surface-treated Al2O3 nanoparticle powder synthesized with an optimally spheroidized crystal structure compared to that produced using non-treated Al2O3 nanoparticle powder. Therefore, this study provides guidelines for fabricating Al2O3-siloxane composite thermal pads with high thermal conductivity in the field of thermal interface materials.
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Affiliation(s)
- Seul-Ki Kim
- Semiconductor Materials Center, Korea Institute of Ceramic Engineering & and Technology, Jinju 52851, Republic of Korea; (S.-K.K.); (Y.-J.K.)
- Department of Materials Engineering, Gyeongsang National University, Jinju 52828, Republic of Korea
| | - Yeong-Jin Koo
- Semiconductor Materials Center, Korea Institute of Ceramic Engineering & and Technology, Jinju 52851, Republic of Korea; (S.-K.K.); (Y.-J.K.)
| | - Hyun Sik Kim
- Analysis and Standards Center, Korea Institute of Ceramic Engineering and Technology, Jinju 52851, Republic of Korea;
| | - Jong-Keun Lee
- Daehan Ceramics Co., Ltd., Yeongam-gun 58452, Republic of Korea; (J.-K.L.); (K.J.)
| | - Kyounghoon Jeong
- Daehan Ceramics Co., Ltd., Yeongam-gun 58452, Republic of Korea; (J.-K.L.); (K.J.)
- Department of Materials Science and Engineering, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Younki Lee
- Department of Materials Engineering and Convergence Technology, Gyeongsang National University, Jinju 52828, Republic of Korea
| | - Eun Young Jung
- The Institute of Electronic Technology, College of IT Engineering, Kyungpook National University, Daegu 41566, Republic of Korea
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Saffarionpour S, Diosady LL. Preparation and characterization of an iron-β-cyclodextrin inclusion complex: factors influencing the host-guest interaction. Food Funct 2023. [PMID: 37161593 DOI: 10.1039/d3fo00090g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Cyclodextrins have received attention recently due to their superior binding with countless hydrophobic molecules. The host-guest interaction between the cyclodextrin cavity and the hydrophobic component not only facilitates the formation of a strong inclusion complex (IC), but also improves its stability against thermal degradation. The functionality of cyclodextrins for the delivery of hydrophilic components is less explored in comparison. This study discusses the application of β-cyclodextrin (βCD) for the delivery of highly bioavailable and hydrophilic iron, ferric sodium EDTA, which exhibits great functionality in the presence of polyphenols and phytates with potential application in food fortification. The formation of IC was dependent on the cyclodextrin amount and alcoholic co-solvent and was influenced by the stirring duration. For ferric sodium EDTA, the highest inclusion rate (IR) of ∼77% was obtained after 72 hours of mixing in 25.4% (v/v) alcohol at a ratio of iron : βCD of 1 : 6. A higher IR (∼96%) was obtained after 6 hours of stirring with less soluble ferrous ammonium phosphate in comparison. The melting temperature (Tm) of the ferrous ammonium phosphate complex increased from ∼172 to ∼294 °C. The high IR and enhanced thermal resistance of the complex make βCDs potential carriers for ferrous ammonium phosphate delivery and fortification of foods processed at high temperatures.
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Affiliation(s)
- Shima Saffarionpour
- University of Toronto, Department of Chemical Engineering and Applied Chemistry, Toronto, Ontario, Canada.
| | - Levente L Diosady
- University of Toronto, Department of Chemical Engineering and Applied Chemistry, Toronto, Ontario, Canada.
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Huld S, McMahon S, Sjöberg S, Huang P, Neubeck A. Chemical Gardens Mimic Electron Paramagnetic Resonance Spectra and Morphology of Biogenic Mn Oxides. ASTROBIOLOGY 2023; 23:24-32. [PMID: 36450112 PMCID: PMC9810355 DOI: 10.1089/ast.2021.0194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 08/01/2022] [Indexed: 06/17/2023]
Abstract
Manganese (Mn) oxides are ubiquitous in nature and occur as both biological and abiotic minerals, but empirically distinguishing between the two remains a problem. Recently, electron paramagnetic resonance (EPR) spectroscopy has been proposed for this purpose. It has been reported that biogenic Mn oxides display a characteristic narrow linewidth in contrast to their pure abiotic counterparts, which is explained in part by the large number of cation vacancies that form within the layers of biogenic Mn oxides. It was, therefore, proposed that natural samples that display a narrow EPR linewidth, ΔHpp < 580G, could be assigned to a biogenic origin. However, in poorly crystalline or amorphous solids, both dipolar broadening and exchange narrowing simultaneously determine the linewidth. Considering that the spectral linewidth is governed by several mechanisms, this approach might be questioned. In this study, we report synthetic chemical garden Mn oxide biomorphs that exhibit both morphologically life-like structures and narrow EPR linewidths, suggesting that a narrow EPR line may be unsuitable as reliable evidence in assessment of biogenicity.
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Affiliation(s)
- Sigrid Huld
- Department of Earth Sciences, Uppsala University, Uppsala, Sweden
| | - Sean McMahon
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Susanne Sjöberg
- Department of Geological Sciences, Stockholm University, Stockholm, Sweden
| | - Ping Huang
- Department of Chemistry, Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - Anna Neubeck
- Department of Earth Sciences, Uppsala University, Uppsala, Sweden
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Yuan T, Hashimoto K, Tazaki A, Hasegawa M, Kurniasari F, Ohta C, Aoki M, Ohgami N, Kato M. Potential application of a hydrotalcite-like compound for reduction of toxicity to aquatic organisms via rapid and efficient removal of hydrogen sulfide. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 321:115861. [PMID: 36050136 DOI: 10.1016/j.jenvman.2022.115861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 07/20/2022] [Accepted: 07/23/2022] [Indexed: 06/15/2023]
Abstract
Hydrogen sulfide (H2S) is known to have wide ranging toxicities not only as a gas but also as dissolved forms in aquatic environments. The diversity of aquatic organisms can be severely affected by hydrogen sulfide at very low concentrations, indicating the urgent necessity to develop an efficient method for removal of hydrogen sulfide in water. In this study, the removal capacity for hydrogen sulfide of our originally developed hydrotalcite-like compound composed of magnesium and iron (MF-HT) was investigated and its potential application for reduction of toxicity to aquatic organisms was evaluated. The MF-HT experimentally showed a high adsorption capacity of 146.5 mg/g with a fast adsorption equilibrium time of 45 min, both of which are top-class compared with those of other adsorbents previously reported. In fact, removal of hydrogen sulfide (1.2-152.5 mg/L) at an average rate of >97.6% was achieved in groundwater samples (n = 16) by the MF-HT within 60 min. The toxicities of groundwater, indicated by inhibition rate for microalgae (primary producers) and immobilization rate for crustaceans (secondary consumers), were reduced by 96.1% and 82.5% in 2-fold and 4-fold diluted groundwater, respectively, after treatment with the MF-HT for 60 min. These results indicate that MF-HT has an excellent safety record for aquatic organisms. After clarifying the adsorption mechanism, excellent reusability of MF-HT was also confirmed after regeneration using 1 M Na2CO3 solution. Considering the efficacy, speed, safety and cost of MF-HT, it could be a novel promising material for solving the problem of hydrogen sulfide pollution in the hydrosphere.
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Affiliation(s)
- Tian Yuan
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan; Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan
| | - Kazunori Hashimoto
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan; Department of Molecular Biology, Faculty of Pharmacy, Meijo University, Nagoya, Aichi, Japan; Voluntary Body for International Healthcare in Universities, Nagoya, Aichi, Japan
| | - Akira Tazaki
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan; Voluntary Body for International Healthcare in Universities, Nagoya, Aichi, Japan
| | - Masahiro Hasegawa
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan
| | - Fitri Kurniasari
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan; Voluntary Body for International Healthcare in Universities, Nagoya, Aichi, Japan
| | - Chihiro Ohta
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan
| | - Masayo Aoki
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan; Voluntary Body for International Healthcare in Universities, Nagoya, Aichi, Japan
| | - Nobutaka Ohgami
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan; Voluntary Body for International Healthcare in Universities, Nagoya, Aichi, Japan
| | - Masashi Kato
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan; Voluntary Body for International Healthcare in Universities, Nagoya, Aichi, Japan.
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Development, Synthesis and Characterization of Tannin/Bentonite-Derived Biochar for Water and Wastewater Treatment from Methylene Blue. WATER 2022. [DOI: 10.3390/w14152407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Novel hybrid carbon–mineral materials were synthesized by the mechanochemical activation of a mixture of tannin and bentonite in a ball mill with further pyrolysis in an argon atmosphere at 800 °C. The influence of the initial mixture ingredients content on the structural, textural, and thermal characteristics of biochars has been described using X-ray diffraction, Raman and Fourier-transform infrared spectroscopy, nitrogen adsorption–desorption, and scanning electron microscopy. The influence of bentonite clay on the carbon phase characteristics due to the formation of more heat-resistant and structured nanocarbon particles in biochars has been proven. The adsorption effectiveness of the materials towards methylene blue was studied. The adsorption data were analyzed applying Langmuir and Freundlich isotherms with high determination coefficients (R2) in the range of 0.983–0.999 (Langmuir) and 0.783–0.957 (Freundlich). The maximum adsorption amount of MB was 5.78 mg/g. The adsorption efficiency of biochars with respect to phenol was also examined. It was shown that the hybrid biochars show differentiated selectivity to the adsorption of organic compounds. It was concluded that the physicochemical properties of the surface of biochars play an important role in the adsorption effectiveness, making them a good candidate for water and wastewater remediation processes.
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Indicator Minerals, Pathfinder Elements, and Portable Analytical Instruments in Mineral Exploration Studies. MINERALS 2022. [DOI: 10.3390/min12040394] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Until recently, the classic approach to mineral exploration studies was to bring the field samples/drill cores collected during field studies to the laboratory, followed by laborious analysis procedures to generate the analytical data. This is very expensive, time-consuming, and difficult for exploring vast areas. However, rapid technological advances in field-portable analytical instruments, such as portable visible and near-infrared spectrophotometers, gamma-ray spectrometer, pXRF, pXRD, pLIBS, and µRaman spectrometer, have changed this scenario completely and increased their on-site applications in mineral exploration studies. LED fluorimeter is a potential portable tool in the hydrogeochemical prospecting studies of uranium. These instruments are currently providing direct, rapid, on-site, real-time, non-destructive, cost-effective identification, and determination of target elements, indicator minerals and pathfinder elements in rock, ore, soil, sediment, and water samples. These portable analytical instruments are currently helping to obtain accurate chemical and mineralogical information directly in the field with minimal or no sample preparation and providing decision-making support during fieldwork, as well as during drilling operations in several successful mineral exploration programs. In this article, the developments in these portable devices, and their contributions in the platinum group elements (PGE), rare earth elements (REE), gold, base metals, and lithium exploration studies both on land and on the ocean bed, have been summarized with examples.
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Potassic-Hastingsite from the Kedrovy District (East Siberia, Russia): Petrographic Description, Crystal Chemistry, Spectroscopy, and Thermal Behavior. MINERALS 2021. [DOI: 10.3390/min11101049] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In this work we report on a petrographic, crystal-chemical, and optical characterization, obtained from different analytical methods, of amphibole species. Potassic-hastingsite, ideally AKBCa2C(Fe2+4Fe3+)T(Si6Al2)O22W(OH)2, has been found in the Kedrovy district (East Siberia, Russia). The sample occurs as well-formed and large radially radiant aggregates of dark green, almost black crystals. The unit cell dimensions are a = 9.9724(3) Å, b = 18.2968(4) Å, c = 5.3573(1) Å, β = 104.945(3)°, V = 944.44(4) Å3, Z = 2. Site populations were determined by combining single-crystal structure refinement and electron probe microanalysis, and Fe3+/Fe2+ ratio was obtained from X-ray fluorescence analysis. Infrared, diffuse light UV/Vis/NIR absorption, and electron spin resonance spectra are presented and discussed. A thermoelastic behavior of a powder of potassic-hastingsite was studied by in situ high-temperature X-ray diffraction. A thermal expansion and subsequent significant contraction in the unit cell volume during a high-temperature X-ray powder diffraction experiment is observed as a consequence of the deprotonation process, which is locally balanced via oxidation of Fe2+. According to the data obtained for potassic-hastingsite, these processes occur within 400–600 °C. The thermal expansion of the mineral is anisotropic; the thermal expansivity coefficients αa:αb:αc (×10−6) = −18.06:9.59:−1.09 at 400 °C, −26.15:−1.52:2.22 at 600 °C and 23.77:−25.06:42.08 at 750 °C.
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Adsorption of Nickel(II) Ions from Synthetic Wastewater Using Activated Carbon Prepared from Mespilus germanica Leaf. ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING 2021. [DOI: 10.1007/s13369-021-06014-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Gieroba B, Kalisz G, Sroka-Bartnicka A, Płazińska A, Płaziński W, Starek M, Dąbrowska M. Molecular Structure of Cefuroxime Axetil Complexes with α-, β-, γ-, and 2-Hydroxypropyl-β-Cyclodextrins: Molecular Simulations and Raman Spectroscopic and Imaging Studies. Int J Mol Sci 2021; 22:ijms22105238. [PMID: 34063471 PMCID: PMC8156438 DOI: 10.3390/ijms22105238] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 05/11/2021] [Accepted: 05/13/2021] [Indexed: 11/16/2022] Open
Abstract
The formation of cefuroxime axetil+cyclodextrin (CA+CD) complexes increases the aqueous solubility of CA, improves its physico-chemical properties, and facilitates a biomembrane-mediated drug delivery process. In CD-based tablet formulations, it is crucial to investigate the molecular details of complexes in final pharmaceutical preparation. In this study, Raman spectroscopy and mapping were applied for the detection and identification of chemical groups involved in α-, β-, γ-, and 2-hydroxypropyl-β-CD (2-HP- β-CD)+CA complexation process. The experimental studies have been complemented by molecular dynamics-based investigations, providing additional molecular details of CA+CD interactions. It has been demonstrated that CA forms the guest–host type inclusion complexes with all studied CDs; however, the nature of the interactions is slightly different. It seems that both α- and β-CD interact with furanyl and methoxy moieties of CA, γ-CD forms a more diverse pattern of interactions with CA, which are not observed in other CDs, whereas 2HP-β-CD binds CA with the contribution of hydrogen bonding. Apart from supporting this interpretation of the experimental data, molecular dynamics simulations allowed for ordering the CA+CD binding affinities. The obtained results proved that the molecular details of the host–guest complexation can be successfully predicted from the combination of Raman spectroscopy and molecular modeling.
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Affiliation(s)
- Barbara Gieroba
- Department of Biopharmacy, Medical University of Lublin, ul. Chodzki 4a, 20-093 Lublin, Poland; (G.K.); (A.S.-B.); (A.P.)
- Correspondence: (B.G.); (W.P.)
| | - Grzegorz Kalisz
- Department of Biopharmacy, Medical University of Lublin, ul. Chodzki 4a, 20-093 Lublin, Poland; (G.K.); (A.S.-B.); (A.P.)
| | - Anna Sroka-Bartnicka
- Department of Biopharmacy, Medical University of Lublin, ul. Chodzki 4a, 20-093 Lublin, Poland; (G.K.); (A.S.-B.); (A.P.)
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, Maria Curie-Skłodowska University, ul. Akademicka 19, 20-033 Lublin, Poland
| | - Anita Płazińska
- Department of Biopharmacy, Medical University of Lublin, ul. Chodzki 4a, 20-093 Lublin, Poland; (G.K.); (A.S.-B.); (A.P.)
| | - Wojciech Płaziński
- Jerzy Haber Institute of Catalysis and Surface Chemistry, ul. Niezapominajek 8, 30-239 Krakow, Poland
- Correspondence: (B.G.); (W.P.)
| | - Małgorzata Starek
- Department of Inorganic and Analytical Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, ul. Medyczna 9, 30-688 Kraków, Poland; (M.S.); (M.D.)
| | - Monika Dąbrowska
- Department of Inorganic and Analytical Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, ul. Medyczna 9, 30-688 Kraków, Poland; (M.S.); (M.D.)
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