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Sudo T, Sagawa M, Adachi S, Kato Y, Nakanishi Y, Nakamura T, Yamashita S, Kamiya H, Okada Y. Understanding Flexdispersion: Structure-Function Relationship Studies of Organic Amphiphilic Ligands. Chemistry 2024:e202304324. [PMID: 38654689 DOI: 10.1002/chem.202304324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 04/22/2024] [Accepted: 04/23/2024] [Indexed: 04/26/2024]
Abstract
Since inorganic nanoparticles have unique properties that differ from those of bulk materials, their material applications have attracted attention in various fields. In order to utilize inorganic nanoparticles for functional materials, they must be dispersed without agglomeration. Therefore, the surfaces of inorganic nanoparticles are typically modified with organic ligands to improve their dispersibility. Nevertheless, the relationship between the tail group structure in organic ligands and the dispersibility of inorganic nanoparticles in organic solvents remains poorly understood. We previously developed amphiphilic ligands that consist of ethylene glycol chains and alkyl chains to disperse inorganic nanoparticles in a variety of organic solvents. However, the structural requirements for amphiphilic ligands to "flexibly" disperse nanoparticles in less polar to polar solvents are still unclear. Here, we designed and synthesized several phosphonic acid ligands for structure-function relationship studies of flexdispersion. Dynamic light scattering analysis and visible light transmittance measurements revealed that the ratio of alkyl/ethylene glycol chains in organic ligands alone does not determine the dispersibility of the nanoparticles in organic solvents, but the arrangement of the individual chains also has an effect. From a practical application standpoint, it is preferable to design ligands with ethylene glycol chains on the outside relative to the particle surface.
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Affiliation(s)
- Tatsuya Sudo
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Masahiko Sagawa
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Sota Adachi
- Department of Applied Biological Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan
| | - Yusuke Kato
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Yuki Nakanishi
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Tatsuya Nakamura
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Shohei Yamashita
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Hidehiro Kamiya
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Yohei Okada
- Department of Applied Biological Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan
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2
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Mochizuki T, Sampei S, Suga K, Watanabe K, Welling TAJ, Nagao D. A Quantitative Approach to Characterize the Surface Modification on Nanoparticles Based on Localized Dielectric Environments. Anal Chem 2024; 96:3284-3290. [PMID: 38355104 PMCID: PMC10902806 DOI: 10.1021/acs.analchem.3c03593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024]
Abstract
Nanoparticles (NPs) are utilized for the functionalization of composite materials and nanofluids. Although oxide NPs (e.g., silica (SiO2)) exhibit less dispersibility in organic solvents or polymers due to their hydrophilic surface, the surface modification using silane coupling agents can improve their dispersibility in media with low dielectric constants. Herein, SiO2 NPs were functionalized using octyltriethoxysilane (OTES, C8) and dodecyltriethoxysilane (DTES, C12), wherein the degrees of surface modification of SiO2@C8 and SiO2@C12 were quantitatively evaluated based on the ratio of modifier to surface silanol group (θ) and the volume fraction of organic modifier to total particle volume (ϕR). The variations of surface properties were revealed by analyzing the Hansen solubility parameters (HSP). Particularly, the surface modification using OTES or DTES significantly affected the polarity (δP) of NPs. The local dielectric environments of surface-modified SiO2 NPs were characterized using a solvatochromic dye, Laurdan. By analyzing the peak position of the steady-state emission spectrum of Laurdan in a NP suspension, the apparent dielectric environments surrounding NPs (εapp) were obtained. A good correlation between ϕR and εapp was observed, indicating that ϕR is a reliable quantity for understanding the properties of surface-modified NPs. Furthermore, the generalized polarization (GP) of NPs was investigated. The surface-modified SiO2 NPs with higher ϕR (≥0.15) exhibited GP > 0, suggesting that the modifiers are well-organized on the surface of NPs. The localized dielectric environment surrounding NPs could be predicted by analyzing the volume fraction of nonpolar moieties derived from modifiers. Alternatively, εapp and GP can be utilized for understanding the properties of inorganic-organic hybrid NPs.
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Affiliation(s)
- Taketo Mochizuki
- Department of Chemical Engineering, Tohoku University, Sendai, Miyagi 9808579, Japan
| | - Shota Sampei
- Department of Chemical Engineering, Tohoku University, Sendai, Miyagi 9808579, Japan
| | - Keishi Suga
- Department of Chemical Engineering, Tohoku University, Sendai, Miyagi 9808579, Japan
| | - Kanako Watanabe
- Department of Chemical Engineering, Tohoku University, Sendai, Miyagi 9808579, Japan
| | - Tom A J Welling
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai, Miyagi 9808578, Japan
| | - Daisuke Nagao
- Department of Chemical Engineering, Tohoku University, Sendai, Miyagi 9808579, Japan
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3
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Saito T, Kubo M, Tsukada T, Shoji E, Kikugawa G, Surblys D, Kubo M. Molecular dynamics simulations for interfacial structure and affinity between carboxylic acid-modified Al2O3 and polymer melts. J Chem Phys 2023; 159:164708. [PMID: 37888762 DOI: 10.1063/5.0169721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 10/10/2023] [Indexed: 10/28/2023] Open
Abstract
Controlling the dispersion state of nanoparticles in a polymer matrix is necessary to produce polymer nanocomposites. The surface modification of nanoparticles is used to enable their dispersion in polymers. Moreover, molecular dynamics (MD) simulations are useful for revealing the interfacial properties between nanoparticles and polymers to aid in the design of materials. In this study, the effect of surface coverage, modifier length, and polymer species on the interfacial structure and affinity between surface-modified Al2O3 and polymer melts were investigated using all-atom MD simulations. Hexanoic, decanoic, and tetradecanoic acids were used as surface modifiers, and polypropylene (PP), polystyrene (PS), and poly (methyl methacrylate) (PMMA) were used as polymers. The work of adhesion Wadh and the work of immersion Wimm were selected as quantitative measures of affinity. Wadh was calculated using the phantom-wall approach, and Wimm was calculated by simply subtracting the surface tension of polymers γL from Wadh. The results showed that Wadh and Wimm were improved by surface modification with low coverage, owing to a good penetration of the polymer. The effect of modifier length on Wadh and Wimm was small. Whereas Wadh increased in the following order: PP < PS < PMMA, Wimm increased as follows: PMMA < PS < PP. Finally, the trend of Wadh and Wimm was organized using the Flory-Huggins interaction parameter χ between the modifier and the polymer. This study demonstrates that the interfacial affinity can be improved by tuning the surface coverage and modifier species depending on the polymer matrix.
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Affiliation(s)
- Takamasa Saito
- Department of Chemical Engineering, Tohoku University, 6-6-07 Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Masaki Kubo
- Department of Chemical Engineering, Tohoku University, 6-6-07 Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Takao Tsukada
- New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Eita Shoji
- Department of Mechanical Systems Engineering, Tohoku University, 6-6-01 Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Gota Kikugawa
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Donatas Surblys
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Momoji Kubo
- Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
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4
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Sudo T, Yamashita S, Koike N, Kamiya H, Okada Y. Dispersibility of TiO 2 Nanoparticles in Less Polar Solvents: Role of Ligand Tail Structures. Chemistry 2023; 29:e202203608. [PMID: 36575960 DOI: 10.1002/chem.202203608] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 12/18/2022] [Accepted: 12/28/2022] [Indexed: 12/29/2022]
Abstract
Nanoparticles (NPs) are inherently prone to aggregation and loss of their size-derived properties, thus it is essential to enhance their dispersibility for applications. In less polar solvents, organic ligands containing oleyl groups are known as good dispersants due to their inefficient shell packing and inhibition of chain-chain crystallization as well as interdigitation between adjacent NPs. However, reagents with oleyl structures, such as oleic acid and oleylamine, can contain trans double bonds and saturated impurities, which might affect the chemical and/or physical properties of the NPs. Nevertheless, the effect of slight differences in surface ligand structure, including isomers, on the dispersibility of NPs has been little studied. We have synthesized five phosphonic acid ligands to investigate the structure-dispersibility relationship in detail. Dynamic light scattering and visible light transmittance revealed that not only regio- but also the stereochemistries of the C=C double bond in the ligand molecule, as well as the choice of solvent, are key factors in enhancing dispersibility.
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Affiliation(s)
- Tatsuya Sudo
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Shohei Yamashita
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Natsumi Koike
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Hidehiro Kamiya
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Yohei Okada
- Department of Applied Biological Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan
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5
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Formation mechanism of surface modified iron oxide nanoparticles using controlled hydrolysis reaction in supercritical CO2. Colloids Surf A Physicochem Eng Asp 2023. [DOI: 10.1016/j.colsurfa.2023.131136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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6
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Ofosu CK, Kang J, Truskett TM, Milliron DJ. Effective Hard-Sphere Repulsions between Oleate-Capped Colloidal Metal Oxide Nanocrystals. J Phys Chem Lett 2022; 13:11323-11329. [PMID: 36453921 DOI: 10.1021/acs.jpclett.2c02627] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Nanocrystal interactions in solvent influence colloidal stability and dictate self-assembly outcomes. Small-angle X-ray scattering is used to study how dilute oleate-capped In2O3 nanocrystals with 7-19 nm core diameters interact when dispersed in a series of nonpolar solvents. Osmotic second virial coefficient analysis finds toluene-dispersed nanocrystals in this size range interact like effective hard spheres with diameters comprising the inorganic core and a ligand-solvent corona with a core-size independent thickness. Hard-sphere-like structure factors are similarly observed for nanocrystals with a 9.7 nm core diameter dispersed in all the solvents investigated. Nanocrystal hydrodynamic diameters from dynamic light scattering measurements correlate with thermodynamic diameters obtained from the osmotic second virial coefficient analysis for all samples. The ability to prepare nanoscale building blocks of different sizes, and dispersed in a variety of solvents, with effective hard-sphere repulsions provides a foundation for assembly, where secondary linking or depletant molecules can be deliberately added to customize interactions to form superstructures such as gel networks or superlattices.
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Affiliation(s)
- Charles K Ofosu
- Department of Chemistry, University of Texas at Austin, Austin, Texas78712, United States
| | - Jiho Kang
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas78712, United States
| | - Thomas M Truskett
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas78712, United States
- Department of Physics, University of Texas at Austin, Austin, Texas78712, United States
| | - Delia J Milliron
- Department of Chemistry, University of Texas at Austin, Austin, Texas78712, United States
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas78712, United States
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7
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Lysenko SN, Astaf'eva SA, Kornilitsina EV, Yakusheva DE, Morozov KI. Osmotic Attraction: A New Mechanism of Nanoparticle Aggregation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:14313-14325. [PMID: 36351051 DOI: 10.1021/acs.langmuir.2c02379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Solvent-induced interactions of nanoparticles in colloidal solutions can substantially affect their physicochemical and transport properties. Predicting these interactions is challenging because the natural causes of the interactions are unclear. Here, we present a comprehensive experimental and theoretical study of the coagulation stability of the surfacted magnetic colloids. The magnetite nanoparticles stabilized by erucic acid were dispersed in 19 different good solvents. The colloidal stability was reduced by the gradual addition of a precipitant. As a precipitant, 19 other liquids were used. We show that coagulation is not associated with either dispersion or magnetic interactions. The coagulation mechanism is due to the osmotic attraction of nanoparticles induced by a specific local distribution of precipitant molecules. The precipitant molecules are repelled from the hydrophobic tails of the surfactant and form a depleted zone inside the surfactant layer leading to the appearance of the osmotic attraction between the nanoparticles and their subsequent coagulation when the critical concentration of the precipitant is reached. The quantitative description of the phenomenon is carried out within the framework of the generalized Asakura-Oosawa model of the attractive depletion forces between two adjacent particles and the Langmuir adsorption model for the equilibrium concentration of precipitant molecules in the surfactant layer of nanoparticles. The calculated precipitant critical concentrations, the coagulation curves of the polydisperse systems, and the variation of the coagulation criterion occurring upon changing the surfactant are in good agreement with the experimental data. The osmotic attraction mechanism is equally suitable for nanoparticles of any nature─plasmonic, semiconductor, or magnetic. This is determined by the surfactant-solvent interactions and is generic for many solvent-mediated systems taken at arbitrary concentrations of precipitant.
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Affiliation(s)
- S N Lysenko
- Institute of Technical Chemistry of UB RAS, Perm614068, Russia
| | - S A Astaf'eva
- Institute of Technical Chemistry of UB RAS, Perm614068, Russia
| | | | - D E Yakusheva
- Institute of Technical Chemistry of UB RAS, Perm614068, Russia
| | - K I Morozov
- Department of Chemical Engineering, Technion - Israel Institute of Technology, Haifa32000, Israel
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8
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Oshima K, Sato N, Nakamura K, Guo H, Smith RL. Simulation and visualization of nano SiO2 - water and decanoic acid-modified nano CeO2 - cyclohexane dispersions under a centrifugal field. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.129558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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9
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Yamashita S, Sudo T, Kamiya H, Okada Y. Colloidal Stability of TiO
2
Nanoparticles: The Roles of Phosphonate Ligand Length and Solution Temperature. Chemistry 2022; 28:e202201560. [DOI: 10.1002/chem.202201560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Indexed: 11/11/2022]
Affiliation(s)
- Shohei Yamashita
- Department of Chemical Engineering Tokyo University of Agriculture and Technology 2-24-16 Naka-cho, Koganei Tokyo 184-8588 Japan
| | - Tatsuya Sudo
- Department of Chemical Engineering Tokyo University of Agriculture and Technology 2-24-16 Naka-cho, Koganei Tokyo 184-8588 Japan
| | - Hidehiro Kamiya
- Department of Chemical Engineering Tokyo University of Agriculture and Technology 2-24-16 Naka-cho, Koganei Tokyo 184-8588 Japan
| | - Yohei Okada
- Department of Applied Biological Science Tokyo University of Agriculture and Technology 3-5-8 Saiwai-cho, Fuchu Tokyo 183-8509 Japan
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10
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Saita S, Takeda SI, Kawasaki H. Hansen Solubility Parameter Analysis on Dispersion of Oleylamine-Capped Silver Nanoinks and their Sintered Film Morphology. NANOMATERIALS 2022; 12:nano12122004. [PMID: 35745345 PMCID: PMC9230637 DOI: 10.3390/nano12122004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/07/2022] [Accepted: 06/07/2022] [Indexed: 12/19/2022]
Abstract
Optimizing stabilizers and solvents is crucial for obtaining highly dispersed nanoparticle inks. Generally, nonpolar (hydrophobic) ligand-stabilized nanoparticles show superior dispersibility in nonpolar solvents, whereas polar ligand (hydrophilic)-stabilized nanoparticles exhibit high dispersibility in polar solvents. However, these properties are too qualitative to select optimum stabilizers and solvents for stable nanoparticle inks, and researchers often rely on their experiences. This study presents a Hansen solubility parameter (HSP)-based analysis of the dispersibility of oleylamine-capped silver nanoparticle (OAm-Ag NP) inks for optimizing ink preparation. We determined the HSP sphere of the OAm-Ag NPs, defined as the center coordinate, and the interaction radius in 3D HSP space. The solvent’s HSP inside the HSP sphere causes high dispersibility of the OAm-Ag NPs in the solvent. In contrast, the HSPs outside the sphere resulted in low dispersibility in the solvent. Thus, we can quantitatively predict the dispersibility of the OAm-Ag NPs in a given solvent using the HSP approach. Moreover, the HSP sphere method can establish a correlation between the dispersibility of the particles in inks and the sintered film morphology, facilitating electronic application of the nanoparticle inks. The HSP method is also helpful for optimizing stabilizers and solvents for stable nanoparticle inks in printed electronics.
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Affiliation(s)
- Satoshi Saita
- Department of Chemistry and Materials Engineering, Faculty of Chemistry, Materials and Bioengineering, Kansai University, Osaka 564-8680, Japan;
| | - Shin-ichi Takeda
- Takeda Colloid Techno-Consulting Co., Ltd., Osaka 564-0051, Japan
- Correspondence: (S.-i.T.); (H.K.)
| | - Hideya Kawasaki
- Department of Chemistry and Materials Engineering, Faculty of Chemistry, Materials and Bioengineering, Kansai University, Osaka 564-8680, Japan;
- Correspondence: (S.-i.T.); (H.K.)
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11
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Orita Y, Kariya K, Wijakmatee T, Shimoyama Y. Synthesis of surface-modified iron oxide nanocrystals using supercritical carbon dioxide as the reaction field. RSC Adv 2022; 12:7990-7995. [PMID: 35424715 PMCID: PMC8982442 DOI: 10.1039/d1ra08580h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 02/25/2022] [Indexed: 11/21/2022] Open
Abstract
We applied the supercritical CO2 technology, which is an excellent solventless process, to the synthesis of surface-modified iron oxide nanocrystals.
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Affiliation(s)
- Yasuhiko Orita
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, 2-12-1 S1-33, Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Keito Kariya
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, 2-12-1 S1-33, Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Thossaporn Wijakmatee
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, 2-12-1 S1-33, Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Yusuke Shimoyama
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, 2-12-1 S1-33, Ookayama, Meguro-ku, Tokyo 152-8550, Japan
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12
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Watanabe A, Magi A, Yoko A, Seong G, Tomai T, Adschiri T, Hayashi Y, Koshimizu M, Fujimoto Y, Asai K. Fabrication of Liquid Scintillators Loaded with 6-Phenylhexanoic Acid-Modified ZrO 2 Nanoparticles for Observation of Neutrinoless Double Beta Decay. NANOMATERIALS 2021; 11:nano11051124. [PMID: 33925291 PMCID: PMC8145323 DOI: 10.3390/nano11051124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 04/18/2021] [Accepted: 04/24/2021] [Indexed: 11/16/2022]
Abstract
The observation of neutrinoless double beta decay is an important issue in nuclear and particle physics. The development of organic liquid scintillators with high transparency and a high concentration of the target isotope would be very useful for neutrinoless double beta decay experiments. Therefore, we propose a liquid scintillator loaded with metal oxide nanoparticles containing the target isotope. In this work, 6-phenylhexanoic acid-modified ZrO2 nanoparticles, which contain 96Zr as the target isotope, were synthesized under sub/supercritical hydrothermal conditions. The effects of the synthesis temperature on the formation and surface modification of the nanoparticles were investigated. Performing the synthesis at 250 and 300 °C resulted in the formation of nanoparticles with smaller particle sizes and higher surface modification densities than those prepared at 350 and 400 °C. The highest modification density (3.1 ± 0.2 molecules/nm2) and Zr concentration of (0.33 ± 0.04 wt.%) were obtained at 300 °C. The surface-modified ZrO2 nanoparticles were dispersed in a toluene-based liquid scintillator. The liquid scintillator was transparent to the scintillation wavelength, and a clear scintillation peak was confirmed by X-ray-induced radioluminescence spectroscopy. In conclusion, 6-phenylhexanoic acid-modified ZrO2 nanoparticles synthesized at 300 °C are suitable for loading in liquid scintillators.
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Affiliation(s)
- Akito Watanabe
- Department of Applied Chemistry, Graduate School of Engineering, Tohoku University, 6-6-07 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan; (A.M.); (Y.H.); (M.K.); (Y.F.); (K.A.)
- Correspondence: ; Tel.: +81-22-795-7219
| | - Arisa Magi
- Department of Applied Chemistry, Graduate School of Engineering, Tohoku University, 6-6-07 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan; (A.M.); (Y.H.); (M.K.); (Y.F.); (K.A.)
| | - Akira Yoko
- WPI-AIMR, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan; (A.Y.); (T.A.)
| | - Gimyeong Seong
- New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan;
| | - Takaaki Tomai
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan;
| | - Tadafumi Adschiri
- WPI-AIMR, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan; (A.Y.); (T.A.)
- New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan;
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan;
| | - Yamato Hayashi
- Department of Applied Chemistry, Graduate School of Engineering, Tohoku University, 6-6-07 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan; (A.M.); (Y.H.); (M.K.); (Y.F.); (K.A.)
| | - Masanori Koshimizu
- Department of Applied Chemistry, Graduate School of Engineering, Tohoku University, 6-6-07 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan; (A.M.); (Y.H.); (M.K.); (Y.F.); (K.A.)
| | - Yutaka Fujimoto
- Department of Applied Chemistry, Graduate School of Engineering, Tohoku University, 6-6-07 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan; (A.M.); (Y.H.); (M.K.); (Y.F.); (K.A.)
| | - Keisuke Asai
- Department of Applied Chemistry, Graduate School of Engineering, Tohoku University, 6-6-07 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan; (A.M.); (Y.H.); (M.K.); (Y.F.); (K.A.)
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13
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Saito T, Shoji E, Kubo M, Tsukada T, Kikugawa G, Surblys D. Evaluation of the work of adhesion at the interface between a surface-modified metal oxide and an organic solvent using molecular dynamics simulations. J Chem Phys 2021; 154:114703. [PMID: 33752377 DOI: 10.1063/5.0040900] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Advancing the practical applications of surface-modified nanoparticles requires that their dispersion in solvents can be controlled. The degree of dispersion depends on the affinity between surface-modified nanoparticles and solvents, which can be quantified using the work of adhesion at the interface. Herein, the affinity between a surface-modified inorganic solid and an organic solvent was evaluated by calculating the work of adhesion at the interface. The phantom-wall method, which is a thermodynamic route for evaluating the work of adhesion at an interface using molecular dynamics simulations, was applied to the decanoic acid-modified Al2O3/hexane interface. Molecular dynamics simulations were performed for flat interface systems to focus on the interactions between substances that affect the affinity on the surface. As a result, the surface coverage of decanoic acid was found to affect the work of adhesion, with a maximum value of 45.66 ± 0.75 mJ/m2 at a surface coverage of 75%. An analysis of the mass density profiles of Al2O3, decanoic acid, and hexane in the vicinity of the interface showed that the increase in the work of adhesion with the surface coverage was due to the penetration of hexane molecules into the decanoic acid layer on the Al2O3 surface. At a surface coverage of 75%, some hexane molecules were trapped in the layer of oriented decanoic acid molecules. These results suggested that the interfacial affinity can be enhanced by controlling the surface modification so that the solvent can penetrate the layer of the modifier.
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Affiliation(s)
- Takamasa Saito
- Department of Chemical Engineering, Tohoku University, 6-6-07 Aramaki, Aoba-ku, Sendai 980-8579, Japan
| | - Eita Shoji
- Department of Mechanical Systems Engineering, Tohoku University, 6-6-01 Aramaki, Aoba-ku, Sendai 980-8579, Japan
| | - Masaki Kubo
- Department of Chemical Engineering, Tohoku University, 6-6-07 Aramaki, Aoba-ku, Sendai 980-8579, Japan
| | - Takao Tsukada
- Department of Chemical Engineering, Tohoku University, 6-6-07 Aramaki, Aoba-ku, Sendai 980-8579, Japan
| | - Gota Kikugawa
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Donatas Surblys
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
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