Clusters of Superparamagnetic Iron Oxide Nanoparticles Encapsulated in a Hydrogel: A Particle Architecture Generating a Synergistic Enhancement of the T<sub>2</sub> Relaxation

Paquet, Chantal; Haan, Hendrick W. de; Leek, Donald M.; Lin, Hung‐Yu; Xiang, Bo; Tian, Ganghong; Kell, Arnold J.; Simard, Benoît

doi:10.1021/nn2002272

Cited by 168 publications

(178 citation statements)

References 34 publications

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“…By functionalizing nanoparticle surfaces, the interaction between a polymer and nanoparticles can be strengthened [11][12][13]. Various types of metal nanoparticles have been used in the production of nanocomposite hydrogels in the field of biomaterials including gold [14], silver [15] and other noble metal nanoparticles, while metal oxide nanoparticles such as iron oxide [16] and zirconia [17] have also been used. Since metal and metal oxide nanoparticles possess the desired electrical conductivity, magnetic properties, and antibacterial properties, nanocomposite hydrogels that contain metal or metal oxide nanoparticles are widely used in conductive scaffolds, electronic switches, actuators, and sensors [18][19][20][21].…”

Section: Metal Nanoparticlesmentioning

confidence: 99%

Incorporation of Conductive Materials into Hydrogels for Tissue Engineering Applications

Min¹,

Koh²

2018

Preprint

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In the field of tissue engineering, conductive hydrogels have been the most effective biomaterials to mimic the biological and electrical properties of tissues in the human body. The main advantages of conductive hydrogel include not only its physical properties, but also its adequate electrical properties, thus providing electrical signals to cells efficiently. However, when introducing a conductive material into a non-conductive hydrogel, a conflicting relationship between the electrical and mechanical properties may develop. This review examines the strengths and weaknesses of the generation of conductive hydrogels using various conductive materials and introduces the use of these conductive hydrogels in tissue engineering applications.

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Section: Metal Nanoparticlesmentioning

confidence: 99%

Incorporation of Conductive Materials into Hydrogels for Tissue Engineering Applications

Min¹,

Koh²

2018

Preprint

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“…70 A polymer-coated Fe 2 O 3 composite shows enhanced T 2 shortening near the particle surface. 71 Naturally, this shortening of the T 2 suggests that the magnetic Co 3 O 4 core has a much larger influence on helping relax those protons that can get closer to the magnetic surface. It follows that thicker silica shells should increasingly separate and minimize the magnetic screening of protons by the magnetic Co 3 O 4 core.…”

Section: ■ Introductionmentioning

confidence: 96%

Microstructure Effects on the Water Oxidation Activity of Co₃O₄/Porous Silica Nanocomposites

2015

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We investigate the effect of microstructuring on the water oxidation (oxygen evolution) activity of two types of Co 3 O 4 /porous silica composites: Co 3 O 4 /porous SiO 2 core/shell nanoparticles with varying shell thicknesses and surface areas, and Co 3 O 4 /mesoporous silica nanocomposites with various surface functionalities. Catalytic tests in the presence of Ru(bpy )3 2+ as a photosensitizer and S 2 O 8 2-as a sacrificial electron acceptor show that porous silica shells of up to -20 nm in thickness lead to increased water oxidation activity. We attribute this effect to either (1) a combination of an effective increase in catalyst active area or consequent higher local concentration of Ru(bpy) 3 2+ ; (2) a decrease in the permittivity of the medium surrounding the catalyst surface and a consequent increase in the rate of charge transfer; or both. Functionalized Co 3 O 4 /mesoporous silica nanocomposites show lower water oxidation activity compared with the parent nonfunctionalized catalyst, likely because of partial pore blocking of the silica support upon surface grafting. A more thorough understanding of the effects of microstructure and permittivity on water oxidation ability will enable the construction of next generation catalysts possessing optimal configuration and better efficiency for water splitting. KeywordsCo3O4/SiO2 core/shells, microstructure effects, nanocatalysts, nanocomposites, water oxidation Disciplines Chemistry CommentsReprinted ( 2− as a sacrificial electron acceptor show that porous silica shells of up to~20 nm in thickness lead to increased water oxidation activity. We attribute this effect to either (1) a combination of an effective increase in catalyst active area or consequent higher local concentration of Ru(bpy) 3 2+ ; (2) a decrease in the permittivity of the medium surrounding the catalyst surface and a consequent increase in the rate of charge transfer; or both. Functionalized Co 3 O 4 / mesoporous silica nanocomposites show lower water oxidation activity compared with the parent nonfunctionalized catalyst, likely because of partial pore blocking of the silica support upon surface grafting. A more thorough understanding of the effects of microstructure and permittivity on water oxidation ability will enable the construction of next generation catalysts possessing optimal configuration and better efficiency for water splitting. KEYWORDS: Co 3 O 4 /SiO 2 core/shells, nanocomposites, nanocatalysts, water oxidation, microstructure effects ■ INTRODUCTIONElectrochemical and photochemical water splitting are ways to produce molecular hydrogen gas, H 2 , a potentially valuable and clean-burning fuel. Water oxidation is the most difficult halfreaction in water splitting, involving the transfer of four electrons and the formation of oxygen−oxygen bonds. 1−4 After many studies devoted to developing more efficient and economic water oxidation catalysts, 5 cobalt-based materials have been identified as some of the most promising due to their relative abundance, high activity, and...

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“…It is known that iron oxide clusters present peculiar magnetic properties [16,18] For example, the net magnetization is higher for SPION clusters than for individual SPIONs [4,18,19], which offers enormous potential in therapeutics [4], magnetic resonance imaging (MRI [16,19,20] and hyperthermia [9,21]. However, obtaining these constructs necessitates a bottom-up approach and control of the synthetic pathways and materials at a basic level, making the chemical aspects critical to creating future nanomaterials for application-oriented purposes.…”

Section: Introductionmentioning

confidence: 99%

Catechol-derivatized poly(vinyl alcohol) as a coating molecule for magnetic nanoclusters

Burnand

Monnier

Redjem

et al. 2015

Journal of Magnetism and Magnetic Materials

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Surface functionalization of superparamagnetic iron oxide nanoparticles (SPIONs) remains indispensable in promoting colloidal stability and biocompatibility. We propose a well-defined and characterized synthesis of a new catechol-functionalized RAFT (reversible addition-fragmentation chain transfer) poly (vinyl alcohol) polymer, which can be anchored onto hydrophobic SPIONs via a one-pot emulsion ligand exchange process. Both single and clustered nanoparticles are obtained and can be separated from each other. As clustered SPIONs are receiving increasing attention, this new macroligand might be of considerable interest for both basic and applied sciences.

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Clusters of Superparamagnetic Iron Oxide Nanoparticles Encapsulated in a Hydrogel: A Particle Architecture Generating a Synergistic Enhancement of the T₂ Relaxation

Cited by 168 publications

References 34 publications

Incorporation of Conductive Materials into Hydrogels for Tissue Engineering Applications

Incorporation of Conductive Materials into Hydrogels for Tissue Engineering Applications

Microstructure Effects on the Water Oxidation Activity of Co₃O₄/Porous Silica Nanocomposites

Catechol-derivatized poly(vinyl alcohol) as a coating molecule for magnetic nanoclusters

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Clusters of Superparamagnetic Iron Oxide Nanoparticles Encapsulated in a Hydrogel: A Particle Architecture Generating a Synergistic Enhancement of the T2 Relaxation

Cited by 168 publications

References 34 publications

Incorporation of Conductive Materials into Hydrogels for Tissue Engineering Applications

Incorporation of Conductive Materials into Hydrogels for Tissue Engineering Applications

Microstructure Effects on the Water Oxidation Activity of Co3O4/Porous Silica Nanocomposites

Catechol-derivatized poly(vinyl alcohol) as a coating molecule for magnetic nanoclusters

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Clusters of Superparamagnetic Iron Oxide Nanoparticles Encapsulated in a Hydrogel: A Particle Architecture Generating a Synergistic Enhancement of the T₂ Relaxation

Microstructure Effects on the Water Oxidation Activity of Co₃O₄/Porous Silica Nanocomposites