Synthesis of Photoswitchable Magnetic Au–Fullerosome Hybrid Nanomaterials for Permittivity Enhancement Applications

et al. 2016

Nanoscale

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We unexpectedly observed a large amplification of the dielectric properties associated with the photoswitching effect and the new unusual phenomenon of delayed photoinduced capacitor-like (i.e. electric polarization) behavior at the interface on samples of three-layered core-shell (γ-FeOx@AuNP)@[C60(>DPAF-C9)](n)2 nanoparticles (NPs) in frequencies of 0.5-4.0 GHz. The detected relative dielectric constant amplification was initiated upon switching off the light followed by relaxation to give an excellent recyclability. These NPs having e(-)-polarizable fullerosomic structures located at the outer layer were fabricated from highly magnetic core-shell γ-FeOx@AuNPs. Surface-stabilized 2 in a core-shell structure was found to be capable of photoinducing the surface plasmonic resonance (SPR) effect by white LED light. The accumulated SPR energy was subsequently transferred to the partially bilayered C60(>DPAF-C9) fullerosomic membrane layer in a near-field (∼1.5 nm) region without producing radiation heat. Since the monostatic SAR signal is dielectric property-dependent, we used these measurements to provide evidence of derived reflectivity changes on a surface coated with 2 at 0.5-4.0 GHz upon illumination of LED white light. We found that a high, >99%, efficiency of response amplification in image amplitude can be achieved.

Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Novel photoswitchable dielectric properties on nanomaterials of electronic core–shell γ-FeO_x@Au@fullerosomes for GHz frequency applications

et al. 2016

Nanoscale

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“…It corresponds to an average of one 1 -C 9 molecule per 1.5 Au atoms (an atomic radius of 0.146 nm) in the product of GN@(FeAuF n ). These atomic ratios led us to roughly estimate a trilayered fullerosome shell thickness on the Au layer of core–shell NPs, consisting of the shell width of ∼8.0 nm reported recently. , Based on the combination of TEM micrographic images and EDS results and analyses, we concluded that the best material component ratios of multilayered GN@(FeAuF n ) nanosheets to be applied in the investigation of their photophysical properties should be either 1.5:1.0:1.5 or 2.0:1.0:2.0 by weight for 1 -C 9 /GN/γ-FeO x @AuNP.…”

Section: Results and Discussionmentioning

confidence: 99%

Reversible Enlargement of Photoswitchable Dielectric Properties by Plasmonic [60]Fullerenyl Core–Shell Nanoparticles on Graphene Nanosheets

Yin

et al. 2020

J. Phys. Chem. C

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Utilization of [60]fullerosome monolayer grafting approach on both sides of graphene nanosheets giving the corresponding sandwiched nanostructures was demonstrated as a key intermediate for the construction of photoswitchable and tunable dielectric graphene nanosheet materials. They were covered by magnetic plasmonic core–shell nanoparticles of γ-FeO x @AuNP and light-harvesting C60(>DPAF-C9) monoadduct conjugates as the shell layer via a subsequent deposition procedure. Resulting multilayered core–shell nanosheet materials were found to be capable of inducing reversible dielectric property amplification effects in a photoswitching manner in the radio frequency (RF) range of 1.0–18 GHz. They were also found to be RF-wave-absorbing materials that led to the observation of minimum reflection coefficient values (low −dB). We substantiated these photophysical properties by relative dielectric (εr′) measurements and related applications using a combination of bistatic angle (θ)-, frequency-, and irradiation-time-dependent measurements. Specifically, we investigated the photoinduced changes of relative dielectric characteristics as a result of accumulated surface plasmon resonance (SPR) energy at the core–shell interlayers in a nanoscale toward potential morphological modulation of RF signals by photoswitching tunability of reflectivity.

“…We selected the latter cup -form to undergo further attachment of a C 60 > cage as the end group of each DPAF-C 9 arm that resulted in a nanostructure of tris[60]fullerenylated cis -tris(diphenylaminofluorene) as cis - cup -tris[C 60 (>DPAF-C 9 )] or cis - cup - 3 -C 9 for the photoswitchable dielectric property amplification study. This design of new stereo-isomeric structures may be beneficial for uses as positive charge carriers in enhancing photoinduced dielectric characteristics [ 23 ] and as the precursor building blocks in the synthesis of several C 60 - and C 70 -based ultrafast photoresponsive nanomaterials in correlation to our recent studies [ 17 , 18 , 19 , 20 ]. Therefore, we applied cis - cup - 3 -C 9 as a photoswitchable dielectric charge-polarizer in the fabrication of microwave-responsive plasmonic trilayered core-shell nanoparticles.…”

Section: Introductionmentioning

confidence: 99%

3D-Conformer of Tris[60]fullerenylated cis-Tris(diphenylamino-fluorene) as Photoswitchable Charge-Polarizer on GHz-Responsive Trilayered Core-Shell Dielectric Nanoparticles

Yin

et al. 2018

Molecules

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Novel 3D-configurated stereoisomers cis-cup-tris[C60>(DPAF-C9)] and trans-chair-tris[C60>(DPAF-C9)] were designed and synthesized in good yields. The former, with three C60> cages per molecule facing at the same side of the geometrical molecular cup-shape, was proposed to provide excellent binding interaction forces at the gold surface of core-shell γ-FeOx@AuNP nanoparticles and to direct the subsequent formation of a fullerene cage array (defined as fullerosome). Upon photoactivation of the Au-layer and cis-cup-tris[C60>(DPAF-C9)] itself, the degree of photoinduced intramolecular e−-transfer from DPAF to a C60> moiety was found to be largely enhanced by the accumulated plasmonic resonance energy at the near-field surface. Distribution of resulting negative charges along the outer (C60>)-derived fullerosome shell layer of the trilayered NPs was correlated with the detected photoswitchable dielectric amplification phenomena using white LED light at 1.0 GHz.