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Antibacterial evaluation of radiolytically synthesized silver nanoparticles with ι-carrageenan stabilizers

Radiation physics and Chemistry 2025年 236卷

作者： Gili, Mon Bryan Z. Manuel, Wendell A. Guillermo, Neil Raymund D. Shankaregowda, Rakshith Gowda H. Phan, Manh-Huong Conato, Marlon T. Vega, Marienette M. Department of Science and Technology Philippine Nuclear Research Institute Commonwealth Avenue Diliman Quezon City 1101 Philippines Materials Science and Engineering Program College of Science University of the Philippines Diliman Diliman Quezon City 1101 Philippines Department of Physics University of South Florida 4202 East Fowler Avenue Tampa 33620 FL United States Institute of Chemistry College of Science University of the Philippines Diliman Diliman Quezon City 1101 Philippines

The synthesis of silver nanoparticles (AgNPs) using green, eco-friendly methods has garnered significant attention due to the potential advantages of using natural polymers, such as ι-carrageenan, as stabilizing agents. However, challenges remain in controlling the size, distribution, and stability of the nanoparticles, as well as optimizing their antimicrobial activity. In this study, gamma irradiation of ι-carrageenan solutions was investigated as a method for synthesizing AgNPs and exploring their antimicrobial properties. The primary objective was to assess how varying radiation doses and ι-carrageenan concentrations affect the formation, size distribution, and antimicrobial activity of the AgNPs. ι-Carrageenan solutions (0.1, 0.5, and 1.0 w/v %) were mixed with 0.2 M silver nitrate (AgNO₃) solutions and irradiated at doses ranging from 0 to 20 kGy using Co-60. UV–vis spectroscopic analysis indicated the successful formation of AgNPs, with surface plasmon resonance (SPR) peaks appearing between 402 and 418 nm. These peaks shifted slightly towards shorter wavelengths as the irradiation rose, signaling a reduction in nanoparticle size. The optimal synthesis of AgNPs occurred at 0.5 % ι-carrageenan concentration and a dose of 15 kGy, where the SPR peak intensity and nanoparticle formation were most pronounced. XRD confirmed the presence of silver nanoparticles with face-centered cubic (FCC) structure. Particle size analysis, using dynamic light scattering (DLS), revealed that AgNPs ranged in size from 85 to 142 nm, with smaller particles forming at higher doses. At a 1 kGy dose, the nanoparticle size averaged 114 nm, but increased doses (15–20 kGy) led to a significant reduction in particle size to 85 nm. This size reduction was attributed to the fragmentation of larger particles as the irradiation dose increased. Fourier-transform infrared (FTIR) spectroscopy showed notable changes in the ι-carrageenan structure, with the formation of new functional gro

关键词： Antimicrobial Gamma-irradiation Radiolysis Silver nanoparticles Ι-Carrageenan

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Phase-transition-free rivets for layered oxide potassium cathodes

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Nano Research 2024年第11期17卷 9671-9678页

作者： Jie Chen Apparao M. Rao Caitian Gao Jiang Zhou Limei Cha Xiaoming Yuan Bingan Lu School of Physics and Electronics Hunan University Changsha 410082 China Department of Physics and Astronomy Clemson Nanomaterials Institute Clemson University Clemson SC USA School of Materials Science and Engineering Central South University Changsha 410083 China Materials Science and Engineering program Guangdong Technion-Israel Institute of Technology Shantou 515063 China Materials Science and Engineering program Technion-Israel Institute of Technology Haifa 32000 Israel MATEC Key Lab Guangdong Technion-Israel Institute of Technology Shantou 515063 China Hunan Key Laboratory of Nanophotonics and Devices School of Physics Central South University Changsha 410078 China

As a cathode material for potassium-ion batteries (PIBs), manganese-based layered oxides have attracted widespread attention due to their low cost, ease of synthesis, and high performance. However, the Jahn-Teller effect caused by Mn3+ and the irreversible phase transformation of the structure leads to poor cycle stability, limiting the development of layered oxides in PIBs. Herein, we demonstrate the use of phase-transition-free CaTiO_(3) as rivets in K_(0.5)Mn_(0.9)Ti_(0.1)O_(2) by a simple solid-state method. As verified by the in situ X-ray diffraction, the CaTiO_(3) rivets effectively prevent the slippage of the transition metal layer during charge and discharge, inhibiting structural degradation. As a result, the obtained K_(0.5)Mn_(0.9)Ti_(0.1)O_(2)-0.02CaTiO_(3) shows excellent cycling stability and rate performance, with high capacities of 119.3 and 70.1 mAh·g^(-1) at 20 and 1000 mA·g^(-1), respectively. At 200 mA·g^(-1), the capacity retention remains 94.7% after more than 300 cycles. This work represents a new avenue for designing and optimizing layered cathode materials for PIBs and other batteries.

关键词： potassium cathodes layered oxide phase-transition-free perovskite rivets

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Blockage effects in the chemotaxis of diffusiophoretic particles

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Soft matter 2025年 2025 May 20页

作者： Zehao Song Matthew Farnese Ahis Shresth Monica Olvera de la Cruz Department of Physics & Astronomy Northwestern University Evanston IL 60208 USA. Applied Physics Program Northwestern University Evanston IL 60208 USA. Center for Computation & Theory of Soft Materials Northwestern University Evanston IL 60208 USA. Department of Materials Science & Engineering Northwestern University Evanston IL 60208 USA.

Transport mechanisms at the micro- and nano-scale play an essential role in regulating intracellular organization. Recent work indicates that directed motion of constituents inside cells can emerge through diffusiophoretic transport, in which colloidal particles move under the influence of chemical gradients. Here, we examine how blockers-passive or actively consuming-reshape those gradients and thereby influence the motion of diffusiophoretic particles. By combining analytical solutions with finite element simulations, we first show that a single blocker can distort a background gradient enough to create or eliminate stagnation points, significantly modifying particle transport. We then introduce a second, explicitly sized blocker at one of these stagnation points and measure how its finite radius alters the diffusiophoretic velocity field for a test particle. Even moderate changes in the second blockers size can cause noticeable shifts in the substrate distribution, highlighting the importance of accounting for explicit particle radii under crowded or consumption-driven conditions. Our findings underscore that subtle geometric variations-such as the radii and positions of two or more blockers-can profoundly affect diffusiophoretic motion, providing a more complete picture of how blocking and crowding phenomena shape intracellular transport.

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Terahertz Cavity Phonon Polaritons in Lead Telluride in the Deep-Strong Coupling Regime

arXiv

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arXiv 2025年

作者： Baydin, Andrey Manjappa, Manukumara Mishra, Sobhan Subhra Xu, Hongjing Doumani, Jacques Tay, Fuyang Kim, Dasom Rappl, Paulo H.O. Abramof, Eduardo Singh, Ranjan Hernandez, Felix G.G. Kono, Junichiro Department of Electrical and Computer Engineering Rice University HoustonTX77005 United States Smalley–Curl Institute Rice University HoustonTX77005 United States Rice Advanced Materials Institute Rice University HoustonTX77005 United States Instrumentation and Applied Physics Department Indian Institute of Science Bangalore560012 India Center for Disruptive Photonic Technologies The Photonics Institute Nanyang Technological University 639798 Singapore Department of Physics and Astronomy Rice University HoustonTX77005 United States Applied Physics Graduate Program Smalley–Curl Institute Rice University HoustonTX77005 United States Group of Research and Development in Materials and Plasma National Institute for Space Research São José dos Campos São Paulo12201-970 Brazil Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University 637371 Singapore Instituto de Física Universidade de São Paulo São Paulo05508-090 Brazil Department of Material Science and NanoEngineering Rice University HoustonTX77005 United States

Lead telluride is an important thermoelectric material due to its large Seebeck coefficient combined with its unusually low thermal conductivity that is related to the strong anharmonicity of phonons in this material. Here, we have studied the resonant and nonperturbative coupling of transverse optical phonons in lead telluride with cavity photons inside small-mode-volume metallic metasurface cavities that have photonic modes with terahertz frequencies. We observed a giant vacuum Rabi splitting on the order of the bare phonon and cavity frequencies. Through terahertz time-domain spectroscopy experiments, we systematically studied the vacuum Rabi splitting as a function of sample thickness, temperature, and cavity length. Under the strongest light–matter coupling conditions, the strength of coupling exceeded the bare phonon and cavity frequencies, putting the system into the deep-strong coupling regime. These results demonstrate that this uniquely tunable platform is promising for realizing and understanding predicted cavity-vacuum-induced ferroelectric instabilities and exploring applications of light–matter coupling in the ultrastrong and deep-strong coupling regimes in quantum technology. Copyright © 2025, The Authors. All rights reserved.

关键词： Phonons

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Synthesis and characterization of few-layered carbon nanotubes decorated with magnetic nanoparticles envisaging potential technological applications

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Surfaces and Interfaces 2025年 66卷

作者： da Silva, Wellington Marcos da Silva, Mauro Francisco Pinheiro de Souza, Rodrigo Nunes Silva, Alysson Martins Almeida Rodrigues, Alisson Mendes Santos, Alexandre Silva da Silva, SebastiãoWilliam Mohallem, Nelcy Della Santina Coaquira, José Antonio Huamaní Graduate Program in Materials Science (PPGCIMA) Faculty UnB Planaltina (FUP) University of Brasília DF Brasilia 73.345-010 Brazil International Center of Physics Institute of Physics Campus Universitário Darcy Ribeiro University of Brasilia DF Brasilia 70.910-900 Brazil Mechanical Engineering Department Faculty of Technology Campus Universitário Darcy Ribeiro University of Brasilia DF Brasilia 70.910-900 Brazil Institute of Physics University of Brasilia Campus Universitário Darcy Ribeiro DF Brasilia 70.910-900 Brazil Department of Chemistry Institute of Exact Sciences Federal University of Minas Gerais Belo Horizonte-MG MG 31270-901 Brazil

In this work, high-quality few-layered carbon nanotubes (CNTs) were synthesized using a novel iron-oxide/sulfur-based catalyst via the chemical vapor deposition method (CVD). To enable external magnetic control for potential technological applications, CNTs incorporating magnetic nanoparticles were also produced. An efficient synthesis route, employing a microwave-assisted reaction, was used to generate and integrate the iron oxide nanoparticles and CNTs. The synthesized nanomaterials were thoroughly characterized using X-ray diffraction (XRD), Raman spectroscopy, thermogravimetric analysis (TGA/DTA), transmission electron microscopy (TEM) and magnetic measurements. The results indicate that the few-layered CNTs (sample CNT-Ox) exhibit a magnetic response, which is further modified upon the incorporation of magnetic nanoparticles (sample CNT-Ox-Mag), suggesting an effective interaction between the CNTs and the magnetic nanoparticles. However, after a reduction process (sample CNT-Ox-Mag-Red), the magnetization increases approximately 20-fold compared to the other two samples. This significant enhancement reflects the presence of a substantial amount (∼48 %) of metallic iron primarily located within the CNTs channel. Raman spectroscopy revealed characteristic bands at 261 and 263 cm⁻¹, confirming the presence of single and few-layered CNTs. TEM images further demonstrate that the nanoparticles are encapsulated within the CNTs. These findings indicate the successful formation of a hybrid CNTs/magnetic nanoparticles system, which serve as a multifunctional platform with promising potential for technological applications. © 2025 Elsevier B.V.

关键词： Carbon nanotubes Magnetic nanoparticles Magnetic properties Novel catalyst Synthesis

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BPS2025 - A feedback trap for bio-orthogonal 3D manipulation of magnetic nanoparticles

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Biophysical Journal 2025年第3期124卷 495a-496a页

作者： Trevor Anderberg Kepler Domurat-Sousa Andres Cook Maya G. Igarashi Nikhil Maserang Justin E. Jureller Aaron Esser-kahn Allison Squires Department of Physics University of Chicago Chicago IL USA School of Molecular Engineering University of Chicago Chicago IL USA Biophysical Science Program University of Chicago Chicago IL USA Department of Physics University of California Berkeley Berkeley CA USA Materials Research Science and Engineering Center University of Chicago Chicago IL USA

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Ultrafast switchable polar and magnetic orders by nonlinear light-matter interaction

arXiv

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arXiv 2025年

作者： Wei, Haoyu Kaplan, Daniel Xu, Haowei Li, Ju Department of Materials Science and Engineering Massachusetts Institute of Technology CambridgeMA02139 United States Tsien Excellence in Engineering Program Tsinghua University Beijing100084 China Department of Applied Physics Yale University New HavenCT06520 United States Center for Materials Theory Department of Physics and Astronomy Rutgers University PiscatawayNJ08854 United States Department of Nuclear Science and Engineering Massachusetts Institute of Technology CambridgeMA02139 United States

An outstanding challenge in materials science and physics is the harnessing of light for switching charge order in e.g., ferroelectrics. Here we propose a mechanism through which electrons in ferroelectric bilayers excited with light cause ionic structural transitions. Using perturbation theory within a many-body formalism, we show that the ionic coupling is mediated by a resonant change in electronic occupation functions, ultimately governed by the quantum geometric tensor (QGT) of the ground state. Furthermore, we show that such transitions are generally accompanied by multiferroic order switching. We demonstrate two examples of light-induced structural and polarization switching under this mechanism using first-principle calculations on bilayer CrI3 and MoTe2 . We show that the two materials can switch between atomic stackings with a light intensity threshold of only 101-102GW/cm2, a value 1-3 orders of magnitude lower than that required by direct light-ion coupling thanks to the superior efficiency of resonant light-electron coupling. Since such switching is fast, highly controllable, contactless, and reversible, it is promising for use in optically controlled nonvolatile memory, nanophotonics and electronic devices. Copyright © 2025, The Authors. All rights reserved.

关键词： Perturbation techniques

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Optically Detected Magnetic Resonance Imaging and Sensing Within Functionalized Additively Manufactured Microporous Structures

arXiv

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arXiv 2025年

作者： Blankenship, Brian W. Rho, Yoonsoo Jones, Zachary Meier, Timon Li, Runxuan Druga, Emanuel Singh, Harpreet Xia, Xiaoxing Ajoy, Ashok Grigoropoulos, Costas P. Laser Thermal Laboratory Department of Mechanical Engineering University of California BerkeleyCA94720 United States Ulsan44919 Korea Republic of Department of Chemistry University of California BerkeleyCA94720 United States Biological Systems and Engineering Division Lawrence Berkeley National Laboratory BerkeleyCA94720 United States Department of Physics Guru Nanak Dev University Punjab Amritsar143005 India Materials Engineering Division Lawrence Livermore National Laboratory LivermoreCA94550 United States Chemical Sciences Division Lawrence Berkeley National Laboratory BerkeleyCA94720 United States CIFAR Azrieli Global Scholars Program 661 University Ave TorontoONM5G 1M1 Canada

Quantum sensing with nitrogen-vacancy centers in diamond has emerged as a powerful tool for measuring diverse physical parameters, yet the versatility of these measurement approaches is often limited by the achievable layout and dimensionality of bulk-crystal platforms. Here, we demonstrate a versatile approach to creating designer quantum sensors by surface-functionalizing multiphoton lithography microstructures with NV-containing nanodiamonds. We showcase this capability by fabricating a 150 μm x 150 μm x 150 μm triply periodic minimal surface gyroid structure with millions of attached nanodiamonds. We demonstrate a means to volumetrically image these structures using a refractive index matching confocal imaging technique, and extract ODMR spectra from 1.86 μm x 1.86 μm areas of highly concentrated nanodiamonds across a cross section of the gyroid. Furthermore, the high density of sensing elements enables ensemble temperature measurements with sensitivity of 0.548 °K/√Hz at 5 mW excitation power. This approach to creating quantum-enabled microarchitectures opens new possibilities for multimodal sensing in complex three-dimensional environments. Copyright © 2025, The Authors. All rights reserved.

关键词： Nanocrystals

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An efficient and accurate framework for calculating lattice thermal conductivity of solids:AFLOW-AAPL Automatic Anharmonic Phonon Library

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npj Computational materials 2017年第1期3卷 79-88页

作者： Jose J.Plata Pinku Nath Demet Usanmaz Jesus Carrete Cormac Toher Maarten de Jong Mark Asta Marco Fornari Marco Buongiorno Nardelli Stefano Curtarolo Department of Mechanical Engineering and Materials Science Duke UniversityDurhamNC 27708USA Institute of Materials Chemistry TU WienA-1060 ViennaAustria Department of Materials Science and Engineering University of CaliforniaBerkeley210 Hearst Memorial Mining BuildingBerkeleyUSA SpaceX 1 Rocket RoadHawthorneCA 90250USA Department of Physics and Science of Advanced Materials Program Central Michigan UniversityMount PleasantMI 48859USA Department of Physics and Department of Chemistry University of North TexasDentonTXUSA Materials Science Electrical EngineeringPhysics and ChemistryDuke UniversityDurhamNC 27708USA

One of the most accurate approaches for calculating lattice thermal conductivity,κ_(l),is solving the Boltzmann transport equation starting from third-order anharmonic force *** addition to the underlying approximations of ab-initio parameterization,two main challenges are associated with this path:high computational costs and lack of automation in the frameworks using this methodology,which affect the discovery rate of novel materials with ad-hoc ***,the Automatic Anharmonic Phonon Library(AAPL)is *** efficiently computes interatomic force constants by making effective use of crystal symmetry analysis,it solves the Boltzmann transport equation to obtain κ_(l),and allows a fully integrated operation with minimum user intervention,a rational addition to the current high-throughput accelerated materials development framework ***“experiment ***”study of the approach is shown,comparing accuracy and speed with respect to other available packages,and for materials characterized by strong electron localization and *** AAPL with the pseudo-hybrid functional ACBN0 is possible to improve accuracy without increasing computational requirements.

关键词： properties. harmonic calculating

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Oscillatory Hall effect from magnetoelectronic coupling in flexoelectronic silicon

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Physical Review B 2024年第8期109卷 L081113-L081113页

作者： Paul C. Lou Ravindra G. Bhardwaj Anand Katailiha W. P. Beyermann Sandeep Kumar Department of Mechanical Engineering University of California Riverside California 92521 USA Department of Physics and Astronomy University of California Riverside California 92521 USA Materials Science and Engineering Program University of California Riverside California 92521 USA

Magnetoelectronic coupling can be defined as cross-domain coupling between electronic and magnetic properties, where modulation in magnetic properties changes the electronic properties. In this Letter, explicit experimental evidence of magnetoelectronic coupling is presented, which is uncovered from the oscillatory Hall effect response in Hall measurement. The strain gradient in a MgO (1.8 nm)/p-Si (∼400 nm) freestanding sample leads to transfer of electrons (∼5×1018cm−3) from valence to conduction band due to flexoelectronic charge separation in the p-Si layer. The resulting flexoelectronic polarization gives rise to the temporal magnetic moment from dynamical multiferroicity. The external magnetic field changes the net temporal magnetic moment, which causes modulations in charge carrier concentration and oscillatory Hall effect. The period of oscillatory Hall response is 1.12 T, which is attributed to the magnitude of the temporal magnetic moment. The discovery of the oscillatory Hall effect adds another member to the family of Hall effects.

关键词： Hall effect Doped semiconductors Electronically polarized systems Flexoelectrics Multiferroics Hall bar

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