This paper reports a methodology for synthesizing and ordering gold nanorods into two-dimensional arrays at a water/hexane interface. This preparation method allows the systematic control of the nanoparticle film thickness. An investigation into the thickness-dependent surface-enhanced Raman scattering (SERS) of the adsorbed molecules revealed the nanorod (NR) films to have 1 order of magnitude stronger SERS enhancement than the nanosphere (NS) under similar experimental conditions. The exposed surface areas of the prepared NR and NS films were analyzed using electrochemical methods, and it was found that they had comparable exposed surface areas. Therefore, the order of magnitude difference in the enhancement factor was not due to the differences in surface area but to their intrinsic difference in the optical coupling of each film. The difference was attributed to the high density of junction points with the NR films in comparison with the corresponding NS films. Scanning emission microscopy showed that the NR films have line contacts with each other but the NS films have point contacts, which can explain the difference in SERS intensity between the NR and NS films.
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http://dx.doi.org/10.1021/ac071440c | DOI Listing |
Nanotechnology
January 2025
Technische Universität München School of Computation Information and Technology, Hans-Piloty-Strasse 1, 85748 Garching bei Muenchen, Munich, 85748, GERMANY.
We investigate the effect of focused-ion-beam (FIB) irradiation on spin waves with sub-micron wavelengths in Yttrium-Iron-Garnet (YIG) films. Time-resolved scanning transmission X-ray (TR-STXM) microscopy was used to image the spin waves in irradiated regions and deduce corresponding changes in the magnetic parameters of the film. We find that the changes of Gairradiation can be understood by assuming a few percent change in the effective magnetizationof the film due to a trade-off between changes in anisotropy and effective film thickness.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China.
Polymer-based dielectric films are increasingly demanded for devices under high electric fields used in new energy vehicles, photovoltaic grid connections, oil and gas exploration, and aerospace. However, leakage current is one of the significant factors limiting the improvement of the insulation performance. This paper tested the leakage current and condensed state structure characteristics of biaxially oriented polypropylene (BOPP) films and obtained the nonlinear characteristics of leakage current of BOPP films in the range of 40-440 V/μm and 40-110 °C.
View Article and Find Full Text PDFLangmuir
January 2025
Chemistry and Structure of novel Materials, University of Siegen, Paul-Bonatz Strasse 9-11, 57068 Siegen, Germany.
The surface charge of metal oxides is an important property that significantly contributes to a wide range of phenomena, including adsorption, catalysis, and material science. The surface charge can be predicted by determining the isoelectric point (IEP) of a material and the pH of a solution. Although there have been several studies of the IEP of metal oxide (nano)particles, only a few have reported the IEP of metal oxide films.
View Article and Find Full Text PDFACS Nano
January 2025
Department of Mechanical Engineering, University of California at Riverside, Riverside, California 92521, United States.
Sensing light's polarization and wavefront direction enables surface curvature assessment, material identification, shadow differentiation, and improved image quality in turbid environments. Traditional polarization cameras utilize multiple sensor measurements per pixel and polarization-filtering optics, which result in reduced image resolution. We propose a nanophotonic pipeline that enables compressive sensing and reduces the sampling requirements with a low-refractive-index, self-assembled optical encoder.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Nanjing University, College of Engineering and Applied Sciences, No. 163 Xianlin Avenue, Qixia District, Nanjing, Nanjing, CHINA.
Electrolyte engineering has emerged as an effective strategy for stabilizing Zn-metal anodes. However, a single solute or solvent additive is far from sufficient to meet the requirements for electrolyte cycling stability. Here, we report a new-type high-entropy electrolyte composed of equal molar amounts of Zn(OTf)2 and LiOTf, along with equal volumes of H2O, triethyl phosphate, and dimethyl sulfoxide, which enhances electrolyte stability by increasing solvation entropy.
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