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Solid-State Fluorescence-based Sensing of TATP via Hydrogen Peroxide Detection
摘要： Fluorenylboronate ester chromophore-based thin films were investigated for the detection of triacetone triperoxide (TATP) vapors via the decomposition product, hydrogen peroxide. Sensing with a high level of sensitivity was achieved using a fluorescence "turn-on" mechanism based on the significant shifts in the absorption and photoluminescence spectra that occurs when the boronate esters were converted to phenoxides by hydrogen peroxide under basic conditions. The addition of an organic base was found to be critical for achieving fast conversion reactions and the formation of the phenoxide anions. Addition of a nitrile group to the fluorenyl boronate ester moiety improved the stability of the material to photooxidation, increased the photoluminescence quantum yields, and enhanced the absorption and emission shifts to longer wavelengths. In real-time sensing measurements, films comprising the cyanofluorenyl boronate ester moiety and tetra-n-butylammonium hydroxide had a response time to acid-decomposed TATP vapor of seconds and a limit of detection of 40 ppb in 60 s.
关键词： fluorenylboronate ester,triacetone triperoxide,phenoxide,nitrile,fluorescence,hydrogen peroxide
更新于2025-09-23 15:23:52
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Insight into the compatibility between C4F7N and silver: Experiment and theory
摘要： Fluorinated nitrile (C4F7N) has received much attention as substitute gas for sulfur hexafluoride (SF6) using in electrical equipment over the past two years. In this paper, we explored the compatibility between C4F7N and silver theoretically and experimentally. The interaction mechanism between C4F7N and silver was investigated based on the density functional theory (DFT) and the composition characteristics of C4F7N and silver after long term interaction were also revealed. It was found that the most energetically favorable adsorption structure has the adsorption energy of 0.69 eV with 0.024e charge transfer. Electron localization function (ELF) also shows evidently electron delocalization region between C4F7N and Ag (1 1 1). Thus the interaction mechanism belongs to physisorption and the van der Waals force plays a major role. The gas composition of C4F7N, the morphology and crystal structure of silver did not have any obvious change after 70 days’ interaction, which indicates the compatibility between C4F7N and silver is great.
关键词： fluorinated nitrile,compatibility,SF6 alternative gas,silver
更新于2025-09-23 15:21:01
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Nanosecond Pulsed Laser Processing Turns Engineering Metal Alloys Antireflective and Superwicking
摘要： In this work, superwicking and antireflective properties are achieved on engineering metal surfaces by creating surface pattern using a high pulse energy nanosecond laser followed by a chemical immersion treatment. The high-energy nanosecond pulse laser scans the metal surface in air. Subsequently, the laser-textured surface is further treated by immersion in a 3-cyanopropyltricholosilane reagent. As a result of these two processes, microgrooves with micro- and nano-scale surface features are generated on the metal surface. Due to the created surface structure and favorable surface chemistry, water sprints uphill defying the gravity. The fast self-propelling movement of water is due to the supercapillary effect of the surface microchannel and the superhydrophilic surface nitrile group. The wicking effect on the processed surface follows the classical square root of time dependence. The processed surface shows good antireflective properties in visible and infrared spectrum. Surface features, surface chemistry, surface wettability, surface reflectivity and surface wicking behavior are measured on AA6061 and Ti-6Al-4V specimens through Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), contact angle goniometer, UV-VIS-NIR spectrometer and high-speed camera.
关键词： Nitrile,Superwicking,Capillary,Nanosecond Laser,Silane
更新于2025-09-12 10:27:22
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Millimeter wave absorbing property of flexible graphene/acrylonitrile-butadiene rubber composite in 5G frequency band
摘要： The coming fifth generation mobile communication technology (5G) puts forward enormous requirements on millimeter wave (MMW) absorbing materials above 24 GHz. In the present work, elastic absorbing composites were fabricated with reduced graphene oxide (RGO) of different reduction time and nitrile rubber (NBR). A series of characterization methods were used to study the reduction degree and the structure of composites, the electromagnetic parameters of composites in 26.5–40 GHz were also measured and used to conduct an analytical computation of reflection loss (RL). It was found that, 3h-RGO/NBR presented the minimum RL of ?45 dB at 35.4 GHz while 7h-RGO/NBR exhibited the widest effective bandwidth (<-10 dB) about 6.5 GHz. In addition, the mechanical properties of composites were also improved by RGO. Therefore, the obtained RGO/NBR composites displayed promising prospect as elastic MMW absorbing materials for 5G applications.
关键词： 5G Frequency Band,reduced graphene oxide,Nitrile rubber,millimeter wave absorbing
更新于2025-09-10 09:29:36
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[ACS Symposium Series] Raman Spectroscopy in the Undergraduate Curriculum Volume 1305 || Solvent Sensitivity of the ?C≡N Group: A Raman Spectroscopic Study
摘要： The cyano or nitrile group, ?C≡N, exhibits a distinct vibrational mode around the 2100–2300 cm-1 region that is highly sensitive to the solvent polarity, hydrogen bonding interactions, and the electric field around it. In this chapter, the solvent sensitivity of the ?C≡N group was studied using Raman spectroscopy. First, the Raman spectra of ?C≡N-containing samples ranging from acetonitrile to nitrile gloves were contrasted. Second, we give an example where the ?C≡N group had an associated pH dependence due to the groups around it. Lastly, we studied the effect of various solvents on the ?C≡N mode. Raman assignments were verified using DFT-based calculations.
关键词： cyano group,DFT calculations,Raman spectroscopy,nitrile group,solvent sensitivity
更新于2025-09-09 09:28:46