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Fast synthesis of gold nanoparticles by cold atmospheric pressure plasma jet in the presence of Au+ions and a capping agent

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Plasma Science and Technology 2024年第7期26卷 108-115页

作者： Tatiana HABIB José Mauricio A.CAIUT Bruno CAILLIER Laboratoire Diagnostics des Plasmas Hors Equilibre(DPHE) Universitéde ToulouseINU ChampollionAlbi 81000France Department of Chemistry The Nanomaterials and Luminescent Systems GroupFaculty of PhilosophyScience and Letters at Ribeirão PretoUniversity of São PauloRibeirão Preto-SP 14040-901Brazil

Homogeneous gold nanoparticles were synthesized under atmospheric pressure using a nonthermal helium plasma jet in a single-step process.A current power supply was used to generate the plasma discharge rich in diverse reactive species.These species induce rapid chemical reactions responsible for the reduction of the gold salts upon contact with the liquid solution.In this study,spherical and monodispersed gold nanoparticles were obtained within 5 min of plasma exposure using a solution containing gold(Ⅲ)chloride hydrate(HAuCl_(4))as a precursor and polyvinylpyrrolidone(PVP)as a capping agent to inhibit agglomerations.The formation of these metal nanoparticles was initially perceptible through a visible change in the sample's color,transitioning from light yellow to a red/pink color.This was subsequently corroborated by UVvis spectroscopy,which revealed an optical absorption in the 520-550 nm range for Au NPs,corresponding to the surface plasmon resonance(SPR)band.An investigation into the impact of various parameters,including plasma discharge duration,precursor and capping agent concentrations,was carried out to optimize conditions for the formation of well-separated,spherical gold nanoparticles.Dynamic light scattering(DLS)was used to measure the size of these nanoparticles,transmission electron microscopy(TEM)was used to observe their morphology and X-ray diffraction(XRD)was also employed to determine their crystallographic structure.The results confirm that homogeneous spherical gold nanoparticles with an average diameter of 13 nm can be easily synthesized through a rapid,straightforward,and environmentally friendly approach utilizing a helium atmospheric pressure plasma.

关键词： gold nanoparticles non-thermal plasma jet helium DBD

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Model investigation of non-thermal phase transition in high energy collisions

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Science China Mathematics 2000年第7期43卷 780-784页

作者：王琴李治明刘连寿 Institute of Particle Physics Huazhong Normal University Wuhan 430079 China

The non-thermal phase transition in high energy collisions is studied in detail in the frame-work of random cascade model. The relation between the characteristic parameter γq of phase transition and the rank q of moment is obtained using Monte Carlo simulation, and the existence of two phases in self-similar cascading multiparticle systems is shown. The relation between the critical point qc of phase transition on the fluctuation parameter a is obtained and compared with the experimental results from NA22. The same study is carried out also by analytical calculation under central limit ap-proximation. The range of validity of the central limit approximation is discussed.

关键词： random cascade multifractal anomalous scaling non-thermal phase transition.

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A New Strategy for Improving the Efficiency of Low-temperature Selective Catalytic Reduction of NOx with CH4via the Combination of non-thermal Plasma and Ag2O/TiO2 Photocatalyst

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Chemical Research in Chinese Universities 2019年第6期35卷 1062-1069页

作者： WANG Hui WANG Jiafeng ZHANG Lei YU Qinqin CHEN Zewen WU Shengji College of Materials and Environmental Engineering Hangzhou Dianzi UniversityHangzhou 310018P.R.China School of Chemistry Chemical Engineering and Life SciencesWuhan University of TechnologyWuhan 430070P.R.China

In the present work,a remarkable combination of non-thermal plasma and photocatalyst was developed to widen the operating temperature window of selective catalytic reduction(SCR)of NOx with CH4,especially to improve the low-temperature removal efficiency of NOx.It was shown that the operating temperature window was significantly widened.Among all the catalysts prepared,1%Ag2O/TiO2 showed the highest catalytic activity for NOx removal due to the utilization of near ultraviolet light.The conversion of NOx to N2 over the in-plasma 1%Ag2O/TiO2 photocatalyst at 60 and 300℃ could achieve 31.8%and 53.0%,respectively.The combination mode of plasma and catalyst affected NOx removal efficiency greatly,the in-plasma catalysis outperformed the post-plasma catalytic mode remarkably,signifying the contribution of photocatalytic processes on the catalysts.Meanwhile,the characterizations of the catalyst demonstrated that the morphology and structure of the Ag2O/TiO2 catalyst were unchanged throughout the non-thermal plasma and photocatalytic processes,implying the superior stability of the catalyst.

关键词： non-thermal plasma,Photocatalyst,NOx Ag2O/TiO2 CH4

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Revisiting “non-thermal” Batch Microwave Oven Inactivation of Microorganisms

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American Journal of Analytical Chemistry 2023年第1期14卷 28-54页

作者： Victor John Law Denis Pius Dowling School of Mechanical and Materials Engineering University College Dublin Dublin Ireland

Over the last few decades there has been active discussion concerning the mechanisms involved in “non-thermal” microwave-assisted inactivation of microorganisms. This work presents a novel non-invasive acoustic measurement of a domestic microwave oven cavity-magnetron operating at fo = 2.45 ± 0.05 GHz (λo ~ 12.2 cm) that is modulated in the time-domain (0 to 2 minutes). The measurements reveal the cavity-magnetron cathode filament cold-start warm-up period and the pulse width modulation periods (time-on time-off and base-time period, where time-on minus base-time = duty cycle). The waveform information is used to reconstruct historical microwave “non-thermal” homogeneous microorganism inactivation experiments: where tap-water is used to mimic the microorganism suspension;and ice, crushed ice, and ice slurry mixture are used as the cooling media. The experiments are described using text, diagrams, and photographs. Four key experimental parameters are indentified that influence the suspension time-dependent temperature profile. First, where the selected process time > the time-base, the cavity-magnetron continuous wave rated power should be used for each second of microwave illumination. Second, external crushed ice and ice slurry baths induce different cooling profiles due to difference in their heat absorption rates. In addition external baths may shield the suspension resulting in a retarding of the time-dependent heating profile. Third, internal cooling systems dictate that the suspension is directly exposed to microwave illumination due to the absence of surrounding ice volume. Fourth, four separated water dummy-loads isolate and control thermal heat transfer (conduction) to and from the suspension, thereby diverting a portion of the microwave power away from the suspension. Energy phase-space projections were used to compare the “non-thermal” energy densities of 0.03 to 0.1 kJ·m-1 at 800 W with reported thermal microwave-assisted microorganism inactivation energy densities of

关键词： thermal non-thermal Microwave-Assisted Microwave Oven Acoustic Food Microorganisms

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Deposition of stain resistance coating by non-thermal plasma brush application to dental whitening

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Plasma Science and Technology 2019年第6期21卷 115-121页

作者：徐雨董晓庆李雪艳 Meng CHEN 张菁 Qingsong YU State Key Laboratory for Modification of Chemical Fibers and Polymer Materials and College of Materials Science and Engineering Donghua University Shanghai 201620 People's Republic of China Department of Mechanical and Aerospace Engineering Missouri University E3411 Lafferre HallColumbia MO 65211 United States of America Stomatology department Eye and Eat Hospital of Fudan University Shanghai 200031 People's Republic of China

A non-thermal plasma brush is employed to deposit stain-resistant SiO2-like coatings on resin composite fillings and bovine teeth.With post-treating by plasma,the hardness of the coating increases from H to 8H and the water contact angle decreases from 98.8° to 61.7°.The Fourier transform infrared spectroscopy (FTIR) results show that,after plasma post-treating,the Si-O-Si and Si-OH bonds of the coating increase.Scanning electron microscope (SEM) images show the coatings to be uniform,without cracks.The coatings present outstanding performance in a stain resistance test both on resin composite and bovine teeth.Being easy to handle and less time consuming than traditional methods,with a body-friendly temperature and material,this plasma brush provides a promising in-situ coating method on patient teeth in dental clinics.

关键词： non-thermal plasma brush stain-resistant coating dental plasma post-treatment

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Study on purification technology of polyacrylamide wastewater by non-thermal plasma

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Plasma Science and Technology 2019年第5期21卷 66-72页

作者：荣俊锋朱凯勋陈明功 School of Chemical Engineering Anhui University of Science and Technology

In this work,non-thermal plasma has been applied to treat polyacrylamide(PAM)wastewater.We have investigated the in fluence of the rule of PAM wastewater initial pH,solution concentration and discharge time,discharge voltage on chemical oxygen demand(COD)degradation rate.At the same time,the effect of pH and discharge time on the viscosity removal rate of PAM solution was also studied.Then,the effect of pH on the viscosity removal rate of 1.0g 1^-1 PAM solution was studied separately.Through orthogonal test,the factors affecting the COD degradation rate of PAM wastewater were determined as follows:discharge time>discharge voltage>solution concentration>wastewater initial pH.1'he COD highest removal rate of PAM wastewater reached 85.74%,when the optimal conditions are as follows:discharge voltage 40 kV,discharge time 5 h,solution concentration 1.0 g 1^-1,pH 1.5.This research provides some basic data and new theoretical basis for PAM wastewater purification.

关键词： non-thermal plasma polyacrylamide COD degradation rate viscosity removal rate discharge voltage

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1,2,4-trichlorobenzene decomposition using non-thermal plasma technology

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Plasma Science and Technology 2020年第3期22卷 71-78页

作者：竹涛张星马名烽王礼锋薛泽宇侯益铭叶泽甫刘桐珅 Institute of Atmospheric Environmental Management and Pollution Control China University of Mining&Technology(Beijing)Beijing 100083People’s Republic of China Shaanxi Key Laboratory of Lacustrine Shale Gas Accumulation and Exploitation(under planning) Xi’an 710075People’s Republic of China Gemeng International Co. LtdTaiyuan 030002People’s Republic of China Beijing Municipal Research Institute of Environmental Protection Beijing 100037People’s Republic of China

non-thermal plasma(NTP)is regarded as a potential application for environmental pollution control due to its ability to remove pollutants.As a major precursor of dioxins,the influence of the parameters of 1,2,4-trichlorobenzene(TCB)decomposition using NTP technology was investigated through a series of experiments,including voltage,frequency,water content,initial concentration,flow rate,and oxygen content.The experimental results show that the energy injected into the NTP system has a positive correlation to voltage and frequency.Oxygen has the greatest influence on TCB decomposition.The optimal reaction condition was at 15 kV,1000 Hz,an initial concentration of 20 mg m^?3,a flow rate of 2 l min^?1,H2O at 4%,and O2 at 0%.Under this condition,the TCB removal efficiency could reach 92%.According to the generated product backstepping,the hydroxyl radical(·OH)plays an important role in TCB decomposition due to its strong oxidation,which participates in the dechlorination and oxidation reactions as free radicals,and the possible decomposition pathway of TCB by NTP is inferred from the identified byproducts.It is of great significance to investigate the influence of the parameters of TCB decomposition using NTP technology in order to provide references for industrial application.

关键词： non-thermal plasma pulse discharge influence parameter 1,2,4-trichlorobenzene decomposition removal efficiency

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non-Linear Ion-Acoustic Solitary Waves in Electron-Positron-Ion Plasma with non-thermal Electrons

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Journal of Modern Physics 2017年第6期8卷 892-902页

作者： S. K. Anguma I. Habumugisha L. Nazziwa E. Jurua N. Noreen Department of Physics Muni University Arua Uganda Department of Physics Kabale University Kabale Uganda Department of Physics Islamic University in Uganda Mbale Uganda Department of Physics Bishop Stuat University Kakoba Uganda Department of Physics Mbarara University of Science and Technology Mbarara Uganda Department of Physics Forman Christian College (Chartered University) Lahore Pakistan

Ion-acoustic solitary (IAS) waves in electron-positron-ion (e-p-i) plasma have been of interest to many researchers probably due to their relevance in understanding the Universe. However, the study of non-linear ion-acoustic waves in e-p-i plasma with non-thermal electrons has not been adequately studied. A theoretical investigation on non-linear IAS waves in e-p-i plasma comprising of warm inertial adiabatic fluid ions and electrons that are kappa distributed, and Boltzman distributed positron is presented here using the Sagdeev potential technique. It was found that existence domains of finite amplitude IAS waves were confined within the limits of minimum and maximum Mach numbers with varying k values. For lower values of k, the amplitude of the solitary electrostatic potential structures increased as the width decreased, while for high values, the potential amplitude decreased as the width of the solitary structure increased.

关键词： non-thermal Electrons Ion-Acoustic Solitary Waves Electron-Positron-Ion Plasmas

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non-thermal Radio Frequency Stimulation of Tubulin Polymerization in Vitro: A Potential Therapy for Cancer Treatment

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Open Journal of Biophysics 2014年第4期4卷 147-168页

作者： John T. Butters Xavier A. Figueroa Bennett Michael Butters Nativis Inc. Seattle WA USA Sciencia Incognita Consulting LLC Seattle WA USA

The use of radio frequency energy is an established technology for certain oncology therapies. Direct inputs of radio frequency (RF) energy as thermal energy are applied to ablate tumors or catalyze secondary reactions in adjunct treatments against certain tumor types. Yet, other applications are being developed which take advantage of properties of RFs that impinge on biological proteins and cells without thermal effects. Here we report a proof-of-concept application of specific, digitally encoded, low power (non-thermal) radio frequency energy in an in vitro preparation of a tubulin polymerization assay. The radio frequency energy signal, designated M2(3), was applied to the tubulin polymerization assay samples during spectrophotometric measurements to assess the effectiveness for enhancing tubulin polymerization. A commercially available taxane (paclitaxel) that promotes tubulin polymerization was used as a control to assess the effectiveness of the M2(3) radio frequency energy signal on tubulin polymerization rates. A low power, specific, digital radio frequency energy signal is capable of promoting tubulin polymerization as effectively as a commercially available taxane.

关键词： Tubulin Paclitaxel Taxane Radio Frequency Energy Digitial Signal Electromagnetic Energy Microtubules non-thermal Polymerization Cancer Tumors

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High Energy Studies on the non-thermal Emissions from Cassiopeia A &Tycho

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International Journal of Astronomy and Astrophysics 2013年第1期3卷 34-48页

作者： Mustafa Bozkurt Tulun Ergin Murat Hudaverdi Enise Nihal Ercan Physics Department Bogazici University Istanbul Turkey Physics Department Yildiz Technical University Istanbul Turkey

Chandra X-ray Observatory and Fermi Gamma Ray Space Telescope analysis of young supernova remnants (SNRs) Cassiopeia A (Cas A) and Tycho were performed to understand the nature of the high energy emission from SNRs and to observationally test the diffuse shock acceleration (DSA) theory. In this study, we present the highest significances of these shell-like and young SNRs in gamma-ray as a strong evidence for cosmic ray accelerators. Gamma-ray analysis of Cas A and Tycho were performed with Fermi-LAT at significances of 26σ and 8σ, respectively. Chandra analyses were performed on the thin filaments from the shells of Cas A and Tycho. Extracted X-ray spectra have been fitted with power-law model predicting the non-thermal emissions. Best fit chi-squared values for the regions from shells of Cas A and Tycho have been presented in the X-ray analyses which are supporting the DSA theory.

关键词： Supernova Remnants non-thermal Emission

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