JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2017
·
IF 1.591
Baijun Liu,Shicheng Sun,Mingyao Zhang,Huixuan Zhang
Particle coagulation technology is a facile approach to prepare large-scale and narrowly dispersed polymer particles. However, diverse shapes such as ellipsolid, snowman, dumbbell, and trimer among others were obtained if the cross-linker was directly added into the initial reaction mixtures due to the restriction of the highly cross-linking particle fusion process. In this study, we prepared sub-200 nm, narrowly dispersed, highly cross-linked, and spherical latex particles using particle coagulation technology by controlling the relation between the cross-linking net formation and particle coagulation. Depending on the addition time or feeding rate of the cross-linker (divinylbenzene, DVB), the particles with different sizes or shapes were obtained. The later the addition start time of DVB, the narrower the particle size distribution of the latex particles. Alternatively, the increase of the continuing feeding time could also be used to decrease the width of particle size distribution of the ultimate latex. In addition, narrowly dispersed and spherical latex particles also could be directly obtained by advancing the particle coagulation time using 2, 2′-Azobis (2-methylpropionamidine) dihydrochloride as a cationic initiator. Our study presents a new method that will further widen the fields of application of particle coagulation technology.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
DEFECT AND DIFFUSION FORUM
·
2018
·
IF 0
Vitaly V. Neshchimenko,Chun Dong Li,Mikhail M. Mikhailov,Andrei Dudin
The effect of protons exposure on the diffuse reflectance spectra of the zinc oxide with different shape particles has been investigated. Particles were micro-, nanocrystals, star and flower shape particles. The synthesis of the particles was carried out by the hydrothermal method using zinc acetate chemicals. The surface morphology, surface area and crystal structure of the particles have been investigated. Evaluating the changes in spectral reflectance it was found that the radiation stability of the micro particles is higher than the radiation stability of the other nanostructured particles. The high stability of the micro particles optical properties is due to the effect of low accumulation of radiation-induced defects.
研究领域:
材料科学
·
辐射物理学
✓ 已验证
产品关联
DOI
JOURNAL OF AEROSOL SCIENCE
·
2021
·
IF 3.433
Yiliang Liu,Michel Attoui,Yueyang Li,Jianmin Chen,Qing Li,Lin Wang
A butanol-based fast condensation particle counter (Fast CPC, Model 3650, Kanomax Inc., Japan) was characterized in this study with three different types of monodisperse particles, including positively and negatively charged nickel-chromium (Ni/Cr) particles, positively charged tetraheptyl ammonium bromide (THABr) and tetrabutyl ammonium bromide (TBABr) particles, and positively charged polyethylene glycol (PEG) particles. The PEG particles were characterized with varied numbers of charges, whereby the charge number effect on particle activation was investigated. The performance of the Fast CPC was compared with a TSI® 3775 CPC and a TSI® 3776 CPC, respectively, under both factory temperature settings and boosted temperature settings, the latter of which corresponded to the brink of butanol homogeneous nucleation. Our results show that size-resolved Ni/Cr particles were detected by the Fast CPC with comparable detection efficiencies regardless of the charge polarity. When the charge number on a PEG particle increased from 1 to 3, an increasing tendency of the detection efficiency was observed, hinting that multiple charges on a particle will facilitate its activation. Particle activation was affected by the particle chemical composition as well, which is suggested by the higher activation efficiencies of PEG particles than those of Ni/Cr particles. The effects of multiple charges and chemical composition on particle activation were both more significant under factory temperature settings, but became less pronounced under boosted temperature settings. In addition to a quicker response time, the Fast CPC was capable of detecting sub-3 nm particles under boosted temperature settings, with the detection efficiency higher than that of the 3775 CPC but lower than that of the 3776 CPC, and can be used as a good candidate for the measurement of rapidly varying concentrations of small particles.
研究领域:
大气科学
·
仪器科学与技术
✓ 已验证
产品关联
DOI
高影响因子
VACUUM
·
2022
·
IF 4.11
Xinjiang Zhang,Ziqing Chen,Zhaohui Liu,Meng He,Zirun Yang,Jiahui Wang
The in-situ hybrid particle-reinforcements are a novel strengthening mode for the advanced metal matrix composites . In this study, Zr matrix composites incorporating the fixed amount of ZrC particles with the different amounts of Y 2 O 3 particles were prepared by the in-situ reaction among Zr, graphite, Y, and ZrO 2 during the arc-melting. Results revealed that the graphite/Zr reaction produced the uniform in-situ ZrC particles in the Zr matrix, and the Y/ZrO 2 reaction formed the Y 2 O 3 particles. In-situ Y 2 O 3 addition refined the Zr matrix and led to the polygonal morphology of the ZrC particle. The coarser Y 2 O 3 grew in bulk, and some fine Y 2 O 3 dendrites were formed along Zr boundaries. The influence of different contents of Y 2 O 3 reinforcements on the hardness and compressive properties were analyzed. Compared with the single ZrC reinforcements, the hybrid Y 2 O 3 introduction resulted in a higher hardness and enhanced compressive strength . This hybrid structures were believed to be favorable to mechanical responses in the composites, and the relevant mechanisms for the hardening and strengthening effect of such hybrid forms were discussed.
研究领域:
材料科学
·
力学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Sciences
·
2017
·
IF 2.865
Yuwei Wu,Qinyan Yue,Yuan Gao,Zhongfei Ren,Baoyu Gao
In this study, bimetallic nanoscale zero-valent iron particles (nZVI), including copper/nanoscale zero-valent iron particles (Cu/nZVI) and nickel/nanoscale zero-valent iron particles (Ni/nZVI), were synthesized by one-step liquid-phase reduction and applied for oxytetracycline (OTC) removal. The effects of contact time and initial pH on the removal efficiency were studied. The as-prepared nanoscale particles were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). Finally, the degradation mechanisms of OTC utilizing the as-prepared nanoparticles were investigated by using X-ray photoelectron spectroscopy (XPS) and mass spectrometry (MS). Cu/nZVI presented remarkable ability for OTC degradation and removed 71.44% of OTC (100 mg/L) in 4 hr, while only 62.34% and 31.05% of OTC was degraded by Ni/nZVI and nZVI respectively. XPS and MS analysis suggested that OTC was broken down to form small molecules by ·OH radicals generated from the corrosion of Fe 0 . Cu/nZVI and Ni/nZVI have been proved to have potential as materials for application in OTC removal because of their significant degradation ability toward OTC.
研究领域:
环境科学
·
材料科学
·
污染治理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Scientific Reports
·
2017
·Vol. 7
·期 1
·1-12
·
IF 4.259
He Meilin,Yan Yongquan,Pei Feng,Wu Mingzhu,Gebreluel Temesgen,Zou Shanmei,Wang Changhai
Carbon nanotubes (CNTs), α-Fe 2 O 3 nanoparticles (nano Fe 2 O 3 ) and MgO nanoparticles (nano MgO) were evaluated for the effects on algae growth and lipid production. Nano Fe 2 O 3 promoted cell growth in the range of 0–20 mg·L −1 . CNTs, nano Fe 2 O 3 and nano MgO inhibited cell growth of Scenedesmus obliquus at 10, 40 and 0.8 mg·L −1 respectively. Neutral lipid and total lipid content increased with the increasing concentration of all tested nanoparticles. The maximum lipid productivity of cultures exposed to CNTs, nano Fe 2 O 3 and nano MgO was observed at 5 mg·L −1 , 5 mg·L −1 and 40 mg·L −1 , with the improvement by 8.9%, 39.6% and 18.5%. High dose exposure to nanoparticles limited increase in lipid productivity, possibly due to the repression on cell growth caused by nanoparticles-catalyzed reactive oxygen species (ROS) generation, finally leading to reduction in biomass and lipid production. Reduced accumulation of fatty acids of C18:3n3, C18:3n6 and C20:2 was observed in cells exposed to nanoparticles.
研究领域:
微生物学
·
生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED POWDER TECHNOLOGY
·
2025
·
IF 4.2
Hengqian Jin,Shufei Wei,Yunpeng Jiang,Huarong Nie,Xinping Zhang,Aihua He
In this study, snowman-like Janus particles (PDVB/PS@SiO 2 ) were proposed as carriers of Ag nanoparticles (Ag@J) to construct a hierarchical hybrid conductive powders by further admixing with MWCNTs for the development of high-performance microwave-absorbing materials. The Ag@J/MWCNT composite powders have several advantages in microwave absorption, such as the polarization of SiO 2 hemispheres, multiple reflections and scattering of electromagnetic waves in the hollow cavity of PDVB/PS hemispheres, improved conductivity and dielectric loss originating from the dense deposition of Ag nanoparticles and incorporation of MWCNTs. Furthermore, the composite powders allow the interfacial polarization and favorable impedance matching. Notably, the asymmetric hemispheres of the Ag@J particles result in close packing, further reducing the transmission of electromagnetic waves. The Ag@J particles demonstrated a minimum reflection loss (RL min ), indicating their potential application in microwave absorption. When further integrated with MWCNTs, the Ag@J/MWCNT composite powders, containing 36.4 wt% of Ag@J, exhibited strong absorption (−27 dB), wide absorption bandwidth (16.5 − 18 GHz), and a low thickness (5.5 mm). The Janus particles reported in this study show high potential applications in microwave-absorbing powder materials.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2023
·Vol. 13
·期 3
·455
·
IF 5.3
Xian Qi,Yaxian Du,Ziqiang Zhang,Xu Zhang
Janus particles for oil–water separation have attracted widespread attention in recent years. Herein, we prepared a bowl-shaped Janus particle that could rapidly separate oil and water through a thiol–ene click reaction and selective etching. Firstly, snowman-like composite microspheres based on silica and mercaptopropyl polysilsesquioxane (SiO2@MPSQ) were prepared by a hydrolytic condensation reaction and phase separation, and the effects of the rotational speed and molar ratios on their microscopic morphologies were investigated. Subsequently, bowl-shaped Janus particles with convex hydrophilic and concave oleophilic surfaces were prepared via a thiol–ene click reaction followed by HF etching. Our amphiphilic bowl-shaped Janus particles could remarkably separate micro-sized oil droplets from an n-heptane–water emulsion with a separation efficiency of >98% within 300 s. Based on the experimental and theoretical results, we proposed the underlying mechanism for the coalescence of oil droplets upon the addition of the amphiphilic bowl-shaped Janus particles.Keywords:Janus particles;bowl-shaped particles;thiol–ene click reaction;oil–water separation
研究领域:
材料科学
·
界面化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2013
·Vol. 1
·期 39
·6355-6363
·
IF 0
Youlin Zhang,Xianggui Kong,Bin Xue,Qinghui Zeng,Xiaomin Liu,Langping Tu,Kai Liu,Hong Zhang
Applying the Stöber method to directly coat noble metal nanoparticles (NPs) such as gold (Au) and silver (Ag) NPs with silica shells presents challenges, since the noble metal NPs are not stable in alcoholic solution and have low chemical affinity for silica. This paper describes a method which uses 11-mercaptoundecanoic acid (MUA) as a linker molecule between the silica shell and the noble metal NPs. MUA binds strongly to the surface of the NPs via a metal–S bond by replacing the standard capping agents on the surface of the NPs. Upon MUA stabilization, the NPs can be transferred into alcohol solution and show chemical affinity for silica. The MUA-modified NPs can be directly coated with thickness controlled, smooth and homogeneous silica shells via the standard Stöber method by varying the amount of tetraethoxysilane (TEOS). Compared with methods reported in the literature for the coating of such particles, this method can not only be used to successfully coat citrated-stabilized Au or Ag NPs, but can also be extended to encapsulate oleylamine (OA)-stabilized Au NPs and cetyltrimethylammonium bromide (CTAB)-stabilized Au nanorods (NRs) by using MUA to displace the original ligand on the surface of the NPs. Additionally, the obtained metal@SiO2 core–shell NPs have been successfully applied as plasmonic nanoantennas for fluorescence enhancement in metal@SiO2@fluorophore NPs.
研究领域:
材料科学
·
纳米技术
·
光学
✓ 已验证
产品关联
DOI
NANOTECHNOLOGY
·
2018
·Vol. 29
·期 15
·154005
·
IF 3.404
Chunyang Dong,Songchang Hu,Mingyang Xing,Jinlong Zhang
A spatially separated, dual co-catalyst photocatalytic system was constructed by the stepwise introduction of RuO2 and Au nanoparticles (NPs) at the internal and external surfaces of a three dimensional, hierarchically ordered TiO2−SiO2 (HTSO) framework (the final photocatalyst was denoted as Au/HRTSO). Characterization by HR-TEM, EDS-mapping, XRD and XPS confirmed the existence and spatially separated locations of Au and RuO2. In CO2 photocatalytic reduction (CO2PR), Au/HRTSO (0.8%) shows the optimal performance in both the activity and selectivity towards CH4; the CH4 yield is almost twice that of the singular Au/HTSO or HRTSO (0.8%, weight percentage of RuO2) counterparts. Generally, Au NPs at the external surface act as electron trapping agents and RuO2 NPs at the inner surface act as hole collectors. This advanced spatial configuration could promote charge separation and transfer efficiency, leading to enhanced CO2PR performance in both the yield and selectivity toward CH4 under simulated solar light irradiation.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2021
·
IF 5.279
Keying Zhang,Guang Zhu,Yunlong Wei,Li Zhang,Yizhong Shen
Accurately monitoring mercury ions (Hg2+) in food and agriculture-related matrixes (e.g., green tea) is of great significance to safeguard food safety. Here, we employed upconversion nanoparticles (UCNPs) and gold nanoparticles (AuNPs) to engineer a cysteine (Cys)-assisted anti-Stokes luminescence sensing platform (UCNPs–AuNPs) for precisely detecting residual Hg2+ in green tea through the competition effect. Initially, AuNPs could effectively quench the luminescence of UCNPs through the luminescence resonance energy transfer process, which was then interrupted by Cys-triggered AuNP aggregation via Au–S, thereby restoring UCNP luminescence. Interestingly, owing to the competition effect with AuNPs toward Cys, Hg2+ could weaken the luminescence restoring efficiency, achieving a Hg2+ concentration-dependent luminescence change. On this basis, a facile, reliable, and sensitive upconversion luminescence sensing platform for monitoring residual Hg2+ in green tea was successfully established. This study offers a novel insight into integrating the competition effect and anti-Stokes luminescence for food- and agriculture-related contaminant monitoring.
研究领域:
食品科学
·
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2017
·
IF 1.591
Baijun Liu,Ming Chen,Mingyao Zhang,Huixuan Zhang
In this study, sub-200 nm, crosslinked latex particles with a narrow particle size distribution were prepared by one-step emulsion polymerization in the presence of particle coagulation. The relationship between the particle shape and particle coagulation was investigated by varying the time of crosslinking network structure formation and particle coagulation. Particles with irregular shapes such as doublet, triplet, and ellipsoid were obtained using divinylbenzene (DVB) and ethylene glycol dimethacrylate (EGDMA) as the crosslinking agents, because the crosslinking network structure of particles was formed before the particle coagulation. In contrast, latex particles with a uniform spherical shape were also prepared using triallyl isocyanurate (TAIC) or dihydrodicyclopentadienyl acrylate (DCPA) as the crosslinking agents by delaying the time of crosslinking network structure formation. Alternatively, uniform spherical latex particles were prepared by bringing forward the particle coagulation time using cationic initiator, 2, 2′-azobis (2-methylpropionamidine) dihydrochloride (AAPH). This study presents a new idea that would further broaden the application of particle coagulation in emulsion polymerization.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）