Synthesis and surface modification of cobalt nanoparticles and electromagnetic property of Co/PPy nanocomposites

Wang, Haicheng; Yan, Zhiran; Deng, Lei; Dong, Hua; Jia, Yihe; Ma, Ning; He, Jun; Yu, Guanghua

doi:10.1007/s12598-014-0438-5

Cited by 7 publications

(3 citation statements)

References 25 publications

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“…On the other hand, the figure shows that the dielectric loss of the composite is higher than the doped PPy material in the low energy region and thus the composite has better absorbing properties. In literature, a maximum dielectric loss of about 1.2 is obtained for PPy/Co core‐shell type material in experiment, [43] which is lower than our result. It is speculated that multiple reasons can be attributed to the difference.…”

Section: Comparison Between Ppy and Ppy/co Compositecontrasting

confidence: 86%

Electromagnetic Properties of Polypyrrole Metallic Magnetic Nanocomposites: First‐Principles Study

Wang

Huang

et al. 2022

ChemistrySelect

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Conductive polypyrrole (PPy) is an excellent polymer material for microwave absorption, which is vital for reducing electromagnetic interference (EMI) for electronic devices. To improve the microwave absorption capability and enhance the thermal stability and mechanical ductility of conductive PPy, metallic magnetic nanoparticles can be added to form PPy nanocomposites. In this paper, we present the first study to compute the electromagnetic properties of PPy nanocomposites based on the first principles method. It is discovered that (1) while doping can improve the microwave absorbing proper-ties of PPy material, the absorption performance does not necessarily increase with the number of doping position; (2) conductivity and absorption coefficient increase significantly for the PPy nanocomposite compared with PPy. The dielectric loss is more than 2 at about 2 eV; (3) reflectivity and absorption coefficient decrease with the increase of PPy content in PPy/Co nanocomposite; (4) the average magnetic moment of the PPy nanocomposite is the same as that of pure nanoparticles, and this indicates that only nanoparticles generate magnetic loss for the nanocomposite.

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Section: Comparison Between Ppy and Ppy/co Compositecontrasting

confidence: 86%

Electromagnetic Properties of Polypyrrole Metallic Magnetic Nanocomposites: First‐Principles Study

Wang

Huang

et al. 2022

ChemistrySelect

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“…This property leads to a poor dispersion for MH whiskers in polymer material. Furthermore, the surface of MH whiskers is hydrophilic, which also results in weak combination between MH whiskers and polymer matrix [4][5][6]. These problems make the composites rarely meet the actual requirement on mechanical properties.…”

Section: Introductionmentioning

confidence: 99%

Magnesium hydroxide whisker modified via in situ copolymerization of n-butyl acrylate and maleic anhydride

Jiang

Wang

et al. 2017

Rare Met.

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Magnesium hydroxide (MH) whiskers were modified via in situ polymerization of n-butyl acrylate and maleic anhydride. Sodium dodecyl sulfonate was used as emulsifier. The modifying effect was evaluated by using contact angle and activation index. The thermal stability, functional groups, structure, morphology, phase composition and surface element valence of MH whiskers were characterized by thermogravimetry-differential scanning calorimetry (TG-DSC), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Results reveal that the contact angle and activation index of modified MH whiskers are 105°a nd 76.5%, the thermal stability shows little change, and the decomposition temperature ranges between 38 and 419°C. The copolymer of n-butyl acrylate and maleic anhydride absorbed on the surface of MH whiskers leads to the increased diameter and makes the surface of whiskers be rougher. Furthermore, the absorption of element C on the surface of MH whiskers increases, and the diffraction intensity of C 1s spectra increases; thus, the compatibility of whiskers in the organic phase can be improved significantly. Lastly, the surface molecular model of MH whiskers modified via in situ copolymerization of n-butyl acrylate and maleic anhydride is established.

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“…However, most of the available pesticide capsules are on the micron scale [30]. By comparison, nanocapsules demonstrate clear advantages for improving the foliar deposition and spread of pesticides and enhancing their bioactivity due to their small-size and large specific surface area [31][32][33][34][35]. The preparation of nanocapsules requires strict conditions [36][37][38][39], however, research on dual-pesticide nanocapsules is relatively scarce.Thifluzamide is a novel and highly effective systemic fungicide that is used for the control of rice sheath blight [40][41][42].…”

mentioning

confidence: 99%

Dual-Functionalized Pesticide Nanocapsule Delivery System with Improved Spreading Behavior and Enhanced Bioactivity

et al. 2020

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The prevention and control of pests and diseases are becoming increasingly difficult owing to extensive pesticide resistance. The synergistic use of pesticides for disease control is an effective way of slowing pesticide resistance, reducing the number of pesticide applications, and protecting the environment. In this study, a dual-functionalized pesticide nanocapsule delivery system loaded with two active ingredients (AIs)—validamycin and thifluzamide—was developed to prevent and control rice sheath blight; the nanocapsule system was based on a water–oil–water double emulsion method combined with high-pressure homogenization technology. Our results showed that the dual-functionalized pesticide nanocapsules were monodisperse spheres with a mean particle size of ~260 nm and had good storage stability. Compared with commercial formulations, the dual-functionalized pesticide nanocapsules exhibited good foliar spread owing to their small size, which is beneficial for reducing the loss of pesticides on the leaves. The 50% median effect concentration and synergistic ratio against Rhizoctonia solani of the dual-functionalized pesticide nanocapsules and commercial formulation were 0.0082 and 0.0350 μg/mL, and 2.088 and 0.917, respectively. These findings indicate that the bioactivity of the dual-functionalized system was significantly better than that of the commercial formulations and that the dual-functionalized system demonstrated a clear synergistic effect between the two AIs. The system presented here is simple, fast, and capable of dual-pesticide loading with significant synergistic effects. Our findings could help to facilitate the improvement of pesticides efficiency and the slowing of pesticide resistance.

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Synthesis and surface modification of cobalt nanoparticles and electromagnetic property of Co/PPy nanocomposites

Cited by 7 publications

References 25 publications

Electromagnetic Properties of Polypyrrole Metallic Magnetic Nanocomposites: First‐Principles Study

Electromagnetic Properties of Polypyrrole Metallic Magnetic Nanocomposites: First‐Principles Study

Magnesium hydroxide whisker modified via in situ copolymerization of n-butyl acrylate and maleic anhydride

Dual-Functionalized Pesticide Nanocapsule Delivery System with Improved Spreading Behavior and Enhanced Bioactivity

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