RSC Advances
·
2018
·Vol. 8
·期 25
·14056-14063
·
IF 2.936
Juanjuan Ma,Chaocun Zhou,Jinlin Long,Zhengxin Ding,Rusheng Yuan,Chao Xu
Graphene-based cocatalysts can improve the photocatalytic properties of semiconductors, but sometimes, they also function as barrier-like materials, influencing the photoactivity of composites. However, in a multi-cocatalyst system, less attention is paid to these negative effects of graphene on the performance of other cocatalysts. In this study, by adjusting the loading sequence of graphene and Ag cocatalyst on the surface of TiO2 spheres, the barrier effect of graphene sheets on Ag nanoparticles could be controlled effectively. As a result, these ternary composites with almost no Ag nanoparticles wrapped by graphene possessed improved properties for the photocatalytic reduction of nitro-aromatics as compared to those with some Ag nanoparticles covered by graphene. Furthermore, this phenomenon of barrier effect caused by graphene could be found in the control reaction with metal silver as the main catalyst; this indicated that by avoiding the possible negative influence of graphene on other cocatalysts, the properties of composites with graphene-containing multi cocatalysts could be further improved.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2020
·
IF 4.469
Tong Liu,Jiayu Wei,Lingwei Ma,Shuan Liu,Dawei Zhang,Haichao Zhao
Herein, the effects of the addition of polyaniline-based plate (PANP) on the anticorrosive properties of epoxy coatings on Q235 mild steel were investigated. PANP was synthesized by a chemical oxidation method, and the barrier effect of the epoxy coatings containing PANPs were characterized by water absorption and oxygen permeability tests. Electrochemical impedance spectroscopy and scanning vibrating electrode technique were utilized for studying the anticorrosion performance and self-healing ability of different coatings. The corrosion product beneath the coatings was characterize by scanning electron microscopy and X-ray powder diffraction. Thanks to the strong barrier effect caused by the well-dispersed PANPs and self-healing behavior derived from the electroactivity of PANPs. The epoxy coating containing 1.0 wt% PANPs has improved corrosion protective performances such as water absorption (2.23 % after 40-day immersion), and O 2 shielding effect (7.92 × 10 –15 cm 3 cm cm –2 s –1 Pa –1 ). Also, the impedance modulus of this coating still reached 1.94 × 10 9 Ω cm 2 after 40 days of immersion in a 3.5 wt% NaCl solution.
研究领域:
材料科学
·
腐蚀与防护
·
电化学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2018
·
IF 2.829
Shengguo Zhou,Yangmin Wu,Wenjie Zhao,Jingjing Yu,Fengwei Jiang,Liqiu Ma
Although substantial statements report the capability of graphene for corrosion prevention , its further application is limited by the non-comprehension of its structural variation in different coatings. Herein, graphene sheets with four structures were incorporated waterborne epoxy to fabricate different types of composite coatings (named EP-G a , EP-G b , EP-GO and EP-GS, respectively) as well as the pure waterborne epoxy coating was fabricated for comparison. The corrosion behaviors of as-fabricated coatings with and without graphene sheets were systematically characterized via potential, impedance testing and Tafel curves by immersing in 3.5 wt % NaCl solution. It was remarkable to point out that EP-G a composite coating could possess a promising long-term corrosion protection capability. The corrosion protection mechanism of graphene-based composite coatings were verified as the barrier effect of impermeable graphene sheets that confirmed by the analysis of corrosion products. Moreover, the scanning vibrating electrode technique in-depth revealed the relationship between the graphene structures and corrosion performances of the composite coatings. With the occurrence of commercialized application of graphene-based coatings, these works displayed a suitable approach toward the long-term corrosion behavior, which was able to be extended to other two-dimensional materials for anti-corrosion coatings.
研究领域:
材料科学
·
腐蚀与防护
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2023
·Vol. 140
·期 39
·e54460
·
IF 3
Yanyan Zheng,Chongyi Chi,Denglong Chen,Tuer Zeng,Yuxia Zhang,Xiaoyu Lu,Qinhui Chen
The filled sheet-like inorganic materials can usually improve the anticorrosion performance of the coating. Herein, the Janus nanosheets (JNSs) with two-dimensional structure were prepared by phase separation method, modified by polyaniline (PANI) on the amino side of JNSs and composited with epoxy resin (EP). Scanning electron microscope (SEM), transmission electron microscopy (TEM), atomic force microscope (AFM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetry (TG) were used to characterize the morphology and chemical structure of JNSs and PANI@JNSs. The anti-corrosion performance of coatings was measured by electrochemical impedance spectroscopy (EIS) and salt spray experiment. Compared with pure EP, the |Z| 0.01Hz of 0.5%-JNSs/EP coating and that of 0.5%-PANI@JNSs/EP coating reached 5.6 × 10 8 and 5.4× 10 10 Ω·cm 2 after immersed for 35 days, nearly 2 and 4 orders of magnitude higher than pure EP respectively. The excellent anti-corrosion performance of 0.5%-PANI@JNSs/EP coating is due to the synergistic effect of physical barrier effect of PANI@JNSs, interfacial interaction between PANI@JNSs and epoxy resin and passivation effect of PANI. Moreover, PANI@JNSs possess both strengthening and toughening effects on composite coating. Janus nanosheets provide a new idea and method for preparing high-performance anticorrosive materials.
研究领域:
材料科学
·
腐蚀与防护
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 10
·7780-7790
·
IF 3.289
Mengting Mo,Wenjie Zhao,Zifei Chen,Eryong Liu,Qunji Xue
In order to further enhance its anti-corrosion properties as a surface coating for protecting various materials from corrosion, polyurethane (PU) needs to be modified by adjusting the chemical composition and interface structure. In this work, a series of functionalized graphene (FG) reinforced PU nanocomposite coatings with regular texture were fabricated using a replication method. The structural and morphological properties of the as-prepared PU composite coatings were characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray photoelectron spectrometer, transmission electron microscopy, scanning electron microscopy and atomic force microscopy. Results showed that FG was dispersed homogeneously in the PU matrix after chemical modification. Moreover, the morphology of the obtained coatings showed a circular cone with a diameter of 8 μm spaced 8, 6 and 4 μm apart, respectively. Most importantly, the presence of surface texture and well-dispersed FG effectively enhanced the anti-corrosion properties of the textured FG/PU composite coating. It is attributed to the hydrophobicity and barrier effect of the obtained coatings, which not only reduce the contact and interaction between water and the surfaces, but also increase the tortuosity of the corrosive medium diffusion pathway.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
PEST MANAGEMENT SCIENCE
·
2021
·Vol. 77
·期 7
·3300-3312
·
IF 4.845
Long Chen,Yuanxiong Lin,Hongjun Zhou,Li Hao,Huayao Chen,Xinhua Zhou
BACKGROUND A large amount of pesticides that are not deposited on desired locations due to drift and rolling, endangering the ecological environment and human health. Therefore, it is urgent to develop environmentally friendly and foliar affinity formulations. The design and construction of pesticide nano-delivery system is considered to be an effective way to solve this problem. RESULTS In this research, polyamine-modified zein (AM-zein) was synthesized by incorporating ethylenediamine-terminated polyethyleneimine into zein to improve its stability as a nanocarrier, enhance electrostatic force between the carrier and pesticides and plant foliage. Avermectin (AVM)-loaded nanoparticles, containing a high positive charge, were prepared by the anti-solvent method using AM-zein as carrier. The nanoparticles can be stored for 30 days without any significant change in the particle size and stably dispersed at pH 5–9. Compared to the commercial emulsifiable concentrate (EC), nanoparticles dispersions exhibited better leaf affinity, and the retention of dispersion increased from 7.82 to 13.86 mg/cm 2 . Interestingly, we have discovered for the first time that the ultraviolet (UV) barrier effect of zein increases while prolonging the UV exposure time; 30.47% of the encapsulated AVM remained intact after exposure to UV for 60 min, compared to only 17.13% for the EC. Insecticidal activity of AVM nanoparticles did not improve compared to EC, but they demonstrated significantly lower toxicity against zebrafish. CONCLUSION This research opens up a new idea for improving the stability of zein nanoparticles, providing a novel path to deliver pesticides efficiently and eco-friendly. © 2021 Society of Chemical Industry.
研究领域:
农业科学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2021
·
IF 5.161
Anxiang Li,Aiping Zhu
Spherical Fe 3 O 4 /polyaniline(PANI) nanocomposites with core-shell structure were prepared by oxidative polymerization of aniline on the Fe 3 O 4 − /aniline(ANI) + nanocomposite template formed by the electrostatic interaction between nano-Fe 3 O 4 and aniline salt. FTIR and UV–Vis results indicate that there is coordination interaction between Fe 3 O 4 and PANI interface. SEM and TEM results show that the thickness of PANI shell increases with the increase of aniline/Fe 3 O 4 mass ratio. Compared with PANI, Fe 3 O 4 /PANI nanocomposites maintain obvious redox activity in neutral medium. The organic composite coating was prepared by filling Fe 3 O 4 /PANI nanocomposites into waterborne acrylate/amino baking paint. The results show that the composition ratio of aniline/Fe 3 O 4 has a great influence on the metal anticorrosive activity of Fe 3 O 4 /PANI nanocomposites. The long-term metal corrosion resistance of Fe 3 O 4 /PANI(1:2) composite coating is three times as compared with unfilled organic coating . The metal anticorrosive mechanism of Fe 3 O 4 /PANI nanocomposites has been revealed to be the excellent nano-barrier effect and the metal surface passivation .
研究领域:
材料科学
·
腐蚀与防护
✓ 已验证
产品关联
DOI
高影响因子
DRUG DELIVERY
·
2017
·
IF 6.402
Zhengwei Huang,Han Wu,Beibei Yang,Longkai Chen,Ying Huang,Guilan Quan,Chune Zhu,Xing Li,Xin Pan,Chuanbin Wu
The objective of this study was to develop a novel anhydrous reverse micelle nanoparticles (ARM-NPs) system to overcome the sedimentation instability of peptide-containing pressurized metered-dose inhalers (pMDIs). A bottom-up method was utilized to fabricate ARM-NPs. Tertiary butyl alcohol (TBA)/water system, freeze-drying and lipid inversion method were successively used to produce the ARM-NPs for pMDI. Various characteristics of ARM-NPs were investigated including particle size, morphology, secondary structure of the peptide drug, aerosolization properties and storage stability. As revealed by the results, ARM-NPs with spherical shape possessed 147.7 ± 2.0 nm of particle size with 0.152 ± 0.021 PdI. The ARM-NPs for pMDI had satisfactory fine particle fraction (FPF) value of 46.99 ± 1.33%, while the secondary structure of the peptide drug was unchanged. Stability tests showed no pronounced sedimentation instability for over 12 weeks at 4–6 °C. Furthermore, a hypothesis was raised to explain the formation mechanism of ARM-NPs, which was verified by the differential scanning calorimetry analysis. The lecithin employed in the reverse micelle vesicles could serve as a steric barrier between peptide drugs and bulk propellant, which prevented the instability of peptide drugs in hydrophobic environment. Homogenous particle size could avoid Ostwald ripening phenomenon of particles in pMDIs. It was concluded that the ARM-NPs for pMDI could successfully overcome sedimentation instability by the steric barrier effect and homogeneous particle size.
研究领域:
药剂学
·
纳米技术
·
药物递送系统
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF PHYSICS D-APPLIED PHYSICS
·
2023
·Vol. 56
·期 42
·425502
·
IF 3.4
Jian Gao,Kangning Wu,Zhuolin Zhang,Jianying Li,Shengtao Li
Smart self-reporting dielectrics (SRDs) have been extensively utilized for intelligentizing and miniaturizing next-generation advanced electrical and electronic devices. However, switchable structures towards the self-reporting function commonly damage electrical properties, severely undermining the reliability and practicality of SRDs. Herein, the smart self-reporting function and superior electrical properties are simultaneously achieved by incorporating ultralow content microsensors with electron-donating encapsulation into the epoxy matrix. The microsensor is a leuco dye system for self-reporting temperature anomalies through thermochromism. The strong electron-donating melamine–formaldehyde encapsulation of microsensors serves to confine the switchable structures and enhance electrical properties by constructing the interfacial barrier effect through triboelectrification. Under an ultralow doping content of 0.5 phr, the electrical conductivity of SRDs is considerably reduced by about 80% at the elevated temperature of 80 °C compared to that of the widely recognized epoxy insulation. The reduction efficiency is far superior to those of numerous micro- and nanofillers. The interfacial barrier effect can be supported by the significantly reduced trapped charge density and trap levels in SRDs based on thermal stimulated depolarization current results. Consequently, the charge injection and transport in SRDs can be distinctly inhibited, realizing the enhancement of electrical properties. The results of this study could provide a facile and efficient strategy for achieving high-performance SRDs, which is appealing and vital for widespread applications of SRDs.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
Insect Science
·
2025
·
IF 3
Delong Kong,Ruyue Zhai,Qiling Liang,Hui Guo,Zitong Wang,Changlu Wang,Tongen Ye,Junli Xiao,Lanfeng Wang,Lufei Xie,Tao Ma,Chunsheng Jia,Desen Wang
Desiccant dusts have been shown to be effective materials in the management of bed bugs ( Cimex spp.). Past research primarily focused on exploring the direct lethal effect of dusts against bed bugs, whereas information on their sublethal effects on bed bugs are limited. In this study, we evaluated the lethal effect of 3 dust products (Johnson's ® Baby powder, Vazor DE powder ™ , and CimeXa™; abbreviated as Baby powder, DE, and CimeXa) against the tropical bed bug, Cimex hemipterus (F.), under laboratory conditions. Results showed that the 3 dust products caused 97%–100% mortality to tropical bed bugs within 14 d, both in no-choice and choice experiments. However, in a brief exposure experiment (crossing a 2.5-cm-wide band), Baby powder exposure caused a significantly lower mortality (23%) than DE (88%) and CimeXa (100%). The more effective dusts (DE and CimeXa) were selected for further evaluation of their sublethal effects on C. hemipterus . DE and CimeXa caused significantly higher mortality (48%–58%) through horizontal transfer than that of control (6%). Brief exposure to DE and CimeXa dusts did not affect tropical bed bug activity and their response to CO 2 . However, CimeXa-exposed tropical bed bugs exhibited reduced feeding and lowered survival rate after feeding. Moreover, both DE and CimeXa dust bands showed strong barrier effects on the crawling of tropical bed bugs. Our results indicate that both DE and CimeXa have great potential for preventing C. hemipterus from reaching protected areas and for controlling C. hemipterus .
研究领域:
昆虫学
·
害虫管理
·
杀虫剂毒理学
·
应用生态学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）