RSC Advances
·
2017
·Vol. 7
·期 23
·13742-13748
·
IF 3.108
Fuyou Lu,Baodong Song,Pei He,Zhi Wang,Jixiao Wang
Two component polyurethane coatings are widely used for materials protection. Herein, a series of acrylic polyurethane coatings were prepared by reaction of hydroxyl acrylic resin and hexamethylene diisocyanate (HDI) biuret. These coatings have different isocyanate to hydroxyl ratios (expressed as NCO/OH). The degradation process of the coatings was evaluated by electrochemical impedance spectroscopy measurement. Then, the results were analyzed using equivalent electrical circuits. Besides, the adhesion and water resistance of the coatings were also investigated. Experimental results demonstrated that the higher the NCO/OH ratios within a certain range, the better the corrosion resistance. Specifically, the coating with NCO/OH = 1.4 provided the best corrosion resistance, and its impedance modulus still remained at close to 1 × 1011 ohms per cm2 after 50 days immersion. However, the corrosion resistance of coatings with NCO/OH = 0.8 and NCO/OH = 1.0 were relatively poor. More interestingly, with the increase in NCO/OH ratios, the coating's adhesion increased slightly and the water resistance improved noticeably.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2021
·
IF 3.383
Xumin Xu,Hongyu Wei,Mingguang Liu,Laishui zhou,Guozhu Shen,Qin Li,Ghulam Hussain,Fan Yang,Reham Fathi,Haiji Chen,Kostya (Ken) Ostrikov
In recent years, steel corrosion, an issue affecting a trillion-dollar industry, is being addressed with nanotechnology technologies. Small clusters and nanoparticles , as well as numerous molecules, are viable solutions, with carbon quantum dots (CQDs) being among the best and most promising. However, the complexity and duration of the CQDs purification process, as well as a few other issues, limit their practical applications as corrosion inhibitors . Therefore, in this study, a new type of nitrogen-doped CQDs (N-CQDs) with an average size of 2.5 ± 0.8 nm were synthesized via hydrothermal reaction of amino-guanidine and citric acid using a robust purification process. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) techniques were used to evaluate the new inhibitor's corrosion mitigation effect on Q235 steel in 0.5 M H 2 SO 4 solution. X-ray photoelectronic spectroscopy (XPS) and FTIR analyses were employed for the chemical composition investigation of as-prepared N-CQDs and surface characterization of Q235 steel samples. The analysis of the impedance module and the current density of Q235 steel in the corrosive solution validates the effective protective performance of the inhibitor. The results showed that the maximum inhibition efficiency of 95.3% was achieved at the concentration of 200 mg/L. Moreover, it was found that the formation of the protective layer on the steel samples results from the Physico-chemical adsorption of the inhibitor on the steel surface and follows the Langmuir adsorption isotherm that was also confirmed via XPS. The quantum chemical calculations show that CQD nitrogen doping has an effect on corrosion inhibition performance. Overall, the corrosion inhibition efficiency of the carbon dots inhibitor is higher at the same concentration than that of most other similar inhibitor types.
研究领域:
材料科学
·
腐蚀与防护
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Membranes
·
2022
·Vol. 12
·期 2
·164
·
IF 4.562
Minyuan Han,Ruixue Zhao,Jianchao Shi,Xiaobo Li,Daoling He,Lang Liu,Le Han
The fouling/wetting of hydrophobic membrane caused by organic substances with low-surface energy substantially limits the development of the membrane distillation (MD) process. The sulfate radical (SO4·−)-based advanced oxidation process (AOP) has been a promising technology to degrade organics in wastewater treatment, and peroxydisulfate (PDS) could be efficiently activated by heat. Thus, a hybrid process of MD-AOP via PDS activated by a hot feed was hypothesized to mitigate membrane fouling/wetting. Experiments dealing with sodium dodecyl sulfate (SDS) containing a salty solution via two commercial membranes (PVDF and PTFE) were performed, and varying membrane wetting extents in the coupling process were discussed at different PDS concentrations and feed temperatures. Our results demonstrated permeate flux decline and a rise in conductivity due to membrane wetting by SDS, which was efficiently alleviated in the hybrid process rather than the standalone MD process. Moreover, such a mitigation was enhanced by a higher PDS concentration up to 5 mM and higher feed temperature. In addition, qualitative characterization on membrane coupons wetted by SDS was successfully performed using electrochemical impedance spectroscopy (EIS). The EIS results implied both types of hydrophobic membranes were protected from losing their hydrophobicity in the presence of PDS activation, agreeing with our initial hypothesis. This work could provide insight into future fouling/wetting control strategies for hydrophobic membranes and facilitate the development of an MD process.Keywords:membrane distillation;peroxydisulfate activation;surfactant;(anti-)wetting;electrochemical impedance spectroscopy
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2019
·
IF 3.42
Youqing Wu,Yi He,Chunlin Chen,Hongjie Li,Yunqing Xia,Taigang Zhou
To enhance the anticorrosive and mechanical performances of carbon nanofibers (CNFs) in epoxy (EP) coatings, molybdenum disulfide (MoS 2 ) and γ- (2, 3-epoxypropoxy) propytrimethoxysilane (KH560) have been combined for inner reinforcement and outer surface modification based on CNFs . The electrochemical impedance spectroscopy, tensile testing and microhardness testing demonstrated that MoS 2 -CNFs (0.8%) composite can prominently enhance the anticorrosive and mechanical performance of the EP coating. Furthermore, the impedance of EP/MoS 2 -CNFs (0.8%) was higher than that of the pure EP and other composite coatings, and the Young’s modulus (EY) and tensile strength (σs) of EP/MoS 2 -CNFs (0.8%) were increased by 65.4% and 56.6%, respectively.
研究领域:
材料科学
·
腐蚀与防护
·
复合材料工程
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2020
·
IF 9.13
Juan Tang,Hui Jia,Situ Mu,Fei Gao,Qingwen Qin,Jie Wang
The polymer coagulant aid can effectively enhance the coagulation-ultrafiltration (C-UF) process for the purification of drinking water . However, when coagulant aid entered the filtration, it may also cause serious membrane fouling as polymer. In-situ Raman spectroscopy and electrochemical impedance spectroscopy(EIS) were applied to monitor the effects of coagulant aids on the membrane. The causes of fouling were assisted discussed through stage cleaning of the membrane. The equivalent circuit fitting was performed on the EIS data and the Raman spectral data were statistically analyzed after peak fitting. EIS and the cluster analysis of Raman spectroscopy provided an earlier feedback on membrane fouling layers compared to flux. The cause of membrane fouling was explained via variation of characteristic functional groups obtained by Raman spectroscopy. When the molecular weight of the coagulant aid was 160 times,80 times and 16 times larger than the MWCO of the UF membrane, the equivalent circuit obtained by fitting the EIS of the UF system satisfied Rs + c(QpRp), Rs(QcRc)(QpRp) and Rs(Qt(Rc(QpRp))) respectively. Partial correlation analysis showed that the corresponding factors causing irreversible fouling of membrane were humic acid(HA), HA and coagulant aids, coagulant aids. Combined with the mean roughness (Ra) of membrane, the coagulant aid performed differently in the cleaning of contaminated membrane and also affected the cleaning of HA.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2022
·
IF 5.304
Liyin Bu,Xiaohui Chen,Qingyuan Song,Ding Jiang,Xueling Shan,Wenchang Wang,Zhidong Chen
In this study, a supersensitive electrochemical impedance spectroscopy (EIS) analysis method combined the molecularly imprinted polypyrrole (MIP) which electropolymerized on the composites of zirconium-based metal organic framework (Uio-66) and carbon dots (CDs) modified glassy carbon electrode (GCE) was developed for chloramphenicol (CAP) determination. The integration of Uio-66 and CDs effectively promoted the sensitivity of the proposed MIP senor by improving the surface area and the charge transfer of electrode. By extraction of CAP template, the specific sites were formed on the MIP surface which can rewrap the CAP target molecules. The CAP determination was based on the charge transfer difference (△Rct) before and after the MIP/ [email protected] /GCE rebinding the CAP. The results showed that △Rct responded good linearity to the logarithm of CAP concetration in the range of 0.1 – 100 pmol/L, with a low detection limit of 0.061 pmol/L (S/N = 3), exhibiting high sensitivity and specificity for the determination of CAP.
研究领域:
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2023
·
IF 7.4
Zhongnan Huang,Wenjie Wang,Yingfei Wang,Han Wang,Yimin Pang,Quan Yuan,Jie Tan,Weihong Tan
Developing rapid, sensitive, and facile nucleic acid detection technologies is of paramount importance for preventing and controlling infectious diseases. Benefiting from the advantages such as rapid response, low cost, and simple operation, electrochemical impedance spectroscopy holds great promise for point-of-care nucleic acid detection. However, the sensitivity of electrochemical impedance spectroscopy for low molecular weight nucleic acids testing is still limited. This work presents a DNA nanolock-based porous electrode to improve the sensitivity of electrochemical impedance spectroscopy. Once the target nucleic acids are recognized by the DNA probes, the pore-attached DNA nanolock caused remarkable impedance amplification by blocking the nanopores. Taking SARS-CoV-2 nucleic acid as a model analyte, the detection limit of the porous electrode was as low as 0.03 fM for both SARS-CoV-2 RNA and DNA. The integration of a porous electrode with a wireless communicating unit generates a portable detection device that could be applied to direct SARS-CoV-2 nucleic acid testing in saliva samples. The portable device could effectively distinguish the COVID-19 positive and negative samples, showing a sensitivity of 100% and a specificity of 93%. Owing to its rapid, ultrasensitive, specific, and portable features, the as-designed DNA nanolock and porous electrode-based portable device holds great promise as a point-of-care platform for real-time screening of COVID-19 and other epidemics.
研究领域:
生物传感技术
·
病毒学
·
医学诊断
✓ 已验证
产品关联
DOI
PubMed
高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Xia Wang,Li Hou,Ling-long Xu,Xiong Li,Huan Jiang,Wen-jie Zhou
In this paper, an inorganic-organic composite modification of nano-TiO 2 has been carried out using aluminum sulfate octahydrate and γ-aminopropyltriethoxysilane (KH550) to obtain AKT with good dispersion performance. The AKT-WPU composite coating with different amounts of nano-TiO 2 added was prepared by blending AKT with waterborne polyurethane (WPU). The nano-TiO 2 , before and after modification, was analyzed by Fourier transform infrared spectroscopy and indicates that alumina and KH550 can be successfully grafted onto the surface of nano-TiO 2 . Our thermogravimetric analysis shows that the heat resistance of the AKT-WPU composite coating was improved. The corrosion resistance of the AKT-WPU composite coatings was investigated by electrochemical impedance spectroscopy and polarization curves. Our results show that the addition of AKT significantly improves the corrosion resistance of the composite coating. The resistive modulus of the composite coating with 0.7% AKT addition amounted to 5.05×10 6 Ω. The corrosion current density is 5.21×10 -9 A, which is more than two orders of magnitude lower than that with the pure WPU coating. The corrosion inhibition efficiency can reach 99.54%. The coating was subjected to a long-term immersion test and observed by a scanning electron microscope. After immersion for 360 h, our results show that the coating still protected the stainless steel.
研究领域:
材料科学
·
防腐蚀工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2023
·
IF 6.6
Xiaochen Liu,Jian Wang,Zheng Wang,Zitong Chen,Dashuai Yan,Meng Zhang,Yanli Wang,Dalei Song,Tao Zhang,Jun Wang
A critical access to high-efficiency anti-corrosion coatings is adding pH-responsive nanocontainers encapsulated with corrosion inhibitors into epoxy resin as it endows the composite coating with significant active long-term corrosion protection . Here, two self-healing coating systems (I-PBZ-EP and II-PBZ-EP) were constructed based on epoxy coating (EP) and benzotriazole-loaded zeolitic imidazolate framework (ZIF-8) encapsulated with polydopamine (PDA) by one-pot and two-pot methods, respectively. Electrochemical impedance spectroscopy (EIS) investigation shows that the low-frequency impedance modulus value (|Z| 0.01Hz ) of I-PBZ-EP still reaches 2.16 × 10 10 Ω·cm 2 which is the highest among all the coatings after 35 d of immersion. |Z| 0.01Hz of the scratched I-PBZ-EP is 1.10 × 10 5 Ω·cm 2 after 13 h of immersion in 3.5 wt% NaCl solution, which far surpasses |Z| 0.01Hz of the scratched II-PBZ-EP, exhibiting its excellent self-healing properties. This is because I-PBZ can release more benzotriazole (BTA) (22.5 mg/L and 13.4 mg/L) than II-PBZ (15.8 mg/L and 9.4 mg/L) under acidic and basic conditions to repair the micro-defects. In short, by changing the loading mode of corrosion inhibitors, I-PBZ-EP with a simpler synthesis method manages to provide the long-term anticorrosion protection for the carbon steel substrate.
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
DESALINATION
·
2024
·
IF 8.3
Lei Yao,Xiaojian Xu,Yang Gui,Yong Li,Zhe Chen,Jue Han,Yuan Liao
Forward osmosis (FO) has been rapidly developed and employed in the industrial and environmental wastewater treatment, whose performance is affected profoundly by membrane fouling. Electrochemical impedance spectroscopy (EIS), as a nondestructive and low-cost evaluation technique, has been increasingly used for the characterization of membrane structures and membrane fouling. However, monitoring ion fouling of FO membranes is difficult with EIS due to the weak signal. In this work, the ion-fouling of various FO membranes was successfully characterized by EIS and the inductance variation was firstly utilized to interpret the degree of FO membrane fouling. Multi-walled carbon nanotubes (MWCNTs) and polydopamine (PDA) were modified onto the thin film nanofibrous composite membrane (#FO-0) as anti-fouling modification (#FO-MWCNTs and #FO-PDA), respectively. The structural measurements of #FO-0, #FO-MWCNTs, and #FO-PDA were achieved by a two-electrode EIS system. Then the ion fouling of FO membranes was monitored by a four-electrode EIS system. Through the equivalent circuit fitting, the correlation between the inductance variation and the membrane fouling was established. The FO experiments further validated the effectiveness of the proposed EIS method. The results indicate that inductance as a detection index is expected to be a convenient tool for studying the ion-fouling phenomenon in the FO process.
研究领域:
环境工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Materials Research Express
·
2019
·Vol. 6
·期 9
·0950a8
·
IF 1.449
She Jia,Zhengjun Yao,Shasha Zhang,Zelei Zhang,Xuewei Tao,Yingying Liu,Linchao Sun
Graphene (Gr) has attracted much attention due to its excellent performance. There are various studies about Gr composite materials; however, the influence of Gr on anticorrosion mechanism was not explored widely. In this paper, the Gr was prepared by oxidation-reduction method and was modified with 3-aminopropyl triethoxysilane for better dispersion. Fourier Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Micrograph (SEM) were utilized to characterize the microstructure of coating and the modification of Gr. X-Ray Diffraction (XRD) was employed to analyse the phase composition of the coating. The anticorrosion performance of coating was investigated by employing polarization curves and electrochemical impedance spectroscopy (EIS). The results showed that the uniformly dispersed Gr nanosheets in Zn-Al-Gr/waterborne epoxy enhanced the protection property of the composite coating. Furthermore, the corrosion resistance properties of the composite coating were optimized by tuning the concentration of the added Gr.
研究领域:
材料科学
·
腐蚀与防护
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2019
·
IF 6.361
Chengxi Zhu,Dong Liu,Zhi Chen,Libo Li,Tianyan You
We reported a carbon nanohorns/gold nanoparticles composites-based impedimetric aptasensor for carbendazim (CBZ) detection in lettuce and orange juice at picogram levels. The increased electron-transfer resistance, resulting from the formation of CBZ-aptamer complex, was recorded by electrochemical impedance spectroscopy as the aptasensor response for CBZ. Under the optimal conditions, the proposed aptasensor displayed a linear response for CBZ ranging from 1 to 1000 pg mL −1 with a detection limit of 0.5 pg mL −1 . Noteworthy, the as-developed aptasensor displayed the lowest detection limit for CBZ among the previously reported methods. Common pesticides (atrazine, thiamethoxam , etc.) with 100-fold concentration did not interfere the CBZ detection. For CBZ detection in lettuce and orange juice, satisfactory recoveries were obtained with standard addition method. Statistics demonstrated that no significant differences were found between the data provided by standard HPLC-MS reference method and developed aptasensing method in term of accuracy and precision. We believe that the proposed aptasensor possesses a potential application for CBZ monitoring in agricultural product and food.
研究领域:
分析化学
·
食品安全
·
纳米技术
✓ 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）