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Article

Sofiya Bano and Sandhya Pillai

The purpose of this paper is to prepare calcium oxide (CaO) nanoparticles by green synthesis technique and study its structural, morphological and optical properties. The…

Abstract

Purpose

The purpose of this paper is to prepare calcium oxide (CaO) nanoparticles by green synthesis technique and study its structural, morphological and optical properties. The prepared samples were calcined at, 200°C, 300°C and 500°C, and the variation in the properties at different temperatures were investigated.

Design/methodology/approach

Green approach has been used in the present work to synthesise the CaO nanoparticles using Murraya Koenigii leaf (curry leaves) extract as a capping agent. This technique involves the use of nontoxic reagents and natural products derived from various parts of plants.

Findings

Studies reveal that CaO nanoparticles with good optical properties can be synthesized successfully by green approach. The optical absorbance spectra show a broad absorption peak around 400–500 nm. FTIR studies confirm the presence of different functional groups that help in the stabilization of CaO nanoparticles. PL emission spectra show a high intensity emission peak at around 231 nm in addition to peaks at 375 nm and 400 nm. XRD studies show planes of CaO cubic phase. SEM images show a nonuniform distribution of spherical particles along with some clusters. EDX spectra confirm the presence of calcium and oxygen.

Practical implications

CaO nanoparticles have wide applications in optical devices as well as in phototherapy. It is thus interesting to devise new and eco-friendly techniques to synthesise these nanoparticles to suit these applications.

Originality/value

This work would provide a new insight into the preparation of different metal oxide nanoparticles by a very simple and cost-effective green technique without the use of toxic reagents.

Details

World Journal of Science, Technology and Sustainable Development, vol. 17 no. 3
Type: Research Article
ISSN: 2042-5945

Keywords

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Article

Lifeng Hao, Jiusheng Li, Xiaohong Xu and Tianhui Ren

Nanoparticles are not well dispersed in non‐polar organic solvents due to their hydrophilic property which limits their applications in lubricant oils. To improve the…

Abstract

Purpose

Nanoparticles are not well dispersed in non‐polar organic solvents due to their hydrophilic property which limits their applications in lubricant oils. To improve the oil‐solubility of nanoparticles, a novel technology was used to prepare a kind of lubricant containing calcium borate nanoparticles.

Design/methodology/approach

The microstructures of the prepared nanoparticles were characterized by transmission electron microscope (TEM) and infrared spectra (IR). Tribological properties of calcium borate nanoparticles used as additive in base oil were evaluated using four‐ball tribotester and SRV tribotester, and the worn surface of the steel ball was investigated by Polarized microscope (PM) and X‐ray photoelectron spectroscopy (XPS). In addition, the dispersing stability and antioxidation property of lubricant containing nanoparticles were also studied.

Findings

The results indicate that the average size of the prepared nanoparticles is in the range of 50‐100 nm, and the surface of the nanoparticles was altered from hydrophilicity to hydrophobicity. At the same time, the nanoparticles can be well dispersed in the base oil totally under novel process which has no significantly negative effect on the antioxidation property. The results of tribological tests show that calcium borate nanoparticles under the novel process (CBNN) show better antiwear property and friction‐reducing property in base oil compared to calcium borate nanoparticles under tradition process (CBNT). Based on the results of PM and XPS, it can be deduced that a continuous resistance film containing depositions and the tribochemical reaction products such as B2O3, FeB, Fe2O3 and CaO formed during the sliding process.

Originality/value

The main innovative thought of this work lies in dealing with the oil‐solubility problem through the combination effect of surface modification and special blend process of lubricating oil, and this method was first used to prepare lubricant containing calcium borate nanoparticles. It should be helpful for the borate nanoparticles used as additives in engine oil, gear oil and other industrial lubricants.

Details

Industrial Lubrication and Tribology, vol. 64 no. 1
Type: Research Article
ISSN: 0036-8792

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Article

Liu Ping, Wang Dongyun, Li Yanbin, Guo Yanqing and Hao Lifeng

The purpose of this paper is to develop a potential nanoparticles lubricant additive for solving the problem of the insolubility and stable dispersity; the complex…

Abstract

Purpose

The purpose of this paper is to develop a potential nanoparticles lubricant additive for solving the problem of the insolubility and stable dispersity; the complex nanoparticles with core-shell structures are less studied in the field. Therefore, this paper determines novel complex nanoparticles and their tribological properties.

Design/methodology/approach

According to the conventional preparation method, the complex nanoparticle styrene/calcium borate (PS/O-CaB) was synthesized. The microstructures of the as-obtained samples were characterized by X-ray diffraction infrared spectroscopy and thermogravimetric analysis. Tribological properties of PS/O-CaB used as lubricating oil additive were evaluated on four-ball tribometer. The worn surface of the steel ball was investigated by a three-dimensional non-contact surface profilometer and X-ray photoelectron spectroscopy (XPS).

Findings

The results of the structure characteristic indicate two different crystalline forms, namely, Ca2B6O11 and Ca2B2O5, and the average size of calcium borate nanoparticles in PS/O-CaB is about 20-40 nm. Moreover, the good tribological properties are due to a wear resistance film containing both depositions and the tribochemical reaction products which comprise B2O3, FeB and Fe2O3.

Originality/value

Novel complex nanoparticles with core-shell structure (PS/O-CaB) were successfully prepared. Moreover, the PS/O-CaB shows excellent tribological capacity such as load-carrying, friction-reducing and antiwear property.

Details

Industrial Lubrication and Tribology, vol. 66 no. 4
Type: Research Article
ISSN: 0036-8792

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Article

Ying Huang, Sheng Han, Sizhou Liu, Yuhong Wang and Jiusheng Li

To develop a potential substitute for conventional lubricant additive and improve the oil-solubility of nanoparticles, calcium borate nanoparticles modified by an…

Abstract

Purpose

To develop a potential substitute for conventional lubricant additive and improve the oil-solubility of nanoparticles, calcium borate nanoparticles modified by an eco-friendly or “green” modifier lauric acid (CBLA) were prepared. The paper aims to discuss these issues.

Design/methodology/approach

The microstructures of the as-obtained samples were characterized by X-ray power diffraction (XRD) transmission electron microscope (TEM) and infrared spectra (IR). The contact angle was also measured. Tribological properties of CBLA used as additive in base oil were evaluated with a four-ball tribotester and compared with a commercial additive. The worn surface was investigated by polarized microscope (PM) and X-ray photoelectron spectroscopy (XPS).

Findings

The results indicate that the average size is in the range of 50-100 nm and the surface of calcium borate was altered from hydrophilicity to hydrophobicity. At the same time, the nanoparticles can be dispersed well in the base oil. Tribological results show that CBLA have good antiwear property and friction-reducing property in base oil, and it can be found that during the sliding process, a continuous wear resistance film was formed which containing depositions and the tribochemical reaction products such as B2O3, FeB, Fe2O3 and CaO.

Originality/value

An eco-friendly or “green” modifier lauric acid could change the surface of calcium borate from hydrophilicity to hydrophobicity, and calcium borate modified by lauric acid has good tribological properties in lubricating oil.

Details

Industrial Lubrication and Tribology, vol. 66 no. 1
Type: Research Article
ISSN: 0036-8792

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Article

Libin Yang, Dong Wang, Hong Gao, Hui Cao, Yuzhen Zhao, Zongcheng Miao, Zhou Yang and Wanli He

This study aims to develop a new kind of functional low molecular weight organic dyes, which is highly efficient, meanwhile inexpensive and easily prepared and modified…

Abstract

Purpose

This study aims to develop a new kind of functional low molecular weight organic dyes, which is highly efficient, meanwhile inexpensive and easily prepared and modified and can be used in photoacoustic (PA) imaging and photothermal therapy (PTT). To further realize the release of molecules under the biomedical condition, the releasing efficiency of micellar nanoparticles under different stimuli were represented.

Design/methodology/approach

A class of azo and Schiff base derivatives with different click reagents were characterized by PA imaging and photothermal (PT) experiments. The molecule with best PT effect was loaded into a temperature-stimuli-sensitive amphiphilic block copolymer which demonstrated the capability of releasing the polymers under the near-infrared (NIR) light of 650 nm.

Findings

The PA and PT effects of a series of azo and Schiff base derivatives with different click reagents were characterized. Introducing the click reagent F4-TCNQ can result in red shift of peaks of PA intensity. Stimulated with 650 nm laser irradiation, the polymer processed higher release rate than being stimulated by temperature stimuli.

Practical implications

This paper not only guides the design of NIR dyes with good PA intensity but also provides a method which has great potential for the application of NIR photothermal dyes in the field of biotechnology for controlled release.

Originality/value

This paper uses click reagents to modify azo and Schiff derivatives and an amphiphilic block copolymer under NIR light to realize controlled release.

Details

Pigment & Resin Technology, vol. 49 no. 4
Type: Research Article
ISSN: 0369-9420

Keywords

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Article

Jiusheng Li, Lifeng Hao, Xiaohong Xu and Tianhui Ren

Sulfurized olefins have been extensively used in many kinds of gear lubricants as EP additives. However, their commercial applications are not totally satisfactory because…

Abstract

Purpose

Sulfurized olefins have been extensively used in many kinds of gear lubricants as EP additives. However, their commercial applications are not totally satisfactory because of the pungent, obnoxious odor and corrosion of copper and copper alloys. The purpose of this paper is to investigate the synergistic effects of one type of calcium borate nanoparticles modified by oleic acid (code to CaBN) and sulfurized olefin, in a kind of mineral base oil MVIS 250, in order to find a potential substitute for sulfurized olefins.

Design/methodology/approach

One kind of calcium borate nanoparticle modified by oleic acid (CaBN) was prepared, and its structures were characterized by inductively coupled plasma atomic emission spectroscopy (ICP‐AES), X‐ray power diffraction (XRD) and transmission electron microscope (TEM). The tribological properties of the complex of CaBN with sulfurized olefins (T321) in base oil were evaluated using four‐ball tribotester and compared with CaBN or T321 as individual component. The worn surfaces were investigated by scanning electron microscope (SEM) and X‐ray photoelectron spectroscopy (XPS). In addition, the corrosion‐inhibiting properties of additives were also studied.

Findings

The results of tests show that there are significant synergistic effects on tribological properties between two kinds of additives. Based on the results of SEM and XPS, it can be deduced that a wear resistance film containing B2O3, FeS, FeS2 and CaO was formed on the worn surfaces during the sliding process. Moreover, CaBN and T321 also show excellent synergistic effect on the corrosion‐inhibiting property.

Originality/value

This paper provides a kind of “green” nanoparticle which possesses excellent synergic effect with sulfurized olefins, and gives another selection for industrial applications in which T321 is needed.

Details

Industrial Lubrication and Tribology, vol. 64 no. 4
Type: Research Article
ISSN: 0036-8792

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Article

Yuxin Miao, Guofeng Pan, Caixuan Sun, Ping He, Guanlong Cao, Chao Luo, Li Zhang and Hongliang Li

The purpose of this paper is to study the effect of doping, annealing temperature and visible optical excitation on CuO-ZnO nanocomposites’ acetone sensing properties and…

Abstract

Purpose

The purpose of this paper is to study the effect of doping, annealing temperature and visible optical excitation on CuO-ZnO nanocomposites’ acetone sensing properties and introduce an attractive candidate for acetone detection at about room temperature.

Design/methodology/approach

ZnO nanoparticles doped with CuO were prepared by sol-gel method, and the structure and morphology were characterized via X-ray diffraction, scanning electron microscope, energy dispersive spectroscopy and Brunauer-Emmett-Teller. The photoelectric responses of CuO-ZnO nanocomposites to cetone under the irradiation of visible light were investigated at about 30°C. The photoelectric response mechanism was also discussed with the model of double Schottky.

Findings

The doping of CuO enhanced performance of ZnO nanoparticles in terms of the photoelectric responses and the gas response and selectivity to acetone of ZnO nanoparticles, in addition, decreasing the operating temperature to about 30ºC. The optimum performance was obtained by 4.17% CuO-ZnO nanocomposites. Even at the operating temperature, about 30ºC, the response to 1,000 ppm acetone was significantly increased to 579.24 under the visible light irradiation.

Practical implications

The sensor fabricated by 4.17% CuO-ZnO nanocomposites exhibited excellent acetone-sensing characteristics at about 30ºC. It is promising to be applied in low power and miniature acetone gas sensors.

Originality/value

In the present research, a new nanocomposite material of CuO-ZnO was prepared by Sol-gel method. The optimum gas sensing properties to acetone were obtained by 4.17% CuO-ZnO nanocomposites at about 30ºC operating temperature when it was irradiated by visible light with the wavelength more than 420 nm.

Details

Sensor Review, vol. 38 no. 3
Type: Research Article
ISSN: 0260-2288

Keywords

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Article

Behnam Seyyedi

The paper introduces a microwave and electrochemical-assisted method for synthesis of chlorine-derived iron phthalocyanine pigment and oxygen reduction reaction catalyst…

Abstract

Purpose

The paper introduces a microwave and electrochemical-assisted method for synthesis of chlorine-derived iron phthalocyanine pigment and oxygen reduction reaction catalyst nanoparticles. The aims of this study are to investigate the possibility of nano-scale particle size (<35 nm), high-efficiency product reaction, remove acidic wastewater, time optimization and maximize number of chlorine on aromatic rings.

Design/methodology/approach

The paper presents a combined synthesis technique, which does not have the problems of the conventional methods. Chlorinated iron phthalocyanine nanoparticles have been fabricated using phthalic anhydride, urea (high purity), electrochemical-generated iron (II) cations and microwave irradiation as promoter. The approach yields a product of high quality, uniform particle size distribution and high efficiency and that was environment-friendly.

Findings

The particle size and time needed for the production of chlorinated iron phthalocyanine were about 35 nm and 7 min, respectively.

Research limitations/implications

The catalyst, that is used in this method, should be weighed carefully. In addition, the solvent should be a saturated solution of NaCl in water.

Practical implications

The method provides a simple and practical solution to improving the synthesis of an iron-based catalyst for oxygen reduction reaction.

Originality/value

The combined method for synthesis of chlorinated iron phthalocyanine was novel and can find numerous applications in the industry, especially as an oxygen reduction reaction non-precious metal catalyst.

Details

Pigment & Resin Technology, vol. 46 no. 2
Type: Research Article
ISSN: 0369-9420

Keywords

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Article

Yanfei Yang, Xiaobo Wang, Sen Mei, Xing Zhu, Shiqiang Chen, Peng Xiong, Zhihai Hu, Kun Xiong and Dong Song Yuan

The purpose of this paper is to investigate the tribological performance and mechanisms of BN/calcium borate nanocomposites (BCBNs) as additives in lubricating oil.

Abstract

Purpose

The purpose of this paper is to investigate the tribological performance and mechanisms of BN/calcium borate nanocomposites (BCBNs) as additives in lubricating oil.

Design/methodology/approach

BCBNs were prepared by heterogeneous deposition method. And the morphology and structure of samples were analysed by transmission electron microscopy, Fourier transform infrared spectra and X-ray powder diffraction pattern. The maximum non-seizure load (PB) of samples was tested using four-ball friction tester. The average friction coefficients and wear tracks were obtained. In addition, tribological mechanism was also investigated using optical microscope, energy dispersive spectroscopy and X-ray photoelectron spectroscope.

Findings

It was found that the nanocomposites present core-shell nanostructure with the thickness of shell around 12 nm and the diameter of particles 100-200 nm, and tribological tests indicate that the PB value of BCBNs was increased by 113 per cent, whereas the average friction coefficient was decreased by 23.6 per cent and the bloom’s wear area was also decreased by 25.2 per cent.

Originality/value

This paper involves investigation on tribological properties and mechanism of the BCBNs with core-shell structure.

Details

Industrial Lubrication and Tribology, vol. 70 no. 1
Type: Research Article
ISSN: 0036-8792

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Article

Ebrahim Yousefi, Morteza Adineh and Mohammad Bagher Askari

The purpose of this paper is to fabricate zirconia-nano alumina porous nanocomposites with different amount of alumina (0-30 Wt.%). Specimens were prepared by solid state…

Abstract

Purpose

The purpose of this paper is to fabricate zirconia-nano alumina porous nanocomposites with different amount of alumina (0-30 Wt.%). Specimens were prepared by solid state sintering method at different temperature (1,400-1,700°C).

Design/methodology/approach

Effects of processing temperature and amount of alumina on microstructure, distribution of nanoparticles, flexural and compressive strengths, micro-hardness and densification were investigated.

Findings

Results indicated that interpenetration of particles and their contacts increased by increasing sintering temperature. As a consequence of better particles contacts and microstructure coarsening, the porosity decreased. As alumina nanoparticles content increased, the amount of porosity decreased conversely and distribution of pores become more uniform. Simultaneous enhancement of temperature and alumina nanoparticles content caused an improvement of flexural and compressive strengths because of an improvement of sintering process resulted from porosity reduction. Increase in hardness and density were observed as porosity values diminished and alumina nanoparticles were distributed well at micro zirconia grain boundaries as a result of increasing the process temperature.

Originality/value

This article contains original research.

Details

Anti-Corrosion Methods and Materials, vol. 65 no. 2
Type: Research Article
ISSN: 0003-5599

Keywords

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