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1

Preparation and characterization of nano magnetic fluid for automotive applications

Thanikachalam J., Nagaraj P., Karthikeyan S.

Archives of Materials Science and Engineering

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2019

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Vol. 96, nr 2

49--55

EN

Purpose: of this paper is to prepare a nano magnetic fluids with nano additives to have the combined characteristics of high yield stress and better magnetic properties for smart vehicles. This study focuses on increasing the sedimentation time of the fluid using suitable nano additive nickel along with graphene as fillers. Design/methodology/approach: Magnetic nano sized nickel particle based electromagneto-rheological fluid was prepared and graphene nanoparticle with thickness less than 10nm was introduced as an additive to reduce its sedimentation. This added plate like graphene acts as filler which seals the interfaces of nickel particles and thereby it improves the resistance to sedimentation. Triton X 100 was added as the surfactant for the fluid to reduce the agglomeration of the particles. Findings: Morphology of pure nickel and graphene were examined using scanning electron microscopy (SEM) images. Research limitations/implications: The important limitations is that freely dispersed micron sized iron particles could settle over a period of time, in the form of cakes at the bottommost, and it is tedious to recuperate as dispersed phase. In this investigation, nano sized nickel particles were used as additive to reduce the sedimentation of micron sized iron particles so that, the mixture is homogeneous for extended period of time. In future, addition of different types composite additives in the magnetorheological fluid could be made for the better sedimentation control. Practical implications: The sedimentation problem is one of the major drawback in the smart fluids, which can be eliminated by adding nano particles. For conventional fluid, the complete sedimentation will occur in 2 hours while the improved nano magnetic fluid with additive has good resistance to settle the micron sized iron particle up to 10 hours. Originality/value: To prepare a low cost magnetorheological fluid with nano additives like nickel particles along with fillers as graphene nano particles. With this addition of nickel and inclusion of graphene, the sedimentation problem in magnetorheological fluids is significantly reduced. This magnetorheological fluids can be used in brakes and dampers of automobiles.

2

Determination of the efficiency factors of the absorption and scattering of nickel nanoparticles

Machulianskyi O., Babych B., Machulianskyi V.

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

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2018

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T. 8, nr 1

4--7

EN

In the dipole approximation for the spherical nickel nanoparticle with a diameter D0 = 2.5 ÷ 7 nm in the spectral range from 0.2 to 1.1 μm at T = 300 K, efficiency factors of the absorption Κa and scattering Κs were determined with the help of the experimental values of the complex specific electrical polarizability. Numerical calculations of the Κa and Κs of the nickel nanoparticles were carried out in accordance with the theories of classical and quantum dimensional effects. It was shown that it is impossible to explain the photoabsorption of nickel nanoparticles by the intraband (Drude) type of absorption even taking into account classical or quantum dimensional effects.

PL

Na podstawie wartości eksperymentalnych zespolonej właściwej polaryzacji elektrycznej zostały wyznaczone współczynniki efektywności absorpcji Κa i rozpraszania Κs w przybliżeniu dipolowym dla sferycznej nanocząstki niklu o średnicy D0 = 2,5 ÷ 7 nm w zakresie spektralnym od 0,2 do 1,1 μm przy T = 300 K. Wykonano obliczenia numeryczne Κa i Κs nanocząstek niklu na podstawie teorii efektów klasycznego i kwantowego. Wykazano, że fotoabsorpcji nanocząstek niklu nie można wyjaśnić absorpcją wewnątrzstrefową (Drudowską), nawet biorąc pod uwagę efekty klasyczne lub kwantowe.

3

Pro-ecological methods for synthesis of nickel nanoparticles for composite applications

Marzec A., Pędzich Z.

Composites Theory and Practice

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2014

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R. 14, nr 2

76--80

EN

Composites containing nickel nanoparticles dispersed in a ceramic polycrystalline matrix are widely utilized materials for different applications. They are utilized in ceramic matrix/metallic additive composites due to their profitable influence on both the mechanical (grain size growth control, stress relaxation on crack tip by plastic deformation) and functional properties. A zirconia/nano-Ni composite is an important material for solid oxide fuel cell electrodes possessing unique electrochemical properties. Another composite composed of alumina and nano-Ni is a widely investigated structural material showing excellent mechanical properties. The paper presents an innovative pro-ecological method for synthesizing nickel nanoparticles to be used in ceramic matrix/metal particle composites, which could be used as an alternative to traditional methods. The proposed biochemical syntheses minimise or even completely eliminate the amount of produced waste and could be implemented as sustainable processes accepting the basic principles of “green chemistry”. The suggested method enables precise size control of the created nanoparticles and at the same time offers numerous advantages in comparison to conventional methods.

PL

Nanocząstki niklu znajdują zastosowanie w wielu dziedzinach. Wykorzystuje się je m.in. w kompozytach ceramiczno-metalicznych, gdzie wpływają pozytywnie nie tylko na mechaniczne właściwości kompozytu (kontrola rozrostu ziaren, relaksacja naprężeń przy wierzchołku pęknięcia na skutek kontaktu z fazą plastyczną), ale również na jego właściwości funkcjonalne. Kompozyty zawierające nanocząstki niklu rozproszone w osnowie polikrystalicznego tlenku cyrkonu są wykorzystywane m.in. do budowy elektrod w ogniwach paliwowych z zestalonym elektrolitem tlenkowym (SOFC). Innym przykładem kompozytu zawierającego nanocząstki niklu jest materiał wykazujący znakomite właściwości mechaniczne zbudowany z nanocząstek niklu i Al2O3. W artykule przedstawiono proekologiczną, innowacyjną metodę syntezy nanocząstek niklu do zastosowania w kompozytach ceramiczno-metalicznych jako alternatywę dla metod tradycyjnych. Zaproponowana metoda pozwala nie tylko na precyzyjną kontrolę wielkości powstających nanocząstek, ale również ich równomierne rozłożenie w matrycy ceramicznej, realizując przy tym zasady „zielonej chemii”.

4

Spectroscopic and dielectric characteristics of nickel-doped porous silica glasses

Macalik B., Suszyńska M., Rysiakiewicz-Pasek E., Krawczyk L., Morawska-Kowal T., Okal J.

Optica Applicata

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2005

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Vol. 35, nr 4

761-767

EN

The direct current conduction and electrical relaxation currents in nickel-doped porous silica glasses were investigated by using the thermally stimulated polarisation and depolarisation current techniques in a wide temperature range. Optical absorption measurements and transmission electron microscopy observations accompanied these studies. All characteristics were found to be affected by the porous matrix and the material filling the pores.