Preparation and characterization of MR fluid consisting of magnetite particle coated with PMMA

Hong, Mi Jeong; Park, B J; Choi, Hyoung Jin

doi:10.1088/1742-6596/149/1/012055

Cited by 7 publications

(6 citation statements)

References 20 publications

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“…48 According to these spectra, free microbial consortium contained functional groups such as -NH, C-N, P]O, -CH 2 , P-OH, P-O-C and -COOH which indicated that bacterial cells contain polysaccharides, nucleotide and protein; 40 the immobilized control had -NH, -CH 2 , C]C, -COOH, mineral crystal compounds and Fe 3 O 4 which suggested that semi-coke, sodium alginate and lactose included mineral crystal and metallic compounds, and organism substance; the immobilized microbial consortium had -NH, -OH, C-N, C]C, -COOH, P]O, mineral crystal compounds and Fe 3 O 4 which was not the merged one. 48 Compared to them, through immobilizationtreatment, asymmetric and symmetric deformation of -CH 2 groups was absent in the spectrum which probably proved that -CH 2 groups changed into carbonate; P-OH and P-O-C translated into P]O; -OH present in the spectrum. Xu et al 40 thought immobilization prevents loss or damage of some molecular groups.…”

Section: Surface Functional Groups On Immobilized and Free Microbial ...mentioning

confidence: 99%

Biodegradation of different petroleum hydrocarbons by free and immobilized microbial consortia

Bao

et al. 2015

Environ. Sci.: Processes Impacts

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The efficiencies of free and immobilized microbial consortia in the degradation of different types of petroleum hydrocarbons were investigated. In this study, the biodegradation rates of naphthalene, phenanthrene, pyrene and crude oil reached about 80%, 30%, 56% and 48% under the optimum environmental conditions of free microbial consortia after 7 d. We evaluated five unique co-metabolic substances with petroleum hydrocarbons, α-lactose was the best co-metabolic substance among glucose, α-lactose, soluble starch, yeast powder and urea. The orthogonal biodegradation analysis results showed that semi-coke was the best immobilized carrier followed by walnut shell and activated carbon. Meanwhile, the significance of various factors that contribute to the biodegradation of semi-coke immobilized microbial consortia followed the order of: α-lactose > semi-coke > sodium alginate > CaCl2. Moreover, the degradation rate of the immobilized microbial consortium (47%) was higher than that of a free microbial consortium (26%) under environmental conditions such as the crude oil concentration of 3 g L(-1), NaCl concentration of 20 g L(-1), pH at 7.2-7.4 and temperature of 25 °C after 5 d. SEM and FTIR analyses revealed that the structure of semi-coke became more porous and easily adhered to the microbial consortium; the functional groups (e.g., hydroxy and phosphate) were identified in the microbial consortium and were changed by immobilization. This study demonstrated that the ability of microbial adaptation to the environment can be improved by immobilization which expands the application fields of microbial remediation.

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Section: Surface Functional Groups On Immobilized and Free Microbial ...mentioning

confidence: 99%

Biodegradation of different petroleum hydrocarbons by free and immobilized microbial consortia

Bao

et al. 2015

Environ. Sci.: Processes Impacts

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“…[5][6][7] These properties can be tuned by optimizing the synthesis parameters and choosing the ingredients. [8][9][10][11] Some problems, such as particle aggregation and settling rate, affect the performance of MR uid and restrict its use in applications. [12][13][14] To rectify these issues, different procedures have been adopted like addition of thixotropic agents or surfactants and use of viscoplastic media, but sometimes these processes hinder the MR effects.…”

Section: Introductionmentioning

confidence: 99%

An improved properties of bidispersed magneto-rheological fluids

et al. 2014

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We have investigated the influence of nanosized particle concentration on rheological properties when mixed with a magnetorheological (MR) fluid. We have also studied the structural, morphological and magnetic properties of ferrofluid-based MR fluids (F-MRFs). Field-induced rheological and viscoelastic properties of F-MRFs with varying shear rate and strain amplitude have been investigated. The HerschelBulkley model was found to fit well with the flow behaviour of F-MRFs. In the oscillatory strain sweep test, F-MRFs show linear viscoelasticity at low strain and the storage modulus (G 0 ) is higher than the viscous modulus (G 00 ), which indicates the existence of strong links among the particles that form the microscopic structures. The storage modulus increases with increasing weight fraction of nanosized particles. Furthermore, the loss factor (ratio of G 00 and G 0 ) was also investigated as a function of magnetic field strength. In addition, time-dependent relaxation behaviour of magnetically induced chain-like structures has also been described. The study reveals that the addition of nanoparticles to MR fluids increases the viscosity as well as the fluid stability under a magnetic field.

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“…In other words, the magnetite undergoes agglomeration and sedimentation due to the large difference between the density of magnetite (5.0−8.0 g cm −3 ) and medium oil (0.8−1.0 g cm −3 ). 20,21 To resolve these problems, several approaches have been proposed. For instance, Choi and co-workers fabricated polystyrene/Fe 3 O 4 core/shell microbeads exhibiting improved sedimentation stability.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Magnetite (Fe 3 O 4 ) has been used for MR material because of its high saturation magnetization, monodisperse and nanoscale size, and relatively lower density than carbonyl iron particles which is another widely used MR material. − On the other hand, the magnetite-based MR fluid had serious drawbacks of low colloidal stability and sedimentation problems. In other words, the magnetite undergoes agglomeration and sedimentation due to the large difference between the density of magnetite (5.0–8.0 g cm –3 ) and medium oil (0.8–1.0 g cm –3 ). , To resolve these problems, several approaches have been proposed. For instance, Choi and co-workers fabricated polystyrene/Fe 3 O 4 core/shell microbeads exhibiting improved sedimentation stability .…”

Section: Introductionmentioning

confidence: 99%

Dual Stimuli-Responsive Smart Fluid of Graphene Oxide-Coated Iron Oxide/Silica Core/Shell Nanoparticles

et al. 2016

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The graphene oxide-coated iron oxide/silica core/shell nanoparticles (Fe3O4/SiO2/GO NPs) are successfully fabricated and adopted as the dual stimuli-responsive smart fluid. The Fe3O4/SiO2/GO NPs exhibit both electrorheological (ER) and magnetorheological (MR) characteristics, attributed to the SiO2/GO layer in the shell part and Fe3O4 in the core part, respectively. Particularly, the ER efficiency of the Fe3O4/SiO2/GO NPs-based ER fluid is ca. 191 at the applied electric field of 3 kV mm–1. Moreover, the MR performance of the Fe3O4/SiO2/GO NPs-based MR fluid is significantly enhanced up to 135-fold at the applied magnetic field of 1 T compared to the zero-field stress. Furthermore, it is remarkable that the Fe3O4/SiO2/GO NPs represent high colloidal stability and outstanding antisettling property because of the electrostatic repulsion between oxygen functional groups on GO nanosheets and the relatively low density compared with other magnetic particles. Dual stimuli-responsive characteristics in addition to the excellent antisedimentation property of the Fe3O4/SiO2/GO NPs-based smart fluid would provide a feasible candidate for practical applications.

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Preparation and characterization of MR fluid consisting of magnetite particle coated with PMMA

Cited by 7 publications

References 20 publications

Biodegradation of different petroleum hydrocarbons by free and immobilized microbial consortia

Biodegradation of different petroleum hydrocarbons by free and immobilized microbial consortia

An improved properties of bidispersed magneto-rheological fluids

Dual Stimuli-Responsive Smart Fluid of Graphene Oxide-Coated Iron Oxide/Silica Core/Shell Nanoparticles

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