共查询到20条相似文献,搜索用时 46 毫秒
1.
Mithun K. Debnath Mohammad A. Rahman Hideto Minami Mohammad M. Rahman Mohammad A. Alam Mohammad K. Sharafat Mohammad K. Hossain Hasan Ahmad 《应用聚合物科学杂志》2019,136(19):47524
This article describes a single-step reproducible approach for the surface modification of micrometer-sized polystyrene (PS) core particles to prepare electromagnetic PS/polyaniline–Fe3O4 (PS/PANi–Fe3O4) composite particles. The electromagnetic PANi–Fe3O4 shell was formed by simultaneous seeded chemical oxidative polymerization of aniline and precipitation of Fe3O4 nanoparticles. The weight ratio of PS to aniline was optimized to produce core–shell structure. PS/PANi–Fe3O4 composite particles were used as adsorbent for the removal of Cr(VI) via anion-exchange mechanism. The composite particles possessed enough magnetic property for magnetic separation. The adsorption was highly pH dependent. Adsorption efficiency reached 100% at pH 2 in 120 min when 0.05 g of composite particles was mixed with 30 mL 5 mg L−1 Cr(VI) solution. The adsorption isotherm fitted best with Freundlich model and maximum adsorption capacity approached 20.289 mg g−1 at 323 K. The prepared composite was found to be an useful adsorbent for the removal of soluble Cr(VI) ions. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47524. 相似文献
2.
Mao Shen Wenping Jia Caiping Lin Guodong Fan Yangmin Jin Xiaoying Chen Guang Chen 《Nanoscale research letters》2014,9(1):558
In this paper, we investigated the functional imaging properties of magnetic microspheres composed of magnetic core and CdTe quantum dots in the silica shell functionalized with folic acid (FA). The preparation procedure included the preparation of chitosan-coated Fe3O4 nanoparticles (CS-coated Fe3O4 NPs) prepared by a one-pot solvothermal method, the reaction between carboxylic and amino groups under activation of NHS and EDC in order to obtain the CdTe-CS-coated Fe3O4 NPs, and finally the growth of SiO2 shell vent the photoluminescence (PL) quenching via a Stöber method (Fe3O4-CdTe@SiO2). Moreover, in order to have a specific targeting capacity, the magnetic and fluorescent bifunctional microspheres were synthesized by bonding of SiO2 shell with FA molecules via amide reaction (Fe3O4-CdTe@SiO2-FA). The morphology, size, chemical components, and magnetic property of as-prepared composite nanoparticles were characterized by ultraviolet-visible spectroscopy, fluorescent spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), scanning transmission electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM), respectively. The results show that the magnetic and fluorescent bifunctional microspheres have strong luminescent which will be employed for immuno-labeling and fluorescent imaging of HeLa cells. 相似文献
3.
Rajnish Kurchania Sachin S. Sawant Richard J. Ball 《Journal of the American Ceramic Society》2014,97(10):3208-3215
Magnetite (Fe3O4)/polyvinyl alcohol (PVA) core–shell composite nanoparticles were successfully synthesized using a coprecipitation of ferrous and ferric chloride followed by coating with PVA. The resulting nanoparticles were characterized using X‐ray diffraction, Fourier Transform Infrared Spectroscopy, Transmission Electron Microscopy, X‐ray photo electron spectroscopy, Zeta potential measurements, UV–Vis spectroscopy, Thermogravimetric Analysis, and Vibrating Sample Magnetometry (VSM). The average particle size was 13 nm. The presence of characteristic functional groups of PVA around the core of magnetite nanoparticles was confirmed by FTIR spectroscopy while the amount of PVA (%) bound to it was estimated by TGA analysis. Zeta potential measurements made by dispersing dilute sonicated samples in a Phosphate Buffer Saline (PBS pH 7.4) confirmed that the particles were negatively charged. The stability and retention of the coating material PVA in PBS (pH7.4) over a period of time were substantiated by UV–Vis spectroscopy. Room‐temperature magnetic measurements were made with a VSM which demonstrated the superparamagnetic nature of the particles with higher saturation magnetization of 56.41 emu/g. Furthermore, in vitro cytocompatibility testing of Fe3O4/PVA core–shell composite nanoparticles was carried out on human cervix cancer cells. This confirmed a 97% cell viability with no significant cytotoxicity and thereby substantiated their biocompatibility. 相似文献
4.
In this study, oil‐based magnetic Fe3O4 nanoparticles were first synthesized by a coprecipitation method followed by a surface modification using lauric acid. Polystyrene/Fe3O4 composite particles were then prepared via miniemulsion polymerization method using styrene as monomer, 2,2′‐azobisisobutyronitrile (AIBN) as initiator, sodium dodecyl sulfate (SDS) as surfactant, hexadecane (HD) or sorbitan monolaurate (Span20®) as costabilizer in the presence of Fe3O4 nanoparticles. The effects of Fe3O4 content, costabilizer, homogenization energy during ultrasonication, and surfactant concentration on the polymerization kinetics (e.g., conversion), nucleation mechanism, and morphology (e.g., size distributions of droplets and latex) of composite particles were investigated. The results showed that at high homogenization energy, an optimum amount of SDS and hydrophobic costabilizer was needed to obtain composite particles nucleated predominately by droplet nucleation mechanism. The morphology of the composite particles can be well controlled by the homogenization energy and the hydrophobicity of the costabilizer. The magnetic composite particles can be made by locating Fe3O4 inside the latex particles or forming a shell layer on their PS core surface depending on the aforementioned polymerization conditions. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
5.
Feige Guo Qiuyu Zhang Hepeng Zhang Baoliang Zhang Junwei Gu 《Journal of Polymer Research》2011,18(4):745-751
In this work, controlled radical polymerization based on 1, 1-diphenylethylene (DPE method) was used to prepare magnetic composite
microspheres. By this method, Fe3O4/P (St-MA) magnetic composite microspheres were prepared via copolymerization of styrene (St) and maleic anhydride (MA) using
DPE as radical control agent in the presence of Fe3O4 nanoparticles. The structure and properties of the magnetic composite microspheres obtained were characterized by IR, 1H-NMR, SEC-MALLS, TEM, TGA, VSM, DLS and other instruments. It was found that the DPE method allows the controlled preparation
of magnetic composite microspheres, and Fe3O4/ P(St-MA) microspheres possess perfect sphere-shaped morphology, homogeneous particle size, carboxylic surface, superparamagnetism
with a saturation magnetization of 14.704 emu/g, and magnetic content with a value of 25%. 相似文献
6.
Hui Du Peng Zhang Fengqi Liu Shihai Kan Dejun Wang Tiejin Li Xinyi Tang 《Polymer International》1997,43(3):274-280
Fe2O3 particles with diameter of 3–5 nm were encapsulated in polymer spheres (styrene/butyl acrylate/acrylic acid terpolymer latex) by emulsion polymerization. Control of the pH value of the medium and modification of the latex prior to the second polymerization were of importance in determining the microstructure and morphology of the composite particles. The interaction between Fe2O3 and seed latex was confirmed by IR spectral changes of the surface groups of the latex particles. Mossbauer spectra gave evidence for the changes of electric density and electric field symmetry around Fe2O3, and surface photovoltage spectra indicated that the Fe2O3 particles were encapsulated in polymer. It was shown by all the results that the composite microspheres of size 80 nm had a core–shell structure with trilayers of seed latex core, Fe2O3 nanoparticles middle layer and polymer shell. © 1997 SCI. 相似文献
7.
Chienwen Huang Jiechao Jiang Chivarat Muangphat Xiankai Sun Yaowu Hao 《Nanoscale research letters》2011,6(1):43
Synthesis of the core/shell-structured Fe3O4/Au nanoparticles by trapping Fe3O4 inside hollow Au nanoparticles is described. The produced composite nanoparticles are strongly magnetic with their surface
plasmon resonance peaks in the near infrared region (wavelength from 700 to 800 nm), combining desirable magnetic and plasmonic
properties into one nanoparticle. They are particularly suitable for in vivo diagnostic and therapeutic applications. The
intact Au surface provides convenient anchorage sites for attachment of targeting molecules, and the particles can be activated
by both near infrared lights and magnetic fields. As more and more hollow nanoparticles become available, this synthetic method
would find general applications in the fabrication of core–shell multifunctional nanostructures. 相似文献
8.
Preparation and characterization of magnetic poly(styrene–glycidyl methacrylate) microspheres for highly efficient protein adsorption by two‐stage dispersion polymerization
下载免费PDF全文
![点击此处可从《应用聚合物科学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Xinwei Zhao Yueping Guan Changfu Xia Tingting Xia Xiaolin Qiu Chuhang Wang Chen Guo 《应用聚合物科学杂志》2016,133(10)
Micrometer‐sized superparamagnetic poly(styrene–glycidyl methacrylate)/Fe3O4 spheres were synthesized by two‐stage dispersion polymerization with modified hydrophobic Fe3O4 nanoparticles, styrene (St), and glycidyl methacrylate (GMA). The morphology and properties of the magnetic Fe3O4–P (St‐GMA) microspheres were examined by scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, thermogravimetric analysis, and attenuated total reflectance. The average size of the obtained magnetic microspheres was 1.50 μm in diameter with a narrow size distribution, and the saturation magnetization of the magnetic microspheres was 8.23 emu/g. The magnetic Fe3O4–P (St‐GMA) microspheres with immobilized iminodiacetic acid–Cu2+ groups were used to investigate the adsorption capacity and selectivity of the model proteins, bovine hemoglobin (BHb) and bovine serum albumin (BSA). We found that the adsorption capacity of BHb was as high as 190.66 mg/g of microspheres, which was 3.20 times greater than that of BSA, which was only 59.64 mg/g of microspheres as determined by high‐performance liquid chromatography. With a rather low nonspecific adsorption, these microspheres have great potential for protein separation and purification applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43005. 相似文献
9.
Jixiao WANG Rui LIU Xiaoyan ZHANG Zhibin ZHOU Zhi WANG Shichang WANG 《Frontiers of Chemical Engineering in China》2008,2(3):231-235
A facile route to prepare Fe3O4/polypyrrole (PPY) core-shell magnetic nanoparticles was developed. Fe3O4 nanoparticles were first prepared by a chemical co-precipitation method, and then Fe3O4/PPY coreshell magnetic composite nanoparticles were prepared by in-situ polymerization of pyrrole in the presence of Fe3O4 nanoparticles. The obtained nanoparticles were characterized by scanning electronic microscopy (SEM), transmission electronic
microscopy (TEM) and laser particle size analyzer. The images indicate that the size of Fe3O4 particles is about 10 nanometers, and the particles are completely covered by PPY. The Fe3O4/PPY core-shell magnetic composite nanoparticles are about 100 nanometers and there are several Fe3O4 particles in one composite nanoparticle. The yield of the composite nanoparticles was about 50%. The sedimentation behavior
of Fe3O4/PPY core-shell magnetic nanoparticles in electrolyte and soluble polymer solutions was characterized. The experimental results
indicate that the sedimentation of particles can be controlled by adjusting electrolyte concentration, solvable polymers and
by applying a foreign field. This result is useful in preparing gradient materials and improving the stability of suspensions. 相似文献
10.
《Carbon》2015
A series of Fe3O4/C core–shell nanospindles with different shell thickness have been synthesized by a wet chemical method and subsequent high-temperature carbonization. The thickness of carbon shell can be well adjusted from 9 to 32 nm by changing the addition amounts of resorcinol and formaldehyde precursors during the coating process. Structure and morphology characterizations reveal that the carbon shell is amorphous structure and uniformly encapsulates on porous Fe3O4 nanospindles. For the first time, a flexible Fe3O4/C/poly(vinylidene fluoride) (PVDF) composite absorber was prepared by embedding the core–shell Fe3O4/C nanospindles in PVDF matrix. The electromagnetic properties of the composite show strong dependence on the carbon-shell thickness. The impedance matching for electromagnetic absorption is improved by the synergy effect between Fe3O4 nanospindles and encapsulated carbon shell. The Fe3O4/C/PVDF composite with thick carbon shell exhibits strong electromagnetic wave absorbing ability with thin absorber thickness. The minimum reflection loss for the absorber with thickness of 2.1 mm can reach −38.8 dB. 相似文献
11.
Masoumeh Bayat 《Polymer》2011,52(7):1645-1653
In order to develop multifunctional nanofibers, the electrical conductivity and magnetic properties of Fe3O4/carbon composite nanofibers have been examined. Polyacrylonitrile (PAN) is used as a matrix to produce magnetic composite nanofibers containing different amounts of magnetite (Fe3O4) nanoparticles. Electrospun composite nanofibers were thermally treated to produce electrically conductive and magnetically permeable composite carbon nanofibers. The composite nanofibers were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffractometry (XRD), Raman spectroscopy, four-point probe and Superconducting Quantum Interference Device (SQUID). Uniform nanofibers were obtained with successful transferring of magnetic properties of Fe3O4 into the as-spun composite nanofibers. The electromagnetic properties were tuned by adjusting the amount of Fe3O4 in the matrix and carbonization process. The electrical conductivity, magnetic moment and also magnetic hysteresis rise up by adding Fe3O4 and increasing carbonization temperature. The high surface area provided by the ultrafine fibrous structures, the flexibility and tuneable electromagnetic properties are expected to enable the expansion of the design options for a wide rage of electronic devices. 相似文献
12.
Sudaryanto Takashi Nishino Masaki Ueno Seiji Asaoka Katsuhiko Nakamae 《应用聚合物科学杂志》2001,82(12):3030-3035
Segmented polyurethane (SPU)/poly(vinyl chloride) (PVC) blends were particulated with γ‐Fe2O3. Interfacial properties of the composite were studied through the adsorption behaviors of SPU and PVC and their blends on γ‐Fe2O3 particles surface. Mechanical properties of the composite were measured with dynamic mechanical analysis and tensile test measurements. PVC with functional groups (FPVC), because of strong interactions, showed preferential adsorption on γ‐Fe2O3 compared with SPU and PVC. Moreover, the γ‐Fe2O3 particles were covered by FPVC in the γ‐Fe2O3/SPU/FPVC composite. The adsorption layer of FPVC protected SPU from catalytic degradation by γ‐Fe2O3, resulting in increasing hydrolytic stability for SPU. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3030–3035, 2001 相似文献
13.
Sadia Salsabil Bristy Mohammad Abdur Rahman Klaus Tauer Hideto Minami Hasan Ahmad 《Ceramics International》2018,44(4):3951-3959
Porous γ-alumina (γ-Al2O3) is one of widely used ceramic materials. To maximize the application potentials attempt was made to prepare multifunctional γ-Al2O3 ceramic composite particles following magnetization and then seeded polymerization with epoxide functional glycidyl methacrylate (GMA). γ-Al2O3 particles were first prepared by a modified sol-gel approach and then doped with variable content Fe3O4 nanoparticles. At higher Fe3O4 content the magnetite nanoparticles were oriented into needle like hairy structure basically grown from the surface of γ-Al2O3 particles. Before the seeded polymerization the magnetic γ-Al2O3 particles were modified with SiO2 layer to improve the compatibility with the PGMA layer. The produced multifunctional ceramic particles were named as γ-Al2O3/Fe3O4/SiO2/PGMA nanocomposite because one of the phases constituting Fe3O4 was in nano-size range. The produced nanocomposite particles possessed superparamagnetic properties and could be isolated from the dispersion medium by external magnetic field. Fourier Transform IR (FTIR) and X-ray photoelectron spectroscopic (XPS) data revealed that final nanocomposite particles contained reactive epoxide groups on or near the surface. The produced multifunctional γ-Al2O3 ceramic nanocomposite particles can be useful in biotechnology, catalysis and adsorbents for pollutant removal. 相似文献
14.
Poly(acrylate-styrene)/poly(acrylate-styrene) core/shell latex particles were synthesized via seeded semi-continuous emulsion polymerization. Both core polymer (CP) and shell polymer (SP) were copolymerized by using three identical monomers of methyl methacrylate (MMA), butyl acrylate (BA) and styrene (St) with different composition ratios. The synthesized core/shell latex particle presents a phase separated state with the interfacial layer between CP and SP. In this study, the weight fractions and the corresponding thickness of this interfacial layer, CP and SP phase in the core/shell latex particle has be successfully calculated by using multi-frequency temperature-modulated differential scanning calorimetry (TOPEM-DSC). The results indicate that the interfacial layer thickness of the core/shell latex particle is determined by the core/shell structure, such as hard core/soft shell (defined as HC/SS) and soft core/hard shell (defined as SC/HS), the glass transition temperature (Tg) of the “hard” phase (correspondingly core or shell for HC/SS or SC/HS structure, respectively), and the existence of hydrophilic monomer during the copolymerization process such as acrylic acid. Meanwhile, the influence of film-formation-temperature on the microstructure of the latex films was systematically explored in this work. 相似文献
15.
R. Arundhathi D. Damodara M. Lakshmi Kantam P. Saravanan Travis Magdaleno Sun Hee Kwon 《Advanced Synthesis \u0026amp; Catalysis》2011,353(9):1591-1600
A high surface, magnetic Fe3O4@mesoporouspolyaniline core‐shell nanocomposite was synthesized from magnetic iron oxide (Fe3O4) nanoparticles and mesoporouspolyaniline (mPANI). The novel porous magnetic Fe3O4 was obtained by solvothermal method under sealed pressure reactor at high temperature to achieve high surface area. The mesoporouspolyaniline shell was synthesized by in situ surface polymerization onto porous magnetic Fe3O4 in the presence of polyvinylpyrrolidone (PVP) and sodium dodecylbenzenesulfonate (SDBS), as a linker and structure‐directing agent, through ‘blackberry nanostructures’ assembly. The material composition, stoichiometric ratio and reaction conditions play vital roles in the synthesis of these nanostructures as confirmed by variety of characterization techniques. The role of the mesoporouspolyaniline shell is to stabilize the porous magnetic Fe3O4 nanoparticles, and provide direct access to the core Fe3O4 nanoparticles. The catalytic activity of magnetic Fe3O4@mesoporousPANI nanocomposite was evaluated in the cross‐coupling of aryl chlorides and phenols. 相似文献
16.
Fei Fei Fang 《Polymer》2009,50(10):2290-2293
Most magnetic materials possess serious sedimentation problem due to their large density when they are adopted as magnetorheological (MR) materials. In this communication, we fabricated novel core-shell structured polystyrene(PS)/Fe3O4 microbeads via a facile method. Porous morphology of the PS obtained by etching silica particles and the loaded Fe3O4 was observed via both SEM and TEM images. XRD pattern confirms crystalline structure of the synthesized iron species. VSM data indicate the change in saturation magnetization before and after introducing organic PS core. Finally, MR performances of the PS/Fe3O4 based MR fluid were investigated via a rotational rheometer and sedimentation stability was found to be improved with a decreased density of the synthesized microbeads. 相似文献
17.
Bifunctional magnetic–fluorescent composite nanoparticles (MPQDs) with Fe3O4 MPs and Mn:ZnS/ZnS core–shell quantum dots (QDs) encapsulated in silica spheres were synthesized through reverse microemulsion
method and characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, vibration
sample magnetometer, and photoluminescence (PL) spectra. Our strategy could offer the following features: (1) the formation
of Mn:ZnS/ZnS core/shell QDs resulted in enhancement of the PL intensity with respect to that of bare Mn:ZnS nanocrystals
due to the effective elimination of the surface defects; (2) the magnetic nanoparticles were coated with silica, in order
to reduce any detrimental effects on the QD PL by the magnetic cores; and (3) both Fe3O4 MPs and Mn:ZnS/ZnS core–shell QDs were encapsulated in silica spheres, and the obtained MPQDs became water soluble. The experimental
conditions for the silica coating on the surface of Fe3O4 nanoparticles, such as the ratio of water to surfactant (R), the amount of ammonia, and the amount of tetraethoxysilane, on the photoluminescence properties of MPQDs were studied.
It was found that the silica coating on the surface of Fe3O4 could effectively suppress the interaction between the Fe3O4 and the QDs under the most optimal parameters, and the emission intensity of MPQDs showed a maximum. The bifunctional MPQDs
prepared under the most optimal parameters have a typical diameter of 35 nm and a saturation magnetization of 4.35 emu/g at
room temperature and exhibit strong photoluminescence intensity. 相似文献
18.
Fe3O4 nanoparticles were modified by n-octadecyltrimethoxysilane (C18TMS) and 3-trimethoxysilylpropylmethacrylate (MPS). The modified Fe3O4 nanoparticles were used to prepare Fe3O4/polystyrene composite particles by miniemulsion polymerization. The effect of surface modification of Fe3O4 on the preparation of Fe3O4/polystyrene composite particles was investigated by transmission electron microscopy, Fourier transform infrared spectrophotometer
(FT-IR), contact angle, and vibrating sample magnetometer (VSM). It was found that C18TMS modified Fe3O4 nanoparticles with high hydrophobic property lead to the negative effect on the preparation of the Fe3O4/polystyrene composite particles. The obtained composite particles exhibited asymmetric phase-separated structure and wide
size distribution. Furthermore, un-encapsulated Fe3O4 were found in composite particles solution. MPS modified Fe3O4 nanoparticles showed poor hydrophobic properties and resulted in the obtained Fe3O4/polystyrene composite particles with regular morphology and narrow size distribution because the ended C=C of MPS on the
surface of Fe3O4 nanoparticles could copolymerize with styrene which weakened the phase separation distinctly. 相似文献
19.
Synthesis,characterization, and properties of cashew gum graft poly(acrylamide)/magnetite nanocomposites
下载免费PDF全文
![点击此处可从《应用聚合物科学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Graft copolymer nanocomposites based on cashew gum and poly(acrylamide) with different concentrations of nano‐iron‐oxide particles (Fe3O4) have been prepared by an in situ polymerization method. The characterization of graft copolymer composite was carried out by FTIR, UV, XRD, SEM, DSC, and TGA, electrical conductivity, and magnetic property [vibrational sample magnetometer (VSM)] measurements. The shift in the spectrum of UV and FTIR peaks shows the intermolecular interaction between metal oxide nanoparticles and the graft copolymer system. The spherically shaped particles observed from the SEM images clearly indicating the uniform dispersion of nanoparticles within the graft copolymer chain. The XRD studies revealed that the amorphous nature of the graft copolymer decreases by the addition of Fe3O4 nanoparticles. The glass transition temperature studied from DSC increases with increase in concentration of metal oxide nanoparticles. Thermal stability of composite was higher than the pure graft copolymer and thermal stability increases with increase in content of nanoparticles. Electrical properties such as AC conductivity and dielectric properties of the composites increased with increase in concentration of metal oxide nanoparticles. The magnetic property of graft copolymer nanocomposites shows ferromagnetic and supermagnetism and the saturation of magnetism linearly increased with increasing the Fe3O4 content in the polymer composite. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43496. 相似文献
20.
As-synthesized Fe3O4 nanoparticles were encapsulated with carbon layers through a simple hydrothermal process. Fe3O4/C nanoparticles were coated with YVO4:Dy3+ phosphors to form bifunctional Fe3O4@C@YVO4:Dy3+ composites. Their structure, luminescence and magnetic properties were characterized by XRD, SEM, TEM, HRTEM, PL spectra and VSM. The experimental results indicated that the as-prepared bifunctional composites displayed well-defined core–shell structures. The ∼12 nm diameter YVO4:Dy3+ shell exhibited tetragonal structure. Additionally, the composites exhibited a high saturation magnetization (13 emu/g) and excellent luminescence properties, indicating their promising potential as multifunctional biosensors for biomedical applications. 相似文献