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1.
Magnetic Fe3O4/waterborne polyurethane nanocomposites were synthesized based on waterborne polyurethane (WPU) and amino-functionalized Fe3O4 by in situ polymerization. The Fe3O4 nanoparticle was found to be uniformly distributed in Fe3O4/WPU nanocomposites with linear or crosslinked structure. In addition, the formation mechanism and magnetic conduction mechanism of stable inorganic–organic nanocomposites were discussed. The experimental results showed that the thermal stability, magnetic, and mechanical properties of magnetic Fe3O4/waterborne polyurethane nanocomposites were improved by amino functionalized Fe3O4. Furthermore, the defoaming property of the emulsion and the hydrophobic property of magnetic Fe3O4/waterborne polyurethane nanocomposites were improved by the 1-hexadecanol-terminated prepolymer. What more, polycaprolactone (PCL)-based Fe3O4/WPU nanocomposites have excellent mechanical properties (The tensile strength is over 30 MPa, the elongation rate is above 300%.) and magnetic properties. Magnetic Fe3O4/waterborne polyurethane nanocomposites will be used in the field of hydrophobic and microwave absorbent materials. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48546.  相似文献   

2.
Two superparamagnetic and heat resistant xanthene based poly(ether-imide) nanocomposites were successfully synthesized. Field emission scanning electron microscopy, transmission electron microscope, X-ray diffraction, thermal gravimetric analysis, vibrating sample magnetometer, Energy-dispersive X-ray spectroscopy and Fourier-transform infrared (FTIR) techniques were used for studying the morphology, crystalline phase, thermal stability and magnetization properties of the nanocomposites. The neat form of the corresponding poly(ether-imide) was also prepared by thermal imidization method and its structure was confirmed by FTIR, proton nuclear magnetic resonance (1H NMR), UV–Vis and photoluminescence (PL) spectroscopies. In order to investigate the effects of modifying the surface of Fe3O4 nanoparticles on thermal properties of the nanocomposites, the surface of Fe3O4 nanoparticles was coated with SiO2 and polysuccinimide (PSI), sequentially. Then, both the unmodified Fe3O4 and surface-modified Fe3O4 (Fe3O4@SiO2–PSI) nanoparticles were used as fillers for the polymer matrix. According to the results, the prepared nanocomposites were superparamagnetic and showed higher thermal stability in comparison to the neat poly(ether-imide). Furthermore, poly(ether-imide)/Fe3O4@SiO2–PSI (PIEN 10b) nanocomposite showed higher thermal stability and dispersed better in the polymer matrix [in comparison to poly(ether-imide)/Fe3O4 (PIEN 10 a)] due to the presence of imide groups and high hydroxyl content of the functional Fe3O4 nanoparticles which caused high interactions between poly(ether-imide) and functional Fe3O4. Furthermore, the presence of methyl, ether and bulky xanthene groups in the poly(ether-imide(backbone improved the solubility of the neat polymer in organic solvents. These properties can be very helpful for extending new applications of poly(ether-imide)s.  相似文献   

3.
A novel biodegradable magnetic‐sensitive shape memory poly(?‐caprolactone) nanocomposites, which were crosslinked with functionalized Fe3O4 magnetic nanoparticles (MNPs), were synthesized via in situ polymerization method. Fe3O4 MNPs pretreated with γ‐(methacryloyloxy) propyl trimethoxy silane (KH570) were used as crosslinking agents. Because of the crosslinking of functionalized Fe3O4 MNPs with poly(?‐caprolactone) prepolymer, the properties of the nanocomposites with different content of functionalized Fe3O4 MNPs, especially the mechanical properties, were significantly improved. The nanocomposites also showed excellent shape memory properties in both 60 °C hot water and alternating magnetic field (f = 60, 90 kHz, H = 38.7, 59.8 kA m?1). In hot water bath, all the samples had shape recovery rate (Rr) higher than 98% and shape fixed rate (Rf) nearly 100%. In alternating magnetic field, the Rr of composites was over 85% with the highest at 95.3%. In addition, the nanocomposites also have good biodegradability. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45652.  相似文献   

4.
In this work, Fe3O4 nanoparticles were chemically grafted with β-cyclodextrin (β-CD@Fe3O4). Fe3O4 nanoparticles were modified using N,N-dimethylformamide as a solvent, β-cyclodextrin as a modifier, and 3-glycidoxypropyltrimethoxysilane as a coupling agent at room temperature. The obtained modified Fe3O4 were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, and thermogravimetric analysis techniques. β-CD@Fe3O4 was incorporated into a poly(lactic acid) matrix to prepare new green nanocomposites with modified properties. β-CD@Fe3O4 showed good dispersion in the poly(lactic acid) matrix and thermal and combustion properties of the nanocomposites were improved.  相似文献   

5.
The main goal in this work was to prepare and characterize a kind of novel superparamagnetic poly(ε-caprolactone)/Fe3O4@graphene oxide (PCL/Fe3O4@GO) nanocomposites via facile in situ polymerization. Fabrication procedure included two steps: (1) GO nanosheets were decorated with Fe3O4 nanoparticles by an inverse co-precipitation method, which resulted in the production of the magnetite/GO hybrid nanoparticles (Fe3O4@GO); (2) incorporation of Fe3O4@GO into PCL matrix through in situ polymerization afforded the magnetic nanocomposites (PCL/Fe3O4@GO). The microstructure, morphology, crystallization properties, thermal stability and magnetization properties of nanocomposites were investigated with various techniques in detail. Results of wide-angle X-ray diffraction showed that the incorporation of the Fe3O4@GO nanoparticles did not affect the crystal structure of PCL. Images of field emission scanning electron microscope and transmission electron microscopy showed Fe3O4@GO nanoparticles evenly spread over PCL/Fe3O4@GO nanocomposites. Differential scanning calorimeter and polar optical microscopy showed that the crystallization temperature increased and the spherulites size decreased by the presence of Fe3O4@GO nanoparticles in the nanocomposites due to the heterogeneous nucleation effect. Thermogravimetric analysis indicated that the addition of Fe3O4@GO nanoparticles reduced the thermal stability of PCL in the nanocomposites. The superparamagnetic behavior of the PCL/Fe3O4@GO nanocomposites was testified by the superconducting quantum interference device magnetometer analysis. The obtained superparamagnetic nanocomposites present potential applications in tissue engineering and targeted drug delivery.  相似文献   

6.
Fe3O4/poly (ε‐caprolactone)‐polyurethane (PCLU) shape memory nanocomposites were prepared by an in situ polymerization method. The thermal properties, magnetic properties, and shape memory properties of the nanocomposites were investigated systematically. The results showed that the Fe3O4 nanoparticles were homogeneously dispersed in the PCLU matrix, which ensured good shape memory properties of nanocomposites in both hot water and an alternating magnetic field (f = 45 kHz, H = 29.7 kA m?1/36.7 kA m?1). The nanocomposites started to recover near 40°C, which is slightly higher than body temperature. Thus, they would not change their deformed shape during the implanting process into the human body. Considering potential clinical applications, 45°C was chosen as shape recovery temperature which is slightly higher than 37°C, and the nanocomposites had high shape recovery rate at this temperature. With increasing content of Fe3O4 nanoparticles, the shape memory properties of the nanocomposites in an alternating magnetic field increased and the best recovery rate reached 97%, which proves that this kind of nanocomposites might be used as potential magnetic sensitive shape memory materials for biomedical applications. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013  相似文献   

7.
An optically active poly(amide‐imide) (PAI) was synthesized from the polymerization reaction of N,N′‐(Pyromellitoyl)‐bis‐l ‐alanine diacid chloride with 2,5‐diaminotoluene. The obtained inorganic metal oxide nanocomposites composed of PAI/nanostructured hematite (α‐Fe2O3) were synthesized through ultrasonic irradiation. The resulting nanocomposites were characterized by Fourier transform infrared spectroscopy, powder X‐ray diffraction, transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The TEM results indicated that the nanoparticles were dispersed homogeneously in PAI matrix on nanoscale. TGA confirmed that the heat stability of the nanocomposites was improved in the presence of α‐Fe2O3 nanoparticles. POLYM. COMPOS., 37:1805–1811, 2016. © 2014 Society of Plastics Engineers  相似文献   

8.
In this article, conductive and magnetic nanocomposites composed of polypyrrole (PPy), magnetite (Fe3O4) nanoparticles (NPs), silver (Ag) NPs, have been successfully synthesized with a two step process. First, the PPy/Fe3O4 was prepared by the ultrasonic in situ polymerization. Next, the PPy/Fe3O4/Ag was synthesized through the electrostatic adsorption. The products were characterized by fourier‐transform infrared (FTIR) spectroscopy, Scanning electron microscopy (SEM), Thermogravimetric (TG), conductivity and magnetization analysis, and the results showed that the Ag NPs with the good conductivity coated uniformly on the surface of PPy/Fe3O4 and improved the conductivity of PPy/Fe3O4/Ag composites. In addition, as compared with PPy/Fe3O4, PPy/Fe3O4/Ag composites also have the excellent electro‐magnetic property and enhanced thermostability. POLYM. COMPOS., 35:450–455, 2014. © 2013 Society of Plastics Engineers  相似文献   

9.
A sonochemical technique is used for in situ coating of iron oxide (Fe3O4) nanoparticles on outer surface of MWCNTs. These Fe3O4/MWCNTs were characterized using a high‐resolution transmission electron microscope (HRTEM), X‐ray diffraction, and thermogravimetric analysis. The as‐prepared Fe3O4/MWCNTs composite nanoparticles were further used as reinforcing fillers in epoxy‐based resin (Epon‐828). The nanocomposites of epoxy were prepared by infusion of (0.5 and 1.0 wt %) pristine MWCNTs and Fe3O4/MWCNTs composite nanoparticles. For comparison purposes, the neat epoxy resin was also prepared in the same procedure as the nanocomposites, only without nanoparticles. The thermal, mechanical, and morphological tests were carried out for neat and nanocomposites. The compression test results show that the highest improvements in compressive modulus (38%) and strength (8%) were observed for 0.5 wt % loading of Fe3O4/MWCNTs. HRTEM results show the uniform dispersion of Fe3O4/MWCNTs nanoparticles in epoxy when compared with the dispersion of MWCNTs. These Fe3O4/MWCNTs nanoparticles‐infused epoxy nanocomposite shows an increase in glass transition (Tg) temperature. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

10.
Herein, the authors report the synthesis of electro-magnetic polyfuran/Fe3O4 nanocomposites using Fe3O4 magnetic nanoparticles of different content as nucleation sites via in situ chemical oxidation polymerization method. Surface, structural, morphological, thermal, electrical and magnetic properties of the nanocomposites were studied by FT-IR, UV-visible spectroscopies, XRD, FESEM, TGA, four probe, and VSM, respectively. The effect of Fe3O4 nanoparticles content on the electrical conductivity and magnetization of nanocomposites was studied. The obtained polyfuran and polyfuran/Fe3O4 nanocomposites were analyzed for their antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. In addition, polyfuran/Fe3O4 nanocomposites have been investigated for application as electrochemical biosensor.  相似文献   

11.
A novel ceramic membrane anti‐solvent crystallization (CMASC) method was proposed to prepare Fe2O3/AP nanocomposites with core‐shell structure. For the preparation of Fe2O3/AP nanocomposites, several key advantages of the CMASC method are as follows. Firstly, both well‐dispersed Fe2O3 nanoparticles and the superfine AP preparation can be achieved at one step. Secondly, no non‐component of solid propellant was involved in this composite process. Thirdly, the size and morphology of Fe2O3/AP nanocomposites can be effectively controlled by using the ceramic membrane with regular pore structure as feeding template. The morphology and structure of Fe2O3/AP nanocomposites were characterized by inductively coupled plasma spectrophotometry (ICP), IR spectroscopy, SEM, and HRTEM. The results verified that the size and morphology of Fe2O3/AP nanocomposites are controllable, and the dispersion of Fe2O3 nanoparticles is greatly improved in Fe2O3/AP nanocomposites. Moreover, the thermal decomposition of the as‐prepared Fe2O3/AP nanocomposites was measured with TG‐DSC. The results showed that the Fe2O3 nanoparticles in Fe2O3/AP nanocomposites exhibit better catalytic activity on the thermal decomposition of AP. In addition, the mechanism was also discussed.  相似文献   

12.
A magnetic polypeptide nanocomposite with pH and near-infrared (NIR) dual responsiveness was developed as a drug carrier for cancer therapy, which was prepared through the self-assembly of Fe3O4 superparamagnetic nanoparticles, poly(aspartic acid) derivative (mPEG-g-PDAEAIM) and doxorubicin (DOX) in water. Fe3O4 nanoparticles were prepared to provide the superparamagnetic core of nanocomposites for tumor targeting via chemical co-precipitation. The protonable imidazole groups of mPEG-g-PDAEAIM with a pKa of ~7 were accountable for the pH-responsiveness of nanocomposites. The photothermal effect of nanocomposites under the irradiation of NIR laser was induced via the interactions between dopamine groups of mPEG-g-PDAEAIM and Fe3O4 superparamagnetic nanoparticles to trigger the drug release. NMR, FT-IR, TEM, hysteresis loop analysis and MRI were utilized to characterize the materials. The DOX loaded nanocomposites exhibited pH-responsive and NIR dependent on/off switchable release profiles. The nanocomposites without drug loading (Fe3O4@mPEG-g-PDAEAIM) showed excellent biocompatibility while DOX loaded nanocomposites caused MCF-7 cells’ apoptosis due to the photothermal/chemotherapy combination effects. Overall, the pH and near-infrared dual responsive magnetic nanocomposite had a great potential for cancer therapy.  相似文献   

13.
Isotactic polypropylene (iPP) and iron oxide (Fe3O4) nanocomposites were mixed by masterbatch blending technique in a single screw extruder machine. The concentrations of Fe3O4 in the iPP/Fe3O4 nanocomposites were 0.5, 1, 2, and 5% by weight. The influence of Fe3O4 nanoparticles on the effectiveness of nucleation, morphology, mode of crystallization, and crystallinity of iPP were studied by differential scanning calorimetry (DSC) and polarized light microscopy (PLM). The introduction of Fe3O4 nanoparticles in the iPP matrix inhibited the formation of β crystals, and caused a shift in the melting point to higher values. The magnitude of the shift was up to 20–21°C which indicates that using the masterbatch technique leads to an enhancement of the dispersion process of the Fe3O4 nanoparticle and the formation of less agglomerates in the iPP/Fe3O4 nanocomposites. The percentage crystallinity, Xc, increased at the low cooling rates of 1 and 2°C/min. At higher cooling rates of 5, 10, and 20°C/min, the masterbatch technique produced nanocomposites of Xc with nonuniform trends. The overall crystallization rate enhancement for the iPP/Fe3O4 nanocomposites is attributed to the presence of Fe3O4 nanoparticles as a nucleating agent which have no significant effect on the growth rate of iPP crystals. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

14.
In field of nanotechnology, polymer based nanocomposites (NCs) with inorganic nanoparticles (NPs) have become a noticeable area of recent researches. In this work, citric acid (CA) was used as a biocompatible “modifier” for the alumina (α-Al2O3) NPs to prevent their agglomeration and create effective interaction with polymer matrix. In addition, chiral poly(amide-imide) (PAI) was synthesized by a direct polycondensation of N-trimellitylimido-L-phenylalanine dicarboxylic acid and 1,5-naphthalenediamine in ionic liquid as green solvent. Then modified (α-Al2O3-CA) NPs were incorporated into the obtained PAI through ultrasonic process for the preparation of PAI/α-Al2O3-CA NCs. Finally, the PAI/α-Al2O3-CA NCs were characterized by different methods.  相似文献   

15.
Magnetic Fe3O4@C nanocomposites with well-defined core@shell structure were synthesized via a facile one-step solvothermal process using ferrocene as both iron and carbon resource in the presence of hydrogen peroxide (H2O2). The as-prepared Fe3O4@C nanocomposites were employed as adsorbent materials for removal of methylene blue (MB) from aqueous solution. Several experimental parameters, including contact time, acidity of the solution, and initial MB concentration were investigated. The result showed that the equilibrium uptake of MB was related to the MB initial concentration as well as acidity of the solution. The adsorption kinetics of MB was dominated by the pseudo-second order reaction model. Significantly, the synthesized Fe3O4@C nanocomposites could be easily isolated from the adsorption system after adsorbing MB and showed prominent reusability. All results indicated that the prepared Fe3O4@C composites had the potential to be used as adsorbents for the removal of dye pollutant from wastewater.  相似文献   

16.
Hydrophilic surface of α-Al2O3 nanoparticles was treated with thiamine as a green modifier for better compatibility with poly(vinyl alcohol) matrix. In this regard, poly(vinyl alcohol)/α-Al2O3-vitamin B1 nanocomposites with different ratios of modified α-Al2O3 (3, 5, and 7?wt%) were prepared through ultrasonic irradiation and their properties were compared with the pure poly(vinyl alcohol). Many techniques were used to study the properties of poly(vinyl alcohol)/α-Al2O3-vitamin B1 nanocomposites. Morphology images of poly(vinyl alcohol)/α-Al2O3-vitamin B1 nanocomposites showed the good dispersion of the α-Al2O3 nanoparticles in poly(vinyl alcohol) matrix in nanometer-scale. The results demonstrated that poly(vinyl alcohol)/α-Al2O3-vitamin B1 nanocomposites give better thermal stability, strain, and E-modulus than the pure poly(vinyl alcohol.  相似文献   

17.
Ultrafine well‐dispersed Fe3O4 magnetic nanoparticles were directly prepared in aqueous solution using controlled coprecipitation method. The synthesis of Fe3O4/poly (2‐acrylamido‐2‐methylpropane sulfonic acid) (PAMPS), Fe3O4/poly (acrylamide‐co‐2‐acrylamido‐2‐methylpropane sulfonic acid) poly(AM‐co‐AMPS) and Fe3O4/poly (acrylic acid‐co‐2‐acrylamido‐2‐methylpropane sulfonic acid) poly(AA‐co‐AMPS) ‐core/shell nanogels are reported. The nanogels were prepared via crosslinking copolymerization of 2‐acrylamido‐2‐methylpropane sulfonic acid, acrylamide and acrylic acid monomers in the presence of Fe3O4 nanoparticles, N,N′‐methylenebisacrylamide (MBA) as a crosslinker, N,N,N′,N′‐tetramethylethylenediamine (TEMED) and potassium peroxydisulfate (KPS) as redox initiator system. The results of FTIR and 1H‐NMR spectra indicated that the compositions of the prepared nanogels are consistent with the designed structure. X‐ray powder diffraction (XRD) and transmission electron microscope (TEM) measurements were used to determine the size of both magnetite and stabilized polymer coated magnetite nanoparticles. The data showed that the mean particle size of synthesized magnetite (Fe3O4) nanoparticles was about 10 nm. The diameter of the stabilized polymer coated Fe3O4 nanogels ranged from 50 to 250 nm based on polymer type. TEM micrographs proved that nanogels possess the spherical morphology before and after swelling. These nanogels exhibited pH‐induced phase transition due to protonation of AMPS copolymer chains. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

18.
Magnetic Fe3O4–poly(aniline‐coo‐anthranilic acid) nanoparticles were prepared by a novel and simple method: anthranilic acid assisted polymerization. The synthetic strategy involved two steps. First, Fe3O4 nanoparticles capped by anthranilic acid were obtained by a chemical precipitation method, and then the aniline and oxidant were added to the modified Fe3O4 nanoparticles to prepare well‐dispersed Fe3O4–poly(aniline‐coo‐anthranilic acid) nanoparticles. Fe3O4–poly(aniline‐coo‐anthranilic acid) nanoparticles exhibited a superparamagnetic behavior (i.e., no hysteresis loop) and high‐saturated magnetization (Ms = 21.5 emu/g). The structure of the composite was characterized by Fourier‐transform infrared spectra, X‐ray powder diffraction patterns, and transmission electron microscopy, which proved that the Fe3O4–poly(aniline‐coo‐anthranilic acid) nanoparticles were about 20 nm. Moreover, the thermal properties of the composite were evaluated by thermogravimetric analysis, and it showed excellent thermal stability. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1666–1671, 2006  相似文献   

19.
《Ceramics International》2019,45(15):18298-18305
Fe3O4-intercalated reduced graphene oxide (Fe3O4-rGO) nanocomposites were synthesized by an in situ reduction process. The results of XRD and XPS analyses suggested the successful formation of a Fe3O4 crystal phase within the rGO sheets. The SEM and TEM images demonstrated that Fe3O4 was flaky and was inserted stably within the rGO layers to form a typical sandwich-like structure. The hysteresis loops revealed the superparamagnetic behavior of the Fe3O4-rGO nanocomposites at room temperature. The electromagnetic parameters revealed that Fe3O4-rGO nanocomposites exhibited multiple dielectric relaxation and magnetic resonance. The reflection loss revealed that the maximum loss was −49.53 dB at 6.32 GHz for a thickness of 3.4 mm while the highest effective absorption bandwidth was 2.96 GHz.  相似文献   

20.
Epoxy polymers, having good mechanical properties and thermal stability, are often used for engineering applications. Their properties can be further enhanced by the addition of iron oxide (Fe3O4) nanoparticles (NPs) as fillers to the resin. In this study, pristine Fe3O4 NPs were functionalized with polydopamine (PDA), (3-glycidoxypropyl)trimethoxysilane (GPTMS), and (3-aminopropyl)trimethoxysilane (APTES). X-ray diffraction and scanning electron microscopy (SEM) were used to study any changes in the crystal structure and size of the NPs while Fourier-Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA) were used to ensure the presence of functional groups on the surface. The mechanical properties of the Fe3O4-based nanocomposites generally improved except when reinforced with Fe3O4/PDA. The maximum improvement in tensile strength (∼34%) and fracture toughness (∼13%) were observed for pristine Fe3O4-based nanocomposites. Dynamic mechanical analysis (DMA) showed that the use of any of the treated NPs improved the material's initial storage modulus and had a substantial impact on its dissipation potential. Also, it was observed that the glass transition temperature measurements by DMA and differential scanning calorimetry were below that of pure epoxy. SEM of the cracked surfaces shows that the incorporation of any NPs leads to an enhancement in its thermal and mechanical properties.  相似文献   

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