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1.
We have prepared a novel kind of magnetic nanoparticle with high adsorption capacity and good selectivity for Pb2+ ions by modifying the magnetic nanoparticles with polyvinyl alcohol (PVA) and thiourea. The resultant magnetic nanoparticles were used to adsorb Pb2+ ions from aqueous solution. The influence of the solution pH, the adsorption time, the adsorption temperature, coexisting ions, and the initial concentration of Pb2+ ions on the adsorption of Pb2+ ions were investigated. The results indicated that Pb2+ ions adsorption was an endothermic reaction, and adsorption equilibrium was achieved within 30 min. The optimal pH for the adsorption of Pb2+ ions was pH 5.5, and the maximum adsorption capacity of Pb2+ ions was found to be 220 mg/g. Moreover, the coexisting cations such as Ca2+, Co2+, and Ni2+ had little effect on adsorption of Pb2+ ions. The regeneration studies showed that thiourea functionalized PVA‐coated magnetic nanoparticles could be reused for the adsorption of Pb2+ ions from aqueous solutions over five cycles without remarkable change in the adsorption capacity. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40777.  相似文献   

2.
Ternary composite films of poly(vinyl alcohol) (PVA), boric acid (BA), and detonation nanodiamond (DND) were prepared by aqueous solution method. Because of its excellent mechanical/thermal properties and low friction coefficient, DND is expected to offer PVA film superior performance if the puzzles of particle agglomeration in polymer matrix and fragile interface reaction between DND and PVA can be settled. BA was used as a crosslinking agent to form a strong network structure between DND and PVA. Investigation on microstructure of PVA/BA/DND films and bonding mechanisms therein shows that BA, DND, and PVA may crosslink by oxo‐bridges owing to the interaction of hydroxyl groups. The Young's modulus (E) of composite films was enhanced by nearly 3.3 times with only 0.8 wt % DND loading, and the antiwear, thermal stability, and waterproof properties can be significantly improved after the crosslinking. Meanwhile, the transparency of composite films can be well preserved even with large DND content. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45449.  相似文献   

3.
In this work, we fabricated plasmonic organic bulk–heterojunction solar cells by inserting hydrophobic gold nanorods (GNRs) into the active layers. Power conversion efficiency was improved from 7.43% to 8.22% because the plasmonic effect of GNRs improved the light harvesting efficiency. Maximum exciton generation rate was increased from 1.35 × 10−26 to 1.51× 10−26m−3 s−1, and the electron mobility was also increased from 8.6 × 10−5 to 1.5× 10−4cm−2 V−1 s−1. As a result, the short circuit current density was improved from 15.5 to 16.7 mA cm−2—the dominant reason for performance enhancement. The open circuit voltage and fill factor were improved simultaneously. The plasmonic device showed a highest PCE of 8.43%, indicating that doping GNRs into active layers is a simple and effective way to fabricate high‐performance organic solar cells. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45920.  相似文献   

4.
In this work, Polypyrrole (PPy), Titanium dioxide nanofiber (TiO2‐nf) are prepared by oxidative polymerization and hydrothermal process respectively. The PPy/TiO2‐nf composite is prepared by in situ oxidative polymerization in the presence of pyrrole monomer and TiO2‐nf. The nanocomposite and TiO2‐nf are then characterized by scanning electron microscopy (SEM) and energy dispersive X‐ray spectroscopy (EDX) techniques and XRD studies. Dielectric studies of PPy/TiO2‐nf composite is carried out in the frequency range of 1 KHz‐3 MHz at varying temperature and it shows anomalous behavior at 1MHz, where its value reaches to its minimum value of 13 at room temperature and this dip remains even at higher temperature. Impedance study is used to understand the grain and grain boundary effects of the material; frequency dependent ac conductivity has two regions separated at 1MHz, which is being explained by hopping conduction and Maxwell‐Wagner type mechanism, respectively. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 40036.  相似文献   

5.
In this work, we have investigated the electrical properties of Au/n‐InP contacts with a thin layer of polyvinyl alcohol (PVA) as an interlayer. The current–voltage (IV) and capacitance–voltage (CV) measurements are carried out in the temperature range of 175–425 K. The Au/PVA/n‐InP Schottky structure show nonideal behaviors and indicates the presence of a nonuniform distribution of interface states. The temperature dependent interface states densities (NSS), ideality factor and barrier height are obtained. An abnormal decrease in zero‐bias barrier height (BH) and increase in the ideality factor ( ) with decreasing temperature have been explained on the basis of the thermionic emission theory with Gaussian distribution (GD) of the BHs due to the BH inhomogeneities. The experimental IV characteristics of Au/PVA/n‐InP Schottky diode has revealed the existence of a double GD with mean BH values of ( ) of 1.246 and 0.899 eV and standard deviation ( ) of 0.176 and 0.137 V, respectively. Consequently, the modified conventional activation energy versus plot gives and Richardson constants ( ) and the values are 1.17 and 0.71 eV and 9.9 and 6.9 A/cm2 K2, respectively, without using the temperature coefficient of the BH. The effective Richardson constant value of 9.9 A/cm2 K2 is very close to the theoretical value of 9.4 A/cm2 K2 for n‐InP. The discrepancy between Schottky barrier heights estimated from IV and CV measurements is also discussed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39773.  相似文献   

6.
Chemical vapor deposition of poly(3‐methylthiophene) and poly (3‐hexylthiophene) as conductive polymers on the surface of polyester fabrics was successfully obtained. Fourier transform infrared spectroscopy confirmed the formation of polymers on surface of fabrics (the fingerprint of polythiophenes, υ 600–1500 cm?1). The uniformity of deposition and nanoparticles (average size of 60 nm) were proved with scanning electron microscopy. Electrochemical impedance spectroscopy showed that P3HT‐coated samples offer higher conductivity in compared to P3MT‐coated samples. The impedance modulus of P3HT‐coated samples was lowered nine times to that of row materials and reached to c8000 Ω. The samples have also shown electrochromic properties under electrical current, changing its color from yellowish green at 0 V to dark green at +12 V for poly (3‐hexylthiophene) samples and from brown at 0 V to red at +12 V for poly(3‐methylthiophene)‐coated fabrics (V = 0 V, λ = 450 nm; V = 12 V, λ = 650 nm). © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40673.  相似文献   

7.
An amino‐functionalized nano‐adsorbent (DETA‐MNPs) was prepared by a process involving: (1) synthesis of superparamagnetic Fe3O4 nanoparticles; (2) introduction of amino groups after which ATRP initiator was anchored; (3) grafting of glycidyl methacrylate (GMA) via SI‐ATRP; and (4) ring‐opening reaction of epoxy groups with diethylenetriamine (DETA). The nano‐adsorbent was characterized by Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), transmission electron microscope (TEM), and vibrating sample magnetometer (VSM) and applied to remove Cu(II) in batch experiments. The effects of pH, Cu(II) concentrations, solution ionic strength, and contact time were investigated. The results show that the DETA‐MNPs are spherical with cubic spine structure, high saturation magnetization (41.9 emu g?1), and an average diameter of 10 nm. The maximum Cu(II) adsorption capacity achieves 83.33 mg g?1 at pH 5.0 by Langmuir model. The adsorption process is highly pH‐dependent and reaches equilibrium within 20 min. Furthermore, the DETA‐MNPs exhibit excellent dispersibility and reusability. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 132, 42859.  相似文献   

8.
Hydrogen production by formic acid (FA) has attracted widespread attention in the field of catalysis and energy chemistry. Here, we develop a highly efficient catalyst for FA dehydrogenation by surface amination of polyacrylonitrile (PAN) supported palladium nanoparticles (Pd NPs). The support of PAN derived from a soap-free emulsion polymerization was ammoniated by simply treating it with ethylenediamine (EDA) solution under heating. Compared with the parent PAN material, the aminated PAN (EDA-PAN) is a more suitable support to achieve high dispersion of Pd NPs with ultra-small particle size (around 1.2 nm), and to fabricate more active and stable supported Pd-based catalyst for FA dehydrogenation. The turnover frequency (TOF) of the Pd/EDA-PAN catalyst could reach to 3989 h−1 at 333 K without using any additional bases or additives. More significantly, the aminated catalyst could even work well at ambient temperature with a TOF of 688 h−1 at 303 K.  相似文献   

9.
Polyaniline/tailored carbon nanotubes composite (PANI/TCN) synthesized via situ polymerization of aniline monomer in the presence of tailored carbon nanotubes (TCN) is reported as electrode material for supercapacitors. The morphology, structure, and thermostability of the composite were characterized by scanning electron microscope, Fourier transform infrared, and thermogravimetric analysis. The electrochemical property of the resulting material was systematically studied using cyclic voltammetry and galvanostatic charge–discharge. The results show that the short rod‐like PANI dispersed well in the TCN with three‐dimensional network structure. The as‐prepared composite shows high specific capacitance and good cycling stability. A specific capacitance of 373.5 F g?1 at a current density of 0.5 A g?1 was achieved, which is much higher than that of pure PANI (324 F g?1). Meanwhile, the composite retains 61.7% capacity after 1000 cycles at a scan rate of 50 mV s?1. The enhanced specific capacitance and capacity retention indicates the potential of composite as a promising supercapacitor electrode material. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 39971.  相似文献   

10.
Conductive electrospun polymer fibers have attracted a great deal of interest in recent years. This study describes the preparation of electrically conductive microfibers composed of polyethersulfone/polydopamine/silver nanoparticles (PES/PDA/Ag NPs). Ag NPs acted as conductive centers, while hydroxyl- and amino-rich functional groups and excellent adhesion properties of PDA served to connect the Ag NPs and PES microfibers. Fourier transform infrared spectroscopy and scanning electron microscopy (SEM) showed that PDA was firmly adhered to PES microfibers. PES/PDA microfibers absorbed considerable amounts of silver ion from AgNO3 solution, resulting in Ag NPs. X-ray diffraction, X-ray photoelectron spectroscopy, and SEM data represented the successful formation of PES/PDA/Ag NPs microfibers. Microfibers with optimal conductivity were obtained using a solution of 2% AgNO3 at pH 9 at 50 °C for 45 min. The electrical resistivity of our PES/PDA/Ag NPs microfibers was only 202 Ω/cm, much lower than that of regular PES microfibers (2.1 × 109 Ω/cm). These results show that the PES/PDA/Ag NPs microfibers are suitable for use as conductive polymer fibers in electromagnetic shielding, and conductivity-sensing applications, and in flexible electronic devices and biosensors. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48788.  相似文献   

11.
In this article, the effects of different silane coupling agents: 3‐glycidyloxypropyltrimethoxysilane (GOTMS), 3‐aminopropyltriethoxysilane (APTES), and 3‐methacryloxypropyltrimethoxysilane (MPTS), on the interface between polyimide (PI) and silica (SiO2), were investigated using molecular dynamic simulation. The results indicate that binding energy between PI molecules and SiO2 surface mainly comes from van der Waals interaction. Proper silane coupling agents generate a thin membrane on the surface of SiO2, which improves the thickness of the transition layer between PI molecules and SiO2 surface. And density of the transition layer was enhanced by APTES significantly. In addition, amino group (? NH2) improves the electrostatic interaction between PI molecules and SiO2 surface rather than epoxy group (? CH? CH2? O) and methacrylic oxide group (? O? CO? C(CH3)?CH2). As a result, APTES enhances the binding energy effectively. However, excessive silane coupling agent increases the distance between PI matrices and SiO2, which deteriorates performance of the interface. In addition, GOTMS and MPTS generate a thick and dense membrane on SiO2 surface, which induces the loose transition layer and poor binding energy. Overlap parameter between PI molecules and SiO2 surface grafted with silane coupling agent can be employed to evaluate the transition layer successfully. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45725.  相似文献   

12.
The polypyrrole (PPy) and polypyrrole‐Au (PPy‐Au) nanocomposite films have been sonoelectrochemically synthesized on St‐12 steel electrodes using the galvanostatic technique. Experimental design according to the Taguchi method has been applied to optimize the factors on the synthesis of PPy‐Au nanocomposite coating. Three factors were used to design an orthogonal array L9: Synthesis time (t), Current density (I), and Concentration of HAuCl4 (C). The synthesized Au nanoparticles during polymerization were characterized by Ultraviolet–visible (UV‐visible) spectroscopy. Characterization of the surfaces was done by scanning electron microscope (SEM), energy dispersive X‐ray spectrum (EDX), and atomic force microscope (AFM). The scanning electron microscopy (SEM) image of PPy shows a smooth surface while PPy‐Au nanocomposite film has a compact morphology. Moreover, energy dispersive X‐ray spectrum (EDX) is evidence for the incorporation of Au nanoparticles. The corrosion protection of coatings was investigated by open circuit potential (OCP) time trends, potentiodynamic polarization technique, and electrochemical impedance spectroscopy (EIS) in a NaCl 3.5% solution. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41087.  相似文献   

13.
Block copolymers composed of styrene and different elastomeric blocks were sulfonated to high ion exchange capacities (IECs). Titanium dioxide (TiO2) nanoparticles were added to these polymers to improve their mechanical and thermal stabilities, while influencing their transport properties for direct methanol fuel cell (DMFC) applications. Materials properties as proton exchange membranes (PEMs) were analyzed using: FT‐IR, water absorption, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), IEC, methanol permeability, and proton conductivity studies. Although there was no effect of TiO2 nanoparticles on the thermal stability of the membranes, significant changes were observed in the mechanical properties of both sulfonated block copolymers studied. Water absorption increased at low TiO2 content, but was then reduced with the incorporation of more nanoparticles. To enhance the interaction between the inorganic fillers and the polymers, sulfonic and amino groups were attached to the surface of the titania nanoparticles. The effect of sulfonated nanoparticles on the properties of the materials was more significant than the effect of the amino functionalized nanoparticles on all the properties evaluated, suggesting enhanced chemical interactions with the ionic domains of the polymer membranes. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42651.  相似文献   

14.
The aim of this study was to investigate the effect of silver nanoparticles (AgNPs) incorporation on the flexural strength (FS) of poly(methyl methacrylate) (PMMA). PMMA specimens (65 mm × 10 mm × 3.3 mm for flexural test, 50 mm × 6 mm × 4 mm for impact test) containing different sizes (40, 50, 60 nm) and concentrations (0.05%, 0.2%) of AgNPs were prepared, along with a control group with no AgNP. Impact strength (IS) and FS of all specimens were measured, and one‐way ANOVA and Tukey–Kramer post hoc multiple comparisons tests were used to identify any statistical differences between groups. The addition of AgNPs has no effect on IS of PMMA. The incorporation of AgNPs affected the FS of PMMA depending on the concentration of nanoparticles. The addition of large‐sized nanoparticles to PMMA increases its FS. Accordingly, adding AgNP with proper concentrations to PMMA may enhance the mechanical properties of denture bases used in clinical practice. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45807.  相似文献   

15.
A surface imprinted core‐shell nanorod with water‐compatible property was first prepared, using a two‐step “living” polymerization technique, with magnetic attapulgite (MATP) as core, and it was applicable in the enhanced selective removal of sulfamethazine residue from pure water environments. MATP was synthesized by an impregnation and pyrolysis method, and polymerable group was subsequently attached onto the surface. The imprinted polymer nanoshell (13 nm) with the “living” fragments was formed via a reverse atom transfer radical precipitation polymerization, avoiding the tedious graft of initiator and providing the easy‐accessible imprinted sites. Ultrathin hydrophilic polymer brushes (2.0 nm) were surface‐grafted to improve their water‐compatibility. The nanoadsorbent exhibited good thermal stability, magnetism, and hydrophilicity through characterization. The nanoadsorbent showed large adsorption capacity toward sulfamethazine from water, which increased with the increase of contact temperature. Langmuir isotherm fitted the equilibrium data better, and the kinetic data (within 45 min) were well‐analyzed by the pseudo‐second‐order kinetic model. Also, the specific adsorption property of the nanoadsorbent was greatly improved through the surface‐grafting, which exhibited excellent selectivity to sulfamethazine compared with other reference antibiotics. Efficient magnetic separation and good reuse of the nanoadsorbent provided the potential possibility for selective recognition and fast removal of antibiotic pollutions from water environments. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40854.  相似文献   

16.
Poly[(pyridine‐4‐yl‐methyl)methacrylate‐co‐butyl methacrylate] [poly(PyMMA‐co‐BMA)] and its ZnO nanocomposites [poly(PyMMA‐co‐BMA)/ZnO] were coated on the mild steel substrate (MS) to improve the corrosion resistance by blocking the destructive ultraviolet radiation (UV‐radiation) and corrosive ions as well. The optical and anticorrosive properties of poly(PyMMA‐co‐BMA) and poly(PyMMA‐co‐BMA)/ZnO (1.0, 1.5, and 2.5 wt %) coatings were evaluated. The surface characterization techniques like UV visible spectroscopy and scanning electron microscope were taken to confirm the formation of poly(PyMMA‐co‐BMA) and poly(PyMMA‐co‐BMA)/ZnO (2.5 wt %) coating on MS. The optical studies revealed that the poly(PyMMA‐co‐BMA)/ZnO (2.5 wt %) coating displays excellent UV blocking properties than other nanocomposite coatings (1.0 and 1.5 wt %). The potentiodynamic polarization and electrochemical impedance spectroscopy studies show that the poly(PyMMA‐co‐BMA) and poly(PyMMA‐co‐BMA)/ZnO (1.0, 1.5, and 2.5 wt %) coated MS in 3.5% (w/v) NaCl provides better protection against corrosion. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46175.  相似文献   

17.
Polystyrene (PS)–γ‐methacryloxypropyl trimethoxy silane (MPTMS) copolymer/zirconia (ZrO2) nanohybrid materials were successfully prepared by the combination of solvothermal and in situ synthesis methods, in which the comonomer was used as chemical bonding agent between the nanoparticles and the matrix, and acetylacetone (AcAc) was used as a size control agent of ZrO2 in the PS matrix. Then, a new transparency film with a relatively high refractive index (1.72) was successfully obtained, in which ZrO2 could be dispersed well in the PS–MPTMS matrix. Field emission scanning electron microscopy images indicated that AcAc was helpful in the dispersion of the nanoparticles, and smaller ZrO2 particles with no aggregation were obtained in the PS–MPTMS matrix. The structure and thermal properties of the hybrid films were investigated by Fourier transform infrared spectroscopy and thermogravimetric analysis, and the surface properties were also examined. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2320–2327, 2013  相似文献   

18.
Janus nanorods are used as a novel rigid compatibilizer to improve the interfacial tension of incompatible A/B homopolymer blends. Dissipative particle dynamics (DPD) methods are preformed to explore the effect of Janus nanorods on the interfacial tension. The results show that Janus nanorods are a good compatibilizer only when the appropriate length is chosen, which is different from the traditional coil compatibilizer (surfactants and block copolymers). The length of the Janus nanorods can significantly influence their orientation through the competition between the entropic and enthalpic effects. The shorter Janus nanorods preferring “standing” have a better efficiency in improving the interfacial tension than the longer ones preferring “lying.” If we can control the orientation of the longer Janus nanorods, they are still a good compatibilizer. This simulation work can widen the application of Janus nanoparticles. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44098.  相似文献   

19.
On the basis of the short‐chained modifier of stearyl‐alcohol poly(ethylene oxide) ether (AEO), an entrapping modification was carried out on the polypropylene (PP) surface for hydrophilic improvement. A swelling layer was confirmed locating in the amorphous region on the PP surface, from which the modifiers could penetrate into the surface. The AEO‐8 modifier achieved the optimal hydrophilic modification on the surface with a contact angle of 20.6° and modifier coverage of 19.2%. A microphase separation was speculated to occur between the poly(ethylene oxide) (PEO) chain of AEO and the PP substrate in the entrapping surface, after which surface‐enriched PEO chains could improve surface hydrophilicity, simultaneously, reserved stearyl chains in the surface could approach modifier fixation. Water immersion durability of the modified surface could be improved by establishing a covalent linkage in the surface‐fixed structure. This work gives more comprehensive insights in the entrapping modification on the semi‐crystalline PP surface based on the short‐chained and block modifier. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43607.  相似文献   

20.
The purpose of this study was to investigate the effect of bare wollastonite (BW) and modified wollastonite (MW) nano‐rods into the styrene butadiene rubber (SBR). SBR nanocomposites were prepared by the incorporation of different wt % (0.3–4.5) of BW and MW nanorods. All nanocomposites were characterized by thermal gravimetric analyzer (TGA) and differential scanning calorimeter (DSC). The particle size and morphology of BW and MW nanorods were characterized by field‐emission scanning electron microscope (FE‐SEM), transmission electron microscope (TEM), and Fourier transform infrared (FTIR) spectrophotometer, while FE‐SEM and AFM analyses were performed for BW/SBR and MW/SBR nanocomposites. The obtained results revealed the existence of stronger interaction between the SBR and MW nanorods into MW/SBR as compared to BW/SBR nanocomposites. FE‐SEM and AFM images showed a perfect dispersion of the MW nanorods in SBR matrix at 3 wt % loading. Thermal stability of MW/SBR nanocomposites was also increased significantly by the addition of MW nanorods. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42811.  相似文献   

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