Hydrophilic goethite nanoparticle as a novel antifouling agent in fabrication of nanocomposite polyethersulfone membrane

The goethite nanoparticle was used as a multifunctional additive to fabricate antifouling polyethersulfone (PES) nanofiltration membranes. The goethite/PES membranes were synthesized via the phase inversion method. The scanning electron microscopy (SEM) photographs showed an increase in pore size and porosity of the prepared membranes with blending of the goethite. The static water contact angle measurements confirmed a hydrophilic modification of the prepared membranes. With increase in the goethite content from 0 to 0.1 wt %, the pure water flux increased up to 12.7 kg/m² h. However, the water permeability decreased using high amount of this nanoparticle. Evaluation of the nanofiltration performance was performed using the retention of Direct Red 16. It was observed that the goethite/PES membranes have higher dye removal capacity (99% rejection) than those obtained from the unfilled PES (89%) and the commercial CSM NE 4040 NF membrane (92%). In addition, the goethite/PES blend membranes showed good selectivity and antifouling properties during long‐term nanofiltration experiments with a protein solution. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43592.     

Preparation of thiourea functionalized polyvinyl alcohol‐coated magnetic nanoparticles and their application in Pb2+ ions adsorption

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.     

Preparation and application of tectoridin‐imprinted magnetite nanoparticles

In this work, the tectoridin‐imprinted magnetite nanoparticles (TIMNPs) were firstly prepared by using tectoridin as template molecule, methacrylic acid as functional monomer, styrene as crosslinking agent, and superparamagnetic Fe₃O₄ particles as magnetic component. TIMNPs with a size of about 161 nm were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), Fourier transform infrared (FT‐IR), X‐ray diffraction (XRD), vibrating sample magnetometer (VSM), and thermogravimetric analysis (TGA). Rebinding experiments were carried out to determine the specific binding properties and adsorption selectivity. The maximum number of binding sites was 69.58 μmol/g and there was only one kind of binding sites existed in TIMNPs. The relative separation factors for tectoridin with its analogues such as baicalin and atenolol were 2.63 and 2.66, respectively. The results indicated that the synthesized TIMNPs had excellent saturation magnetization, binding capacity, and absorption selectivity. TIMNPs could be one of the most promising candidates for tectoridin extraction. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43806.     

Poly(vinyl alcohol)/CaCO3‐diacid nanocomposite: Investigation of physical and wetting properties and application in heavy metal adsorption

Poly(vinyl alcohol) (PVA) nanocomposite and modified CaCO₃ nanoparticles (NPs) were fabricated by ultrasound agitation method with particle content altering from 3, 5, and 8 wt %. The CaCO₃ surface was successfully treated by 10 wt % of bioactive dicarboxylic acid (DA). The influences of loading modified NPs on the thermal, mechanical, adsorption, contact angle, and physical properties of the poly(vinyl alcohol) nanocomposite films were thoroughly studied. The results showed that incorporation of modified CaCO₃ into the PVA matrix had better performance than the pure PVA. Meanwhile, tensile strength, Young's modulus, and thermal stability are enhanced from 33.36 MPa, 1.26 GPs, and 242.918C (neat PVA) to 81.7 MPa, 4.81 GPa, and 312.95 °C (PVA/CaCO₃‐DA NC 5 wt %), respectively. Also, the adsorption capacity of the PVA/CaCO₃‐DA NCs 5 and 8 wt % revealed that the NC films could act as an appropriate absorbent for the removal of Cd(II) ions with maximum adsorption capacity of about 20.70 and 25.19 mg g^?1 for Cd(II), respectively. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45414.     

Carbon nanohorn‐graphene nanoplate hybrid: An excellent electrode material for supercapacitor application

This study describes the capacitor behavior of carbon nanohorn (CNH)/graphene nanoplate (GNP) hybrid (CNGN). The well‐CNH‐decorated GNP‐plate electrode materials show high capacitance value (≈677 F/g) and can be extensively used in new generation for energy storage. In the hybrid (CNGN), two nanofillers jointly affect the capacitance behavior and increase the capacitance value of the CNGN hybrid. Homogeneous coating of CNH over the GNP plate plays an effective role to enhance the capacitance behavior of the composite. Field emission scanning electron microscopy and high‐resolution transmission electron microscopy analysis of the composite confirmed the CNH coating on the GNP plate. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42118.     

Multi stimuli-responsive HPC-PAA/Eu(AA)3Phen complex nanogels and their decoration with 3-APBA for detecting glucose

In this paper, novel multi stimuli-responsive complex nanogels of hydroxypropylcellulose (HPC)-PAA/Eu(acrylic acid [AA])₃Phen were synthesized by radical polymerization method with HPC, rare earth complex (Eu(AA)₃Phen) and AA as raw materials, and the 3-aminophenylboronic acid (3-APBA) decorated nanogels (HPC-PAAPBA/Eu(AA)₃Phen) were fabricated via condensation of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride with 3-APBA. The microstructure, morphology and diameter of the nanogel were characterized by Fourier transform infrared spectrometer, UV–Visible spectrophotometer, transmission electron microscope, dynamic light scattering. Moreover, the fluorescence responsive performance of complex nanogels to temperature, pH value and glucose concentration was investigated by photoluminescence spectroscopy. The results showed that both of the as-prepared nanogels were uniform in size and had good monodispersity. The temperature and pH value had significant effects on the particle size and the fluorescence emission intensity of the HPC-PAA/Eu(AA)₃Phen complex nanogels; after decoration with 3-APBA, the obtained HPC-PAAPBA/Eu(AA)₃Phen nanogels showed excellent stimulus-response to glucose concentration.     

Preparation and properties of Waterborne polyurethane/nanosilica composites: A diol as extender with triethoxysilane group

Waterborne polyurethane (WPU) was prepared from toluene diisocyanate, polypropylene glycol, 2,2‐bis(hydroxymethyl)propionic acid and a diol containing triethoxysilane group as the chain extender which was synthesized via Michael addition between 3‐triethoxysilylpropylamine and 2‐hydroxyethylacrylate. Different amounts of nanosilica were incorporated into the WPU to prepare WPU/nanosilica composites. The results showed that the particle size of the emulsions increased and their viscosity decreased first and then increased with increasing the amount of nanosilica. Incorporation of nanosilica into WPU enhanced the water contact angle and thermal stability of the composites films, meanwhile, their tensile strength and hardness increased first and then decreased. However, increasing the amount of nanosilica resulted in reduction in the elongation at break of the films. It suggested that nanosilca was anchored into the side chain of WPU due to the condensation process between the triethoxysilane group in the side chain of WPU molecular and the silanols group on the surface of nanosilica. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40526.     

A comparative study for the behavior of 3D-printed and compression molded PLA/POSS nanocomposites

Because of the biocompatible and nontoxic character of both PLA (polylactide) and POSS (Polyhedral Oligomeric Silsesquioxane) nanoparticles, recently being a significant alternative for biomedical parts; the main purpose of this study was to investigate performance of the 3D-printed PLA/POSS nanocomposites with respect to the compression molded PLA/POSS specimens. Due to the higher uniformity and higher homogeneity in the distribution of POSS nanoparticles in each PLA matrix layer, mechanical tests (tensile, flexural, and toughness) revealed that the improvements in the strength, elastic modulus and fracture toughness values of the 3D-printed specimens were much higher compared to their compression molded counterparts, the benefits starting from 13% increasing up to 78%. It was also observed that there was almost no deterioration in the physical structure and mechanical properties of the 3D-printed specimens, even after keeping them 120 days at 37°C in a physiological solution prepared by using the standard PBS (phosphate buffered saline) tablet.     

Effects of alkyl/vinyl-modified nanosilicas on negative or positive high voltage direct current breakdown strength and tensile properties in silicone rubber nanocomposites

To develop silicone/nanosilica insulation materials for high voltage direct current (HVDC), hydrophilic surface of fumed nanosilica was changed to hydrophobic by modifying with various ratios of alkylsilane and alkylsilane/vinylsilane coupling agents and the effects of the modified nanosilicas on the HVDC breakdown strength under negative or positive polarities were studied. Dielectric and tensile properties were also studied. The surface modification was confirmed by Fourier-transform infrared spectroscopy (FT-IR) analysis and the weights of the alkyl and alkyl/vinyl groups on the modified nanosilicas were measured by thermogravimetric analysis (TGA). Silicone rubber nanocomposites were prepared by mixing a liquid silicone rubber (LSR) and the modified nanosilicas, in which the mixing ratio of the LSR to the nanosilicas was fixed to be 20 wt%. Transmission electron microscopy (TEM) was used to observe the even dispersion of the nanosilica particles in the LSR matrix, and it was found that the surface-modified nanosilicas were well dispersed in the form of nano-clusters with 20–60 nm in size. Electrical properties (±HVDC breakdown strength and dielectric properties) and mechanical properties (tensile strength and elongation-at-break) were estimated, and it was found that ±HVDC breakdown strength and tensile strength were maximal when the surface modification ratio of alkyl: alkyl/vinyl groups was 50: 50 wt%.     

Preparation and characterization of poly(ethylene glycol) stabilized nano silver particles by a mechanochemical assisted ball mill process

Nano silver particles with an average mean crystallite size of between 10 and 12 nm were synthesized from different molecular weights of poly(ethylene glycol) as a stabilizing agents, through solid state oxidation of silver nitrate using a higher energy planetary ball mill. Ultraviolet‐Visible spectra were used to confirm the synthesis of nano silver particles. The surface plasmon resonance bands were observed around 410 nm. Fourier transformed infrared spectrum, X‐ray diffraction, and transmission electronic microscopy techniques were used to characterize the nano silver particles synthesized. Thermal stability was determined using thermogravimetic analysis and the elemental composition of the sample was determined by energy dispersive X‐ray analysis. The nano silver particles synthesized, exhibited very good antibacterial activity against Gram‐positive bacteria (Bacillus) and Gram‐negative bacteria (Pseudomonas aeruginosa). Based on the obtained results, it was additionally explored that the size and the stabilization of the nano silver particles synthesized, strongly depend on the molecular weight of poly(ethylene glycol). © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43027.     

Reusable magnetic nanocluster coated with poly(acrylic acid) and its adsorption with an antibody and an antigen

The synthesis of negatively charged magnetite nanoclusters grafted with poly(acrylic acid) (PAA) and their application as reusable nanosupports for adsorption with antibodies and antigens are presented in this article. They were facilely prepared via the free‐radical polymerization of PAA in the presence of functionalized magnetite nanoparticles to obtain highly negative charged nanoclusters with a high magnetic responsiveness and good dispersibility and stability in water. According to transmission electron microscopy, the sizes of the nanoclusters ranged between 200 and 500 nm, without large aggregation visually observed in water. The hydrodynamic size of the nanocluster consistently increased with increasing pH of the dispersion; this indicated its pH‐responsive properties, which was due to the repulsion of the anionic carboxylate groups in the structure. This nanocluster was successfully used as an efficient and reusable support for adsorption with anti–horseradish peroxidase antibody. It preserved higher than a 97% adsorption ability of the antibody after eight reuse cycles; this signified the potential of this novel nanocluster as a reusable support in the magnetic separation applications of other bioentities. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46160.     

Preparation and characterization of mPEG‐g‐α‐zein biohybrid micelles as a nano‐carrier

A new kind of block copolymer micelles methoxy polyethylene glycol (mPEG) grafted α‐zein protein (mPEG‐g‐α‐zein) was synthesized. The chemical composition of mPEG‐g‐α‐zein was identified with the help of FT‐IR and ¹H‐NMR. The biohybrid polymer can self‐assemble into spherical core–shell nanoparticles in aqueous solution. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to investigate the self‐assembled morphology of mPEG‐g‐α‐zein. Dynamic light scattering (DLS) results showed that the particle size of mPEG‐g‐α‐zein was about 90 nm. Moreover, the nanoparticles had a very low critical micelle concentration value with only 0.02 mg/mL. Then, the anticancer drug curcumin (CUR) was encapsulated into the biohybrid polymer micelles. The in vitro drug release profile showed a zero‐order release of CUR up to 12 h at 37°C. Cell viability studies revealed that the mPEG‐g‐α‐zein polymer exhibited low cytotoxicity for HepG2 cells (human hepatoma cells). Consequently, the mPEG‐g‐α‐zein micelles can be used as a potential nano‐carrier to encapsulate hydrophobic drugs and nutrients. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42555.     

Microfibers nanocomposite based on polyacrylonitrile fibers/bismuth oxide nanoparticles as X-ray shielding material

The main focus of the current study was to fabricate fibrous nanocomposite based on polyacrylonitrile (PAN) fibers containing Bi₂O₃ NPs as the X-ray shielding material. Bi₂O₃ NPs were synthesized based on the solid dispersion evaporation method and dispersed into PAN polymer solution with different weight concentrations. The electrospinning technique was used to fabricate nanocomposite. The morphology, surface functional group, wettability, elemental analysis, and X-ray shielding efficacy of the fabricated nanocomposite were thoroughly evaluated. The dimeter of the fibrous nanocomposites containing 10, 20, and 30 wt% Bi₂O₃ NPs were 1.33 ± 0.08, 1.01 ± 0.11, and 1.69 ± 0.32 μm, respectively. EDX elemental analysis showed that NPs were uniformly distributed into/onto the fibers. The X-ray shielding studies showed that the prepared nanocomposites effectively attenuate the intensity of the X-ray. The entrance surface dose for the negative control was 24.10 ± 1.71 mSv and the application of the nanocomposites significantly reduced the entrance surface dose. The results showed NPs concentration-dependent CT number shift as the indication of X-ray protection and the highest value was obtained by 30 wt% NPs. The obtained results implied that the fabricated nanocomposites effectively attenuate the radiation and they could be applied as the X-ray shielding materials.     

PEGylation of MnO nanoparticles via catechol–Mn chelation to improving T1‐weighted magnetic resonance imaging application

To enhance biocompatibility and physiological stability of hydrophobic MnO nanoparticles as contrast agent of T₁‐weighted magnetic resonance imaging (MRI), dopamine‐functionalized poly(ethylene glycol) (PEG) was used to coat the surface of about 5 nm MnO nanoparticles. Although hydrophilic coating might decrease longitudinal relaxivity due to inhibiting the intimate contact between manganese of nanoparticle surface and proton in water molecules, higher longitudinal relaxivity was still maintained by manipulating the PEGylation degree of MnO nanoparticles. Moreover, in vivo MRI demonstrated considerable signal enhancement in liver and kidney using PEGylated MnO nanoparticles. Interestedly, the PEGylation induced the formation of about 120 nm clusters with high stability in storing and physiological conditions, indicating passive targeting potential to tumor and prolonged circulation in blood. In addition, the cytotoxicity of PEGylated MnO nanoparticles also proved negligible. Consequently, the convenient PEGylation strategy toward MnO nanoparticles could not only realize a good “trade‐off” between hydrophilic modification and high longitudinal relaxivity but also contribute additional advantages, such as passive targeting to tumor and long blood circulation, to MRI diagnosis of tumor. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42360.     

Embedded silver‐nanowire electrode in an acrylic polymer–silicate nanoparticle composite for highly robust flexible devices

In this study, we explored Ag‐nanowire electrodes embedded on the surface of an elastic acrylic polymer–silicate nanoparticle composite resin (iGloss) for mechanically robust flexible electronic devices. Nanoindentation analysis indicated that the iGloss film was suitable for flexible electronic applications, having modulus and hardness values similar to those of a conventional poly(ethylene terephthalate) (PET) substrate. In situ resistance monitoring for up to 3000 bending cycles revealed that the Ag‐nanowire–iGloss electrode was highly flexible without showing an increase in the resistance. In addition, while a PET substrate carrying Ag nanowires exhibited significantly degraded optical properties with an increase in scratch damage, the Ag‐nanowire–iGloss electrode exhibited superior wear resistance, even when it was subjected to a severe mechanical scratch test. Finally, as a possible application, we demonstrated a flexible, organic, light‐emitting diode with an Ag‐nanowire–iGloss electrode as both the anode and the substrate. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45203.     

Preparation and evaluation of aconitine imprinted microspheres and its application to body fluid samples

To extract aconitine from body fluid samples, aconitine‐molecularly imprinted polymer microspheres with the optimum molar ratios of template/monomer/cross‐linker (1:8:40) as selective sorbents were synthesized by precipitation polymerization. Excellent retention of aconitine on the molecularly imprinted microspheres (MIMs) cartridge was achieved by optimizing the MISPE process, and the binding capacity reached 0.802mg/g, yielding an imprinting factor of 4.76. The MIMs also showed high selectivity for aconitum alkaloids, but not for other kinds of poisonous alkaloids. High recoveries (>89%) for aconitine, hypaconitine, and mesaconitine were got in spiked serum samples. The working curves show linear dependence on aconitine concentration in the range of 2.0–0.1 µg/mL, and the detection limits of aconitine, hypaconitine, and mesaconitine were 16.7, 18.3, 10.2 ng mL^–1, respectively. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Fabrication and optimization of EGCG‐loaded nanoparticles by high pressure homogenization

In this study, we investigated the effects of the number of high pressure homogenization cycles and alginate (AG)‐to‐chitosan (CS) ratio on the physicochemical properties (mean size, polydispersity index, surface charge, encapsulation efficiency, and free radical scavenging) of (‐)‐epigallocatechin‐3‐gallate (EGCG)‐loaded nanoparticles. Nanoparticles prepared with alginate and chitosan concentrations of 0.01% and three cycles of high pressure homogenization exhibited a small size (293 nm) and a zeta potential of +37.49 mV, and were thus considered to be optimal for encapsulation. The highest encapsulation efficiency of 80.1% was achieved by using an EGCG concentration of 100 µg/g, which also resulted in the highest 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activities of 81.8% and 69.3% for pH 2.6 and pH 6.9, respectively. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43269.     

Effects of interlayer density and surfactant on coupled thermal stress and moisture absorption in modified montmorillonite/polypropylene nanocomposite

Modified montmorillonite/polypropylene nanocomposites (NCs) are increasingly used in industrial applications such as subsea pipelines because hexadecyltrimethyl ammonium montmorillonite (HDTMA⁺-Mt) enhances thermomechanical and barrier properties of the amorphous polymer. Two coupled physics of moisture adsorption and thermal loading are investigated. Molecular dynamics simulates HDTMA⁺-Mt polymer NC using three force fields including polymer consistent force field and condensed-phase optimized molecular potentials, and embedded-atom method. Mechanical properties and self-diffusion coefficient are investigated at temperature levels of 100 and 298 K, and water content of 0.021 and 0.133 g/g. These properties are evaluated at 1.0 atm pressure for four different volume fractions (vol%) of the HDTMA⁺-Mt. The modeling procedure is verified by obtaining the glass transition temperature (T_g) of the NC by scanning the temperature from 200 K (glassy state) up to 325 K (rubbery state). It is observed that the T_g is very close to the experimental value available in the literature. The result of the modeling shows that the increase of clay content of the NC decreases the self-diffusion coefficient of the material. It is seen that the clay nanoparticle can significantly hinder the degradation of mechanical properties of the NC even when both temperature and water content increase.     

Preparation of polyvinylpyrrolidone/graphene oxide/epoxy resin composite coatings and the study on their anticorrosion performance

Waterborne epoxy resin (EP) is often used as anticorrosive coating in the industrial field. However, small holes and gaps can be formed during the curing process. The corrosive medium easily penetrates the anticorrosive coating and corrodes the metal matrix. Herein, polyvinylpyrrolidone (PVP) and graphene oxide (GO) were doped into EP to improve the shielding and resistance to corrosive media. The composite coatings were prepared successfully by solution blending method. In the PVP/GO composite materials, original spatial structure of GO was changed and the composite was mainly combined by covalent bonding. The surface morphology of hybrid filler was flat and uniform, and the structural defects of GO was reduced. Compared with single-layer anticorrosive coating, the corrosion potential of PVP/GO/EP coating moved forward and the corrosion current density decreased. The ideal corrosion resistance of PVP/GO/EP composite coatings was mainly because agglomeration of GO sheet was obviously avoided after it was modified by PVP. Furthermore, the hybrid filler can be uniformly dispersed in the aqueous EP. It blocked the gaps and holes inside the coatings, which could contribute to form anticorrosive coatings.     

磺酸基化多孔酵母碳微球制备及其吸附性能研究

以酵母和羟乙基磺酸水溶液为原料,在200℃下一步水热合成了磺酸基化多孔酵母碳微球。以SEM、EDS、XRD、FTIR、BET、Zeta电位分析等为表征手段。SEM和XRD结果表明,改性酵母微球为荔枝状结构,同时改性前后,无定形碳的结构没有发生变化。Zeta电位和FTIR图谱分析表明,酵母碳表面成功负载了磺酸基团。采用中和滴定的方法测得产物表面磺酸基团的含量,该材料具有优异的吸附性能。以亚甲基蓝为吸附对象,通过研究不同浓度的亚甲基蓝、pH对吸附过程的影响,该吸附过程遵循二阶动力学方程,粒内扩散是整个吸附过程的速率控制步骤。