Application of Modified Silica Coated Magnetite Nanoparticles for Removal of Iodine from Water Samples

The adsorption of iodine onto silica coated magnetite nanoparticles(im-SCMNPs) that modified with imidazole was investigated for removal of high concentrations of iodine from wastewater. Modified silica magnetite nanoparticles showed high efficiency in removing iodine from wastewater samples. The optimum pH for iodine removal was 7.0-8.0. The adsorption capacity was evaluated using both the Langmuir and Freundlich adsorption isotherm models. The size of the produced magnetite nanoparticles was determined by X-ray diffraction analysis and scanning electron microscopy. Synthesized magnetite nanoparticles showed the high adsorption capacity and would be a good method to increase adsorption efficiency for the removal of iodine in a wastewater treatment process. The Langmuir adsorption capacity(qmax) was found to be 140.84 mg/g of the adsorbent.

Enhanced Immunostimulatory Properties in CpG-Oligonucleotides Modified by Gold Nanoparticles

Whether the immunostimulatory effects of CpG-oligonucleotides （CpG ODNs） could be enhanced by the use of gold nanoparticles （Au-NP） was investigated.The CpG ODNs were modified by the Au-NP （CpG /Au-NP） and their uptake and distribution in murine N9 microglial cells were studied.The immunostimulatory effects of CpG /Au-NP on N9 cells,human B cells and plamacytoid dendritic cells （pDCs） were examined.Results showed that the uptake of CpG /Au-NP in N9 cells was much higher than that of CpG ODNs and CpG /Au-NP localized in the cytoplasm of N9 cells.The amount of TNF-α and IL12p40 in N9 cells was increased greatly by the use of Au-NP.And the amount of IL-6 in B cells and IFN-α in pDCs was also significantly increased,while the activation of B cells was not changed.These results reveal that the Au-NP can be used as a delivery media for the oligonucleotides-based therapeutics.

A novel nanofluid of modified carbon black nanoparticles for enhanced oil recovery in low permeability reservoirs

A novel nanofluid of modified carbon black(MCB)nanoparticles was initially developed for enhanced oil recovery(EOR)in low permeability reservoirs.The MCB nanoparticles were obtained via a three-step reaction involving modification by oxidation,acyl chlorination,and activated grafting.MCB nano-particles were spherically dispersed,with an average size of 72.3 nm.Compared with carbon black(CB)nanoparticles,dispersed MCB nanoparticles can effectively reduce the oil-water interfacial tension(IFT)to 10^(-2)mN/m and change the surface wettability of sand particles.Based on the results of core flooding experiments,the MCB nanoparticles exhibited a better EOR capacity than surfactants and CB nano-particles,and the final oil recovery was significantly increased by 27.27%.The core scanning test showed that the MCB nanoparticles could plug high permeability channels by adsorbing onto the surfaces of sand particles and forming larger aggregates that bridge across pores or throats,resulting in a higher swept volume.The synergistic effects of improved swept volume and oil displacement efficiency were the EOR mechanisms of the MCB nanoparticles.The studies indicate that these MCB nanoparticles have excellent potential for EOR in low permeability reservoirs.

Neuroprotective effect of Angiopep-2 peptide modified scutellarin-loaded PEGylated PAMAM dendrimer nanoparticles on ischemic stroke by modulating the Toll-like receptors-dependent MyD88/IKK/NF-κB signaling pathway

OBJECTIVE The greatest challenge in chemotherapy of ischemic stroke is the construction a suitable delivery system to overcome the poor physicochemical properties of drug and its low permeability across the blood brain barrier(BBB).METHODS In the present study,dendrimer,polyamidoamine(PAMAM),was synthesized as the nano-drug carriers.Angiopep-2,which has been proved excellent ability to cross the BBB,was exploited as the targeting ligand to conjugate PAMAM via bifunctional polyethylene glycol(PEG).Then scutellarin(STA)was encapsulated into the functionalized nanoparticles(NPs)to formulate Angiopep-2 modified STA-loaded PEG-PAMAM NPs.Ischemic stroke model was established to evaluate the treatment efficacy and protective mechanism of Angiopep-2-STA-PEG-PAMAM NPs.RESULTS The pharmacokinetics and biodistribu-tion demonstrated that Angiopep-2-STA-PEG-PAMAM NPs exhibited significantly higher plasma concentration from 1 h to 10 h after intravenous administration and improve accumulation in brain(4.7-fold)compared with STA solution.Moreover,prolonged elimination half-life(4.8-fold)and lower clearance(3.4-fold)were observed.The brain uptake study of 6-coumarin confirmed that Angiopep-2-PEG-PAMAM NPs possessed better brain targeting efficacy(3.2-fold)than PEG-PAMAM NPs.Angiopep-2-STA-PEG-PAMAM NPs obviously ameliorated infarct volume,neurological deficit,histopathological severity and neuronal apoptosis.In addition,Angiopep-2-STA-PEG-PAMAM NPs markedly inhibited the calcium content and the levels of IL-12p40,IL-13,IL-17 and IL-23.Furthermore,Angiopep-2-STA-PEG-PAMAM NPs significantly decreased the m RNA and protein expressions of HMGB1,TLR2,TLR4,TLR5,My D88,TRIF,TRAM,IRAK-4,TRAF6,IкBα,IKKβand NF-кBp65.CONCLUSION The results suggested that Angiopep-2modified scutellarin-loaded PEG-PAMAM nanocarriers possessed remarkable neuroprotective effects on ischemic stroke through modulation of inflammatory cascades and HMGB1/TLRs/MyD 88-induced NF-κB activation pathways.

Preparation of Regenerated Silk Fibroin Hybrid Fibers with Hydrogen Peroxide Sensing Properties by Wet Spinning

Silk is widely used in the production of high-quality textiles.At the same time,the amount of silk textiles no longer in use and discarded is increasing,resulting in significant waste and pollution.This issue is of great concern in many countries where silk is used.Hydrogen peroxide as a naturally occurring compound is an important indicator of detection in both biology and the environment.This study aims to develop a composite fiber with hydrogen peroxide-sensing properties using discarded silk materials.To achieve this goal,firstly,polydopamine(PDA)was used to encapsulate the ZnFe_(2)O_(4) NPs to achieve the improvement of dispersion,and then regenerated silk fibroin(RSF)and PDA@ZnFe_(2)O_(4)/RSF hybrid fibers are prepared by wet spinning.Research has shown that PDA@ZnFe_(2)O_(4)/RSF demonstrates exceptional sensitivity,selectivity,and stability in detecting hydrogen peroxide,while maintaining high mechanical strength.Furthermore,the complete hybridization of PDA@ZnFe_(2)O_(4) with silk fibroin not only results in the combination of the durability of silk fibroin and PDA@ZnFe_(2)O_(4)’s rigidity,ensuring a reliable service life,but also makes PDA@ZnFe_(2)O_(4)/RSF exhibit excellent catalytic activity and biocompatibility.Therefore,the composite fiber exhibits exceptional mechanical properties and reliable hydrogen peroxide sensing capabilities,making it a promising material for biological and medical applications.

Effects of Trace Amount Modified SiC Nanoparticles and Electromagnetic Stirring (EMS) on Microstructure and Mechanical Properties of 7055 Aluminum Alloy

The effects of trace amount modified SiC nanoparticles and electromagnetic stirring(EMS)on mierostructures and mechanical properties of 7055 aluminum alloy are investigated experimentally.The result shows that the original developed coarse dendrite and columnar with obvious orientation microstructure turns into homogeneous equiaxed microstructure with the application of trace amount modified SiC nanoparticles and EMS.A minimum grain size is 96 μm and has been observed when the addition of modified SiC nanoparticles is 0.05%and the current of EMS is 100A.The ultimate tensile strength is increased by 15.8%and the elongation is improved by 50%compared to those without modified SiC nanoparticles and EMS.Moreover,the compound effects of trace amount modified SiC nanoparticles and EMS is discussed to explain the mechanisms of grain refinement and mechanical properties on 7055 aluminum alloy.

Geo-environmental and mechanical behaviors of As(V)and Cd (Ⅱ)co-contaminated soils stabilized by goethite nanoparticles modified biochar

Goethite nanoparticles modified biochar(FBC)could address the weak effectiveness of conventional biochar commonly to process heavy metal(loids)(HMs)co-contamination with different charges.However,few studies have focused on the change of soil mechanical properties after stabilization.In this study,FBC was synthesized to stabilize simultaneously arsenic(As(V))(anions)and cadmium(Cd (Ⅱ))(cations)in co-contaminated soils.Batch adsorption,leaching toxicity,geotechnical properties and micro-spectroscopic tests were comprehensively adopted to investigate the stabilization mechanism.The results showed that FBC could immobilize As(V)mainly through redox and surface precipitation while stabilizing Cd (Ⅱ)by electrostatic attraction and complexation,causing soil agglomeration and ultimately making rougher surface and stronger sliding friction of contaminated soils.The maximum adsorption capacity of FBC for As(V)and Cd (Ⅱ)was 31.96 mg g^(−1) and 129.31 mg g^(−1),respectively.Besides,the dosages of FBC required in contaminated soils generally were approximately 57%higher than those in contaminated water.FBC promoted the formation of small macroaggregates(0.25-2 mm)and the shear strengths of co-contaminated soils by 21.40%and 8.34%,respectively.Furthermore,the soil reutilization level was significantly improved from 0.14-0.46 to 0.76-0.83 after FBC stabilization according to TOPSIS method(i.e.,technique for order preference by similarity to an ideal solution).These findings confirm the potential of FBC in immobilizing As(V)and Cd (Ⅱ)of co-contaminated soils and provide a useful reference for green stabilization and remediation of HMs co-contaminated sites.

Homogeneous and nanomolar detection of hydrazine by indigocarmine as a mediator at the surface of TiO_2 nanoparticles modified carbon paste electrode

The homogeneous electrocatalytic oxidation of hydrazine（HZ） has been studied by indigocarmine（IND） as a mediator at the surface of TiO_2 nanoparticles modified carbon paste electrode（TNMCPE）.Cyclic voltammetry was used to study the electrochemical behavior of IND at different scan rates.The voltammetric response of the modified electrode was linear against the concentration of HZ in the ranges of 3.0×l0^（-8）-7.0×10~6 mol/L with differential pulse voltammetry method.The detection limit（3σ） was determined as 27.3 nmol/L.To evaluate the applicability of the proposed method to real samples,the modified CPE was applied to the determination of HZ in water samples.

Fabrication of bimetallic Ag/Fe immobilized on modified biochar for removal of carbon tetrachloride

As an effective conventional absorbent, biochar exhibited limited adsorption ability toward small hydrophobic molecules. To enhance the adsorption capacity, a novel adsorbent was prepared by immobilizing nanoscale zero-valent iron onto modified biochar（MB） and then the elemental silver was attached to the surface of iron（Ag/Fe/MB）. It＇s noted that spherical Ag/Fe nanoparticles with diameter of 51 nm were highly dispersed on the surface of MB. As the typical hydrophobic contaminant, carbon tetrachloride was selected for examining the removal efficiency of the adsorbent. The removal efficiencies of carbon tetrachloride by original biochar（OB）, Ag/Fe, Ag/Fe/OB and Ag/Fe/MB were fully investigated. It＇s found that Ag/Fe/MB showed higher carbon tetrachloride removal efficiency, which is about 5.5 times higher than that of the OB sample due to utilizing the merits of high adsorption and reduction. Thermodynamic parameters revealed that the removal of carbon tetrachloride by Ag/Fe/MB was a spontaneous and exothermic process, which was affected by solution p H, initial carbon tetrachloride concentration and temperature. The novel Ag/Fe/MB composites provided a promising material for carbon tetrachloride removal from effluent.

Preparation and characterization of Pd/Fe bimetallic nanoparticles immobilized on Al_2O_3/PVDF membrane:Parameter optimization and dechlorination of dichloroacetic acid

Using a liquid-solid phase inversion method, a hybrid matrix poly（vinylidene fluoride）（PVDF） membrane was prepared with alumina（Al2O3） nanoparticle addition. Pd/Fe nanoparticles（NPs） were successfully immobilized on the Al2O3/PVDF membrane, which was characterized by Scanning Electron Microscopy（SEM） and Transmission Electron Microscopy（TEM）. The micrographs showed that the Pd/Fe NPs were dispersed homogeneously. Several important experimental parameters were optimized, including the mechanical properties, contact angle and surface area of Al2O3/PVDF composite membranes with different Al2O3 contents. At the same time, the ferrous ion concentration and the effect of hydrophilization were studied. The results showed that the modified Al2O3/PVDF membrane functioned well as a support. The Al2O3/PVDF membrane with immobilized Pd/Fe NPs exhibited high efficiency in terms of dichloroacetic acid（DCAA） dechlorination. Additionally, a reaction pathway for DCAA dechlorination by Pd/Fe NPs immobilized on the Al2O3/PVDF membrane system was proposed.

Highly sensitive determination of promazine in pharmaceutical and biological samples using a ZnO nanoparticle-modified ionic liquid carbon paste electrode

In this work we describe the first report for the determination of promazine using a nanostructure- modified ionic liquid carbon paste electrode in aqueous solutions. To achieve this goal, a novel modified carbon paste electrode using ZnO nanoparticles and l-methyl-3-butylimidazolium bromide as a binder （ZnO/NPs/ILs/CPE） was fabricated. The oxidation peak potential of promazine at the surface of the ZnO/ NPs/ILs/CPE appeared at 685 mV, which was about 65 mV lower than the oxidation potential at the surface of CPE under similar conditions. Also, the peak current was increased to about 4.0 times higher at the surface of ZnO/NPs/ILs/CPE compared to that of CPE. The linear response range and detection limit were found to be 0.08-450 and 0.04 μmol/L, respectively. The modified electrode was successfully used for the determination of promazine in real samples with satisfactory results.

Mixed convection of alumina-water nanofluid inside a concentric annulus considering nanoparticle migration

A theoretical investigation was conducted of laminar fully developed mixed convection of alumina-water nanofluid through a vertical annulus, to improve its heating/cooling performance. We focused on con- trolling the nanoparticle migration and studying how it affected the heat transfer rate and pressure drop. Because the nanoparticles have very small dimensions, we only considered Brownian motion and ther- mophoretic diffusivity as the main causes of nanoparticle migration. Because thermophoresis is very sensitive to temperature gradients, we imposed various temperature gradients using asymmetric heat- ing. Considering hydrodynamically and thermally fully developed flow, the governing equations were reduced to two-point ordinary boundary value differential equations and were solved numerically. The imposed thermal asymmetry changed the direction of nanoparticle migration and distorted the velocity, temperature, and nanoparticle concentration profiles. Moreover, we found optimum values for the radius ratio （ζ） and heat flux ratio （ε）; with these optimum values, the nanofluid enhanced the efficacy of the system.