Nano

In this research, molecular dynamic (MD) simulations computation is applied to generally study the coating behavior of palmitic acid molecules and aluminum (Al) nanoparticle (ANP) surface through single and multi-molecule models. Changes and comparisons of adsorption distance, energy, effectiveness and stability are generally discussed in this study. Those obtained results indicate that the adsorption configuration of palmitic acid and Al has shown the adsorption polarity clearly. For carboxyl terminal of palmitic acid and Al surface, when their critical adsorption angle is around 60^∘, its distance is within 9 Å. Besides, the decisive atomic group of palmitic acid molecule is carboxyl, whose oxygen atom with double bond can adsorb the Al atom stably. This adsorption effect and formation is close to the covalent bond. During the adsorption process, van der Waals force acts on the long-distance attraction, and the Coulomb force acts more critically as the short-range adsorption force. Finally, the gas coating has proper advantages over the liquid coating, as the erosion of Al surface is much lower when it is surrounded by gas-phased palmitic acid.

In this work, antimony trioxide nanoparticles (Sb₂O₃NPs)-doped polyvinyl alcohol (PVA${}_{0.75}$) and polyvinyl pyrrolidone (PVP${}_{0.25}$) (i.e., PVAP@$x$Sb₂O₃NPs, $x=0,0.02$, and 0.04) composite films were prepared using the casting method. Light optical microscopy (LOM), scanning electron microscopy (SEM), and Fourier infrared spectrums (FTIR) were used to investigate PVAP@$x$Sb₂O₃NPs films. Sb₂O₃NPs were well dispersed within the matrix. FTIR showed a strong interaction between the matrix material and NPs. The density increased by up to 75% after adding 0.04wt.% of Sb₂O₃NPs. The mechanical ultrasound properties (MUS) were measured with different ultrasound frequencies in the ranges of (25, 30, 35, 40 and 45kHz). MUS coefficients such as ultrasonic velocity, absorption coefficient, and bulk modules were significantly improved after the impact of NPs by up to 20%, 115% and 230%, respectively. The reduction of electrical properties such as dielectric and loss constant was associated with an increase in frequency. The dielectric constant of PVAP@Sb₂O₃NPs was increased by about 80% after loading. AC electrical conductivity revealed an improvement with an increase in frequency and loading ratio. The results demonstrate a promising material for electromechanical, energy harvesting, and pressure sensor applications.

Radiotherapy is a simple and effective method for the treatment of rhinitis cancer, but some patients are resistant to radiotherapy and affect the curative effect. Previous studies have confirmed that miR-205 can be used as a biomarker for the feasibility of radiotherapy in nasopharyngeal carcinoma (NPC). In this study, a biosensor for the detection of miR-205 was constructed by using graphene oxide (GO) and fluorescent DNA probes, and using DNase I to generate fluorescent signals for cyclic amplification. The results showed that the lowest detection limit of this sensor for detecting miR-205 was 475 pM, which was 4.86 times lower or 4.86 times better than that of conventional methods without amplification, and showed better detection specificity. It is expected to provide a convenient and effective tool for studying the radio resistance mechanism of NPC and for personalized therapy for NPC patients.

Chitosan, a cationic polymer, is loaded on Ni-doped copper monosulfide (CuS) NPs with optimal Ni doping concentration, and electrochemical, third-order nonlinear, magnetic and antibacterial characteristics of chitosan unloaded and loaded CuS:Ni nanoparticles are compared. The crystallite size of pure CuS increased with Ni doping and the 10wt.% Ni-doped CuS NPs exhibit a maximum crystallite size of 41nm. The presence of Ni in the doped samples was acknowledged by the existence of Ni 2p${}_{3∕2}$ and Ni 2p${}_{1∕2}$ peaks at binding energies 851eV and 873.1eV, respectively from the XPS spectrum. Optical reflectance decreased with Ni doping and the optical band gap varied from 2.56eV to 2.4eV. Specific capacitance increased with Ni doping. Diamagnetic nature of CuS changed to ferromagnetic with Ni doping. The 10wt.% Ni-doped CuS exhibits a high third-order nonlinear absorption coefficient and susceptibility value. Bacterial growth inhibition nature of CuS improved with Ni doping. Among the doped samples, the 10wt.% Ni-doped sample exhibits improved electrochemical, third-order nonlinear, magnetic and antibacterial properties. Keeping this as the optimized Ni concentration, chitosan was loaded. Chitosan-loaded samples exhibited a reduction in crystallite size and an increase in band gap. A high specific capacitance of 96F/g was realized for the chitosan-loaded sample. Saturation magnetization of 10wt.% CuS:Ni decreased with chitosan loading.

The advanced two-stage synthesis method of the Ni–Co–Cu/carbon magnetic nanocomposite as promising material for electromagnetic wave absorption was proposed. Synthesis condition for consolidated Ni–Co–Cu solid solution nanoparticles with an average size of less than 100nm uniformly distributed in the carbon matrix was discussed. The effect of different pyrolysis temperatures (500–700^∘C) and Cu concentration in the precursor (from 5 to 30wt.%) on the microstructure of Ni–Co–Cu nanocomposite, its particle size and magnetic properties was investigated by of XRD, TEM and magnetic hysteresis.

The saturation magnetization and remanence showed non-monotonic dependences on Cu concentration in samples. The coercive force was varied from 110 to 177Oe depending on Cu content in nanoparticles. The correlation between magnetic properties and microstructure of Ni–Co–Cu/carbon nanocomposites was discussed assuming the transition of nanoparticles to superparamagnetic and single-domain states depending on their sizes.

Anisotropic gold nanoparticles (AuNPs) were synthesized using microwave (MW)-assisted route. Lemon extract was used as both reducing and stabilizing agent. Subsequent UV treatment was carried out to modify the particle size and shape. Distribution of triangular and pentagonal-shaped particles were found to increase in number. Moreover, up to 60% increase in particle size was also observed. Change in optical property and appearance of plasmon modes were clear indication of the modification caused. Local density of photonic states (LDOS) and electric field distribution were obtained through computational simulation using MATLAB toolbox. Experimental results were used as the input values for the simulation. Dipolar distribution was observed along the boundaries of the spherical NPs, while for triangular and pentagonal-shaped NPs, they were found to be concentrated along their edges and corners. The results presented here encourage us to choose an alternative eco-friendly, quick and simple route to synthesize gold NPs of various shapes for various application such as in viral detection, nanobiomaterials, biomedical images, detection-therapy, etc.

We demonstrate the aging mechanisms of ultra-high-rate lithium iron phosphate (LiFePO${}_4)$/graphite batteries for electromagnetic launch (EML) applications. These lithium-ion batteries (LIBs) are repetitively charged at a rate of 1C and discharged at a rate of 70C for 300 times. After 300 cycles, the capacity retention is 79.9%, and the internal resistance rises from 1.4m$\mathrm{\Omega }$ to 2.4m$\mathrm{\Omega }$. The scanning electron microscopy (SEM) results show that the surface of the anode presents an absolutely different morphology after 300 cycles, indicating the occurrence of severe secondary reactions. The X-ray diffraction (XRD) and X-ray photoelectron spectroscope (XPS) results reveal that part of LiFePO₄ is replaced by FePO₄ in the cathode of fully discharged LIBs during repetitive cycling, meaning the occurrence of loss of active lithium. Moreover, the Fourier transform infrared spectroscopy (FTIR) and XPS results display that the surface of the anode is coated by a layer of compounds including Li₂CO₃, ROCO₂Li and LiF after 300 cycles, which is the cause of loss of active lithium and results in the decline of capacity. As the first research about the aging mechanisms of ultra-high-rate LiFePO₄/graphite batteries, this work brings comprehension of the degradation of EML-used LIBs, which is of great significance to EML technology.

In this paper, well-defined Mg-Al LDHs nanosheets with high yield are prepared by the following sequential procedures: hydrothermal preparation of Mg-Al-CO${}_3^{2-}$ LDHs, followed by expanding interlayer spacing by NH₄NO₃ treatment. The results show that the concentration of the layer expansion agent (NH₄NO${}_3)$ and the exfoliation solvent play a key role in the exfoliation result. The basal spacing changed from 0.758nm to the range of 0.758–0.895nm when the concentration of NH₄NO₃ was increased up to 5 M, which infers that the increase of layer space is caused by the synergy of NH${}_4^{+}$ and NO${}_3^{-}$. Among the three exfoliation solvents (formamide, N-methyl pyrrolidone and isopropyl alcohol), formamide showed the highest exfoliation effect. From the characteristic XRD patterns, the as-obtained colloidal aggregates of the exfoliated nanosheets do not show the characteristic diffractions of LDHs, while the typical peaks at 10.562${}^{\circ }$, 20.032${}^{\circ }$ and 21.185${}^{\circ }$ assigned to LDHs are observed after drying of the colloidal aggregates. Moreover, a transparent LDH film is also successfully prepared by coating colloidal aggregates of nanosheets on a glass substrate without using any adhesive. The stable film exhibits the strong adsorption ability of Methyl Orange.

Exploiting advanced regenerable adsorbents for efficient uranium adsorption from seawater is a promising route to address uranium resources shortages. Herein, inspired by the mechanism of plant homeostasis, natural polyphenols are combined with cotton matrix to construct a polyphenol-functionalized cotton (Cot-TA-APTES) for efficient uranium extraction. Compared with pristine cotton, the polyphenol-functionalized cotton displays a rapid adsorption kinetic, and the maximum extraction efficiency for U(VI) is up 96.07% at pH 5.0 and 30${}^{\circ }$C. Additionally, Cot-TA-APTES shows a higher adsorption selection ability for U(VI) than other interfering ions. Based on FT-IR and XPS, the excellent extraction efficiency and favorable selectivity of Cot-TA-APTES for U(VI) are due to the combination of U(VI) and functional coating groups. This natural polyphenol/cotton-based absolutely bio-derived adsorbent provides a novel and potentially applicable strategy for constructing an adsorbent for nuclear environmental remediation and uranium extraction from seawater with cost-effective and biosafety.