فهرست مطالب

Journal of Ultrafine Grained and Nanostructured Materials
Volume:53 Issue: 1, Jun 2020

  • تاریخ انتشار: 1399/04/11
  • تعداد عناوین: 11
  • Aimin Chu *, Yuping Zhao, Ud-Din Rafi, Li Tian, Shibo Guo, Hongmei Xu, Huajian Zhang Pages 1-8
    CrN/Cu composite powders were synthesized by employing a novel two-step technique. Firstly, the Cr2O3+CuO precursors were prepared by the solution combustion synthesis (SCS) method using cupric nitrate, urea, and chromium nitrate as initial materials. Subsequently, the SCS precursors were calcined at 850 °C in NH3 for 6 h, and transformed to CrN/Cu composite powders. The composite powders consist of the uniform subsphaeroidal particles with the particle size ranging from 200 to 300 nm. After the friction-wear test, the removal volume of the sintered CrN/Cu composite specimen (0.0218 mm3) is almost 80 times smaller than that of the sintered pure copper specimen (1.6634 mm3). The addition of CrN can improve the tribological performance of sintered copper significantly. Moreover, the electrical conductivity of the sintered CrN/Cu composite specimen is high to 85.6% of IACS (International Annealed Copper Standard).
    Keywords: CrN, Cu composite powder, precursor, Solution Combustion Synthesis, Aminolysis, Tribological performance
  • Farzin Mohseni, Hamid Reza Madaah Hoseini *, Hooman Shokrollahi, Tayebeh Gheiratmand Pages 9-14
    In this work, nanocrystalline Fe85Si10Ni5 soft magnetic powders were prepared by mechanical alloying and subsequent annealing to reduce the internal stresses and lattice strains. The powders were mixed with phenolic resin and warm pressed to produce nanostructured soft magnetic composites. The effect of annealing time and temperature on the crystalline structure, microstructure and magnetic properties of the powders and composite samples were investigated by XRD, SEM, VSM and LCR techniques. The results show that the annealing causes a significant improvement in the soft magnetic properties of the powders. By increasing the pressure and temperature in the compaction process, the density and permeability of the bulk samples increaseda. Moreover, increasing the phenolic resin content from 0.8 to 1.2 wt. % improves the electrical resistivity of the nanostructured soft magnetic composites.
    Keywords: Soft Magnetic Composite, Nanocrystalline Fe-Si-Ni alloys, Mechanical alloying, Magnetic properties
  • Hamed Daneshvar, Mir Saman Safavi, Vida Khalili, Jafar Khalil-Allafi * Pages 15-22
    In this study, NiTi thin films were deposited on the glass and NaCl substrates by means of magnetron sputtering method. The influence of aging temperature, over the range 300-500 oC, on phase transformation and mechanical properties of the sputtered NiTi thin films were studied by differential scanning calorimetry (DSC) and nano-indentation assay, respectively. The DSC curves showed that the aged specimens at 350, 400, and 500°C underwent two steps transformation during cooling process while a three steps transformation has been observed for the film aged at 450°C. This behavior clearly demonstrated the heterogeneity in chemical composition and microstructure of the sputtered thin film, which consequently resulted in the martensitic transformation of R and remained B2 to B19' within two steps. According to nano-indentation analysis results, a peak point at aging temperature of 450°C is reached. The temperature hysteresis of all aged films was about 1°C, which can be considered as a positive sign for sensor application.
    Keywords: NiTi thin film, Magnetron sputtering, Aging temperature, Mechanical Behavior, Phase Transformation, Sensor
  • Fahimeh Ansari, Saeed Sheibani *, Uriel Caudillo-Flores, Marcos Fernández-García Pages 23-30
    A series of CuO-Cu2O/TiO2 nanocomposite samples were prepared by the sol-gel method. Before applying the sol-gel method, the Cu(OH)2 nanostructure on Cu powders were formed by in-situ solution treatment. The samples were characterized through some techniques and the photocatalytic performance of CuO-Cu2O/TiO2 nanocomposites for gas-phase 2-propanol photo-oxidation under UV and sunlight type illumination was evaluated. The effect of calcination process on the synthesis and photocatalytic activity of the samples was studied. The calcination process plays an important role in improving the properties of nanocomposite powders. The results showed that the nanocomposite formed successfully in desirable structure and morphology. The nanocomposite is composed by the mixture of TiO2 particle with an average particle size of about 300 nm and the copper oxide nanorods with a diameter of 50-100 nm. In this nanocomposite, the copper oxides nanostructures and TiO2 particles are the main components to form the heterojunction structure and provide enhanced photocatalytic performance compared to the TiO2 sample. The reaction rate of the most active nanocomposite sample prepared at the optimum conditions is almost 6 times larger than the TiO2 references.
    Keywords: Copper Oxide, TiO2, Nanocomposite, Gas Phase Photodegradation, Calcination
  • Seyed Omid Reza Sheykholeslami, Mohamadreza Etminanfar *, Jafar Khalil-Allafi Pages 31-38
    In this paper, a facile method for preparing sub-micron spherical mesoporous silica by the sol-gel process and cationic surfactant cetyltrimethylammonium bromide (CTAB) as a soft template was reported. Moreover, the effect of surfactant concentration on the specific surface area and the total pore volume was investigated. The specific surface area, pore characteristic, morphology, chemical composition, and structure of mesoporous silica were studied using various methods. The N2 adsorption test showed that increasing the CTAB concentration from 4.6 mM to 7.2 mM increases the specific surface area from 416.48 to 564.07 m2g-1. However, the maximum pore volume was obtained at 5.9 mM CTAB. The spherical shape of the powders was confirmed by field emission scanning electron microscopy. Besides, X-ray diffraction, fourier transform infrared spectra, and energy dispersive spectrometry analysis indicated that the synthesized samples are SiO2, with an amorphous structure. Based on the structure and properties of obtained synthesized mesoporous silica, it is a good candidate for a drug reservoir and the carrier for new controlled drug delivery systems.
    Keywords: Mesoporous, silica, Surfactant, CTAB, Specific surface area, Pore volume
  • Nafiseh Mollaei, Seyed Mahmood Fatemi *, Mohammadreza Abootalebi, Hossein Razavi Pages 39-47
    Zinc based alloys have recently attracted great attention as promising biodegradable metals. Zinc exhibits moderate degradation rates in biological fluid and the zinc releases during the degradation process is considered safe to human systems. However, these materials exhibit critical limitations in terms of mechanical properties for medical applications. Adding alloying elements as well as grain refinement by thermomechanical processing are considered as effective techniques to address this problem. Severe plastic deformation (SPD) methods were considered in recent few years to process the zinc-based bioalloys to achieve acceptable mechanical characteristic while retaining their desired biocorrosion behavior. Summarizing present literature implied that Mg, Ag, Mn, and Ca containing zinc bioalloys may provide an improved strength and ductility approaching the common mechanical criteria. However, due to low melting temperature of zinc, there remains new uncertainties in mechanical response as future challenge, including low creep resistance and high susceptibility to natural aging at body temperature.
    Keywords: Zinc alloys, Severe Plastic Deformation, Microstructure, Mechanical properties
  • Mohsen Asgari, Mohammad Honarpisheh *, Hadi Mansouri Pages 48-59
    In this study, constraint groove pressing (CGP) process and ultrasonic assisted CGP (UCGP) process were investigated on the process forces, mechanical properties of the sheet, including hardness and tensile tests and grain size. Pure copper sheets were used as samples in this research. Samples were tested both with and without ultrasonic vibrations for mechanical properties and grain size up to 4 passes. The results of tensile tests showed that by applying CGP process, the strength of the samples increases significantly in the first two passes and then decreases. Hardness test results showed an increase which had the highest rate after the first pass. As expected, CGP process was very effective to create fine-grained metal structure. Also, process forces were investigated in both CGP and UCGP processes and then compared in 3 methods of 2 dimension (plane strain) simulation, 3 dimension simulation and experimental examination. After all, a good agreement was achieved.
    Keywords: constraint groove pressing, ultrasonic vibrations, Finite element, Mechanical properties
  • Leila Khanizadeh, Raana Sarvari *, Bakhshali Massoumi, Samira Agbolaghi, Younes Beygi-Khosrowshahi Pages 60-70
    The stimuli-responsive nanocomposites were designed as drug delivery nanocarriers. Thanks to promising properties such as large surface area and easy chemical functionalization, the graphene derivatives can be used for the drug delivery applications. For this purpose, in the current work, the poly(L,D-lactide)-block-poly(N-isopropylacrylamide-rand-acrylic acid) grafted from reduced graphene oxide (rGO-graft-PDLA-block-P(NIPAAm-rand-AAc)) was synthesized by thering opening polymerization (ROP) and atom transfer radical polymerization(ATRP). As compared with the traditional radical polymerizations, living polymerizations are among the most-utilized methods to achieve surface initiated polymer brushes as they provide excellent control over the polymers composition. The average sizes of rGO-graft-PDLA-block-P(NIPAAm-rand-AAc) nanocomposite using the dynamic light scattering (DLS) measurements at pH values of 4.0 and 7.4 were 240 and 150 nm, respectively. The lower critical solution temperature (LCST) of rGO-graft-PDLA-block-P(NIPAAm-rand-AAc) was determined to be 39 °C through the ultraviolet-visible (UV-Vis) spectroscopy. The doxorubicin hydrochloride (DOX)-loading capacity was 99 %. The release of DOX increased at 42 °C compared to 37 °C. The results confirmed that the pH- and temperature-dependent releasing of this drug nano-carrier was beneficial for the anticancer at the tumor-like environment. The biocompatibility was also confirmed by assessing the survival rate of breast cancer cell line (MCF7) using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The synthesized nanoparticles would have an excellent potential in the anticancer drug delivery.
    Keywords: rGO, NIPAAm, PDLA, graft polymerization, drug delivery, stimuli-responsivity
  • Shaghayegh Vahedi, Rouhollah Mehdinavaz Aghdam *, Ali Hossein Rezayan, Mahmoud Heydarzadeh Sohi Pages 71-77
    Chitosan based nanofibers containing carbon nanotubes were applied on AZ31 magnesium alloy via electrospinning. The magnesium substrate was initially anodized in a NaOH solution in order to improve the adhesion between the coating and substrate. Electrospinning parameters were optimized and homogenous nanofibers composite coatings were produced. Addition of carbon nanotubes reduced the size of the chitosan nanofibers. Also the size distribution of the fibers became more uniform. The chemical structure of the coatings was also evaluated by FTIR test and it verified stabilization of the nanofibers coating in a supersaturated sodium carbonate solution.Raman spectra showed the D and G band which corroborates the presence of Carbon Nanotubes in the coating.
    Keywords: Magnesium alloy, Chitosan, Carbon Nanotube, Nanofiber, Nanocomposite, Electrospinning
  • Shahab Nasseri *, Ali Yaqubov, Abdolali Alemi, Ali Nuriev Pages 78-90
    In recent decades, the presence of heavy metal ions in wastewater has become an important public concern worldwide. Adsorption is a commonly used technique for removing various types of materials including metal ions from contaminated water sources. However, common methods for adsorption are not completely efficient at low ion concentrations; therefore, adsorbents should be improved in order to reach an acceptable level of adsorption efficiency. In this study, the removal of two heavy metals ions, zinc and copper, from synthetic aqueous solutionusing Nano-bentonite was investigated.  Modified bentonite was obtained by calcination of bentonite at 600℃ for 2h. Response surface methodology (RSM) and central composite design (CCD) were used to optimize the operating factors of the adsorption process. Operation time, adsorbent dosage, ion concentration and pH were the variables and percentage of ion removal was considered as the response. HCl and NaOH were used as chemical agents to adjust pH at optimum level of operating condition for Cu2+ and Zn2+ removal which were as follows: Cu2+ initial concentration: 110.1 mg/L, pH:7.3, time: 96.8 min, adsorbent dosage: 2.1 g/l, and Zn2+ initial concentration: 105 mg/L, pH: 6.9, time: 73.1 min and adsorbent dosage: 2 g/l. Results and 3D plots exhibited significant proof for accepting the competence of the modified Nano-bentonite as an efficient adsorbent for metals ion removal.
    Keywords: response surface methodology, heavy metal adsorption, Wastewater treatment, Nano bentonite
  • Amineh Shafaei, Gholam Reza Khayati *, Reyhane Hoshyar Pages 91-97
    This study is a green approach for the synthesis of silver nanoparticles (AgNPs) using morphine ampoules (MO) as reducing and capping agents. The toxicity effects of prepared particles were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on breast cancer cells. UV–visible spectrum, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), environmental scanning electron microscopy (ESEM), transmission electron microscopy (TEM), and dynamic light scattering (DLS) techniques were employed for characterization of prepared particles. A review mechanism has been done based on density functional theory (DFT). The results confirmed the formation of spherical and crystalline AgNPs with the average particle size of 50nm. Also, DFT analysis revealed that the reduction was occurred by connection of MO constituents to the NO3 part of AgNO3. In addition of reducing effect, the capping characteristics of MO biomolecules were proved by FTIR spectra. Moreover, comparison of Anti-proliferation Activity of MO-AgNPs was 69% higher than MO at similar dosage. Therefore, in addition to use MO as a painkiller in the treatment of cancer, it can also be used as a factor for the synthesis of AgNPs with enhanced its anticancer properties.
    Keywords: Green Synthesis, Morphine ampoules, Breast cancer cells, Density functional theory, Biomaterials, nanoparticles