@article { author = {Bolouki, A. and Rashidi, L. and Vasheghani-Farahani, E. and Piravi-Vanak, Z.}, title = {Study of Mesoporous Silica Nanoparticles as Nanocarriers for Sustained Release of Curcumin}, journal = {International Journal of Nanoscience and Nanotechnology}, volume = {11}, number = {3}, pages = {139-146}, year = {2015}, publisher = {Iranian Nanotechnology Society}, issn = {1735-7004}, eissn = {2423-5911}, doi = {}, abstract = {Curcumin (CUR) is a hydrophobic molecule and beneficial antioxidant with known anticancer property. The bioavailability of curcumin is low because of its hydrophobic structure. Mesoporous silica nanoparticles (MSN) loaded by CUR were used as nanocarriers for sustained release of CUR in four different media such as simulated gastric,intestinal, colon and body fluids (SGF, SIF, SCF, and SBF, respectively). In this study MSN and its amine-functionalized (AP-MSN) were synthesized, loaded by CUR and then characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), N2 adsorption isotherms, X-ray diffraction (XRD) and thermal gravimetric analysis (TGA). TGA showed that the amount of CUR loaded into MSN and AP-MSN (named MSN-CUR, AP-MSN-CUR, respectively) was 1.44 and 9.5%, respectively. Entrapment efficiency of CUR in MSN and AP-MSN was found to be 3.6 and 23.75%, respectively. Release rate of CUR from AP-MSN-CUR was slower than that from MSN-CUR at different pHs of media. In addition, the release rate of CUR from AP-MSN-CUR in acidic buffer solution was slower than that in alkaline media.}, keywords = {Antioxidant,curcumin,Mesoporous silica nanoparticles,Release}, url = {https://www.ijnnonline.net/article_14567.html}, eprint = {https://www.ijnnonline.net/article_14567_62eb20a54a86ca972b373fde4f8649b1.pdf} } @article { author = {Hosseini, M.G. and Shahryari, E. and Najjar, R. and Ahadzadeh, I.}, title = {Study of Super Capacitive Behavior of Polyaniline/manganese Oxide-Carbon Black Nanocomposites Based Electrodes}, journal = {International Journal of Nanoscience and Nanotechnology}, volume = {11}, number = {3}, pages = {147-157}, year = {2015}, publisher = {Iranian Nanotechnology Society}, issn = {1735-7004}, eissn = {2423-5911}, doi = {}, abstract = {The supercapacitive behavior of polyaniline/MnO2-carbon black (PANI/MnO2-CB), MnO2-CB nanocompositesand CB was studied. MnO2-CB made by the in situ direct coating method to deposit MnO2 onto CB; then PANI coating was coated on it. Morphology of the nanocomposite was studied by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The electrochemical properties of electrodes were investigated by cyclic voltammetry (CV), galvanostatic charge–discharge and electrochemical impedance spectroscopy (EIS) techniques in 0.5 M Na2SO4. The specific capacitance of 179.8 F. g-1 was obtained for PANI/MnO2-CB compared with 121 F. g-1 for MnO2-CB and 44.87 F. g-1 for CB. The EIS results also revealed improved capacitive properties of CB by the addition of MnO2 and PANI.}, keywords = {Chemical polymerization,Cycle stability,life time,PANI/MnO2-CB,Supercapacitor}, url = {https://www.ijnnonline.net/article_14568.html}, eprint = {https://www.ijnnonline.net/article_14568_59d8ebdd04dd8262f552a177fcb77ddd.pdf} } @article { author = {Maani Miandoab, E. and Tajaddodianfar, F. and Nejat Pishkenari, H. and Ouakad, H. M.}, title = {Analytical Solution for the Forced Vibrations of a Nano-Resonator with Cubic Nonlinearities Using Homotopy Analysis Method}, journal = {International Journal of Nanoscience and Nanotechnology}, volume = {11}, number = {3}, pages = {159-166}, year = {2015}, publisher = {Iranian Nanotechnology Society}, issn = {1735-7004}, eissn = {2423-5911}, doi = {}, abstract = {Many of nonlinear systems in the field of engineering such as nano-resonator and atomic force microscope can be modeled based on Duffing equation. Analytical frequency response of this system helps us analyze different interesting nonlinear behaviors appearing in its response due to its rich dynamics. In this paper, the general form of Duffing equation with cubic nonlinearity as well as parametric excitations is considered and its frequency response is derived utilizing Homotopy Analysis Method (HAM) for the first time. Although time response of different Duffing systems has been analyzed using HAM, derivation of its frequency response equation by applying this powerful method has not been presented. The main advantage of proposed simple closed-form solution is that it is not restricted to weakly nonlinear systems in contrast with perturbation methods. Because of numerous applications of Micro-electro-mechanical resonator and its rich and nonlinear dynamics, it is considered as a case study in this paper and the obtained analytical equation is applied to find its frequency response. The validation of analytical method is verified by comparing the results with numerical simulations. It is also shown that proposed closed-form equation for nano-resonator frequency response can capture both hardening and softening behavior of nano-resonator as well as jump phenomenon. The results of this paper can be useful in analysis of different engineering systems modeled by general Duffing equation.}, keywords = {Duffing equation,frequency response,Homotopy analysis method,Nano-resonators}, url = {https://www.ijnnonline.net/article_14569.html}, eprint = {https://www.ijnnonline.net/article_14569_bad3789a40f583b7ce01ad685ef959c0.pdf} } @article { author = {Mohamadnia, Z. and Ahmadi, E. and Ghasemnejad, M. and Hashemikia, S. and Doustgani, A.}, title = {Surface Modification of Mesoporous Nanosilica with [3-(2-Aminoethylamino) propyl] Trimethoxysilane and Its Application in Drug Delivery}, journal = {International Journal of Nanoscience and Nanotechnology}, volume = {11}, number = {3}, pages = {167-177}, year = {2015}, publisher = {Iranian Nanotechnology Society}, issn = {1735-7004}, eissn = {2423-5911}, doi = {}, abstract = {Mesoporous silica nanoparticles with unique structure (SBA-15) were synthesized and modified by [3-(2-Aminoethylamino) propyl] trimethoxysilane (AEAPTMS). The synthesized nanoparticles were characterized by TGA, N‌2‌ adsorption, SEM, FTIR, CHN elemental analysis. The total weight loss for the modified SBA-15 is 15.2% and thermal analysis revealed that 1.5 mmol AEAPTMS/1g SBA-15 had been grafted. The modified particles were used as a drug delivery system. Ibuprofen as common nonsteroidal anti-inflammatory drugs was used to evaluate the controlled drug release properties of modified SBA-15.The results show that the modification of SBA-15 with organic groups such as [3-(2-Aminoethylamino) propyl] trimethoxysilane and (3-aminopropyl) triethoxysilane (APTES) improve the organophilicity of the SBA-15 and the drug loading efficiency. The results of drug delivery experiments reveal that the surface modification of SBA-15 with amino groups significantly decreases the drug delivery rate. The data obtained from the in vitro release studies was used to evaluate the kinetic mechanism of release; the initial 60% release of drug at pH 7.4 fits with the Korsmeyer – Peppas model, when diffusion is the main drug release mechanism.}, keywords = {Drug Delivery,Ibuprofen,Nano silica,SBA-15,Surface modification}, url = {https://www.ijnnonline.net/article_14570.html}, eprint = {https://www.ijnnonline.net/article_14570_14bdd42fc3d7c825687289515cff604e.pdf} } @article { author = {Motamedi, M. and Mosavi Mashhadi, M.}, title = {Nanobiomechanical Properties of Microtubules}, journal = {International Journal of Nanoscience and Nanotechnology}, volume = {11}, number = {3}, pages = {179-184}, year = {2015}, publisher = {Iranian Nanotechnology Society}, issn = {1735-7004}, eissn = {2423-5911}, doi = {}, abstract = {Microtubules, the active filaments with tubular shapes, play important roles in a wide range of cellular functions, including structural supports, mitosis, cytokinesis, and vesicular transport, which are essential for the growth and division of eukaryotic cells. Finding properties of microtubules is one of the main concerns of scientists. This work helps to obtain mechanical properties of microtubule. For this aim, interaction energy in alpha-beta, beta-alpha, alpha-alpha and beta-beta dimers was calculated using the molecular dynamic simulation and GROMACS software package. Force-distance diagrams for these dimers were obtained using the relation between potential energy and force. Each dimer has nearly 8500 atoms. There are more than 100 tubulins in a microtubule with 13 protofilaments and 0.1 µm length. So, molecular dynamic simulation of a microtubule will be a very difficult task. Then, it would be better to build a structural mechanic model which has rather similar properties with microtubule. The first and most important step for this process is to obtain the interaction force between tubulins. Therefore, instead of the each tubulin we can consider one sphere with 55 kDa weights that connect to another tubulin with a nonlinear connection such as nonlinear spring. The mechanical model of microtubule was used to calculate Young’s modulus based on finite element method. The Young’s modulus has good agreement with previous works.}, keywords = {Finite element,Microtubules,Nanoproperties,Young’s Modulus}, url = {https://www.ijnnonline.net/article_14571.html}, eprint = {https://www.ijnnonline.net/article_14571_5abd21ff288d13c4888142bc1b6a08e1.pdf} } @article { author = {Nadafan, M. and Malekfar, R. and Dehghani, Z.}, title = {Investigation in to Properties of Polyurethane Closed Cell by High Loading of SiO2 Nanoparticles}, journal = {International Journal of Nanoscience and Nanotechnology}, volume = {11}, number = {3}, pages = {185-192}, year = {2015}, publisher = {Iranian Nanotechnology Society}, issn = {1735-7004}, eissn = {2423-5911}, doi = {}, abstract = {In this research the composition of polyurethane closed cell (PUCC) with two different concentrations of SiO2 nanoparticles (1.0 and 2.0 wt%) have been prepared. Optical microscopy and SEM imaging, watering uptake, FTIR and Raman spectroscopy of the synthesized samples were carried out. The optical microscopy imaging of samples showed differences in the appearance of matrix produced by applying different concentrations of SiO2 nanoparticles (NPs). The mean cell size of the foams decreased with the addition of SiO2 NPs from 0.0 wt% up to 2.0wt%.Variation in the water uptake of specimens is related to the function of SiO2NPs concentrations. The degree of phase separation and the hydrogen bonding index in samples were evaluated in terms of their FTIR spectroscopy data. The apparent and real densities of foams were measured and then total, open and closed porosity of samples were calculated. With elevating the amount of nanoparticles the open porosity of samples almost increased, while the closed and total porosity decreased. The Raman spectra of the synthesized samples were used for evaluating possible interaction between SiO2 NPs and PUCC foams.}, keywords = {FTIR,Polyurethane,Raman spectroscopy,silica}, url = {https://www.ijnnonline.net/article_14572.html}, eprint = {https://www.ijnnonline.net/article_14572_1c2dbe638f1152be87dce51192d825ce.pdf} } @article { author = {Shariati, M. and A. Farzi, G. and Dadrasi, A. and Amiri, M. and Rashidi Meybodi, R.}, title = {An Experimental Study on Toughening Mechanisms of Fillers in Epoxy/ Silica Nanocomposites}, journal = {International Journal of Nanoscience and Nanotechnology}, volume = {11}, number = {3}, pages = {193-199}, year = {2015}, publisher = {Iranian Nanotechnology Society}, issn = {1735-7004}, eissn = {2423-5911}, doi = {}, abstract = {In this paper, a systematic study on the effects of particle size and hybrid of two different size of silica nanoparticles on the toughening mechanisms of bisphenol-A epoxy was conducted. Nanosilica particles with mean diameter of 17 nm and 65 nm were blended into epoxy system. Probable synergy effects of these two nanoparticles on Young’s modulus and yield strength have been investigated. Results showed that the addition of the silica nanoparticles and also increasing content of nanoparticles improved Young’s modulus in all composites. In addition, the particle size did not show a considerable effect on the Young’s modulus and the use of both types of particles in a composite showed negligible synergy effect. On the other hands, results revealed that the addition of these nanoparticles did not change the yield stress of composites significantly. The fracture surfaces of composites were studied by Scanning electron microscopy. It was revealed that in all three series of nanocomposites, crack deflection, crack forking and debonding were the most important mechanisms.}, keywords = {Silica Nanoparticles,Crack deflection,Debonding,Toughening}, url = {https://www.ijnnonline.net/article_14573.html}, eprint = {https://www.ijnnonline.net/article_14573_207fb333383c344cddf989a2319db54c.pdf} } @article { author = {Cheraghian, G. and Khalili Nezhad, S. Sh. and Bazgir, S.}, title = {Improvement of Thermal Stability of Polyacryl amide Solution Used as a Nano-fluid in Enhanced Oil Recovery process by Nanoclay}, journal = {International Journal of Nanoscience and Nanotechnology}, volume = {11}, number = {3}, pages = {201-208}, year = {2015}, publisher = {Iranian Nanotechnology Society}, issn = {1735-7004}, eissn = {2423-5911}, doi = {}, abstract = {Research in nanotechnology in the petroleum industry is advancing rapidly and an enormous progress in the application of nanotechnology in this area is to be expected. In particular, adding nanoparticles to fluids may drastically benefit enhanced oil recovery and improve well drilling, by changing the properties of the fluid, rocks wettability alteration, advanced drag reduction, strengthening the sand consolidation, reducing the interfacial tension and increasing the mobility of the capillary trapped oil. In this study, we focus on roles of clay nano-particles on viscosity of polymer, temperature and salinity of polymer solutions different nanoparticles. The viscosity of these polymer solutions was measured using a rheometer and in each measurement, the shear rate was changed, and the effect of this change on the viscosity was measured. Results showed that increasing temperature on the viscosity of solution plays a positive role when the dispersed clay nanoparticles are present in the solution.}, keywords = {Nanoclay,Polymer Viscosity,Reservoir temperature,Salinity}, url = {https://www.ijnnonline.net/article_14576.html}, eprint = {https://www.ijnnonline.net/article_14576_8c81b1bc2d472158338fb50f4e441171.pdf} } @article { author = {Nikmanesh, S. and Doroodmand, M.M. and Sheikhi, M.H.}, title = {Specific Fast Response CH4 Gas Sensor Based on Metal Oxide, Tungsten Carbide /SnO2Core-Shell Modified Interdigitated Electrode}, journal = {International Journal of Nanoscience and Nanotechnology}, volume = {11}, number = {3}, pages = {209-217}, year = {2015}, publisher = {Iranian Nanotechnology Society}, issn = {1735-7004}, eissn = {2423-5911}, doi = {}, abstract = {In this study, a specific CH4 sensor is fabricated based on interdigitated electrode that modified with core-shell of tungsten carbide/tin oxide (WC/SnO2) nanoparticles by wet chemical method in different percents of carbon and tungsten. The morphology of wet chemical-synthesized WC/SnO2 core-shell was evaluated by different methods such as patterned X-ray diffraction (XRD), and particle size analyzer (PSA). The fabricated sensor is selected as specific nanomaterial for CH4 detection. In the fabricated CH4 sensor, change in resistance of the sensor was considered as the detection system. In this study, figures of merits such as linearity, specificity, response time were also evaluated. No serious interference was evaluated for different foreign gases, introduced to a certain concentration of CH4. The reliability of the fabricated CH4 sensor was evaluated via measuring CH4 in several gaseous samples. A fast response time about 8s and recovery time 11s has obtained from (5.0% WC-doped SnO2).}, keywords = {CH4 gas sensor,SnO2,Core-shell,Fast response time}, url = {https://www.ijnnonline.net/article_14581.html}, eprint = {https://www.ijnnonline.net/article_14581_e5df714fb5ef44e0faf1908535408933.pdf} } @article { author = {Pourfayaz, F. and Iranpour, S. and Shojaei, O.}, title = {Effect of Acid Treatment of Carbon Nanotubes on Their Adsorption Capacities of Benzene and Toluene}, journal = {International Journal of Nanoscience and Nanotechnology}, volume = {11}, number = {3}, pages = {219-224}, year = {2015}, publisher = {Iranian Nanotechnology Society}, issn = {1735-7004}, eissn = {2423-5911}, doi = {}, abstract = {Toluene and benzene were eliminated using multi-walled carbon nanotubes (MWCNTs). In order to investigate influence of acid treatment on the MWCNTs adsorption capacities, the MWCNTs were functionalized by nitric acid (10 M) under reflux conditions for 2 h. Fourier transform infrared (FTIR) and Raman spectroscopy were employed to confirm the formation of functional groups on the nanotubes surface. Specific surface areas of the nanotubes were also measured using the Brunauer–Emmett–Teller (BET) method. Adsorption capacities of the functionalized and unfunctionalized MWCNTs were obtained and then compared with each other. FTIR and Raman spectra proved the formation of functional groups on the MWCNTs surface as a result of this acid treatment. Adsorption capacities measurements revealed that the functionalized MWCNTs have large adsorption capacities of toluene and benzene as compared with the unfunctionalized MWCNTs. This enhancement of adsorption capacities was ascribed to an increase in the specific surface area of the nanotubes due to this acid treatment. }, keywords = {Acid treatment,Carbon nanotubes,Functionalization,Nanoadsorbent}, url = {https://www.ijnnonline.net/article_14582.html}, eprint = {https://www.ijnnonline.net/article_14582_83dea33ac7b76ed64d30ae04f117443a.pdf} }