Journal articles: 'Size and temperature of nanomaterials'

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Goyal, Monika, and B. R. K. Gupta. "Study of shape, size and temperature-dependent elastic properties of nanomaterials." Modern Physics Letters B 33, no. 26 (September 20, 2019): 1950310. http://dx.doi.org/10.1142/s021798491950310x.

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The impact of shape, size and temperature on elastic properties of nanomaterials is studied in this work. We have extended the melting temperature expression for nanostructures formulated by Guisbiers et al. and obtained the expression of elastic moduli and thermal expansivity for nanomaterials. An isobaric Tait equation of state is combined with Guisbiers model and the model so obtained is applied to analyze the shape, size and temperature effect on Young’s modulus and thermal expansivity in nanomaterials. The present computed results are compared with the simulated results and available experimental data. The Young’s modulus is observed to decrease as particle size is reduced while thermal expansivity increases with decrease in the size of nanomaterial. The Young’s modulus shows decrease with increase in temperature and decrement is observed maximum in spherical nanomaterials and minimum in nanofilms (NFs). Rate at which modulus is decreasing is found to increase as particle size is reduced. Good consistency of present predicted results with the available theoretical and experimental data is observed. The present calculated results are thus found consistent with the general trend of variation.

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Arora, Neha, Deepika P. Joshi, and Uma Pachauri. "Size and shape dependent Debye temperature of Nanomaterials." Materials Today: Proceedings 4, no. 9 (2017): 10450–54. http://dx.doi.org/10.1016/j.matpr.2017.06.398.

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Zhou, Xiao-Ye, Bao-Ling Huang, and Tong-Yi Zhang. "Size- and temperature-dependent Young's modulus and size-dependent thermal expansion coefficient of thin films." Physical Chemistry Chemical Physics 18, no. 31 (2016): 21508–17. http://dx.doi.org/10.1039/c6cp03294j.

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Paritskaya, Lyudmila N., Yuri S. Kaganovsky, and V. V. Bogdanov. "Size-Dependent Interdiffusion in Nanomaterials." Solid State Phenomena 101-102 (January 2005): 123–30. http://dx.doi.org/10.4028/www.scientific.net/ssp.101-102.123.

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The phenomenon of low-temperature homogenization (LTH) during interdiffusion is studied under condition a t Dv £ 2 / 1 ) ( (Dv is the bulk diffusion coefficient, a is the lattice parameter) using nano-objects of binary Cu-Ni and Cr-Ni systems compacted from nano-powders and produced by mechanical alloying. Two stages of LTH were detected: at the first stage (t £ 103 s) the volume fraction of solution rapidly grows; at the second stage (t > 103 s) the volume fraction of solutions grows slowly with practically constant average solution concentration. The first stage of LTH correlates with active grain growth caused by small size (l) of structural element and nonequilibrium structure of nano-objects. Obtained results are analyzed theoretically in terms of interdiffusion along migrating GBs due to grain growth at the first stage and DIGM mechanism at the second stage. It is shown that the GB concentration distribution during interdiffusion along migrating GBs and the kinetics of LTH depend on a parameter l/l where 2 / 1 ) / ( b b V sD d l= is the characteristic diffusion length. The mechanisms and criteria of LTH are proposed.

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Zhang, Xianhe, Weiguo Li, Dong Wu, Yong Deng, Jiaxing Shao, Liming Chen, and Daining Fang. "Size and shape dependent melting temperature of metallic nanomaterials." Journal of Physics: Condensed Matter 31, no. 7 (December 31, 2018): 075701. http://dx.doi.org/10.1088/1361-648x/aaf54b.

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RAWAT, KOMAL, and MONIKA GOYAL. "Theoretical study of Specific heat and thermal conductivity variation in nanomaterials." High Temperatures-High Pressures 49, no. 3 (2020): 279–98. http://dx.doi.org/10.32908/hthp.v49.827.

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In the present paper, the authors study the specific heat dependence on shape, size and dimension of the nanomaterials. Using an analytic quantitative model for melting temperature, the expression of specific heat for nanomaterials is deduced. Further, the model is extended to study the shape, size and dimension effect on thermal conductivity of nanoparticles. Phonon scattering term is taken into consideration for calculation of thermal conductivity of nanomaterial to explain the roughness and scattering effect on thermal property. The specific heat is observed to increase from model calculations as size of the nanomaterial decreases. However, the thermal conductivity in nanoparticles is observed to decrease with size decrement of nanoparticle. It is observed that inclusion of phonon scattering term help to better understand the variation in thermal conductivity. The variation in specific heat and thermal conductivity with size is determined for spherical, regular tetrahedral, octahedral nanoparticles, cylindrical and hexagonal nanowires and nanofilms. The results calculated from model are in good consistency with the available experimental and simulated results and help to judge the suitability of the present model.

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Syvolozhskyi, O., I. Ovsiienko, L. Matzui, and T. Len. "The peculiarity of intercalation of carbon nanomaterials containing nanotubes." Bulletin of Taras Shevchenko National University of Kyiv. Series: Physics and Mathematics, no. 3 (2018): 109–12. http://dx.doi.org/10.17721/1812-5409.2018/3.17.

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The possibility of intercalation of carbon nanomaterials containing carbon nanotubes is considered. Carbon nanomaterials containing multiwall carbon nanotubes of different structure and size were intercalated by iodine chloride with use standard one-temperature method. As it is shown by electron microscopic studies, after intercalation the size and morphology of carbon nanotubes are essentially changed. The diameter of carbon nanotubes increases two times more. This increase in diameter is due to the penetration of iodine chloride molecules between layers of a multiwall carbon nanotubes or into the inner cavity of nanotubes. According to X-ray diffraction, the position of the most intense band in the 00ldiffractogram of carbon nanomaterial moves to the region of smaller angles after intercalation. The exact angular position of the 00l-band corresponds to reflection from the intercalate layers for the third stage compound. The hysteresis in the temperature dependence of resistivity for compacted intercalated carbon nanomaterial is observed. This hysteresis is explained by the change of the charge carriers effective relaxation time at the scattering on the phonons of the graphite layer and the intercalate layer. Such change occurs at the phase transitions in the intercalate layers from an ordered "quasicrystalline state" to an unordered "quasiliquid" state.

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Zhang, Yi. "Review of Physical Properties and Preparation of Nano-Superconducting Materials." Advanced Materials Research 816-817 (September 2013): 65–69. http://dx.doi.org/10.4028/www.scientific.net/amr.816-817.65.

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New materials play an important part in today high and new technology.Superconducting nanomaterial has become the most vibrant in new material research due to its unique physical and chemical properties. This paper focuses on how small-size effect affects superconducting transition temperature, and summarizes the concrete preparation methods of superconducting nanomaterials, hoping to provide a reference for material researchers.

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SINGH, MADAN, and MAHIPAL SINGH. "Impact of size and temperature on thermal expansion of nanomaterials." Pramana 84, no. 4 (November 20, 2014): 609–19. http://dx.doi.org/10.1007/s12043-014-0844-0.

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Lu, H. M. "Size Dependent Interface Energy of Nanomaterials." Solid State Phenomena 155 (May 2009): 3–70. http://dx.doi.org/10.4028/www.scientific.net/ssp.155.3.

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The reduction of size of the low dimensional materials leads to a dramatic increase of surface-to-volume ratio. The properties of a solid are essentially controlled by related surface/interface energies. Although such changes are believed to dominate behaviors of nanoscale structures, little experience or intuition for the expected phenomena, especially the size dependent properties and their practical implications, are modeled. In this contribution, the classic thermodynamics as a powerful traditional theoretical tool is used to model different bulk interface energies and the corresponding size dependences where emphasis on the size dependence of interface energy is given, which is induced by size dependence of coherent energy of atoms within nanocrystals. It is found that solid-vapor interface energy, liquid-vapor interface energy, solid-liquid interface energy, and solid-solid interface energy of nanoparticles and thin films fall as their diameters or thickness decrease to several nanometers while the solid-vapor interface energy ratio between different facets is size-independent and is equal to the corresponding bulk ratio. The predictions of the established analytic models without any free parameter, such as size and temperature dependences of these four kinds of interface energies, are in agreement with the experimental or other theoretical results of different kinds of low dimensional materials with different chemical bond natures.

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Tepale, Nancy, Victor V. A. Fernández-Escamilla, Carlos Álvarez, Eric Flores-Aquino, Valeria J. González-Coronel, Daniel Cruz, and Manuel Sánchez-Cantú. "Morphological and Rheological Characterization of Gold Nanoparticles Synthesized Using Pluronic P103 as Soft Template." Journal of Nanomaterials 2016 (2016): 1–11. http://dx.doi.org/10.1155/2016/7494075.

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The synthesis of gold nanoparticles (Au-NPs), using Pluronic®P103 as soft template to design tuned hybrid gold/P103 nanomaterials, is reported here. The effect of the concentration of P103 and the synthesis temperature on the growth, size, and morphology of Au-NPs were studied. The rheological properties of these hybrid nanomaterials at different measured temperatures were studied as well. By increasing the concentration of P103, the micelles progressively grew due to an increase in the number of surface cavities. These cavities came together causing large nucleation centers and developing larger Au-NPs. The synthesis temperature was varied to induce significant dehydration of the P103 micelles. Below the cloud point temperature micelles underwent distinct changes related to spherical-to-polymer-like micelles transitions. Two nanostructures were formed: (1) small Au-NPs arranged on the surface of micelles, which acted as soft templates, and (2) large and independent Au-NPs. Above the cloud point temperature, Au-NPs were related to the shape and size of the P103 micellar aggregates. Rheological measurements showed that viscosity was sensitive to the concentration of P103. Also, it was demonstrated that synthesis temperature had a considerable influence on viscosity of the produced nanomaterials.

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Xanthopoulou, Thoda, Boukos, Krishnamurthy, Dey, Roslyakov, Vekinis, Chroneos, and Levashov. "Effects of Precursor Concentration in Solvent and Nanomaterials Room Temperature Aging on the Growth Morphology and Surface Characteristics of Ni–NiO Nanocatalysts Produced by Dendrites Combustion during SCS." Applied Sciences 9, no. 22 (November 15, 2019): 4925. http://dx.doi.org/10.3390/app9224925.

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The morphology and surface characteristics of SCS(Solution Combustion Synthesis)-derived Ni–NiO nanocatalysts were studied. The ΤΕΜ results highlighted that the nanomaterial’s microstructure was modified by changing the reactants’ concentrations. The dendrites’ growth conditions were the main factors responsible for the observed changes in the nanomaterials’ crystallite size. Infrared camera measurements demonstrated a new type of combustion through dendrites. The XPS analysis revealed that the NiO structure resulted in the bridging of the oxygen structure that acted as an inhibitor of hydrogen adsorption on the catalytic surface and, consequently, the activity reduction. The RF-IGC indicated three different kinds of active sites with different energies of adsorption on the fresh catalyst and only one type on the aged catalyst. Aging of the nanomaterial was associated with changes in the microstructure of its surface by a gradual change in the chemical composition of the active centers.

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FUJITANI, YUJI, and TAKAHIRO KOBAYASHI. "MEASUREMENT OF AEROSOLS IN ENGINEERED NANOMATERIALS FACTORIES FOR RISK ASSESSMENT." Nano 03, no. 04 (August 2008): 245–49. http://dx.doi.org/10.1142/s179329200800109x.

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In relation to potential health risks, there is little available information on exposure to aerosols containing nanometer-size particles in work environments in factories producing engineered nanomaterials. We measured the concentrations and size distributions of particles of nanometer-sized to coarse-sized particles in an engineered carbon nanomaterial factory and a titanium dioxide factory. In addition, particles were collected with a quartz fiber filter in the engineered carbon nanomaterial factory, and their morphology was examined by scanning electron microscopy and their carbon composition was examined with a carbon analyzer. In the carbon nanomaterial factory, the particle number increased to more than 105 cm-3 when a vacuum cleaner was used to clean the inside of the producing device, and the particle number increased for particles with a diameter of about 100 nm compared with the background. This is the only case an increase in particle numbers is observed during this measurement. The emitted particles appear to consist of agglomerates of carbon nanomaterial particles smaller than 100 nm. The major fraction was the EC3 fraction (EC: elemental carbon; combustion at 800°C in a 98:2 He / O 2 atmosphere), which is a minor fraction in diesel engine particulate matter. This suggests that the combustion temperature can be used to differentiate atmospheric particulate matter from engineered carbon material. Personal sampling conducted in addition to stationary measurements in the titanium dioxide factory indicated that stationary measurements can be used to generate representative data on the basis of the particle number but not the particle mass.

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Zhong, Zhi-Cheng, Zhao-Jun Jing, Kui-Yuan Liu, and Tong Liu. "Acetylene Sensing by ZnO/TiO2 Nanoparticles." Journal of Nanoelectronics and Optoelectronics 15, no. 1 (January 1, 2020): 41–45. http://dx.doi.org/10.1166/jno.2020.2726.

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We adopted the sol–gel and hydrothermal methods to prepare the TiO2 nanomaterials doped with ZnO. We adopted X-ray diffraction, scanning electron microscopy, and the Brunauer–Emmett–Teller method to investigate the materials’ structures and morphologies. The results showed that the prepared TiO2 nanomaterials had uniform size and good dispersibility. Gas sensors were fabricated and their performances in acetylene sensing were assessed. The results show that the sensor prepared with the ZnO/TiO2 nanomaterial doped with 10 wt% ZnO gave fast response and recovery times for acetylene gas at different concentrations. When the operating temperature was 280 °C, the gas sensor detected 200 ppm acetylene gas with a response sensitivity of 9.9, a response time of 5 s, and a recovery time of 2 s.

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Kan, Hong Min, Miao Sun, Ning Zhang, Xiao Yang Wang, and Hai Bo Long. "Nanomaterials for Hydrogen Storage." Applied Mechanics and Materials 587-589 (July 2014): 216–19. http://dx.doi.org/10.4028/www.scientific.net/amm.587-589.216.

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The nanocrystalline materials for hydrogen storage offer a breakthrough in prospects for practical applications. Their excellent properties are from the combined engineering of many factors: alloy composition, surface properties, microstructure, grain size and others. Nanoengineering can speed up the kinetics, lower the enthalpy of formation and reduce the temperature of releasing hydrogen. The main focus is on the nanostructured metal hydrides, preparing nanograined materials and the effects of nanomaterials on the hydrogen storage properties in this review.

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KUMAR, RAGHUVESH, GEETA SHARMA, and MUNISH KUMAR. "SIZE AND TEMPERATURE EFFECT ON THERMAL EXPANSION COEFFICIENT AND LATTICE PARAMETER OF NANOMATERIALS." Modern Physics Letters B 27, no. 25 (September 23, 2013): 1350180. http://dx.doi.org/10.1142/s0217984913501807.

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A simple theoretical model is developed to study the effect of size and temperature on the coefficient of thermal expansion and lattice parameter of nanomaterials. We have studied the size dependence of thermal expansion coefficient of Pb , Ag and Zn in different shape viz. spherical, nanowire and nanofilm. A good agreement between theory and available experimental data confirmed the model predictions. We have used these results to study the temperature dependence of lattice parameter for different size and also included the results of bulk materials. The temperature dependence of lattice parameter of Zn nanowire and Ag nanowire are found to present a good agreement with the experimental data. We have also computed the temperature and size dependence of lattice parameter of Se and Pb for different shape viz. spherical, nanowire and nanofilm. The results are discussed in the light of recent research on nanomaterials.

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Chen, Ying, Peng Liu, and Zhi Wu Yu. "Research on the Sol-Gel Method of Preparing Ternary Nano SiO₂-Al₂O₃-TiO₂ Materials." Key Engineering Materials 609-610 (April 2014): 281–87. http://dx.doi.org/10.4028/www.scientific.net/kem.609-610.281.

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Tetraethyl orthosilicate (TEOS), butyl titanate [Ti (OBu)4] and aluminium isopropoxide were used as molecular precursor of ternary nanoSiO2-Al2O3-TiO2 materials. The influences of temperature and the dosage of compounds on the characteristic of ternary nanomaterials were investigated. Transmission electron microscopy (TEM), x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were employed to investigate the characteristics of the nanomaterials synthesized by the sol-gel method. In addition, the adsorption of nanomaterials for different kinds of surfactants was also studied. Results revealed that the influences of temperature, compounds dosages and water on the size of ternary nanomaterials had a significant impact. With the increase of ammonia dosage, the concentration of the OH- ion became higer, and system showed a faster reaction rate. The higer temperature of the system was, the larger size of the ternary nanomaterials was. Moreover, the higer tempreature woule also lead to divide into layer and precipitate. Optimal parameters can be chosen to prepare monodispersed ternary nanoSiO2-Al2O3-TiO2 materials. Results also showed that the surface characteristic of ternary nanoSiO2-Al2O3-TiO2 particles differed from nanosilica, which manifested in forms of the adsorption dosage of surfactants.

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Basina, Georgia, Hafsa Khurshid, Nikolaos Tzitzios, George Hadjipanayis, and Vasileios Tzitzios. "Facile Organometallic Synthesis of Fe-Based Nanomaterials by Hot Injection Reaction." Nanomaterials 11, no. 5 (April 28, 2021): 1141. http://dx.doi.org/10.3390/nano11051141.

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Fe-based colloids with a core/shell structure consisting of metallic iron and iron oxide were synthesized by a facile hot injection reaction of iron pentacarbonyl in a multi-surfactant mixture. The size of the colloidal particles was affected by the reaction temperature and the results demonstrated that their stability against complete oxidation related to their size. The crystal structure and the morphology were identified by powder X-ray diffraction and transmission electron microscopy, while the magnetic properties were studied at room temperature with a vibrating sample magnetometer. The injection temperature plays a very crucial role and higher temperatures enhance the stability and the resistance against oxidation. For the case of injection at 315 °C, the nanoparticles had around a 10 nm mean diameter and revealed 132 emu/g. Remarkably, a stable dispersion was created due to the colloids’ surface functionalization in a nonpolar solvent.

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Kumar, Raghuvesh, Sandhya Bhatt, and Munish Kumar. "Size and shape dependence of Debye temperature and Raman frequency of nanomaterials." Modern Physics Letters B 29, no. 04 (February 10, 2015): 1550004. http://dx.doi.org/10.1142/s0217984915500049.

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A simple theoretical model is developed to study the size and shape dependence of Debye temperature and Raman frequency of nanomaterial. We have studied the effect of size and shape on Debye temperature of nanocrystalline Fe , Co , Al and Ag . The model is extended to study the effect of size and shape on the Raman frequency of nanocrystalline SnO 2, CeO 2 and CdSe . The results obtained are compared with the available experimental data. A good agreement between the theory and experimental data supports the validity of the model developed. We also report the results for nanowire and nanofilm in the absence of experimental data, which may help the researchers engaged in the experimental studies.

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Piacenza, Elena, Alessandro Presentato, Marta Bardelli, Silvia Lampis, Giovanni Vallini, and Raymond J. Turner. "Influence of Bacterial Physiology on Processing of Selenite, Biogenesis of Nanomaterials and Their Thermodynamic Stability." Molecules 24, no. 14 (July 11, 2019): 2532. http://dx.doi.org/10.3390/molecules24142532.

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We explored how Ochrobactrum sp. MPV1 can convert up to 2.5 mM selenite within 120 h, surviving the challenge posed by high oxyanion concentrations. The data show that thiol-based biotic chemical reaction(s) occur upon bacterial exposure to low selenite concentrations, whereas enzymatic systems account for oxyanion removal when 2 mM oxyanion is exceeded. The selenite bioprocessing produces selenium nanomaterials, whose size and morphology depend on the bacterial physiology. Selenium nanoparticles were always produced by MPV1 cells, featuring an average diameter ranging between 90 and 140 nm, which we conclude constitutes the thermodynamic stability range for these nanostructures. Alternatively, selenium nanorods were observed for bacterial cells exposed to high selenite concentration or under controlled metabolism. Biogenic nanomaterials were enclosed by an organic material in part composed of amphiphilic biomolecules, which could form nanosized structures independently. Bacterial physiology influences the surface charge characterizing the organic material, suggesting its diverse biomolecular composition and its involvement in the tuning of the nanomaterial morphology. Finally, the organic material is in thermodynamic equilibrium with nanomaterials and responsible for their electrosteric stabilization, as changes in the temperature slightly influence the stability of biogenic compared to chemogenic nanomaterials.

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Kumar, R., G. Sharma, and M. Kumar. "Effect of Size and Shape on the Vibrational and Thermodynamic Properties of Nanomaterials." Journal of Thermodynamics 2013 (September 19, 2013): 1–5. http://dx.doi.org/10.1155/2013/328051.

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A simple theoretical model is developed to study the size and shape dependence of vibrational and thermodynamic properties of nanomaterials. To show the real connection with the nanomaterials we have studied Debye temperature, Debye frequency, melting entropy, and enthalpy in different shapes, namely, spherical, nanowire, and nanofilm of -Fe, Sn, Ag, and In. The results obtained are compared with the experimental data. A good agreement between the model predictions and the experimental data supports the theory developed in the present paper.

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Bhatt, Sandhya, Raghuvesh Kumar, and Munish Kumar. "Specific heat and thermal conductivity of nanomaterials." Modern Physics Letters B 31, no. 02 (January 20, 2017): 1750011. http://dx.doi.org/10.1142/s0217984917500117.

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A model is proposed to study the size and shape effects on specific heat and thermal conductivity of nanomaterials. The formulation developed for specific heat is based on the basic concept of cohesive energy and melting temperature. The specific heat of Ag and Au nanoparticles is reported and the effect of size and shape has been studied. We observed that specific heat increases with the reduction of particle size having maximum shape effect for spherical nanoparticle. To provide a more critical test, we extended our model to study the thermal conductivity and used it for the study of Si, diamond, Cu, Ni, Ar, ZrO2, BaTiO3 and SrTiO3 nanomaterials. A significant reduction is found in the thermal conductivity for nanomaterials by decreasing the size. The model predictions are consistent with the available experimental and simulation results. This demonstrates the suitability of the model proposed in this paper.

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Bednarčík, J., R. Nicula, Karel Saksl, M. Stir, and E. Burkel. "Microstructure Evolution during Thermal Processing : Insight from In-Situ Time-Resolved Synchrotron Radiation Experiments." Materials Science Forum 550 (July 2007): 607–12. http://dx.doi.org/10.4028/www.scientific.net/msf.550.607.

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The magnetic, mechanical or chemical properties of nanocrystalline materials strongly differ from the ones of their coarse-grained counterparts. Moreover, significant changes of the phase diagrams were already evidenced for nanostructured alloys. Thermal processing with or without applied pressure controls the microstructure development at the nanometer scale and thus essentially decides upon the final nanomaterial behaviour and properties. A common route for the synthesis of metallic nanomaterials is the devitrification of amorphous precursors obtained via non-equilibrium processing, e.g. by rapid solidification or high-energy ball-milling. Time-resolved in-situ X-ray diffraction experiments may nowadays be performed at high-brilliance synchrotron radiation sources for a variety of temperature-pressure conditions. The temperature-time evolution of the grain-size distribution and microstrain can be monitored in detail at specimen-relevant scales. Together with local information from electron microscopy and chemical analysis, in-situ X-ray experiments offer a complete set of tools for engineering of the microstructure in nanomaterials. The effect of individual processing steps can be distinguished clearly and further tuned. An example is provided, concerning the high-temperature microstructure development in Co-rich soft magnetic nanostructured alloys.

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Solozhenko, Vladimir. "Creation of nanomaterials by extreme pressure-temperature conditions." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C193. http://dx.doi.org/10.1107/s2053273314098064.

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Nanomaterials in the form of zero-, one- and two-dimensional nanostructures make a high-impact background for both science and technology. At the same time, the synthesis of bulk nanostructured materials remains the least-explored but challenging domain that allows combining the desired physical, chemical and mechanical properties and gives rise to nanoelectronics, nanomechanics, band-gap engineering, etc. The common methods of soft chemistry allow obtaining nanoparticles whose direct sintering unavoidably leads to the grain growth and lost of nanostructure. The extreme pressure is a parameter of choice to suppress the self-diffusion responsible for high-temperature recrystallization. The bulk nanostructured materials shows the superior fracture toughness and extremely high hardness as compared to corresponding microcrystalline bulks. The remarkable changes in physical and mechanical properties, however, do not affect the original thermal and chemical stability of the phase(s). All this opens unique opportunities for high-temperature superabrasive and electronic applications of such materials. Finally, the extreme pressure-temperature conditions are powerful and promising tool for grain-size control during direct solid-state phase transformations. The simultaneous variation of pressure and temperature makes possible to combine different nucleation, growth and aggregation regimes with high flexibility, and, therefore, to go deep into nanoscale engineering.

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Goltsev, Anatoliy, Mykola Bondarovych, Natalya Babenko, Yuliya Gaevska, Tatiana Dubrava, and Maksim Ostankov. "Use of Nanomaterials in Cryobiology and Cryomedicine." Problems of Cryobiology and Cryomedicine 30, no. 4 (December 17, 2020): 313–30. http://dx.doi.org/10.15407/cryo30.04.313.

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The review considers the possibility of using modern nanotechnological developments aimed to achieve alternative cryobiological goals. On the one hand, the use of nanomaterials will increase the functional value of thawed cells due to such unique characteristics of nanoparticles as size, shape, surface charge, chemical composition, etc. Nanomaterials can be used as nanocontainers for impermeable cryoprotective agents (CPAs) and cause significant changes in crystal formation, thermal conductivity and other properties of cells, tissues and organs, that increases the efficiency of their cryopreservation. On the other hand, the combined use of nanomaterials and low-temperature freezing factors is considered a promising method of destruction of pathologically altered cells and tissues, as it minimizes the risk of recurrence of oncopathology after insufficient freezing-out of the tumor site.

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S, Priyanka, Dhachanamoorthi N, and Nandhin M. "Annealed effects of poly- o- toluidine (POT) nanomaterial at different temperatures." Nanoscale Reports 3, no. 1 (April 30, 2020): 34–38. http://dx.doi.org/10.26524/nr.3.7.

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Poly-O-Toluidine (POT) nanomaterials were prepared by using chemical oxidative polymerization method. The polymerization process was carried out using the monomer o- toluidine (1M), ammonium peroxydisulphate (APS) (0.5M) as oxidant and the dopant sulphuric acid (3M). The resultant polymer materials are heat treated at various temperatures such as 200°C, and 400°C. The prepared POT materials are characterized by using different Spectroscopic techniques, Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet Visible (UV-VIS) Spectrometry, Particle Size Analyser (PSA), and biological application like Anti-Bacterial activities. The FTIR study shows the various functional groups in POT. The optical properties of prepared polymer material band gap, electron transition are calculated by using UV-VIS techniques. The PSA studies are revealed that the measurement of the size distribution of individual particles in a POT nanomaterials. The antibacterial activity of the POT nanomaterials are indicates that the several microorganisms. These POT nanomaterials are used to examines that the Chemical, optical, size of the nanomaterials and antibacterial activity for different Bactria.

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Brewer, Erik, Jason Coleman, and Anthony Lowman. "Emerging Technologies of Polymeric Nanoparticles in Cancer Drug Delivery." Journal of Nanomaterials 2011 (2011): 1–10. http://dx.doi.org/10.1155/2011/408675.

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Polymeric nanomaterials have the potential to improve upon present chemotherapy delivery methods. They successfully reduce side effects while increasing dosage, increase residence time in the body, offer a sustained and tunable release, and have the ability to deliver multiple drugs in one carrier. However, traditional nanomaterial formulations have not produced highly therapeutic formulations to date due to their passive delivery methods and lack of rapid drug release at their intended site. In this paper, we have focused on a few “smart” technologies that further enhance the benefits of typical nanomaterials. Temperature and pH-responsive drug delivery devices were reviewed as methods for triggering release of encapsulating drugs, while aptamer and ligand conjugation were discussed as methods for targeted and intracellular delivery, with emphases onin vitroandin vivoworks for each method.

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Merlin, I., C. Vedhi, K. Muthu, and A. Syed Mohamed. "Influence of pH and Temperature on The Structure and Size of Tin Oxide Nanoparticles." Volume 4,Issue 5,2018 4, no. 5 (December 25, 2018): 564–66. http://dx.doi.org/10.30799/jnst.182.18040527.

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A systematic study on the preparation of tin oxide nanoparticles using the precipitation method has been conducted. The preparation of nanomaterials was by varying reaction parameters such as pH and temperature. The tin oxide nanoparticles were characterized by using AFM, SEM, XRD and UV-Vis. Particle size was obtained using XRD studies the value is 28.8 nm, 35.2 nm, 30.8 nm and 33.8 nm. It was found that the alteration of pH and temperature changes the particle size.

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Xu, J. Y., X. C. Lei, R. Yang, and Z. Z. Fan. "In Situ Formation of Carbon Nanomaterials on Bulk Metallic Materials." Journal of Nanomaterials 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/690630.

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Carbon nanomaterials were synthesized in situ on bulk 316L stainless steel, pure cobalt, and pure nickel by hybrid surface mechanical attrition treatment (SMAT). The microstructures of the treated samples and the resulted carbon nanomaterials were investigated by SEM and TEM characterizations. Different substrates resulted in different morphologies of products. The diameter of carbon nanomaterials is related to the size of the nanograins on the surface layer of substrates. The possible growth mechanism was discussed. Effects of the main parameters of the synthesis, including the carbon source and gas reactant composition, hydrogen, and the reaction temperature, were studied. Using hybrid SMAT is proved to be an effective way to synthesize carbon nanomaterials in situ on surfaces of metallic materials.

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Jana, Subhra. "Advances in nanoscale alloys and intermetallics: low temperature solution chemistry synthesis and application in catalysis." Dalton Transactions 44, no. 43 (2015): 18692–717. http://dx.doi.org/10.1039/c5dt03699b.

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Advances made in the synthesis of size and shape-tunable nanoscale alloys and intermetallics using the low-temperature solution-phase synthesis approaches have been discussed in this perspective, keeping a focus on the utility of these nanomaterials in understanding the catalysis.

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Chhabra, Hina, and Munish Kumar. "Modeling for size and shape dependence of critical temperature for different type of nanomaterials." Journal of Physics and Chemistry of Solids 135 (December 2019): 109075. http://dx.doi.org/10.1016/j.jpcs.2019.109075.

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Islam, M. S., J. Kurawaki, Y. Kusumoto, M. Abdulla-Al-Mamun, and M. Z. Bin Mukhlish. "Hydrothermal Novel Synthesis of Neck-structured Hyperthermia-suitable Magnetic (Fe₃O₄, γ-Fe₂O₃ and α-Fe₂O₃) Nanoparticles." Journal of Scientific Research 4, no. 1 (December 24, 2011): 99. http://dx.doi.org/10.3329/jsr.v4i1.8727.

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Novel neck-structured Fe3O4, γ-Fe2O3 and α-Fe2O3 magnetic nanoparticles were successfully prepared by a modified hydrothermal method. Ferrous chloride tetrahydrate was solely used as a precursor for the novel nanomaterials. The X-ray diffractometric study revealed the purity of the nanomaterials thus synthesized. All of the products were characterized using a field-emission scanning electron microscope (FE-SEM) and a transmission electron microscope (TEM) for the particle size and morphology. Neck-structured particle morphology was observed for the first time in all of iron oxides with magnetic properties. The particle size observed was 50–60 nm. The synthesized nanomaterials showed excellent magnetization values when magnetic hysteresis loops were measured using a superconducting quantum interference device (SQUID). Moreover, the as-prepared magnetic nanoparticles suspensions showed significant temperature increments under an AC (alternating current) magnetic-field induction condition at room temperature which indicates the hyperthermia feasibility. Keywords: Magnetic materials; Neck-structured; Hyperthermia; Heat dissipation. © 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v4i1.8727J. Sci. Res. 4 (1), 99-107 (2012)

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Shen, Xinchun, Xiaoqun Mo, Robyn Moore, Shawnalea J. Frazier, Takeo Iwamoto, John M. Tomich, and Xiuzhi Susan Sun. "Adhesion and Structure Properties of Protein Nanomaterials Containing Hydrophobic and Charged Amino Acids." Journal of Nanoscience and Nanotechnology 6, no. 3 (March 1, 2006): 837–44. http://dx.doi.org/10.1166/jnn.2006.126.

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Protein polymers are being used or considered for biobased adhesives and coating materials. Most adhesives derived from macro protein molecules work through receptors or cross-links to bring about adhesion. The adhesion mechanism of protein polymers would lead to better understanding of adhesives and the discovery of new practical properties of protein polymers at both nano- and macro-scales. The objective of this research work was to study adhesion properties of protein polymers at nanoscale (a peptide adhesive with nanometer-scale units that range in size of several nanometers, defined as protein nanomaterial). Seven protein nanomaterial samples with different degrees of adhesive strength were designed and synthesized using solid phase chemistries. All protein nanomaterials contain a common hydrophobic core flanked by charged amino acid sequences. The adhesion properties of the protein nanomaterials were investigated at different pH values and curing temperatures. The protein nanomaterials self aggregate and interact with the wood surface. The protein nanomaterial KKK-FLIVIGSII-KKK identified in this study had high adhesive strength toward wood. It had the highest shear strength at pH 12, with an amino acid sequence that was very hydrophobic and uncharged. This protein nanomaterial underwent structural analyses using circular dichroism, laser-Fourier transform infrared, and laser desorption mass spectrometry. At pH 12 this peptide adopted a pH-induced beta-like conformation. Adhesive strength reflects contributions of both hydrogen bonding and van der Waals interactions. Ionic and covalent bonds do not appear to be significant factors for adhesion in this study.

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Yang, Shuangxia, Lianying Wang, Shuang Yue, Yanluo Lu, Jing He, and Dongye Zhao. "Influence of reduction temperature on composition, particle size, and magnetic properties of CoFe alloy nanomaterials derived from layered double hydroxide precursors." Dalton Trans. 43, no. 22 (2014): 8254–60. http://dx.doi.org/10.1039/c4dt00137k.

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Lu, Shaozhe, Jiahua Zhang, Jishen Zhang, E. Shulin, Haifeng Zhao, and Yongshi Luo. "Laser Spectroscopy of GdPO4 · nH2O:Eu Nanomaterials." Journal of Nanoscience and Nanotechnology 16, no. 4 (April 1, 2016): 3613–16. http://dx.doi.org/10.1166/jnn.2016.11835.

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One-dimensional GdPO4 · nH2O:Eu nanowires and nanorods of different sizes and the same structure were synthesized by hydrothermal method. Nanowire and nanorods had width and length of about 10 nm/50 nm and 80 nm/1 μm, respectively. Adjusting reaction system PH value by adding alkali metal NaOH, the size and shape of the product can be tuned. The high resolution spectra, excitation spectra, and laser selective excitation spectra at low temperature were determined. Nanorod compared with nanowire, photoluminescence was enhanced, and the excitation spectrum and laser selective excitation spectra were broadened. These results suggest that Eu3+ in GdPO4 · nH2O nanorod and nanowire were located in different local environments.

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Zhang, Qiang, Zhenyin Hai, Jie Wang, Aoqun Jian, Qianqian Duan, Jianlong Ji, Wendong Zhang, and Shengbo Sang. "Synthesis and Characterization of C-TiO2 Nanomaterials Via Carbon Assistance Method." Current Nanoscience 15, no. 3 (February 19, 2019): 260–66. http://dx.doi.org/10.2174/1872212112666180628152321.

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Background: With the increasing serious problem of water environment pollution, it is a hot spot to study the high efficient sewage treatment method. Owning to the photosensitization of carbon nanomaterials, carbon doped TiO2 (C-TiO2) has higher photocatalytic activity. Method: Here, we proposed a new method, carbon-assisted method, to prepare C-TiO2 nanomaterials. We first used degreasing cotton as a dispersant to fully absorb the TiCl4 sol. Results: After high-temperature calcination, C-TiO2nanomaterials were obtained. Characterizations results showed that the high specific surface area C-TiO2 nanomaterials in the size of about 50 nm showed a broader light absorption and narrower bandgap spectrum than P25 (commercial TiO2 nanoparticles). Conclusion: The C-TiO2 nanomaterials showed stronger photocatalytic ability than P25.

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Aydin, Cihat. "Tin Oxide Based Nano Electroceramics Obtained from Sol–Gel Process: The Modified of the Structural and Opto-Electrical Properties with the Al Doping." Journal of Nanoelectronics and Optoelectronics 13, no. 10 (October 1, 2018): 1460–67. http://dx.doi.org/10.1166/jno.2018.2446.

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Nano electroceramic samples of undoped and Al doped SnO2 were synthesized by the sol–gel calcination process. The structural, morphological, electrical and optical properties of samples were characterized. X-ray diffraction analysis results confirm that all of the synthesized nanopowders are polycrystalline with a tetragonal structure. The crystallite size values of the prepared nanocomposites were calculated in the range of 21.32–34.33 nm. The values of crystallite size indicate that the prepared powders have nanostructure. The grain size and morphological parameters of the undoped and Al-doped SnO2 nanopowders calculated. AFM measurements suggest that Al dopants ratio could be an effect to control surface parameters of the SnO2 nanomaterials. The optical band gap (Eg) of prepared nanomaterials were calculated using Tauc plot method for the various atomic ratios of Al. The calculated Eg values for samples are found to be in the range from 3.51 to 3.69 eV. The electrical conductivity of undoped and Al doped Tin oxide nanopowders were carried out at the temperature range from 290 to 420 K. It demonstrates that the electrical conductivity at room temperature and the activation energy of samples increase with the Al doping. The obtained results suggest that the structural, morphological, optical and electrical properties of SnO2 based nanomaterials can be controlled and changed with Al content.

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Yu, Li Yan, Li Na Sui, and Zuo Lin Cui. "Synthesis of Carbon Nanofibers: A Catalyst Derived from Cupric Carbonate Basic during Acetylene Decomposition." Materials Science Forum 610-613 (January 2009): 579–84. http://dx.doi.org/10.4028/www.scientific.net/msf.610-613.579.

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Two types of helical and straight carbon nanofibers, have been synthesized by the decomposition of acetylene using cupric carbonate basic as catalyst precursor at low temperature. The obtained carbon nanomaterials were characterized by transmission electron microscope, scanning electron microscope, and X-ray power diffraction. The size of the catalyst nanoparticles remaining inside the resultant nanofibers was determined. The carbon nanofiber diameters, ranging from 30 to 400 nm, closely correlated with the size of the catalytic nanoparticle. The growth mechanism of carbon nanomaterials was also studied. The nanocopper particle size had a considerable effect on the morphology of carbon nanofibers. The helical carbon nanofibers with a symmetric growth mode were synthesized with the nanocopper catalyst particles having a grain size less than 50 nm. When the average catalyst particle size determined was around 50–300 nm, the straight carbon nanofibers were obtained dominantly.

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Sarwar, Amna, Jin Wang, Muhammad Saqib Khan, Umar Farooq, Nadia Riaz, Abdul Nazir, Qaisar Mahmood, et al. "Iron Oxide (Fe3O4)-Supported SiO2 Magnetic Nanocomposites for Efficient Adsorption of Fluoride from Drinking Water: Synthesis, Characterization, and Adsorption Isotherm Analysis." Water 13, no. 11 (May 27, 2021): 1514. http://dx.doi.org/10.3390/w13111514.

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This research work reports the magnetic adsorption of fluoride from drinking water through silica-coated Fe3O4 nanoparticles. Chemical precipitation and wet impregnation methods were employed to synthesize the magnetic nanomaterials. Moreover, the synthesized nanomaterials were characterized for physicochemical properties through scanning electron microscopy, Fourier-transform infrared spectroscopy, and X-ray powder diffraction. Screening studies were conducted to select the best iron oxide loading (0.0–1.5 wt%) and calcination temperature (300–500 °C). The best selected nanomaterial (0.5Fe-Si-500) showed a homogenous FeO distribution with a 23.79 nm crystallite size. Moreover, the optimized reaction parameters were: 10 min of contact time, 0.03 g L−1 adsorbent dose, and 10 mg L−1 fluoride (F−) concentration. Adsorption data were fitted to the Langmuir and Freundlich isotherm models. The Qm and KF (the maximum adsorption capacities) values were 5.5991 mg g−1 and 1.869 L g−1 respectively. Furthermore, accelerated adsorption with shorter contact times and high adsorption capacity at working pH was among the outcomes of this research work.

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Efremova, Maria V., Yulia A. Nalench, Eirini Myrovali, Anastasiia S. Garanina, Ivan S. Grebennikov, Polina K. Gifer, Maxim A. Abakumov, et al. "Size-selected Fe3O4–Au hybrid nanoparticles for improved magnetism-based theranostics." Beilstein Journal of Nanotechnology 9 (October 16, 2018): 2684–99. http://dx.doi.org/10.3762/bjnano.9.251.

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Size-selected Fe3O4–Au hybrid nanoparticles with diameters of 6–44 nm (Fe3O4) and 3–11 nm (Au) were prepared by high temperature, wet chemical synthesis. High-quality Fe3O4 nanocrystals with bulk-like magnetic behavior were obtained as confirmed by the presence of the Verwey transition. The 25 nm diameter Fe3O4–Au hybrid nanomaterial sample (in aqueous and agarose phantom systems) showed the best characteristics for application as contrast agents in magnetic resonance imaging and for local heating using magnetic particle hyperthermia. Due to the octahedral shape and the large saturation magnetization of the magnetite particles, we obtained an extraordinarily high r 2-relaxivity of 495 mM−1·s−1 along with a specific loss power of 617 W·gFe −1 and 327 W·gFe −1 for hyperthermia in aqueous and agarose systems, respectively. The functional in vitro hyperthermia test for the 4T1 mouse breast cancer cell line demonstrated 80% and 100% cell death for immediate exposure and after precultivation of the cells for 6 h with 25 nm Fe3O4–Au hybrid nanomaterials, respectively. This confirms that the improved magnetic properties of the bifunctional particles present a next step in magnetic-particle-based theranostics.

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Puspita, Dewi Azzahra, Lutfi Rohman, Artoto Arkundato, and Ratna Dewi Syarifah. "Phase Transition of Fe₃O₄ Magnetic Material Based on Observation of Curie Temperature and Hysteresis Curve: Micromagnetic Simulation Study." European Journal of Applied Physics 3, no. 2 (March 23, 2021): 3–10. http://dx.doi.org/10.24018/ejphysics.2021.3.2.45.

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Phase transition yesng happens to the material magnetite (Fe3O4) is an interesting phenomenon to study because it has many important applications, one of which is RAM (Radar Absorbing Material). The magnetic properties of nanomaterials are known to be influenced by their size. In this simulation research, the research objective was to analyze the temperature value of the Curie and the hysteresis curve of the Fe3O4 material with variations in the size of the material sample cube of 5 nm, 8 nm, 10 nm, 12 nm, and 15 nm. In this study, using a micromagnetic simulation method based on atomistic models with the Vampire program. The results showed that the Curie temperature value in the Fe3O4 material was influenced by variations in the size of the material. The Curie temperature values when the side sizes of the cube are 5 nm, 8 nm, 10 nm, 12 nm, and 15 nm, namely 650 K, 635 K, 650 K, 665 K and 645 K. The characteristics of the hysteresis curve for Fe3O4 material based on simulations at each material size (5 nm, 8 nm, 10 nm, 12 nm, and 15 nm) for several temperatures (0 K, 328 K, 473 K and 773 K) indicate that there is a change in the coercivity and field values. saturation.

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Dong, Pan, Weiguo Li, Ziyuan Zhao, Xuyao Zhang, Ying Li, Mengqing Yang, Shifeng Zheng, Yi He, and Yanli Ma. "Theoretical prediction of size and dimension dependent critical temperature for ferroelectric, ferromagnetic and superconductive nanomaterials." Journal of Physics and Chemistry of Solids 154 (July 2021): 110043. http://dx.doi.org/10.1016/j.jpcs.2021.110043.

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Osada, Minoru, and Takayoshi Sasaki. "New Perovskite Nanomaterials and Their Integrations into High-k Dielectrics." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2011, CICMT (September 1, 2011): 000072–77. http://dx.doi.org/10.4071/cicmt-2011-tp11.

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We report on a bottom-up manufacturing for high-k dielectric films using a novel nanomaterial, namely, a perovskite nanosheet (LaNb2O7) derived from a layered perovskite by exfoliation. Solution-based layer-by-layer assembly of perovskite nanosheets is effective for room-temperature fabrication of high-k nanocapacitors, which are directly assembled on a SrRuO3 bottom electrode with an atomically sharp interface. These nanocapacitors exhibit high dielectric constants (k > 50) for thickness down to 5 nm while eliminating problems resulting from the size effect. We also investigate dielectric properties of perovskite nanosheets with different compositions (LaNb2O7, La0.95Eu0.05Nb2O7, and Eu0.56Ta2O7) in order to study the influence of A- and B-site modifications on dielectric properties.

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Brovko, Olga, Irina Palamarchuk, Konstantin Bogolitsyn, Nikolay Bogdanovich, Artem Ivakhnov, Dmitriy Chukhchin, Kristina Khviuzova, and Natalia Valchuk. "Carbon nanomaterials based on interpolyelectrolyte complex lignosulfonate-chitosan." Holzforschung 73, no. 2 (February 25, 2019): 181–87. http://dx.doi.org/10.1515/hf-2017-0221.

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AbstractA new approach to the formation of “fullerene-like” carbon-nitrogen carbogels based on the interpolyelectrolyte complex lignosulfonate-chitosan (IPEC LSNa-CT) was developed. It was established that carbogel maintained the morphology of the precursor complex, i.e. the spherical geometry and the particle size of its main fractions (40–55 nm) were stored in the carbonizate. The influence of pyrolysis (Py) temperature was studied in the range of 500–1000°C on the structure of carbonizate. Carbogels obtained under different processing conditions have a well-developed microporous structure. The specific surface area of carbogels reduced with increasing Py temperature according to their nitrogen content. The maximum specific surface area (438.3 m2g−1) corresponds to the carbogel obtained at 600°C, while the maximum nitrogen content of this sample is 4.4%. The internal porosity of the material and the volume of supermicropores are reduced with increasing Py temperature due to the accumulation of double and triple carbon bonds in the carbogel. Apparently, the structure-forming N-atoms participate in the formation of condensed nitrogen-containing and cyclic structures as a donor of the electron pair and as such they accelerate the carbonization process.

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Das, Rabindra N., Konstantinos I. Papathomas, Mark D. Poliks, and Voya R. Markovich. "Nanomaterials for “Green” Electronics." International Symposium on Microelectronics 2010, no. 1 (January 1, 2010): 000622–29. http://dx.doi.org/10.4071/isom-2010-wp3-paper3.

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This paper examines the use of nanomaterials in the area of “green” technology. A variety of green materials for advanced organic packaging have been developed. These include capacitors and resistors as embedded passives, resin coated Cu (RCC) as buildup layers, highly conducting nano-micro media for Z-interconnects, lead free assembly paste, ZnO based additives, magnetic materials, inductors and thermal interface materials (TIM). Nanocomposites can provide high capacitance densities, ranging from 5 nf/inch2 to 25 nF/inch2, depending on composition, particle size and film thickness. The electrical properties of capacitors fabricated from BaTiO3-epoxy nanocomposites showed a stable capacitance over a temperature range from 20°C to 120 °C. A variety of printable discrete resistors with different sheet resistances, ranging from 1 ohm to 120 Mohm, processed utilizing a large panel format (19.5 × 24 inches) have been fabricated. Low resistivity nanocomposites, with volume resistivity in the range of 10−4 ohm-cm to 10−6 ohm-cm depending on composition, particle size, and loading can be used as conductive joints for high frequency and high density interconnect applications. A variety of metals including Cu, Ag, LMP (low melting point) and LMP-coated Cu fillers have been used to make halogen free, lead free electrically conducting adhesive technology as an alternative to solders. Halogen free resin modified with ceramics/organic particles can produce low Dk resin coated Cu (RCC) with Dk value in the range between 4.2 and 2.5. Similarly, low loss RCC materials can be produced by combining HF resin with low loss fillers. The mechanical strength of the various RCC was characterized by a 90 degree peel test and measurement of tensile strength. RCC exhibited peel strength with Gould's JTC-treated Cu as high as 6 lbs/inch for halogen free RCC. These halogen free RCC materials exhibit coefficients of thermal expansion (CTE), ranging from 27 ppm/°C to 32ppm/°C. The paper also describes a nanoparticle dispersion approach to prepare nanogels and nanofluids as thermal interface materials. Altogether, this is a new direction in the development of Green Packages and more specifically in the development of coreless substrates for semiconductor packaging.

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Ali, Zeeshan, Gang Jin, Zhili Hu, Zhifei Wang, Muhammad Ammar Khan, Jianguo Dai, and Yongjun Tang. "A Review on NanoPCR: History, Mechanism and Applications." Journal of Nanoscience and Nanotechnology 18, no. 12 (December 1, 2018): 8029–46. http://dx.doi.org/10.1166/jnn.2018.16390.

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Polymerase Chain Reaction (PCR) is one of the most common technologies used in many laboratories to produce millions of copies of targeted nucleic acid under in vitro conditions. However, PCR faces multiple challenges including limited availability of DNA in the sample, high GC contents of the template, low efficiency, and specificity in amplification. Moreover, some DNA fragments are very difficult to amplify due to their secondary structure and high melting temperature requirement. To overcome these challenges, many approaches including the application of PCR additives in PCR mixture; change in instrument design; optimization of PCR system by using the accurate concentration of magnesium ions, primers, and cycle number; enzyme modification; and setting up the new touchdown and nested PCR strategies have been adopted. Although these approaches have enriched the output of PCR, they are not all-purpose and optimization can be case dependent. Nanometer-sized materials (nanomaterials) have offered a possible solution to these problems as these materials have exceptional physio-chemical properties as compared to macroscopic materials. Among these nanomaterials, silicon-based materials, carbon-based materials, semiconductor quantum dots (QDs), and some metals are well-known PCR enhancer. Hence, new PCR has been designed to utilize the unique properties of nanomaterial and is known as nanomaterial-assisted PCR or simply nanoPCR. Results of many studies have shown that the combination of these nanomaterials and biomolecules can mimic the DNA replication process successfully as present in the living organism. In this review, we have discussed the role of these different nanomaterials one by one and also discussed the mechanisms through which these nanomaterials enhance the efficiency of PCR.

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Yurchenko, D., L. Oleksenko, N. Maksymovych, G. Fedorenko, and I. Matushko. "CARBON MONOXIDE ADSORPTION SEMICONDUCTOR SENSOR CREATED ON THE BASE OF THE NANOSIZED MATERIAL Pt/SnO2." Bulletin of Taras Shevchenko National University of Kyiv. Chemistry, no. 1(55) (2018): 70–72. http://dx.doi.org/10.17721/1728-2209.2018.1(55).18.

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Nanosized material SnO2 was obtained by a sol-gel technique to create a sensor purposed for determination of carbon monoxide concentration in air. Platinum was added to the nanosized tin dioxide by a wet impregnation method using H2PtCl6 solution. According to TEM data the average size of the SnO2 particles in the obtained nanosized tin dioxide was equal to 10–11 nm. Sensor nanomaterials based on SnO2 and Pt/SnO2 powders which were sintered at 620°C in air atmosphere consisted of spheric particles with average sizes 20 and 14–15 nm, correspondingly. Phase compositions of the obtained nanomaterials were studied by the XRD method. Only a phase of cassiterite was detected for the nanomaterials with and without platinum. The absence of any reflexes of platinum-containing phases in the diffraction pattern of Pt/SnO2 is most likely due to the low content of platinum in the material. It was shown that dopping the nanosized SnO2 materials by platinum lead to increase their catalytic activities in the reaction of CO oxidation: the temperature of practically complete conversion of CO using Pt/SnO2 catalyst was equal to 110°С. The sensor created on the base of Pt/SnO2 nanomaterial was found to be more sensitive to CO than the one created without platinum in the range of its heater power consumption 0.25–0.45 W. High catalytic activity of the Pt/SnO2 nanomaterial in the reaction of CO oxidation is a reason of such sensor sensitivity increase. The dependence of the sensitivity of the sensor on the heater power consumption has a maximum that can be explained by the change of the amount of oxygen chemisorbed on the sensor gas sensitive layer when the sensor temperature is increased. The maximal sensor sensitivity to CO is γ = 10 at the optimal heater power consumption of the sensor (0.3 W). The created sensor to CO based on the nanomaterial Pt/SnO2 was found to be very fast. The response time of the sensor (τ0,9) was equal to 4,5 sec and the relax time (τrelax) was equal to 9.8 sec. It was shown that the created sensor based on nanomaterial Pt/SnO2 has high sensitivity to carbon monoxide and possess good dynamic properties, which makes the sensor to be promising for usage it in gas analytical devices purposed for determination of CO in air.

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So, Soon Hyeong, Jun Ho Jang, Sae Jin Sung, Seung Jae Yang, Ki Tae Nam, and Chong Rae Park. "Demonstration of the nanosize effect of carbon nanomaterials on the dehydrogenation temperature of ammonia borane." Nanoscale Advances 1, no. 12 (2019): 4697–703. http://dx.doi.org/10.1039/c9na00501c.

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Nguyen, Tien Anh, and Hoi Thi Nguyen. "Effects of zinc contents and calcination temperature on the structure and magnetic properties of Co1-xZnxFe2O4 nanomaterials synthesized by co-precipitation." Science and Technology Development Journal - Natural Sciences 2, no. 3 (May 23, 2019): 85–93. http://dx.doi.org/10.32508/stdjns.v2i3.757.

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Nanomaterials of cobalt ferrite (CoFe2O4) doped with zinc have been synthesized by co-precipitation using KOH solution of 10-4 M as a precipitant. The effect of zinc contents and calcination temperature on the structure and magnetic properties of Co1-xZnxFe2O4 were studied. The parameters of the crystalline cubic lattice (a ~ 8.4 Å) and the crystalline size (d = 20–30 nm) increased with increasing the calcination temperature and zinc content in the samples. However, the remanent magnetization, saturation magnetization, coercive force and M at the maximum field decreased with increasing the zinc content. The nanomaterials of cobalt ferrite doped with zinc have Hc values in the range of 8.67–179.63 Oe, Mr values in the range of 1.33–16.90 emu/g, which are quite smaller than those of original CoFe2O4 material (Hc=497.89 Oe, Mr=36.29 emu/g); moreover, the nanomaterials prepared have Ms values in the range of 56.00 – 99.97 emu/g, which are similar to those of original CoFe2O4 material (Ms= 88.67 emu/g) and are quite higher than those of original ZnFe2O4 material (Ms ~ 1.2 emu/g).

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Tiwari, Arunendera Kumar, Tripti A. Jain, Sonal Choubey, and Parmendra Kumar Bajpai. "Synthesis and Characterization of Cadmium Chalcogenide Nanomaterial (CdE; E=Se/Te) from Novel Single Source Molecular Precursor." Current Nanoscience 14, no. 2 (February 1, 2018): 160–68. http://dx.doi.org/10.2174/1573413714666171207155555.

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Background: Metal chalcogenide nanomaterials represent an important group of efficient materials, in which the subtle variations in shape, size and phase of nano-powders resulted in physical properties (e.g., electronic and optical) differing from their bulk counterparts, which makes them useful materials for various technological devices. Objective: Synthesis and growth of chalcogenide nano powders from novel single source molecular precursors (i.e., Cd(II) bis-(aminopropane) selenide, Cd(II) bis-(aminoethane) telluride) for the production of cadmium chalcogenide (CdE, E= Se/Te) at nano scale. Method: Single source molecular precursor inserted in quinoline, acting as a coordinating solvent at suitable temperature, yielded vacuum dried powders of CdSe and CdTe nanomaterials. Results: The average particle size was estimated as CdSe ≈ 3 nm, and CdTe ≈ 29 nm from powder X-ray diffraction pattern of synthesized nanoparticles. The produced nanomaterials possess optical properties and calculated energy band gap of nanoparticles as CdTe = 5.2 eV and CdSe = 4.0 eV from UV-Visible spectra. Conclusion: The economical, harmless single source molecular method may be a striking technique to fabricate metal chalcogenide nanoparticles.

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Journal articles on the topic 'Size and temperature of nanomaterials'

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