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1
Ni, Jun, Lei Zhang, Chengjun Wang, Weibo Wang, and Ge Jin. "Study on the Effect of Cations on the Surface Energy of Nano-SiO2 Particles for Oil/Gas Exploration and Development Based on the Density Functional Theory." Molecules 29, no. 4 (2024): 916. http://dx.doi.org/10.3390/molecules29040916.
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Although nano SiO2 exhibits excellent application potential in the field of oil and gas exploration and development, such as drilling fluid, enhanced oil/gas recovery, etc., it is prone to agglomeration and loses its effectiveness due to the action of cations in saline environments of oil and gas reservoirs. Therefore, it is crucial to study the mechanism of the change in energy between nano SiO2 and cations for its industrial application. In this paper, the effect of cations (Na+, K+, Ca2+, and Mg2+) on the surface energy of nano SiO2 particles is investigated from the perspective of molecular motion and electronic change by density functional theory. The results are as follows: Due to the electrostatic interactions, cations can migrate towards the surface of nano SiO2 particles. During the migration process, monovalent cations are almost unaffected by water molecules, and they can be directly adsorbed on the surface by nano SiO2 particles. However, when divalent cations migrate from a distance to the surface of nano SiO2 particles, they can combine with water molecules to create an energy barrier, which can prevent them from moving forward. When divalent cations break through the energy barrier, the electronic kinetic energy between them and nano SiO2 particles changes more strongly, and the electrons carried by them are more likely to break through the edge of the atomic nucleus and undergo charge exchange with nano SiO2 particles. The change in interaction energy is more intense, which can further disrupt the configuration stability of nano SiO2. The interaction energy between cations and nano SiO2 particles mainly comes from electrostatic energy, followed by Van der Waals energy. From the degree of influence of four cations on nano SiO2 particles, the order from small to large is as follows: K+ < Na+ < Mg2+ < Ca2+. The research results can provide a theoretical understanding of the interaction between nano SiO2 particles and cations during the application of nano SiO2 in the field of oil and gas exploration and development.
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Ding, Jin, Zhenming Yue, Jiao Sun, and Jun Gao. "Effects of nano-silicon dioxide surface modification on the morphology and mechanical properties of ABS/PMMA blends." Journal of Polymer Engineering 38, no. 7 (2018): 617–23. http://dx.doi.org/10.1515/polyeng-2017-0260.
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Abstract This work analyzed the effects of nano-silicon dioxide (nano-SiO2) fillers on the morphology and mechanical properties of acrylonitrile-butadiene-styrene (ABS)/poly(methyl methacrylate) (PMMA) blends. Nano-SiO2 particles were selectively dispersed in the PMMA phase, and the toughness of the ternary blends was significantly improved when the contents of the nano-SiO2 fillers were below 2 wt%. The stearic acid treatment of nano-SiO2 particles prevented the adhesion between constituents and markedly diminished the toughness of the blends. Nano-SiO2 particles were alternatively treated with a silane coupling agent to promote adhesion. The toughness was better in blends for filler contents below 2 wt% than in pure nano-SiO2 particles. However, the presence of nano-SiO2 fillers decreased the surface glossiness of the blends. This work provides new insights into the processes by which nanomaterials toughen ABS/PMMA blends.
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Zhang, Peng, Qingfu Li, Juan Wang, Yan Shi, Yuanxun Zheng, and Yifeng Ling. "Effect of Nano-Particle on Durability of Polyvinyl Alcohol Fiber Reinforced Cementitious Composite." Science of Advanced Materials 12, no. 2 (2020): 249–62. http://dx.doi.org/10.1166/sam.2020.3680.
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In this study, the influence of nano-particle on flowability and durability of polyvinyl alcohol (PVA) fibers reinforced cementitious composite containing fly ash was evaluated. In the cementitious composite, Portland cement was replaced with 1.0%, 1.5%, 2.0% and 2.5% (by weight) of nano-particles. Two kinds of nano-particle of SiO2 and CaCO3 nano-particles were adopted in this study. PVA fibers were incorporated to the composite at a dosage of 0.9% (by volume). The flowability of the fresh cementitious composite was assessed using slump flow measurements. The durability of hardened cementitious composite includes carbonation resistance, permeability resistance, cracking resistance as well as freezing-thawing resistance, which were evaluated by the depth of carbonation, the water permeability height, cracking resistance ratio of the specimens, and relative dynamic elastic modulus of samples after freeze-thaw cycles, respectively. Our results showed incorporation of nano-particles had a little disadvantageous effect on flowability of PVA fiber reinforced cementitious composite, and the flowability of the fresh mixtures decreased with increases in the nano-particles content. The decrease in flowability of cementitious composite resulted by nano-SiO2 particles is more remarkable than nano-CaCO3 particles. The addition of both nano-SiO2 and nano-CaCO3 particles significantly improved the durability of PVA fiber reinforced cementitious composite. However, the improvement of nano-SiO2 on durability is much better than that of nano-CaCO3. When the amount of SiO2 nano-particle was less than 2.5%, the durability of cementitious composites increased with nano-SiO2 content. The microstructure of PVA fiber reinforced cementitious composite becomes much denser due to filler effect of nano-particle and generation of particles of hydrated products C–S–H gels. Both of SiO2 and CaCO3 nano-particle improved the microstructure of PVA fiber reinforced cementitious composite, and nano-SiO2 particles might be more beneficial for PVA fibers to play the role of reinforcement than nano-CaCO3 particles in the composites.
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Xu, Yi Kun, and Mao-Sheng Zhan. "Gradient Microstructure Analysis of PI-SiO2 Hybrid Tubular Films." Materials Science Forum 475-479 (January 2005): 1575–78. http://dx.doi.org/10.4028/www.scientific.net/msf.475-479.1575.
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PI-SiO2 hybrid seamless tubular films with gradient microstructure were prepared by sol-gel insitu polymerization and rotational moulding process. Energy Dispersive X-Ray Spectrometry (EDS) and Field Emitter Scanning Electron Microscope (FE-SEM) were used to evaluate the spatial gradient distribution of SiO2 in the PI-SiO2 hybrid tubular films. The experimental results showed that the SiO2 particles were dispersed at nanoscale in the PI matrix, and that the size and the dispersivity of the SiO2 particles changed gradiently along the tubular film cross-section. The lower the SiO2 distribution density, the smaller the SiO2 particles. When the SiO2 content exceeded a certain value, some SiO2 nano-particles aggregated into nano-clusters with thyrsiform structure, and the nano-clusters aggregated more into limbate globoids.
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Zhang, Peng, Qingfu Li, Yuanzhao Chen, Yan Shi, and Yi-Feng Ling. "Durability of Steel Fiber-Reinforced Concrete Containing SiO2 Nano-Particles." Materials 12, no. 13 (2019): 2184. http://dx.doi.org/10.3390/ma12132184.
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An experimental study was conducted to investigate the effect ofnano-SiO2 and steel fiber content on the durability of concrete. Five different dosages of nano-SiO2 particles and five volume dosages of steel fiber were used. The durability of concretes includes permeability resistance, cracking resistance, carbonation resistance, and freezing-thawing resistance, and these were evaluated by the water permeation depth, number of cracks, total cracking area per unit area of the specimens, carbonation depth of the specimens, and the relative dynamic elastic modulus of the specimens after freezing-thawing cycles, respectively. The results indicate that the addition of nano-SiO2 particles significantly improves the durability of concrete when the content of nano-SiO2 is limited within a certain range. With the increase of nano-SiO2 content, the durability of concrete first increases and then decreases. An excessive number of nano-SiO2 particles could have an adverse effect on the durability of the concrete. The addition of the correct amount of steel fibers improves the carbonation resistance of concrete containing nano-particles, but excessive steel fiber reduces the carbonation resistance. Moreover, the addition of steel fibers reduces the permeability resistance of concrete containing nano-particles. The incorporation of steel fiber enhanced the freezing-thawing resistance and cracking resistance of concrete containing nano-particles. With increasing steel fiber content, the freezing-thawing resistance of the concrete containing nano-particles increases, and the cracking resistance of the concrete decreases gradually.
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Zhang, Jie, Yongsheng Ji, Zhanguo Ma, et al. "Strengthening Mechanism for the Mechanical Properties of Cement-Based Materials after Internal Nano-SiO2 Production." Nanomaterials 12, no. 22 (2022): 4047. http://dx.doi.org/10.3390/nano12224047.
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This study focuses on overcoming the agglomeration issue of nano-SiO2 powder in cement, facilitating the strengthening mechanism of cement-based materials. A nano-SiO2 precursor solution (NSPS) was added to cement-based materials to replace nano-SiO2 powder. The influencing laws of the alkalinity and dosage of the NSPS on the mechanical properties of cement were investigated. Further, the strengthening mechanism of the mechanical properties of cement-based materials after internal nano-SiO2 production was analysed. The results show that (1) when the alkalinity of the precursor solution is a weak acid (pH = 6), the compressive strength of cement-based materials after internal nano-SiO2 production is 25%~36% higher than that of pure cement-based materials and 16%~22% higher than that of cement-based materials with silica fume; (2) when the solid content of SiO2 in the current displacement solution is about 0.16% of the cement mass, the compressive strength of the prepared cement-based material is the highest. With the continuous increase in the solid content of SiO2 in the precursor solution, the compressive strength of cement-based materials after internal nano-SiO2 production decreases but is always greater than the compressive strength of the cement-based material mixed with nano-SiO2 micro powder. According to a microstructural analysis, nano-SiO2 particles that precipitate from the precursor solution can facilitate the hydration process of cement and enrich the gel products formed on the cement particle surface. In addition, new network structures among cement particles are formed, and precipitated nano-SiO2 particles fill in the spaces among these cement particles as crystal nuclei to connect the cement particles more tightly and compact the cement-based materials. This reinforces the mechanical properties of cement-based materials.
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Qu, Xiao Fei, Dan Dan Xie, Yu Fei Wang, and Kai Wang. "Fabrication and Characterization of SiO2/TiO2 Nano-Hybrid Particles." Key Engineering Materials 727 (January 2017): 335–42. http://dx.doi.org/10.4028/www.scientific.net/kem.727.335.
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SiO2/TiO2 nano-hybrid particles were successfully prepared by hydrothermal method by using titanium tetrafluoride (TiF4) as the titanium source, silicon dioxide as template. The factors of hydrothermal temperature and hydrothermal time on the morphologies and photocatalytic activity of SiO2/TiO2 nano-spheres were systematically discussed in this paper. The structures and properties of the SiO2/TiO2 nano-hybrid particles were studied by some techniques such as SEM, TEM, XRD and BET analysis. The results indicated that TiO2 prepared by hydrothermal method were anatase crystal, and in the form of polycrystalline. The formation mechanism of SiO2/TiO2 nano-hybrid particles was also discussed.
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Han, Zhi Dong, Qing Rui Zhao, Li Min Dong, Ze Wu, and Xian You Zhang. "Microwave Absorption of BaLa0.5Fe11.5O19/SiO2 Nano-Powders." Advanced Materials Research 105-106 (April 2010): 380–82. http://dx.doi.org/10.4028/www.scientific.net/amr.105-106.380.
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Nano-size BaM hexaferrites (BaLa0.5Fe11.5O19) were synthesized in the presence of SiO2 nano- particles by sol-gel method. The X-ray diffraction (XRD) patterns of ferrites annealed at above 900°C manifested that all the species had hexagonal crystal structure and no diffraction peaks of SiO2 found. Compared with BaLa0.5Fe11.5O19 powders, those synthesized in the presence of SiO2 nano-particles presented in smaller powder size, as proved by scanning electron microscopy (SEM). As a result, SiO2 nanoparticles promoted the formation of more homogeneous and finer ferrite crystal while the structure of hexaferrites consisted with that synthesized without SiO2 nano-particles. Microwave absorbing properties were evaluated. As a result, BaLa0.5Fe11.5O19/SiO2 showed good microwave absorbing properties with the maximum absorption more than 20dB.
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Tian, Wenxin, Chao Tang, Qian Wang, Shiling Zhang, and Yali Yang. "The Effect and Associate Mechanism of Nano SiO2 Particles on the Diffusion Behavior of Water in Insulating Oil." Materials 11, no. 12 (2018): 2373. http://dx.doi.org/10.3390/ma11122373.
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Moisture has a significant effect on the internal insulation performance of transformers, and is closely related to the breakdown voltage of transformer insulating oil. In the present work, we studied the effect of nano-SiO2 particles on the diffusion of water in insulating naphthenic mineral oil using molecular dynamics simulation. Six models were established, three of which contained nano-SiO2 particles together with water concentration of 1 wt.%, 2 wt.%, or 3 wt.%. For each model variations in free volume, mean square displacement, and interaction energy were assessed. The addition of nano SiO2 particles was found to reduce the free volume fraction of the model and as well as the free motion of water molecules in the oil. These particles also increased the interaction between the oil and water molecules, indicating that insulating oil containing nano-particles has a greater binding effect on water. The diffusion coefficient of water in oil containing nano-SiO2 particles was reduced, such that water molecules were less likely to diffuse. The results also show that these particles adsorb water molecules in the oil and to reduce diffusion. Consequently, the addition nano-scale SiO2 particles could potentially improve the breakdown voltage of the insulating oil.
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Zhang, C. H., Y. P. Bai, L. X. Liu, Z. Q. Zhang, and Q. Y. Li. "Preparation of a Novel Epoxy/SiO2 Hybrid Coating." Advanced Composites Letters 14, no. 1 (2005): 096369350501400. http://dx.doi.org/10.1177/096369350501400102.
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In this paper, epoxy/SiO2 hybrid coating was successfully prepared through sol-gel technique, the structure and thermal properties of epoxy/SiO2hybrid coating were investigated. First, γ-isocyanatopropyltriethoxysilane “(KBE-9007)” was used to modify the epoxy resin so that the ethoxysilane could be grafted on the epoxy resin. Nano-SiO2 precursor was synthesized by tetraethoxysilane(TEOS) through sol-gel technique. Then the modified epoxy resin and the nano-SiO2 precursor were mixed for 4 hours to let the macromolecules of epoxy resin graft on the surface of nano-SiO2, and modified nano-SiO2 precursor was obtained. At last, epoxy/SiO2 hybrid coating was produced by using the modified nano-SiO2 precursor. The graft reaction was confirmed by the analyses of FT-IR. The analyses of XPS indicated that there are lots of SiO2 particles and Si-C covalent bonds on the surface of epoxy/SiO2 hybrid coating, they also suggested that most TEOS had changed into SiO2 particles and Si-C covalent bond had been formed between epoxy resin and SiO2. The analyses of SEM fracture surface image of epoxy/SiO2 hybrid coating showed that SiO2 particles dispersed in epoxy matrix homogeneously and the size of the particles was between 50nm and 100 nm. Thermoanalysis Instrument was employed to detect the thermal properties of epoxy coating and epoxy/SiO2 hybrid coating, the results indicated that the thermal decomposition temperature of epoxy/SiO2 hybrid coating is 21.7 °C higher than that of epoxy coating, the thermal properties of the epoxy/SiO2 hybrid coating were improved because of the introduction of nano-SiO2.
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Shi, Guang, Li Jun He, Chu Zhi Chen, Jian Fu Liu, Qin Zhong Liu, and Hong Yu Chen. "A Novel Nanocomposite Based on Recycled Poly(Ethylene Terephthalate)/ABS Blends and Nano-SiO2." Advanced Materials Research 150-151 (October 2010): 857–60. http://dx.doi.org/10.4028/www.scientific.net/amr.150-151.857.
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Recycled PET is an important resource of waste, which reused with polar or crystallization polymers, such as PC, PA and PE, by melting blend method have been well studied. But the study of rPET blend with nonpolar and amorphous polymer is still inadequate. In the present work, nano-SiO2 particles were introduced to recycled PET/ABS/AES (55/40/5) blends by extrusion processing. It has been investigated how nano-SiO2 particles influences the morphology and mechanical properties of rPET/ABS blends by the use of AES as compatibilizer. It showed a uniform dispersion of the nano-SiO2 components, and the two-continuous phase of rPET/ABS was more evenly when the content of nano-SiO2 particles at a low level. The tensile strength and beam impact strength of rPET/ABS/AES blends were increased at the same time by adding nano-SiO2 particles..
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Yu, Lili, Junwang Meng, Zhenzhong Tang, Lizhi Zhu, Junyan Zhu, and Xiaojun Ma. "Investigation of the dimensional stability of ACQ-treated southern pine when supplemented with wax and different types of nano-SiO2." BioResources 12, no. 4 (2017): 8672–82. http://dx.doi.org/10.15376/biores.12.4.8672-8682.
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Southern pine (Pinus spp.) wood cubes were treated with amine copper quaternary (ACQ) solutions supplemented with wax and different types of nano-SiO2 particles. The effects of various types of nano-SiO2 on the dimensional stability of ACQ-treated wood were investigated, including water absorption, swelling, and shrinkage. The results showed that nano-SiO2/wax treatments improved the hydrophobicity of the ACQ-treated wood; various types of nano-SiO2 particles had different effects on the water absorption by the wood. The best water absorption resistance was observed with the ACQ-treated wood modified with nano-SiO2 that had a specific surface area of 380 m2/g. However, the nano-SiO2/wax treatment had a negligible effect on the swelling and shrinkage resistance of the ACQ-treated wood; various types of nano-SiO2 did not affect the swelling and shrinkage of the wood.
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Jiang, Yu Ling, Jin Jing Guo, and Hui Zhao. "Preparation and Cavilation Erosion Resistance of High Strength Nanocoating Cylinder Liner." Nano Hybrids and Composites 34 (February 23, 2022): 61–67. http://dx.doi.org/10.4028/p-y7gdd5.
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Using ammonium persulfate as an oxidant and nano-silica as dispersing medium,o-toluidine was oxidized to form a core-shell structure poly (o-toluidine)/nano-SiO2 particle. Investigation of particle yield by ICP-AES method, the adhesion method was used to study the adhesion between coating and cylinder liner. The cavitation resistance of the coating cylinder was studied by the vibration gas cavitation method. The results showed that poly(o-toluidine) was uniformly coated around the nano-silica particles to which forms stable poly (o-toluidine)/nano-SiO2 with core-shell structure, when m(SiO2):m(POT)=1:8，n((NH4)2S2O3):n(POT)=1:1,and the temperature was controlled from 10 to 15°C, the composite poly(o-toluidine)/nano-SiO2 particles were prepared and the yield reached 85%. Composite poly(o-toluidine)/nano-SiO2 particles as a functional component and epoxy resin as a film-forming agent were used to prepare composite poly(o-toluidine)/nano-SiO2/epoxy resin coated cylinder liner with good cavitation resistance, t100=885min.
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Zhang, Mao Hua. "Pore Characteristics of Pavement Concrete with Nano-Particles." Applied Mechanics and Materials 275-277 (January 2013): 2073–76. http://dx.doi.org/10.4028/www.scientific.net/amm.275-277.2073.
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Pore characteristics of pavement concrete with nano-particles (TiO2 or SiO2) are experimentally studied and compared with that of plain pavement concrete. The test results indicate that the addition of nano-particles improves the pore structure of concrete. The refined extent of pore structure of concretes increase with decreasing content of nano-particles. The pore structure of concrete with nano-TiO2 is better than that of concrete with the same content of nano-SiO2.
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Gao, Mingze, Jiaming Yang, Hong Zhao, Hui He, Ming Hu, and Shuhong Xie. "Preparation Methods of Polypropylene/Nano-Silica/Styrene-Ethylene-Butylene-Styrene Composite and Its Effect on Electrical Properties." Polymers 11, no. 5 (2019): 797. http://dx.doi.org/10.3390/polym11050797.
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Compared with traditional insulation materials, such as cross-linked polyethylene (XLPE), polypropylene (PP) is famous for its better recyclable and thermal properties, as well as its good electrical performance. However, the problem of poor impact strength has restricted the application of pure PP in high-voltage, direct current (HVDC) cables. In this paper, styrene-ethylene-butylene-styrene block copolymer (SEBS) was used as a toughening filler, and nano-SiO2 was expected to improve the electric properties of the nano-composite. By controlling the masterbatch system, the dispersion characteristics of nano-SiO2 in the ternary composite system were changed. When PP/SiO2 was used as the masterbatch and then blended with SEBS, nano-SiO2 tended to disperse in the PP phase, and the number of nano-particles in the SEBS phase was lower. When PP/SEBS was used as the masterbatch, nano-SiO2 was distributed in both the PP phase and the SEBS phase. When SEBS/SiO2 was used as the masterbatch, nano-SiO2 tended to be dispersed in the SEBS phase. The different dispersion characteristics of nano-SiO2 changed the crystallization and mechanical properties of the ternary composite system and produced different electrical performance improvement effects. The results of our experiment revealed that the space charge suppression capability was positively correlated with the direct current (DC) breakdown strength improvement effect. Compared with the DC performance of 500 kV commercial XLPE materials, the self-made PP-based ternary composite system has better space charge suppression effects and higher DC breakdown strength. When nano-SiO2 was more dispersed in the PP phase, the space charge improvement effect was best. When the nano-SiO2 particles were more dispersed in the SEBS phase, the expected electrical property improvement was not obtained. Scanning electron microscopy showed that the nano-SiO2 particles in the SEBS phase were more dispersed at the interface than in the SEBS matrix, indicating that the nano-particles were poorly dispersed, which may be a reason why the electrical properties of the composite system were not significantly improved.
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Du, Bin, Feng Chen, Rubai Luo, Shisheng Zhou, and Zhengneng Wu. "Synthesis and Characterization of Nano-TiO2/SiO2-Acrylic Composite Resin." Advances in Materials Science and Engineering 2019 (January 3, 2019): 1–7. http://dx.doi.org/10.1155/2019/6318623.
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Waterborne acrylic resin is widely used as a binder of waterborne printing ink because of its excellent comprehensive properties. However, its further developments and applications are hindered by its poor UV resistance and water resistance. Therefore, an approach to prepare acrylic resin with excellent UV resistance and water resistance is described in this present study. The nano-TiO2/SiO2 composite particles were first modified with a silane coupling agent (KH-570) and a titanate coupling agent (NDZ-101) and then embedded into acrylic resin via a blending method. Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and thermogravimetry analysis (TGA) were applied to investigate the structure and morphology of the modified nano-TiO2/SiO2 composite particles. The effects of the modified nano-TiO2/SiO2 composite particles on the UV and water resistance of the acrylic resin were investigated by UV spectroscopy and water resistance analysis. The weight loss of modified nano-TiO2/SiO2 was about 20% when heated to 600°C, which indicated that the nano-TiO2/SiO2 composite particles were modified by the coupling agents successfully. The UV-Vis spectra of acrylic resin showed that the UV resistance was improved upon the addition of nano-TiO2/SiO2. The water absorption of the nano-TiO2/SiO2-acrylic resin was less than 5%, indicating that the water resistance of the material was improved.
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Rong, Zhidan, Mingyu Zhao, and Yali Wang. "Effects of Modified Nano-SiO2 Particles on Properties of High-Performance Cement-Based Composites." Materials 13, no. 3 (2020): 646. http://dx.doi.org/10.3390/ma13030646.
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In this research, silane coupling agent was used to modify the surface of nano-SiO2, particles and the effects of modified nano-SiO2 particles on the mechanical properties of high-performance cement-based composites and its mechanism were systematically studied. The results indicated that the optimum modification parameters were a coupling agent content of 10%, reaction temperature of 65 °C, and reaction time of 8 h. Compared with the unmodified nano-SiO2, the modified nano-SiO2 promoted and accelerated the hydration process of cement. The pozzolanic effect, filling effect, and nucleation effect of modified nano-SiO2 made the microstructure of the composite more compact, and thus improved static mechanical properties of cement-based composites.
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Qiu, Ji, Xiang Bo Suo, Shi Ning Ma, Gang Shuai, and Hong Mei Wang. "A Effects of Nano-Particles Additives on Wear Performance of Micro-Arc Oxidation Coating Prepared on 2A12 Aluminum Alloy." Advanced Materials Research 1120-1121 (July 2015): 735–39. http://dx.doi.org/10.4028/www.scientific.net/amr.1120-1121.735.
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Nano-particle reinforced composite coatings were prepared on 2A12 aluminum alloy by micro-arc oxidation and the effect of nano particles on wear performance of coating was studied. By means of SEM, CETR micro-nano-indenter friction and wear tester and white-light interferometer, the surface morphology and the friction and wear property were tested. Results showed that compared with the coating without nano-particle addition, the size and amount of pores on coatings were decreased substantially after additon with 20nm nano-SiO2 particles, 80nm nano-SiO2 particles and 80nm nano-TiO2 particles, and the wear resistance of the micro-arc oxidation coating was improved.
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Sahu, Devashri, G. M. Kannan, Mukul Tailang, and R. Vijayaraghavan. "In Vitro Cytotoxicity of Nanoparticles: A Comparison between Particle Size and Cell Type." Journal of Nanoscience 2016 (August 23, 2016): 1–9. http://dx.doi.org/10.1155/2016/4023852.
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The reduction in size of Zinc oxide (ZnO) and Silicon dioxide (SiO2) particles from micron to nano scale offers unique physical characteristics on one hand while making them cytotoxic on other hand. The present study was aimed at comparing cytotoxic effects of ZnO and SiO2 nanoparticles with their micron size and secondary aim was to compare responses of these particles to two different cell types, namely, human lung epithelial cells (L-132) and human monocytes (THP-1). The L-132 and THP-1 cells were exposed to nano and micron size of ZnO and SiO2 particles with different concentrations (5–500 μg/mL) for 24 h, and cytotoxicity was analyzed by MTT assay, live-dead staining, and TC-50 was calculated. ZnO and SiO2 particles showed concentration-dependent cytotoxicity in both cell lines. In size-dependent study, ZnO particles exhibited nearly equal toxicity profile in L-132 cells while in THP-1 cells nano ZnO showed more toxicity than its micron size. The SiO2 particles showed more toxicity in their nano size than micron size in both cell lines. Human monocytes, THP-1 cells, were more sensitive towards the toxicity of both particles than human lung cells, L-132. The results highlight the difference of cytotoxicity between particle sizes and differential sensitivity of cells towards the particles of same composition. In conclusion, ZnO and SiO2 particles exhibited concentration-dependent toxicity, which was more in their nano size than micron counterpart. However, the toxic response varies depending on type of cell exposed due to differential sensitivity.
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Heo, Gwang-Hee, Jong-Gun Park, Ki-Chang Song, Jong-Ho Park, Hyung-Min Jun, and Zhongguo John Ma. "Improving the Interfacial Bond Properties of the Carbon Fiber Coated with a Nano-SiO2 Particle in a Cement Paste Matrix." Advances in Civil Engineering 2020 (September 29, 2020): 1–18. http://dx.doi.org/10.1155/2020/8838179.
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To improve the interfacial bond properties of the carbon fiber coated with a nano-SiO2 particle in a cement paste matrix, the present study proposed a method of coating nano-SiO2 particles on the surface of the carbon fiber by the chemical reaction of a silane coupling agent (glycidoxypropyltrimethoxysilane, GPTMS) and colloidal nano-SiO2 sol in an alkaline environment. To verify whether a nano-SiO2 particle was effectively modified on the surface of the carbon fiber, the surface morphology, chemical composition, and chemical structure were characterized and analyzed by several techniques such as the scanning electron microscope (SEM), energy-dispersive spectrometer (EDS), and Fourier-transform infrared spectroscopy (FT-IR). Nano-SiO2 particles were entirely covered and uniformly distributed on the surface of the carbon fiber, resulting in the formation of a thin layer of nano-SiO2 particles. A thin layer of nano-SiO2 particles reacted with Ca(OH)2 to form a calcium-silicate-hydrate (C-S-H) gel, which is most helpful to increase the form between the fiber and the matrix. In addition, a pull-out test of the tow carbon fibers was performed to verify the effect of the new surface modification method on the interfacial bond properties of the carbon fiber embedded in the cement paste matrix. The experimental results showed that the frictional bond strength of the carbon fiber coated with a nano-SiO2 particle was significantly increased compared to the plain carbon fiber. These results were expected to improve the interfacial bonding force of hardened cement paste from the formation of the C-S-H gel produced through the chemical reaction of nano-SiO2 particles coated on the surface of the carbon fiber with Ca(OH)2. In particular, it was confirmed that the carbon fiber-reinforced cement paste (CFRCP) specimens coated with a nano-SiO2 particle and silica fume which replaced 10 wt.% of cement by mass showed the highest pull-out resistance performance at 28 days of age. The new surface modification method developed in this study can be very beneficial and helpful in improving the interfacial bond properties of CFRCP.
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Sorkhabi, Tannaz Soltanolzakerin, Mehrab Fallahi Samberan, Krzysztof Adam Ostrowski, Tomasz M. Majka, Marcin Piechaczek, and Paulina Zajdel. "Preparation and Characterization of Novel Microgels Containing Nano-SiO2 and Copolymeric Hydrogel Based on Poly (Acrylamide) and Poly (Acrylic Acid): Morphological, Structural and Swelling Studies." Materials 15, no. 14 (2022): 4782. http://dx.doi.org/10.3390/ma15144782.
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In this paper, novel microgels containing nano-SiO2 were prepared by in situ copolymerization using nano-SiO2 particles as a reinforcing agent, nanosilica functional monomer (silane-modified nano-SiO2) as a structure and morphology director, acrylamide (AAm) as a monomer, acrylic acid (AAc) as a comonomer, potassium persulfate (KPS) as a polymerization initiator, and N,N′-methylene bis (acrylamide) (MBA) as a crosslinker. In addition, a conventional copolymeric hydrogel based on poly (acrylamide/acrylic acid) was synthesized by solution polymerization. The microgel samples, hydrogel and nanoparticles were characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). A FESEM micrograph of copolymeric hydrogel showed the high porosity and 3D interconnected microstructure. Furthermore, FESEM results demonstrated that when nano-SiO2 particles were used in the AAm/AAc copolymerization process, the microstructure and morphology of product changed from porous hydrogel to a nanocomposite microgel with cauliflower-like morphology. According to FESEM images, the copolymerization of AAm and AAc monomers with a nanosilica functional monomer or polymerizable nanosilica particle as a seed led to a microgel with core–shell structure and morphology. These results demonstrated that the polymerizable vinyl group on nano-SiO2 particles have controlled the copolymerization and the product morphology. FTIR analysis showed that the copolymeric chains of polyacrylamide (PAAm) and poly (acrylic acid) (PAAc) were chemically bonded to the surfaces of the nano-SiO2 particles and silane-modified nano-SiO2. The particulate character of microgel samples and the existence of long distance among aggregations of particles led to rapid swelling and increasing of porosity and therefore increasing of degree of swelling.
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Fan, Xin. "Preparation and Mechanical Property of PLLA/Nano-SiO2 Composite." Advanced Materials Research 476-478 (February 2012): 367–70. http://dx.doi.org/10.4028/www.scientific.net/amr.476-478.367.
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Blends of Poly(L-lactide) (PLLA) and nano-SiO2 powder were prepared via solution mixing. Effect of nano-SiO2 particles on the crystallinity of PLLA in composite was investigated by X-ray diffraction, the result indicated that the incorporation of nano-SiO2 did not influence the crystallinity of PLLA in composite. The bending strength and modulus of the PLLA/nano-SiO2 composites with varying nano-SiO2 content were tested, showing that the bending strength reduced with the increase of nano-SiO2 content and the bending modulus increased. The SEM graphs of PLLA/nano-SiO2 composites were illustrated that the cross-section of composites varied from brittle to ductile fracture with the content of nano-SiO2 increasing up to 10 %, and changed from ductile to brittle fracture with further increasing of nano-SiO2 content.
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Nguyen Thi, My Hanh, and Phung Ton That. "Employing SiO2 nano-particles in conformal and in-cup structures of 8500 K white LEDs." Bulletin of Electrical Engineering and Informatics 10, no. 3 (2021): 1709–17. http://dx.doi.org/10.11591/eei.v10i3.3042.
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SiO2 nano-particles have been examined in a distant phosphor structure for the elevated luminous quality and better consistency of white light-emitting diodes with angular-dependent associated color temperature (CCT). The luminous scattering ability could be increased by applying SiO2 nano-particles contain silicone to the outside of the phosphorus coating. In specific, the strength of blue light at wide angles is increased and differences in CCT can be minimized. In addition, owing to the sufficient refractive indices of silicone-containing SiO2 nanoparticles between the air and phosphorus layers, the luminous flux was improved. This new configuration decreases angular-dependent CCT deviations in the range of -700 to 700 from 1000 to 420 K. In comparison, at a 120 mA driving current, the rise of lumen flux increased by 2.25% relative to an usual distant phosphor structure without SiO2 nano-particles. As a result, in a distant phosphor structure, the SiO2 nano-particles could not only enhance the uniformity of illumination but also enhance the output of light.
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My, Hanh Nguyen Thi, and Ton That Phung. "Employing SiO2 nano-particles in conformal and in-cup structures of 8500 K white LEDs." Bulletin of Electrical Engineering and Informatics 10, no. 3 (2021): pp. 1709~1717. https://doi.org/10.11591/eei.v10i3.3042.
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SiO2 nano-particles have been examined in a distant phosphor structure for the elevated luminous quality and better consistency of white light-emitting diodes with angular-dependent associated color temperature (CCT). The luminous scattering ability could be increased by applying SiO2 nano-particles contain silicone to the outside of the phosphorus coating. In specific, the strength of blue light at wide angles is increased and differences in CCT can be minimized. In addition, owing to the sufficient refractive indices of silicone-containing SiO2 nanoparticles between the air and phosphorus layers, the luminous flux was improved. This new configuration decreases angular-dependent CCT deviations in the range of -700 to 700 from 1000 to 420 K. In comparison, at a 120 mA driving current, the rise of lumen flux increased by 2.25% relative to an usual distant phosphor structure without SiO2 nano-particles. As a result, in a distant phosphor structure, the SiO2 nano-particles could not only enhance the uniformity of illumination but also enhance the output of light.
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Yu, Cong, GuanJun Zhang, and Yangzi Liu. "Influence of SiO2 nanoparticles and Fe3O4 solution on the consolidation of geological soft soil." Materials Express 13, no. 11 (2023): 1936–43. http://dx.doi.org/10.1166/mex.2023.2548.
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Soft soil is widely distributed in coastal areas and needs to be treated first when used as a foundation. A method of incorporating nano SiO2 particles and nano Fe3O4 solution is proposed to address the consolidation problem of geological soft soil. During the process, nanomaterials are selected and a preparation method for incorporating nanomaterial soil is designed. Subsequently, the experimental device is designed and the main instrument usage methods are specified, resulting in a complete experimental process design. The experimental results showed that in the generation of electron microscope images of soil, the soil mixed with nano SiO2 particles or nano Fe3O4 solution has a denser characterization; In the experiment of current variation in soil, the maximum current of the soil mixed with nano SiO2 particles is 0.1052 A at 72 hours; In the soil drainage test, the maximum total drainage of the soil mixed with nano Fe3O4 material at the end reached 1907 mL; In the soil pH value experiment, the pH value of the soil is higher when the proportion of nano SiO2 material added is 3‰ and the proportion of nano Fe3O4 material added is 2‰. The above results indicate that the geological soft soil consolidation method designed by the research institute incorporating nano SiO2 materials or nano Fe3O4 materials can effectively improve the drainage and mechanical properties of the soil.
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Yu, Ying, Min Zhi Rong, and Ming Qiu Zhang. "Friction and Wear of Epoxy Composites Containing Silica Nanoparticles Grafted by Hyperbranched Aromatic Polyamide." Polymers and Polymer Composites 20, no. 8 (2012): 673–82. http://dx.doi.org/10.1177/096739111202000802.
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Nano-sized SiO2 particles grafted with hyperbranched aromatic polyamide were employed as fillers for fabricating epoxy based composites. The hyperbranched aromatic polyamide was selected because its terminal amine groups could take part in the curing reaction of epoxy resin and covalently connect silica nanoparticles with the matrix. The experimental results proved the occurrence of this reaction, and indicated that the presence of the grafted SiO2 in epoxy does not change the overall curing mechanism of epoxy. In comparison to the composites filled with untreated nano-SiO2 particles, the composites with the grafted nano-SiO2 exhibited significantly improved sliding wear resistance and reduced frictional coefficient owing to the strong filler/matrix interfacial bonding. Moreover, hyperbranched aromatic polyamide grafted nano-SiO2 was more effective to enhance tribological properties of epoxy than linear polymers grafted versions.
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Ohno, Tomoya, Takeshi Matsuda, Naoki Wakiya, and Hisao Suzuki. "Preparation of the TiO2 - SiO2 nano-hybrid particles by Nano-coating of TiO2 layer on Monodispersed SiO2 Nano-particles." Transactions of the Materials Research Society of Japan 32, no. 1 (2007): 155–58. http://dx.doi.org/10.14723/tmrsj.32.155.
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Patel, Krishan Kumar, and Rajesh Purohit. "Dispersion of SiO2 Nano Particles on Epoxy Based Polymer Nano Composites and its Characterization." Oriental Journal of Chemistry 34, no. 6 (2018): 2998–3003. http://dx.doi.org/10.13005/ojc/340641.
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In present work we developed and characterized the thermosetting epoxy polymer nano composites containing different weight percentage (wt. %) of SiO2 nano particles ranging from 1 to 4 wt. % were prepared through solvent casting route. grain analysis, FTIR, shape recovery, impact stress, tensile, flexural strength and hardness were studied. The properties of composites were improved at 3 wt. % SiO2 nano particles, further loading of nano particles beyond 3 wt. % properties goes to suppressed which may depends on the dispersion of particles within matrix. Shape recovery test was done in this epoxy which may open the new gate for low cost shape memory polymer as we can say novelty of this experiment. The distribution and size of nano particles in epoxy based polymer matrix were examined through AFM analysis finally outlined.
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Han, Zhi Dong, Li Min Dong, Ze Wu, and Xian You Zhang. "Structure and Magnetic Properties of BaLa0.5Fe11.5O19/ SiO2." Key Engineering Materials 368-372 (February 2008): 626–28. http://dx.doi.org/10.4028/www.scientific.net/kem.368-372.626.
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The paper aims at synthesizing La substituted BaM hexaferrites (BaLa0.5Fe11.5O19) in the presence of SiO2 nano-particles by sol-gel method. Effects of SiO2 nano-particles on the structure and particle size of hexaferrites are investigated by XRD and SEM. Magnetic properties of BaFe12O19, BaLa0.5Fe11.5O19 and BaLa0.5Fe11.5xO19/SiO2 are compared by vibrating sample magnetometer (VSM). The XRD patterns of BaLa0.5Fe11.5O19/SiO2 calcined at 1000°C manifest that all the species have hexagonal crystal structure and no diffraction peaks of SiO2 are found. Compared with BaLa0.5Fe11.5O19 powders, those synthesized in the presence of SiO2 nanoparticles present in smaller powder size, as proved by SEM. The results of VSM reveal that BaLa0.5Fe11.5O19 possesses much higher saturation magnetization than BaFe12O19. BaLa0.5Fe11.5xO19/SiO2 also shows higher saturation magnetization than BaFe12O19, but lower than BaLa0.5Fe11.5O19 because of addition of nano-SiO2.
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Alireza Naji Givi, Suraya Abdul Rashid, Farah Nora A. Aziz, and Mohamad Amran Mohd Salleh. "Particle size effect on the permeability properties of nano-SiO2 blended Portland cement concrete." Journal of Composite Materials 45, no. 11 (2010): 1173–80. http://dx.doi.org/10.1177/0021998310378908.
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In this study, nano-SiO2 has been used as a high reactive pozzolan to develop the microstructure of the interfacial transition zone between the cement paste and the aggregate. Mechanical tests of blended cement-based concretes exposed that in addition of the pozzolanic reactivity of nano-SiO2 (chemical aspect), its particle grading (physical aspect) also revealed considerable influences on the blending effectiveness. It was concluded that the relative permeability reduction (relative to the control concrete made with plain cement) is higher for coarser nano-SiO2 after 90 days of moisture curing. However, finer nano-SiO2 particles showed better effects in early ages. These phenomena can be due to the free spacing between mixture particles that was associated with the global permeability of the blended cement-based concretes. This article presents the results of the effects of particle size ranges involved in nano-SiO2 blended Portland cement on the water permeability of concrete. It is revealed that the favorable results for coarser nano-SiO2 reflect enhanced particle packing formation accompanied by a reduction in porosity and particularly in particle spacing after 90 days.
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Sanjuán, M. A., C. Argiz, J. C. Gálvez, and E. Reyes. "Combined effect of nano-SiO2 and nano-Fe2O3 on compressive strength, flexural strength, porosity and electrical resistivity in cement mortars." Materiales de Construcción 68, no. 329 (2018): 150. http://dx.doi.org/10.3989/mc.2018.10716.
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The compressive strength, flexural strength, porosity and electrical resistivity properties of cement mortars with nano-Fe2O3 and nano-SiO2 are studied. Amorphous silica is the main component of pozzolanic materials due to its reaction with calcium hydroxide formed from calcium silicate (C3S and C2S) hydration. The pozzolanic reaction rate is not only proportional to the amount of amorphous silica but also to the surface area available for reaction. Subsequently, fine nano-Fe2O3 and nano-SiO2 particles in mortars are expected to improve mortar performance. The experimental results showed that the compressive strength of mortars with nano-Fe2O3 and nano-SiO2 particles were lower than those obtained with the reference mortar at seven and 28 days. It was shown that the nano-particles were not able to enhance mechanical strength on every occasion. The continuous microstructural progress monitored by mercury intrusion porosimetry (MIP) measurements, pore-size distribution (PSD), total porosity and critical pore diameter also confirmed such results.
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Ms.S.Bharathi and Mr.S.Manikandan. "EXPERIMENTAL ANALYSIS OF ABRASION RESISTANCE IN PAVER BLOCKS WITH NANO-PARTICLE ADDITIVE." international journal of engineering technology and management sciences 9, no. 2 (2025): 918–23. https://doi.org/10.46647/ijetms.2025.v09i02.116.
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The abrasion resistance of paver blocks containing nano-particles for pavement is experimentallystudied. Both nano-TiO2 and nano-SiO2 are, respectively, employed to be as the additives. Forcomparison, the abrasion resistance of plain paver block and the paverblock containing polypropylene(PP) fibers is also experimentally studied in this work. The test results indicate that the abrasionresistance of concretes containing nano-particles andPP fibers is significantly improved. However,the indices of abrasion resistance of paver block containing nano-particles are much larger than thatof paver block containing PP fibers. The abrasion resistance of paver block containing nano-TiO2 isbetter than that containing the same amount of nano-SiO2. The enhanced extent of the abrasionresistanceof paver block decreases with increasing content of nano-particles. Finally, the relationshipbetween the indices of abrasion resistance and compressive strength of concrete, water absorptiontest will find out.
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Chen, Xiaolong, Yutong Zheng, Yuzhi Jiang, Yaxiong Ji, Shifeng Wang, and Fujia Yu. "Simple and Rapid High-Yield Synthesis of Sub-100 nm Nano-SiO2·0.5H2O Particles Based on Wollastonite." Coatings 9, no. 10 (2019): 662. http://dx.doi.org/10.3390/coatings9100662.
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Amorphous nano-SiO2·nH2O particles has drawn much attention in industrial applications because of the features of high purification, low density, large specific surface area, fine decentralization, good optical, and mechanical performances. However, the applications have been hindered by the exorbitant price and the serious agglomeration. In this work, using wollastonite as reactant, H2SO4 as solvent, and adding sodium dodecyl benzene sulfonate (SDBS) as surfactant, sub-100 nm amorphous nano-SiO2·0.5H2O particles with good dispersibility, controllable agglomeration, narrow size distribution, and high yield were prepared by a low-cost and simple chemical method. The prepared sphere-like amorphous nano-SiO2·0.5H2O particles with average diameter of 70 nm were absorbed by the SDBS on the surface. The reaction conditions were systematically studied and the optimal technologic condition of the preparation was also confirmed. The achievement had a great perspective for the industrialization of high-quality nano-SiO2·nH2O particles, which hold great promise for various applications, such as plasmonic and catalytic nanoparticles supporting, polymeric matrices strengthening, drug delivery, and adsorption processes.
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Zhang, Peng, Ya-nan Zhao, Chen-hui Liu, Peng Wang, and Tian-hang Zhang. "Combined effect of nano-SiO2 particles and steel fibers on flexural properties of concrete composite containing fly ash." Science and Engineering of Composite Materials 21, no. 4 (2014): 597–605. http://dx.doi.org/10.1515/secm-2013-0179.
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AbstractThis paper presents an experimental study to evaluate the combined effect of nano-SiO2 particles and steel fibers on flexural properties of concrete composites containing fly ash. In this study, five different nano-SiO2 contents (1%, 3%, 5%, 7%, and 9%) and five different steel fiber contents (0.5%, 1%, 1.5%, 2%, and 2.5%) were used. The results indicate that addition of nano-SiO2 and steel fibers decreases the workability of the concrete composites containing fly ash, and both the slump and slump flow decrease gradually with the increase in nano-SiO2 and steel fiber content. Besides, the addition of nano-SiO2 can greatly increase the flexural strength and flexural modulus of elasticity of concrete composites containing fly ash. There is a tendency for the increase in the flexural strength flexural modulus of elasticity with an increase in the nano-SiO2 content when the nano-SiO2 content is below 5%, while both of the two flexural parameters begin to decrease after the nano-SiO2 content above 5%. Furthermore, steel fibers have great improvement on the flexural properties of concrete composites containing fly ash and nano-particles. The flexural strength and flexural modulus of elasticity of concrete composites containing fly ash and nano-SiO2 are more than those of the concrete composite without steel fibers. Both of the two flexural parameters increase with the increase in steel fiber content when the steel fiber content is below 2%, while the flexural parameters begin to decrease after the steel fiber content is above 2%.
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Chang, C. I., Y. N. Wang, H. R. Pei, C. J. Lee, X. H. Du, and J. C. Huang. "Microstructure and Mechanical Properties of Nano-ZrO2 and Nano-SiO2 Particulate Reinforced AZ31-Mg Based Composites Fabricated by Friction Stir Processing." Key Engineering Materials 351 (October 2007): 114–19. http://dx.doi.org/10.4028/www.scientific.net/kem.351.114.
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Friction stir processing (FSP) has been applied to fabricate 10~20 vol% nano-sized ZrO2 and 5~10 vol% nano-sized SiO2 particles into an Mg-AZ31 alloy to form bulk composites under the FSP parameters of advancing speed of 800 rpm and pin rotation of 45 min/min. The microstructures and mechanical properties of the resulting composites were investigated. The clustering size of nano-ZrO2 and nano-SiO2 particles, measuring average ~200 nm was relatively uniformly dispersed, and the average grain size of the both Mg alloy of the composites varied within 1.0~2.0 μm after four FSP passes. No evident interfacial product between ZrO2 particles and Mg matrix was found during the FSP mixing in AZ31-Mg/ZrO2. However, significant chemical reactions at the AZ31-Mg/SiO2 interface occurred to form the Mg2Si phase. The mechanical responses of the nano-composites in terms of hardness and tensile properties are examined and compared.
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Li, Qing Hua, and Jian Hua Zhang. "Effects of Nano Fillers on the Conductivity, Adhesion Strength and Reliability of Isotropic Conductive Adhesives (ICAs)." Key Engineering Materials 353-358 (September 2007): 2879–82. http://dx.doi.org/10.4028/www.scientific.net/kem.353-358.2879.
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Isotropic Conductive Adhesives (ICAs) were prepared using epoxy resin as matrix, latent curing agent as hardener, and silver particles as the conducting filler. The effects of nano-fillers (SiO2 nano-particles and carbon nanotubes) on the conductivity, adhension strength and reliability of ICAs were investigated experimentally in this paper. The results showed that these two nano fillers can improve both the conductivity and adhesion strength of ICAs, which maybe attributed to the nano-particles forming physico-chemical bonds with epoxy resin. These physico-chemical bonds increase the contact area and then minish the interspace of Ag particles, so it reduces electrical resistance and enables a high current flow. And the increasing contact area will improve the contact strength between Ag particles and epoxy resin. Under the reliability testing with the high temperature and high humidity (85°C/85RH), the SiO2 nano-particles can improve the reliability of ICAs apparently, while carbon nanotubes can not. This is because insulating material can prevent silver migration.
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Li, Xi Hong, Yao Xiao, Biao Wang, Ya Qing Lu, Yao Tang, and Cheng Jun Wang. "Effects of Nano-Particles on Resistance of DOP Migration from Flexible PVC." Advanced Materials Research 160-162 (November 2010): 401–6. http://dx.doi.org/10.4028/www.scientific.net/amr.160-162.401.
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The effects of nano-particles (CaCO3, SiO2 and organic modified montmorillonite (OMMT) on the suppression of DOP migration from PVC matrix and mechanical properties of PVC composites were evaluated. The results indicated that the three kinds of nano-particles could improve the ability of anti-migration of DOP in flexible PVC. A certain content of nano-particle could decrease the migration rate of DOP. The addition of 5 phr SiO2 decreased the extraction rate of DOP to 15.6%, and SiO2-5/PVC composite film possessed superior anti-extraction property. The introduction of 5 phr OMMT reduced the volatilization of DOP to 0.067%, and OMMT-5/PVC exhibited the lowest volatilization of DOP. Inorganic nano-particles with high surface energy were easy to aggregate, and the influences of aggregation on the properties of composites were clearly detrimental, which results in a drastic decrease of polymer anti-migration and mechanical performance.
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Kumar, Kakara S. J., M. V. Seshagiri Rao, V. Srinivasa Reddy, and S. Shrihari. "Performance evaluation of nano-silica concrete." E3S Web of Conferences 184 (2020): 01076. http://dx.doi.org/10.1051/e3sconf/202018401076.
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In this paper, the study of the influence of nano-silica (nano-SiO2) on the properties of the interface between CSH gel and cement particles and its effect on nano-mechanical properties of the products at the interface zone was examined. In this paper M50 grade SCC mixes were developed using 5% micro-silica and various percentages of 0.5%, 1.0% and 1.5% nano-SiO2. For 1.0% nano-SiO2 addition to M50 grade SCC mix, the compressive strength is maximum. Similarly concrete quality using non-destructive techniques, water absorbtion capacity and porosity are also assessed.
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Luo, Xiaoqian, Lingwei Kong, and Wei Bai. "Effect of Superhydrophobic Nano-SiO2 on the Hydraulic Conductivity of Expansive Soil and Analysis of Its Mechanism." Applied Sciences 13, no. 14 (2023): 8198. http://dx.doi.org/10.3390/app13148198.
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The present work determined the influence of superhydrophobic nano-SiO2 on the hydraulic conductivity and pore size distribution of expansive soil, and analysed the mechanism of modification between superhydrophobic nano-SiO2 and expansive soil from a microscopic view. Superhydrophobic nano-SiO2 was added to expansive soil as a modifier. Our samples were of two types, i.e., unmodified (without nano-SiO2) and modified (with 0.2%, 0.4%, 0.6%, 0.8%, and 1.0% nano-SiO2 by weight of the parent soil). The hydraulic conductivity decreased with increasing nano-SiO2 content. Fourier transform mid-infrared test revealed that some silanols in soil and nano-SiO2 were dehydrated and condensed to form siloxanes. We inferred that nano-SiO2 can attach onto the surface of soil particles to form a hydrophobic membrane, which reduced the soil expansion and the change in pore size distribution. And microscopic tests showed that the pore volume and hydrophilicity of the soil samples decreased with increasing SiO2 content. According to the Young–Laplace equation, the minimum permeable pore radius was calculated in the hydraulic-conductivity test. With increasing nano-SiO2 content, the volume of permeable pore decreased. It had an excellent linear relationship with the hydraulic conductivity and permeable pore volume of samples containing different nano-SiO2 contents. Therefore, superhydrophobic nano-SiO2 could effectively reduce hydraulic conductivity by changing the pore size distribution of expansive soil.
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Sharef, Enas M., and Jamal M. A. Ali. "The Effect of Micro and Nano Material on Critical Heat Flux (CHF) Enhancement." Al-Khwarizmi Engineering Journal 15, no. 1 (2019): 109–16. http://dx.doi.org/10.22153/kej.2019.06.003.
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The Nano materials play a very important role in the heat transfer enhancement. An experimental investigation has been done to understand the behaviors of nano and micro materials on critical heat flux. Pool boiling experiments have used for several concentrations of nano and micro particles on a 0.4 mm diameter nickel chrome (Ni-Cr) wire heater which is heated electrically at atmospheric pressure. Zinc oxide(ZnO) and silica(SiO2) were used as a nano and micro fluids with concentrations (0.01,0.05,0.1,0.3,0.5,1 g/L), a marked enhancement in CHF have been shown in the results for nano and micro fluids for different concentrations compared to distilled water. The deposition of the nano particles on the heater surface was the reason behind the enhancement of the wettability of the surface which will increase the CHF, this nano particles deposition will form a porous layer and the mechanism of the formation of this layers is that as vapor bubbles grow, the evaporating liquid in the micro layer leaves behind Nano particles which then will be concentrated at the base of the bubble to form this pours layer. The higher wettability can produce CHF enhancement, the enhancement ratio of Nano fluid is observed to be higher than that of micro fluid, the optimum enhancement ratios of nano fluid is (1 g/l) which observed to be 9.2 % for ZnO and 8.7% for Sio2, and also (1 g/l) for micro fluid which observed to be 8.1%for ZnO and 7.4%for SiO2.
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Fujimoto, Masayuki, Tomoya Ohno, Hisao Suzuki, Hiroshi Koyama, and Junzo Tanaka. "Nanostructure of TiO2 Nano-Coated SiO2 Particles." Journal of the American Ceramic Society 88, no. 11 (2005): 3264–66. http://dx.doi.org/10.1111/j.1551-2916.2005.00583.x.
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Picanço, Wagner M., Bianca de A. Feitosa, Noam G. da Silva, et al. "Aniline-oriented polymerization over nano-SiO2 particles." Journal of Molecular Structure 1167 (September 2018): 118–26. http://dx.doi.org/10.1016/j.molstruc.2018.04.087.
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Kheyrkhah, Mohsen, Mohsen Janmohammadi, Amin Abbasi, and Naser Sabaghnia. "The Effects of Micronutrients (Fe And Zn) and Beneficial Nano-Scaled Elements (Si And Ti) on Some Morphophysiological Characteristics of Oilseed Rape Hybrids." Agriculture (Pol'nohospodárstvo) 64, no. 3 (2018): 116–27. http://dx.doi.org/10.2478/agri-2018-0012.
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Abstract Current experiment was conducted to investigate the effects of foliar application of different nutrients (control, nano-chelated Fe, nano-chelated Zn, nano-TiO2, nano-Si) on seed yield and morpho-physiological characteristics of oilseed rape cultivars (Hydromel, Neptune, Nathalie, Danube, Alonso). The highest pod numbers was achieved by foliar application of Zn and nano-SiO2 in cv. Hydromel and Neptune. The heaviest seeds were recorded for plants treated with nano-SiO2. The highest seed yield was recorded for cv. Hydromel and Neptune treated with Fe and nano-TiO2. The highest indole acetic acid was recorded in cv. Hydromel treated with Zn and nano-SiO2. The evaluation of plant pigments revealed that foliar application of nano-SiO2 and TiO2 significantly increased the concentration of carotenoids and Chlorophyll a, b. Overall, the results indicate that cultivating the high yielding hybrids (Hydromel, Neptune, Nathalie) along with the application of iron, SiO2 and TiO2 nano-particles can greatly improve plant performance
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Thirumavalavan, P., Venckatesh Rajendran, and Rajeshwari Sivaraj. "Synthesis, Characterization of SiO2/TiO2 and SiO2/Al2O3 Nano-Composites for the Photo-Degradation of Acid Brown- 43 dye with Irradiation of Solar Light." Oriental Journal of Chemistry 34, no. 5 (2018): 2637–42. http://dx.doi.org/10.13005/ojc/340555.
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In this study we have found that photo degradation of Acid brown- 43 dye with irradiation Solar light Using synthesized SiO2/ TiO2 and SiO2/Al2O3 Nano-composites which prepared by chemical precipitation technique using microwave irradiation. The structure and morphology of SiO2/TiO2 and SiO2/Al2O3) Nano composites were characterized by SEM, EDAX & TEM analysis. The similarities in photo degradation mechanism, SiO2 , Al2O3 and TiO2 have as good as band gap energy, and possess worthy standing as photo-catalysts. SiO2/TiO2 and SiO2/Al2O3 nanoparticles have large surface area and thus provide a large number of active sites for interaction among the particles of different oxides. This synthesized Nano-composites of SiO2/TiO2 and SiO2/Al2O3 photo-catalyst sample showed tremendous photo-catalytic activity for the degradation of Acid Blue - 43 under direct exposure to solar irradiation with respect to exposed time and dose of Nano-composites.
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Qaid, Dalya Shaker, and Abbas Alwi Sakhir. "Experimental study of a domestic refrigerator using (SiO 2 /PAG oil/R- 134a) nano-refrigerant as a replacement for pure R-134a." Al-Qadisiyah Journal for Engineering Sciences 15, no. 1 (2022): 038–41. http://dx.doi.org/10.30772/qjes.v15i1.830.
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This research studies the influence of using SiO2 nano-particles of 50nm in a Vapor Compression Refrigeration System (VCRS), along with Poly-alkylene Glycol (PAG) oil and R-134a mixed to create a nano-refrigerant. In this work, the nano-particles were performed in three different concentrations (0.1%, 0.3%, and 0.5%) and mixed with 200ml of PAG oil. AVCR system was built at the mechanical engineering department laboratory in Al-Qadisiyah University to study the Coefficient of Performance (COP) and the consumed energy by the compressor in the two cases of adding the nano-particles and using a pure refrigerant. The paper showed an increase in the system's COP from 2.3 to 2.81 when using a concentration of 0.5% of SiO2/PAG oil/R-134a, increasing the refrigeration effect and decreasing the consumed power.
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Chen, Xiao Dong, Tie Jun Ma, Hai Zhang та Rong Sheng Chen. "Synthesis, Characterization and Properties of Poly (ε-Caprolactone) Glycol Based Casting Polyurethane Elastomers Containing Nano-Size Sio2 Particles". Advanced Materials Research 148-149 (жовтень 2010): 1394–99. http://dx.doi.org/10.4028/www.scientific.net/amr.148-149.1394.
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Poly(ε-caprolactone) (PCL) glycol based casting polyurethane elastomers (CPUE) filled with nano-SiO2 particles within different surface properties were synthesized by mean of in-situ polymerization. The macro-static/dynamic mechanical properties and micro-dispersed state were characterized by an electronmechanical universal testing machine, a durometer, a rubber resilience experimental machine, a dynamic-mechanical analyzer (DMA) and a scanning electron microscope (SEM). The tensile modulus at 100% and 300%, elongation at break, tensile strength and tear strength of PCL urethane nanocomposites increased substantially in the presence of a certain amount of nano-SiO2 compared with their pristine state. Furthermore, the tensile strength and tear strength at 100 of the PCL CPUE with 5% nano-SiO2 pretreated by γ-glycidochloropropyl methyl trimethoxy silane (SI-CA) were 1.50 and 1.94 times than those of the pure PCL CPUE, respectively. The addition of the nano-SiO2 had little effect on the hardness, but the impact resilience decreased slightly. DMA analyses showed that the loss factor peaks of two nano-SiO2 polyurethane composites were higher obviously than the pure PCL CPUE and the glass transition temperature （Tg）of the two nano-SiO2 polyurethane composites increased to higher temperature region. SEM fractographs showed that the surface treatment by the optimum silane coupling agent influenced the dispersibility of nano-SiO2 in the PCL CPUE distinctly. The agglomerating phenomenon, and even some nano-agglomerates with more than 1 μm diameter can be observed in the PCL CPUE with 5% untreated nano-SiO2, but the nano-SiO2 pretreated by SI-CA was dispersed in the PCL CPUE in nano-scale.
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Xing, Lei, Tian Xia, and Qiaoxin Zhang. "Effect of Hydrophobic Nano-SiO2 Particle Concentration on Wetting Properties of Superhydrophobic Surfaces." Nanomaterials 12, no. 19 (2022): 3370. http://dx.doi.org/10.3390/nano12193370.
Full textAbstract:
As a unique surface wettability, superhydrophobicity has great application value. A variety of preparation methods for superhydrophobic surfaces have been reported, which have the disadvantages of high cost and complicated process. In order to design a method that is easy to operate, low-cost, and suitable for large-scale preparation of superhydrophobic surfaces, in this paper, hydrophobic nano-SiO2 particles are used as spray fillers, and superhydrophobic surfaces are successfully obtained by the spraying process. According to the classical Cassie and Wenzel theory, the influence of the concentration change of hydrophobic nano-SiO2 particles on their wettability is explained, and the appropriate spray concentration parameters are obtained. The results show that the proportion of hydrophobic nano-SiO2 particles is lower than 0.05 g/mL, which will lead to insufficient microstructure on the surface of the coating, and cannot support the droplets to form the air bottom layer. However, an excessively high proportion of hydrophobic nano-SiO2 particles will reduce the connection effect of the silicone resin and affect the durability of the surface. Through theoretical analysis, there are Wenzel state, tiled Cassie state, and stacked Cassie state in the spraying process. When the substrate surface enters the Cassie state, the lower limit of the contact angle is 149°. This study has far-reaching implications for advancing the practical application of superhydrophobic surfaces.
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Sun, Wei Wei, Wen Hao Fan, Shao Ping Chen, Yi Yun Li, and Qing Sen Meng. "The Effect of Nano-SiO2 Addition on Electrical Properties of the Thermoelectric Compound Ca3Co4O9." Advanced Materials Research 465 (February 2012): 292–95. http://dx.doi.org/10.4028/www.scientific.net/amr.465.292.
Full textAbstract:
Abstract. Ca3CO4O9/x wt.%SiO2 composites were prepared by using field-activated pressure-assisted synthesis(FAPAS) process. The effects of nano-SiO2 addition on the microstructure and thermoelectric properties of the Ca3CO4O9 were investigated. With an increasing of the of SiO2 content, the size of Ca3Co4O9 particles decreased. The Seebeck coefficient decreased after the doping of nano-SiO2. The electrical conductivity firstly increased and then decreased with increasing amount of nano-SiO2 and the highest value belong to the Ca3CO4O9/0.5 wt.% SiO2 - sample. With the highest electric conductivity and slightly decreased Seebeck coefficient, the Ca3CO4O9/0.5 wt.%SiO2-sample achieved the highest power factor of 0.349 mw/mk2 at 800 °C, which is 8% higher than the value of pure Ca3CO4O9 reported in the literature.
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Zhang, Mao Hua, Hong Guang Wang, and Jian Min Zhang. "Mechanical Property of Pavement Concrete with Nano-Particles." Advanced Materials Research 168-170 (December 2010): 1896–99. http://dx.doi.org/10.4028/www.scientific.net/amr.168-170.1896.
Full textAbstract:
Mechanical properties of pavement concrete with nano-particles are experimentally studied and compared with that of plain pavement concrete. The test results indicate that the flexural, compressive and splitting tensile strengths of pavement concrete with nano-particles are all improved with different extent. Firstly, the mechanical properties of pavement concrete are enhanced with the increasing content of nano-particles, and the peak values are achieved at certain content. Subsequently, the mechanical properties of pavement concrete are reduced with the increasing content of nano-particles. The optimum amount of nano-TiO2 and nano-SiO2 added into pavement concrete are respectively 1.0% and 2.0%. There is a significant linear relationship between flexural and compressive strengths of pavement concrete with nano-particles.
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Stojanovic, Dusica, Goran Vukovic, Aleksandar Orlovic, et al. "Dispersion and deagglomerat1on of nano-SiO2 particles with a silane modification reagent in supercritical CO2." Chemical Industry 61, no. 3 (2007): 109–16. http://dx.doi.org/10.2298/hemind0703109s.
Full textAbstract:
The supercritical CO2 method was used in order to perform deagglomeration and improve the dispersion of nano-SiO2 particles. ?-Met-hacryloxypropyltrimethoxysilane was used as the surface modification reagent. The conventional method for coating nano-SiO2 particles was used as the comparison method. Considerable improvement of the dispersion and deagglomeration was found using supercritical CO2. Analysis of the TEM micrographs and DLS results showed the reduction of the average size of the agglomerates with the silane coupling reagent. Thermogravimetric analysis (TGA) showed that the particles treated in super?critical CO2 were more thermally stable than particles treated by conventional method. Encapsulation of several particles coated with the silane coupling reagent was observed in certain parts of the primary particles. A chemical reaction takes place between the modification reagent, MEMO silane, and active hydroxyl groups on the surface of the nano-SiO2 particles. A larger quantity of MEMO silane reacted using the con?ventional method instead of the supercritical method. On the other hand, the reacted silane molecules were better arranged around the particle surface in the supercritical method because of the formation of covalent or self-assembled structures. Polycondensed structures were preferentially obtained in the conventional method. This was achieved by using supercritical CO2, which has a high solvating power such as organic solvents and physical properties (low viscosity, low surface tension and high diffusion coefficient) similar to gases on the other side. These properties enable the sufficient and uniform wettability of nano-SiO2 particle surfaces. These results are important for obtaining nanofillers with improved dispersion and polymer wettability. Such nanofillers can be used to obtain composite materials with considerably improved mechanical characteristics.