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Nanobioremediation Technologies for Clean Environment
Published in Amitava Rakshit, Manoj Parihar, Binoy Sarkar, Harikesh B. Singh, Leonardo Fernandes Fraceto, Bioremediation Science From Theory to Practice, 2021
B. Chakrabarti, P. Pramanik, S.P. Mazumdar, R. Dubey
Graphene oxides and modification of graphene oxide or graphene with metal oxides or organics produce various nanocomposites which are useful in removal of pollutants from air and water (Wang et al. 2013). Various researchers reported that use of graphene and its other composite for the removal of heavy metals from wastewater was getting more attention due to its high surface area, mechanical strength, light weight, flexibility and chemical stability (Azamat et al. 2015, Dong et al. 2015, Vu et al. 2016, Zare-Dorabei et al. 2016, Ding et al. 2014). Besides these, different types of silicon nanomaterial like silicon nanotubes, silicon nanoparticles and silicon nanosheets are also used as nano-adsorbents. In addition to this, nanoclays, polymer-based nanomaterials, nanofibres, and aerogels are some of the nanomaterials used for adsorption of heavy metals from wastewater. Although use of CNTs for pollutant removal have several advantages, high cost of CNTs hinder their commercial use. Therefore, for production and use at commercial scale the technology needs to become economically viable.
Relativistic Augmented Cylindrical Wave Method
Published in Pavel N. D’yachkov, Quantum Chemistry of Nanotubes, 2019
Geometry of the hexagonal silicon nanotubes can be constructed by folding a monolayer of silicon hexagons (silicene) in the form of cylinder. (Ezawa 2012a,b). Since the hexagonal silicon and carbon nanotubes have the same cylindrical structure and topology of chemical bonds, and the Si and C atoms belong to the same group of elements in the periodic table, one can expect a certain similarity between the spin properties of carbon and silicon nanotubes. The silicon nanotubes are obtained experimentally in various ways (Grünzel et al. 2013). It is possible to use them for creating field-effect transistors, waveguides, optoelectronic elements, chemical and biological sensors, for creating heterojunctions by combining carbon and silicon nanotubes (Wu et al. 2012, Park et al. 2009, Song et al. 2010, Espinosa-Soria and Martínez 2016, Ma et al. 2018). In literature, there are several examples of nonempirical calculations of the band structure of silicon nanotubes, but all neglecting the spin-orbit interaction effects and screw symmetry (Hever et al. 2012, Baňacký et al. 2013, Ezawa 2012a, b, Wang et al. 2017).
Silicon nanopowder synthesis by inductively coupled plasma as anode for high-energy Li-ion batteries
Published in Klaus D. Sattler, Silicon Nanomaterials Sourcebook, 2017
Dominic Leblanc, Richard Dolbec, Abdelbast Guerfi, Jiayin Guo, Pierre Hovington, Maher Boulos, Karim Zaghib
Nano-sized silicon structures are known to overcome the deteriorating effects of volumetric expansion as a result of their ability to relax the mechanical stresses. Various silicon nanostructures with high cycle life were demonstrated in the literature (silicon nanotubes, nanowires, nanoparticles). In general, as the size of silicon nanopowders decreases, their stability in cycling increases (Abel et al. 2012). In situ transmission electron microscopy (TEM) observations of the lithiation process suggested that no fracturing occurs when the Si particles are smaller than a threshold diameter of 150 nm (Liu et al. 2012; McDowell et al. 2013) (Figure 20.18).
Nonlinear coupled mechanics of nanotubes incorporating both nonlocal and strain gradient effects
Published in Mechanics of Advanced Materials and Structures, 2020
Mergen H. Ghayesh, Ali Farajpour
On the other hand, the NSGT-based constitutive equation of the Euler–Bernoulli nanoscale tube can be expressed as: where E and lm are, respectively, Young's modulus and the strain gradient coefficient of the NSGT continuum model. In addition, the nonlocal length-scale coefficient is indicated by e0a in which e0 and a represent the calibration constant and a geometric parameter related to the internal structure of the nanotube, respectively [37]. For instance, this parameter is usually set to the length of the C-C bond for a carbon nanotube [38]. However, other types of nanotubes such as silver, Cu, and silicon nanotubes can have a different value for a since their internal structures are entirely different. It should be noted that in the present study, for simplification purposes, the size-dependent effects along the thickness direction of the nanoscale tube are neglected. However, a nonlocal strain gradient model incorporating the thickness effect has been recently proposed by Li et al. [39] in order to predict the size-dependent static stability of ultrasmall beams. In their valuable paper, which can be used for future studies on nanotubes, they reported that the size-dependent effect of thickness can change the softening and hardening response of the stiffness. Using Eqs. (1)–(3) as well as Eq. (10), the stress resultants of the tube are formulated as:
Adsorption of cadmium by a high-capacity adsorbent composed of silicate-titanate nanotubes embedded in hydrogel chitosan beads
Published in Environmental Technology, 2020
Roxana Quiroga-Flores, Asma Noshad, Reine Wallenberg, Linda Önnby
In this study, we have produced a composite made of titanium-silicon nanotubes (STNTs) and chitosan that were produced in the form of hydrogel beads (STNTs-Ch beads). The composite was further characterized by studying the crystal phases and textural properties along with the interaction of the two components by Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and scanning electron microscopy, both coupled to energy X-ray dispersive spectrometer (XEDS). The composite was used for Cd2+ adsorption in batch solutions and to treat real leachate by using packed columns. Finally, we studied the recycling and the reuse of the composite, in parallel with an assessment of the saved amount of consumed chemicals involved in the process.
Use of nanoparticles for dye adsorption: Review
Published in Journal of Dispersion Science and Technology, 2018
Ioannis Anastopoulos, Ahmad Hosseini-Bandegharaei, Jie Fu, Athanasios C. Mitropoulos, George Z. Kyzas
Nanomaterials in adsorption uses can be classified into different groups such as: (a) nanoparticles (metallic, metal oxide, nanostructured mixed oxides, magnetic), (b) carbonaceous nanomaterials (carbon nanotubes, carbon nanoparticles, carbon nanosheets), (c) silicon nanomaterials (silicon nanotubes, silicon nanoparticles, silicon nanosheets), (d) nanoclays, (e) nanofibers, (f) polymer-based nanomaterials, and (g) xerogels and aerogels.[45]