Sensitivity Of Boron Nitride Nanotube Research Articles

The effect of chitosan adsorption on the stability characteristics of single- and double-walled boron-nitride nanotubes under compressive force using molecular dynamics simulations

In this study, the buckling behavior of functionalized single- and double-walled boron-nitride nanotubes (SWBNNTs and DWBNNTs) with a monomer of chitosan using molecular dynamics (MD) simulations is explored. The effect of chemical adsorption of chitosan molecule on the critical buckling force and strain is investigated. The results show that the critical buckling force considerably increases as the chitosan is attached to the side wall of boron-nitride nanotube which is more considerable for larger radii of nanotube. Moreover, increasing the number of walls reduces the sensitivity of boron-nitride nanotube to the functionalization compared with similar SWBNNTs. Further, it is shown that critical buckling of functionalized BNNTs increases by rising the weight percentage of chitosan. Considering the critical strain, it is observed that functionalization reduces the critical strain of functionalized BNNTs which is more pronounced in the case of SWBNNTs with bigger radii. Moreover, the buckling mode shape of functionalized BNNTs is presented.

Computational Investigation of 2,3,7,8-Tetrachlorodibenzo-Para-Dioxin (TCDD) Adsorption on Boron Nitride-Nanotube (BNNT)

The sensitivity of boron nitride nanotube (BNNT) to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is investigated by M06-2X/6-31++G**. There are different locations on BNNT to close and interact with the TCDD. In this study, the thermodynamic and electric properties, quantitative structure–activity relationship (QSAR), HOMO-LUMO energy, and other parameters are calculated for all these probabilities. The results show, the BNNTs (12, 0) can be used as nano-sensors and nano-filtration to reduce and eliminate the TCDD.

Ga-doped and antisite double defects enhance the sensitivity of boron nitride nanotubes towards Soman and Chlorosoman

Adsorption of Soman and Chlorosoman over the outer surface of boron nitride nanotube (BNNT) was studied using density functional theory (DFT) calculations to consider its sensitivity toward mentioned nerve agents. Then, we studied the sensitivity of Ga-doped BNNT and double-antisite defective BNNT (d-BNNT) effects towards adsorbed molecule resulting in eye-catching sensitivity of defected adsorbents representing strong chemical adsorption on the Ga-doped BNNT, while they are mainly physisorbed on the pure BNNT with negligible electronic properties. Density of states (DOSs) was analyzed for further understanding of electronic properties of the applied configurations. Charges were moved from BNNT to the single molecules while in case of Ga-doped and d-BNNT; the charges were transferred from single molecules to the defected adsorbents. These along with outcomes of quantum molecular descriptors, difference in energy gap (Eg), and dipole moments clearly reveal that the d-BNNT is a promising sensor material for the detection of these nerve agents.

Adsorption properties of boroxol ring doped zigzag boron nitride nanotube toward NO molecule using DFT

In previous researches it is demonstrated that reactivity and sensitivity of boron nitride nanotubes (BNNTs) toward gas molecules can be modified by impurity. In this work, oxygen defect for three nitrogen sites was used to study the adsorption of NO molecule through the surface of boroxol ring of oxygen doped BNNT (7,0) with different adsorption patterns, including side-on and end-on. All calculations are performed using the DFT-B3LYP/6-31G[Formula: see text] level of theory, and their electronic energies are corrected by gCP and D3 correction terms. High binding energies indicate that NO molecule undergoes chemical adsorption with large charge transfer from the tube which can significantly change electronic properties of the tube. Density of state (DOS) and partial DOS (PDOS) analyses revealed that adsorption of NO molecule on the boroxol ring position is covalent in nature with significant effect on the electronic properties of tube. The Laplacian of electron density, Lagrangian kinetic energy density, Hamiltonian kinetic energy density and potential energy density at bond critical points between the tube and NO indicate that the interaction between the tube and NO molecule is covalent in nature. Topological analysis of the electron localization function shows that electrons in the new formed bonds are approximately localized, meaning that the nature of adsorption process is chemical covalent. The studied nanotube is a suitable candidate to filter and eliminate NO gas molecule.

Adsorption of carbon monoxide on boroxol-ring-doped zigzag boron nitride nanotube: Electronic study via DFT

Previous works have already demonstrated that reactivity and sensitivity of boron nitride nanotubes (BNNTs) toward gas molecules can be modified by impurity. In this work, three nitrogen atoms of BNNT \( (7,0)\) are replaced with oxygen to study the adsorption of CO molecule through the surface of boroxol ring with different adsorption patterns, including side-on and end-on. All calculations have been done using the DFT-B3LYP/6-31G * level of theory, and their electronic energies are corrected by gCP and D3 correction terms. The calculated binding energies are large, which indicates that CO molecule undergoes chemical adsorption. NBO results showed that the charge transfer occurs from the tube to the gas molecule, which can slightly change the electronic properties of the tube. Density of state (DOS) and partial DOS (PDOS) analysis revealed that adsorption of CO molecule on the boroxol ring position is covalent in nature. The Laplacian of electron density, Lagrangian kinetic energy density, Hamiltonian kinetic energy density, and potential energy density at bond critical points between the tube and CO indicate that the interaction between the tube and CO molecule is covalent in nature. Topological analysis of the electron localization function shows that electrons in the new formed bonds are approximately localized, meaning that the nature of the adsorption process is chemical covalent.

Boosting sensitivity of boron nitride nanotube (BNNT) to nitrogen dioxide by Fe encapsulation

The pristine boron nitride nanotube (BNNT) exhibits a poor chemical reactivity to some adsorbates, thus greatly limiting its application for the gas sensor. In the present work, using density functional theory (DFT) methods, we put forward a novel strategy to enhance the sensitivity of BNNT to nitrogen dioxide (NO2) by the encapsulation of a single Fe atom inside its cavity. The results suggest that the NO2 molecule can be only physically adsorbed on the pristine BNNT with a small adsorption energy (−0.10eV). After the inclusion of the Fe atom inside BNNT (Fe@BNNT), the interaction of NO2 molecules with this tube is significantly enhanced, leading to a transformation from the physisorption of on pristine BNNT to the current chemisorption. Interestingly, up to five NO2 molecules can be adsorbed on this encapsulated BNNT along its circumference with the average adsorption energy of −0.52eV, corresponding to a short recovery time (6ms). Moreover, 0.38 electrons are transferred from the Fe@BNNT to the adsorbed NO2 molecules, which is enough to induce the obvious change of its electrical conductance. Thus, we predict that the encapsulation of Fe atom inside BNNT would greatly boosts its sensitivity to NO2 molecules, indicating its potential application as NO2 sensors.

Sensitivity of Boron Nitride Nanotubes toward Biomolecules of Different Polarities

The effect of molecular polarity on the interaction between a boron nitride nanotube (BNNT) and amino acids is investigated with density functional theory. Three representative amino acids, namely, tryptophane (Trp), a nonpolar aromatic amino acid, and asparatic acid (Asp) and argenine (Arg), both polar amino acids are considered for their interactions with BNNT. The polar molecules, Asp and Arg, exhibit relatively stronger binding with the tubular surface of BNNT. The binding between the polar amino acid molecules and BNNT is accompanied by a charge transfer, suggesting that stabilization of the bioconjugated complex is mainly governed by electrostatic interactions. The results show modulation of the BNNT band gap by Trp. Interestingly, no change in band gap of BNNT is seen for the polar molecules Asp and Arg. The predicted higher sensitivity of BNNTs compared to carbon nanotubes (CNTs) toward amino acid polarity suggests BNNTs to be a better substrate for protein immobilization than CNTs.