scholarly journals Effect of hydration on the physical properties of glucose

2019 ◽  
Vol 9 (4) ◽  
pp. 4114-4118 ◽  
Keyword(s):  
Quantum Mechanics ◽  
Dipole Moment ◽  
Band Gap ◽  
Electronic Properties ◽  
Band Gap Energy ◽  
Molecular Electrostatic Potentials ◽  
Total Dipole Moment ◽  
Gap Energy ◽  
Homo Lumo ◽  
Electro Negativity

The effect of hydration on the electronic properties of glucose (Gl) is studied by quantum mechanics by using DFT procedures atB3LYP/6-31g(d,p). Total dipole moment, the highest and the lowest occupied molecular orbital (HOMO/LUMO band gap energy) and molecular electrostatic potentials (ESPs) are calculated at the same level of theory for all model molecules. The results indicated that there is an enhancement in the electronic properties of Gl where TDM of Gl is increased from2.5454Debye to 4.3157Debye while HOMO/LUMO band gap energy is decreased from 13.0994 eV to 3.2749 eV. Also, the calculated ESP results are indicated that the electro-negativity is increased due to hydration which means that the reactivity is increased and hence the electronic properties are improved.

Effect of Blending on the Enhancement of Electronic Properties of Biopolymers

2016 ◽  
Vol 13 (10) ◽  
pp. 6800-6802
Author(s):  
Naziha Suliman Alghunaim
Keyword(s):  
Hydrogen Bonding ◽  
Dipole Moment ◽  
Molecular Modeling ◽  
Band Gap ◽  
Electronic Properties ◽  
Band Gap Energy ◽  
The Other ◽  
Total Dipole Moment ◽  
Gap Energy ◽  
Chitosan Blends

Chitosan (Cs), gelatin (Gel) and starch (Str) are blended together to investigate the effect of blending upon the electronic properties of biopolymers. Three blends namely 25%, 50% and 75% of (Cs/Gel) and (Cs/Str) respectively. FTIR were utilized to ensure the occurrence of the proposed blend. The FTIR spectra show the occurrence of hydrogen bonding which indicated that the assigned blend is formed as a result of hydrogen bonding of NH2 and COOH terminals. Electronic properties are indicated with molecular modeling technique at PM6 semiemperical level. Modeling results indicate that, as far as starch and gelatin ratios increased in chitosan blends, the band gap energy is decreased in one hand while the total dipole moment is increased on the other hand.

Modeling the Electronic Properties for CNT Interacted with ZnO, CuO and Co3O4

2021 ◽  
Author(s):  
Walaa M. Taha ◽  
Mohamed Morsy ◽  
Nadra A. Nada ◽  
Medhat IBRAHIM
Keyword(s):  
Metal Oxides ◽  
Band Gap ◽  
Electronic Properties ◽  
Band Gap Energy ◽  
Total Dipole Moment ◽  
Adsorbed State ◽  
Complex State ◽  
Hartree Fock ◽  
Mechanism Of Interaction ◽  
Homo Lumo

Abstract Because of the wide applications of carbon nanotubes (CNTs) and magic properties of metal oxides, Hartree-Fock (HF)/STO-3G quantum mechanical calculations were applied to study the electronic properties of CNTs and its interaction with ZnO, CuO and Co3O4. Calculations were conducted to calculate HOMO/LUMO band gap energy ∆E, moleculare electrostatic potential (MESP) and total dipole moment (TDM) for CNTs, CNT-Zn-O, CNT-Cu-O, CNT-Co-O and CNT-O-Zn, CNT-O-Cu, CNT-O-Co following the two mechanism of interaction as adsorbed and complex state. The calculations show that the interaction of CNTs with metal oxides increases its reactivity where MESP indicated to more distribution charges and an increasing in the TDM value after interaction of CNTs with metal oxides. Where, the interaction of CNT-Co-O as adsorbed state has the highest TDM with lowest band gap ∆E which confirms that CNT-Co3O4 can be used in sensing devices.

scholarly journals On the molecular modeling analyses of sodium carboxymethyl cellulose treated with acetic acid

2019 ◽  
Vol 8 (2) ◽  
pp. 553-557 ◽  
Keyword(s):  
Acetic Acid ◽  
Band Gap ◽  
Carboxymethyl Cellulose ◽  
Density Functional ◽  
Band Gap Energy ◽  
Sodium Carboxymethyl Cellulose ◽  
Functional Theory ◽  
Gap Energy ◽  
Model Molecule ◽  
Homo Lumo

Model molecules for sodium carboxymethyl cellulose (Na-CMC) (monomer), glycerol, acetic acid and Na-CMC-glycerol-acetic acid are optimized with Density Functional Theory (DFT) at B3LYP/3-21G*. For the optimized models, total dipole moment (TDM), the highest occupied and lowest unoccupied molecular orbitals (HOMO/LUMO band gap energy), and molecular electrostatic potentials (ESP) are calculated at the same method to give an explanation for the possibility of using Na-CMC-Glycerol-acetic acid model molecule in electrochemical devices, gas sensors and batteries. As a result of the substitution of Na-CMC with glycerol, TDM increased from 7.7141 Debye to 22.4942 Debye which is approximately equal to three times that of Na-CMC. However, HOMO/LUMO band gap energy decreased from 0.9040 eV to 0.5072 eV. After the addition of acetic acid to Na-CMC-glycerol model, TDM increased to24.7270 Debye and HOMO/LUMO band gap energy decreased to 0.4939 eV. Both TDM and HOMO/LUMO band gap energy values are improved by increasing the acetic acid units, where TDM became 25.3510 Debye and HOMO/LUMO band gap energy decreased to 0.3815 eV. The results of ESP indicated that the addition of glycerol and acetic acid to Na-CMC increased the electronegativity of Na-CMC which in turn enhanced its electronic properties.

scholarly journals Structural, Spectroscopic and Optical Properties of Monohydrated Adenine: A Theoretical Study

2016 ◽  
Vol 64 (2) ◽  
pp. 157-161
Author(s):  
M Alauddin ◽  
MM Islam ◽  
MA Aziz
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Theoretical Study ◽  
Minimum Energy ◽  
Band Gap Energy ◽  
Gap Energy ◽  
B3lyp Level ◽  
A Minor ◽  
Homo Lumo ◽  
Hydrogen Bonded

The structural, spectroscopic (IR, NMR and UV-Vis), electronic and optical properties of monohydrated adenine (monohydrated 6-aminopurine, C5H5N5.H2O) are investigated theoretically using DFT/B3LYP level of theory. Three minimum energy structures have been identified for monohydrated of adenine where H2O molecule is doubly hydrogen bonded with adenine.1H NMR analysis shows that the protons which are hydrogen bonded become deshielded and chemical shift moves to the higher frequency region.Five IR active mode of vibrations were found at 3108, 3295, 3665, 3676 and 3719 cm-1 which are assigned as bonded -OH vibration of H2O, Bonded -NH vibration of NH2, Free -NH vibration of adenine (9 N), Free -NH vibration of NH2, Free -OH vibration of H2O, respectively and agree well with the available experimental results. The investigation of electronic properties shows that the HOMO-LUMO band gap energy of monohydrated adenine at B3LYP level is 5.15 eV. The major electronic transition (from HOMO to LUMO (83%) (π→π*)) occurs at 258 nm (4.80 eV) with a minor transition at 237 nm (5.23 eV). Theoretically it is observed that the HOMO-LUMO band gap energy is for monohydrated adenine is lower than that of adenine. Dhaka Univ. J. Sci. 64(2): 157-161, 2016 (July)

scholarly journals New chromophores based on combination of ethylenedioxythiophene and carbazole fragments: synthesis and optoelectronic properties

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
A.N. Bakiev ◽  
O.A. Mayorova ◽  
A.A. Gorbunov ◽  
I.V. Lunegov ◽  
E.V. Shklyaeva ◽  
...  
Keyword(s):  
Band Gap ◽  
Visible Spectrum ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Good Solubility ◽  
Film Forming ◽  
Photovoltaic Applications ◽  
Key Steps ◽  
Homo Lumo ◽  
Stokes Shifts

AbstractTwo new D-π-A chromophores composed of an electron-donating carbazole unit linked through π- bridges, bearing 3,4-ethylenedioxythiophene (EDOT) moiety, with an electron withdrawing dicyanovinyl group (DCV) were successfully synthesized involving Suzuki or Heck cross-coupling and Knöevenagel reactions as the key steps. The obtained compounds absorb light over a broad spectral range, including the visible spectrum. The HOMO/LUMO energies and band gap energy values (Eg) were calculated on the basis of the experimental optical and electrochemical data: HOMO, LUMO, Eg (eV), −5.51, −3.14, 2.37 (4), −5.34, −3.14, 2.20 (7). The presence of the HC=CH unit in compound 7 resulted in the increase of the HOMO energy level, the decrease of a band gap value and red shifts of the absorption and emission bands in comparison with those of 4. Large Stokes shifts and broadband luminescence inherent to both chromophores suggest their use as materials for luminescent solar collectors (LSCs). The obtained compounds demonstrated good solubility and suitable thin-film forming properties. For this reason, they may be suitable for solution-processable photovoltaic applications.

Selective Photochemical Dry Etching of Compound Semiconductors: Enhanced Control Through Secondary Electronic Properties

1988 ◽  
Vol 129 ◽  
Author(s):  
Carol I. H. Ashby
Keyword(s):  
Quantum Yield ◽  
Band Gap ◽  
Electronic Properties ◽  
Compound Semiconductors ◽  
Dry Etching ◽  
Band Gap Energy ◽  
Carrier Generation ◽  
Gap Energy ◽  
Free Carriers ◽  
Carrier Recombination

ABSTRACTWhen laser-driven etching of a semiconductor requires direct participation of photogenerated carriers, the etching quantum yield will be sensitive to the electronic properties of a specific semiconductor material. The band-gap energy of the semiconductor determines the minimum photon energy needed for carrier-driven etching since sub-gap photons do not generate free carriers. However, only those free carriers that reach the reacting surface contribute to etching and the ultimate carrier flux to the surface is controlled by more subtle electronic properties than the lowestenergy band gap. For example, the initial depth of carrier generation and the probability of carrier recombination between the point of generation and the surface profoundly influence the etching quantum yield. Appropriate manipulation of process parameters can provide additional reaction control based on such secondary electronic properties. Applications to selective dry etching of GaAs and related materials are discussed here.

Density Functional Theory (DFT) Study: Electronic Properties of Silicene under Uniaxial Strain as H2S Gas Sensor

2016 ◽  
Vol 675-676 ◽  
pp. 15-18 ◽  
Author(s):  
Sasfan Arman Wella ◽  
Irfan Dwi Aditya ◽  
Triati Dewi Kencana Wungu ◽  
Suprijadi
Keyword(s):  
Band Gap ◽  
Electronic Properties ◽  
Density Functional ◽  
Band Gap Energy ◽  
Engineering Strain ◽  
Functional Theory ◽  
First Principle Calculation ◽  
Gap Energy ◽  
Center Configuration ◽  
Structural And Electronic Properties

First principle calculation is performed to investigate structural and electronic properties of strained silicene (silicon analogue of graphene) when absorbing the hydrogen sulfide molecule gas. Two configuration of silicene-H2S system, center and hollow configuration, is checked under 0% (pure), 5%, and 10% uniaxial engineering strain. We report that the silicene-H2S system in center configuration has larger binding energy compare to the silicene-H2S system in hollow configuration. The results show that H2S is physisorbed on silicene. In this work, we also find the change of band gap energy (~60 meV) is appearing when H2S interacted with silicene in center configuration, whereas the band gap energy of silicene has no change when interacted with H2S in hollow configuration.

On the Spectroscopic Analyses of Polytetrafluoroethylene Coated with Nano ZnO and SiO2

2022 ◽  
Author(s):  
Maroof A. Hegazy ◽  
Rasha Ghoneim ◽  
Hend A. Ezzat ◽  
Heba Y. Zahran ◽  
Ibrahim S. Yahia ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Band Gap ◽  
Density Functional ◽  
Quantitative Structure Activity Relationship ◽  
Band Gap Energy ◽  
Layer By Layer ◽  
Functional Theory ◽  
Gap Energy ◽  
Model Structures ◽  
Homo Lumo

Abstract On polytetrafluoroethylene (PTFE) polymer nanocomposites coated with basically two metal oxides (MOs), SiO2 and ZnO, as well as a mixture of the two MOs, density functional theory (DFT) computations were performed. The B3LYPL/LAN2DZ model was used to evaluate PTFE polymer nano composites suggested model structures. The physical and electrical properties of PTFE modified on surface with ZnO and SiO2 coated layer by layer change Total dipole moment (TDM) and HOMO/LUMO band gap energy ∆Eto be 13.0082 Debye and 0.6889 eV, respectively. Moreover, TDM and band gap energy (∆E) improved to 10.6053 Debye and 0.2727 eV, respectively, when the nanofiller was increased to 8 atoms. In addition, the results of the Molecular Electrostatic Potential (MESP) and the Quantitative Structure Activity Relationship (QSAR) showed that PTFE coated with ZnO and SiO2 improved electrical characteristics and thermal stability. As PTFE coated with ZnO and SiO2 layer by layer, all stability characteristics, including electrical and thermal stability, were enhanced. The improved PTFE can be used as a corrosion-inhibiting layer for astronaut suits, according to the predicted results.

scholarly journals Molecular modeling analyses for polyvinylidene X (X=F, Cl, Br and I)

2019 ◽  
Vol 9 (2) ◽  
pp. 3890-3893 ◽  
Keyword(s):  
Dipole Moment ◽  
Molecular Modeling ◽  
Bond Length ◽  
Electronic Properties ◽  
Energy Gap ◽  
Semiempirical Calculations ◽  
Physical Parameters ◽  
Total Dipole Moment ◽  
Electro Negativity

Polyvinylidene (PVDF) substituted with different halogens (F, Cl, Br and I) has been studied theoretically by performing some semiempirical calculations at PM3 to obtain some physical parameters and improve the electronic properties. As a result of substitution bond length increases from 1.1083 Ǻ to 1.9921 Ǻ; bond angels decreased from 105.5120° to95.3750°; total dipole moment is increased from 0.0013 to 9.8242 Debye and the energy gap is decreased from 14.2929 to 6.1591eV. In addition, ESP results are indicated that the electro-negativity of the studied model molecules is increased upon substitution. The change in these calculated physical parameters reflects the reactivity of PVD.

Geometrical, vibrational and physical properties of polyvinyl chloride nanocomposites: Molecular modeling approach

2019 ◽  
Vol 18 (08) ◽  
pp. 1950037 ◽  
Author(s):  
A. Refaat ◽  
M. A. Ibrahim ◽  
H. Elhaes ◽  
R. Badry ◽  
H. Ezzat ◽  
...  
Keyword(s):  
Infrared Spectrum ◽  
Metal Oxides ◽  
Band Gap ◽  
Polyvinyl Chloride ◽  
Band Gap Energy ◽  
Water Molecules ◽  
Geometrical Parameters ◽  
Molecular Electrostatic Potentials ◽  
Energy Band Gap ◽  
Homo Lumo

B3LYP/6-31G([Formula: see text], [Formula: see text]) quantum mechanical calculations were conducted to study polyvinyl chloride (PVC) and PVC with metal oxides (ZnO and CuO). Accordingly, model molecules for PVC; PVC/[Formula: see text]ZnO; PVC/[Formula: see text]CuO and PVC/[Formula: see text]ZnO/[Formula: see text]CuO, where [Formula: see text] and [Formula: see text], 2 and 3, were proposed. The calculated results of total dipole moment (TDM), HOMO–LUMO energy band gap, and molecular electrostatic potentials (ESPs) indicated that the conductivity of PVC is increased and its surface became more reactive due to interaction with metal oxides. The effect of hydration on PVC was also studied at the same level of theory in order to assess the effect of up to 23 water molecules on PVC. The TDM value of PVC is increased but HOMO/LUMO band gap energy value is decreased because of hydration. Moreover, the results of calculated ESP indicated that the reactivity in the presence of water molecules increased, which could indicate possible degradation of PVC. Additionally, some geometrical parameters were studied. Furthermore, the scaled infrared spectrum (IR) for PVC was also calculated at B3LYP/6-31G ([Formula: see text], [Formula: see text]) and indicated that there are two bands at 2990[Formula: see text]cm[Formula: see text] and 2975[Formula: see text]cm[Formula: see text] in comparison with Fourier transform infrared spectrum (FTIR).

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