Analysis of Structural, Optical and Electronic Properties of Polymeric Nanocomposites/Silicon Carbide for Humidity Sensors

Hind Ahmed,Hayder M. Abduljalil,Ahmed Hashim 한국전기전자재료학회 2019 Transactions on Electrical and Electronic Material Vol.20 No.2

The nanocomposites are really promising for industrial, environmental and medical applications. In this work, new types of nanocomposites have been prepared from (PVA–TiO 2 ) nanocomposites doped by SiC nanoparticles for humidity sensor with high sensitivity, fl exible, high corrosion resistance and low cost. The experimental and theoretical studies on structural and optical properties of (PVA–TiO 2 –SiC) nanocomposites have been investigated. The optical microscope and FTIR studies were examined. The optical properties of nanocomposites were examined in wavelength range (220–800) nm. The results showed that the optical absorbance of (PVA–TiO 2 ) nanocomposites increases with increasing of the SiC nanoparticles concentrations. The energy band gap of (PVA–TiO 2 ) nanocomposites decreases while the optical constants increase with the increase in SiC nanoparticles concentrations. The (PVA–TiO 2 –SiC) nanocomposites tested for humidity sensors at relative humidity range (40–80) RH.%. The experimental results showed that the electrical resistance for (PVA–TiO 2 –SiC) nanocomposites decreases with increase in relative humidity. The (PVA–TiO 2 –SiC) nanocomposites have highly sensitivity for relative humidity.

Design of PMMA Doped with Inorganic Materials as Promising Structures for Optoelectronics Applications

Angham Hazim,Hayder M. Abduljalil,Ahmed Hashim 한국전기전자재료학회 2021 Transactions on Electrical and Electronic Material Vol.22 No.6

In this work, studying the effect of adding nanoparticles on the optimized geometrical parameters, electronic and spectroscopic properties of pure (PMMA), (PMMA-Al 2 O 3 ), (PMMA-ZrO 2 ), (PMMA-Al 2 O 3 -Ag) and (PMMA-ZrO 2 -Ag) nanocomposites were investigated. The electronic and structural properties involved the (energy gap, fermi energy, electrophilic index and chemical potential). The spectral properties included the IR and UV–Visible. The studied nanocomposites were designed by the Gaussian View 0.5 program then relaxed by performing the B3LYP-DFT hybrid functional together with SDD basis sets for nanocomposites) by Gaussian 0.9 package of programs to study and analyze of ground state and spectroscopic properties of structures. The values of energy gap showed that the E g decreases and Fermi energy E F increases with adding of the nanoparticles to polymer. In general, most of the studied nanocomposites have direct electronic transition from the valence to conduction band with wavelength lies in the range of solar spectrum. Finally, studied nanocomposites can be used in many optoelectronics applications.

First Principles Calculations of Electronic, Structural and Optical Properties of (PMMA–ZrO2 –Au) and (PMMA–Al 2O3 –Au) Nanocomposites for Optoelectronics Applications

Angham Hazim,Hayder M. Abduljalil,Ahmed Hashim 한국전기전자재료학회 2021 Transactions on Electrical and Electronic Material Vol.22 No.2

This study focuses on the quantum mechanical treatment of the geometrical optimization and the electronic structure problems of a nanomaterial PMMA and nanocomposites. The hybrid functional B3LYP/6-31G level of DFT is used to investigate four molecules divided into two groups, they are PMMA as an original basis molecule and (PMMA–Au), (PMMA–Al 2 O 3 –Au), (PMMA–ZrO 2 –Au) nanocomposites as the two group. The DFT calculations have been performed using Gaussian 09 package of programs. The geometrical optimization included both bonds in °A and angles in deg. The calculated electronic properties included the total energy, HOMO and LUMO energies, energy gap, ionization energy, electron affi nity, electronegativity, electrochemical hardness, electronic softness and Electrophilic index. The geometrical optimization of PMMA and nanocomposites has been found in good agreement with the experimental data because of its relaxed geometrical parameters. One of the important results was obtain in this study, is the decreasing of the energy gap. This states that these nanocomposites arethe nearest to semiconductor due to the both HOMO and LUMO levels become more adjacent. These consequences mention to construct new structures with new electronic properties. All nanocomposites need small energy to become cationdue to ionization potential is decrease with addition nanoparticles to the pure PMMA, but the electronic affinity is an increase with with addition nanoparticles to the pure PMMA. The total ground state energy of the PMMA have largest value of total energy compared for other nanocomposites, where E T decreased with addition nanoparticles to pure PMMA. The hardness decrease with addition nanoparticles to the pure PMMA, therefore all the nanocomposites are softer, and this reduces the resistance of a species to lose electrons. Good relax for the structures of the studied PMMA was obtained theoretically, in which, the angles C–C, C=O and C–H in pure PMMA are remain in the same ranges for other nanocomposites. In general, most of the studied nonocomposites direct electronic transition from the valence to conduction band with wave length lies in the range of solar spectrum. The obtained results showed that the (PMMA–ZrO 2 –Au) and (PMMA–Al 2 O 3 –Au) nanocomposites have huge applications in electronics and photo-electronics fi elds.

Structural, Optical and Electronic Properties of Novel (PVA–MgO)/SiC Nanocomposites Films for Humidity Sensors

Hind Ahmed,Hayder M. Abduljalil,Ahmed Hashim 한국전기전자재료학회 2019 Transactions on Electrical and Electronic Material Vol.20 No.3

The polyvinyl alcohol (PVA) and magnesium oxide (MgO) nanocomposites and (PVA–MgO) nanocomposites doped by Silicon carbide (SiC) nanoparticles have been fabricated with diff erent concentrations of Silicon carbide and (PVA–MgO) nanocomposites. Both experimental and theoretical studies on structural and optical properties of novel (PVA–MgO–SiC) nanocomposites for humidity sensors were examined for fi rst time with low cost, fl exible and high sensitivity. The (PVA–MgO–SiC) nanocomposites were intended with various concentrations of Silicon carbide nanoparticles. The experimental results of optical properties for (PVA–MgO–SiC) nanocomposites indicated that the absorbance, absorption coeffi cient, extinction coeffi cient, refractive index, imaginary and real dielectric constants and optical conductivity of (PVA–MgO) nanocomposites increase with an increase in Silicon carbide nanoparticles concentrations. The absorbance increases from 0.432 to 2.55 a.u while the transmittance decreases from 0.779 to 0.230 a.u. The energy gap decreases from 4.4 to 2.1 eV. The energy gap theoretically decreases from 7.07 to 3.04 eV. The experimental results of novel (PVA–MgO–SiC) nanocomposites applications showed that (PVA–MgO–SiC) nanocomposites have high sensitivity for relative humidity. The results obtained were compared with theoretic results obtained by using Gaussian 09 program and Gaussian view 5.0.8 program and using density functional theory (DFT) at B3LYP level with 6 - 31G basis set.

Structural, Spectroscopic, Electronic and Optical Properties of Novel Platinum Doped (PMMA/ZrO2) and (PMMA/Al2O3) Nanocomposites for Electronics Devices

Angham Hazim,Hayder M. Abduljalil,Ahmed Hashim 한국전기전자재료학회 2020 Transactions on Electrical and Electronic Material Vol.21 No.6

This work reports a theoretical study to investigate the electronic structure and optimized geometry for pure PMMA and PMMA doped with ZrO 2 , Al 2 O 3 and Pt nanoparticles for electronics devices. The studied structures are initially relaxed by employing the hybrid functional three parameter Lee–Yang–Parr B3LYP density functional theory at Gaussian 09 package of programs and Gaussian view 5.0.8 program. The PMMA is origin molecule before adding nanoparticles, also this work includes calculations of the electronic properties which contain total energy, energy of highest occupied molecular orbital, energy of lowest unoccupied molecular orbital, energy gap, ionization potential, electronic affi nity, hardness, softness, electronegativity and electrophilic index. The geometrical optimization of PMMA has been found in good agreement with the experimental data due to its relaxed geometrical parameters. The electronic variables, such as, I E , E A , , S, H and ω are computed by the orbital vertical (Koopmans theorem), the nanocomposites studied need small energy to become cation due to ionization potential is smaller than original PMMA, but the electronic affi nity are larger than the original PMMA. So, the hardness for nanocomposites was lowering values as compared with PMMA, therefore all the new molecules are softer, and this reduces the resistance of a species to lose electrons, and the total energy of the studied PMMA was decreased with added nanoparticles to the pure PMMA, total energy is a refl ection of, binding energy of each sheet. The results showed that the nanoparticles added to PMMA reduces the energy gap. All nanoparticles constructed in this work have energy gap lower than that of original PMMA and the (PMMA–ZrO 2 –Pt) nanocomposites have the lowest value of energy gap. These results refer to construct new structures with new electronic properties to use it for modern electronics fields.

Structural, Optical and Electronic Properties of Novel (PVA–MgO)/SiC Nanocomposites Films for Humidity Sensors

Hind Ahmed,Hayder M. Abduljalil,Ahmed Hashim 한국전기전자재료학회 2019 Transactions on Electrical and Electronic Material Vol.20 No.2

The polyvinyl alcohol (PVA) and magnesium oxide (MgO) nanocomposites and (PVA–MgO) nanocomposites doped by Silicon carbide (SiC) nanoparticles have been fabricated with diff erent concentrations of Silicon carbide and (PVA–MgO) nanocomposites. Both experimental and theoretical studies on structural and optical properties of novel (PVA–MgO–SiC) nanocomposites for humidity sensors were examined for fi rst time with low cost, fl exible and high sensitivity. The (PVA–MgO–SiC) nanocomposites were intended with various concentrations of Silicon carbide nanoparticles. The experimental results of optical properties for (PVA–MgO–SiC) nanocomposites indicated that the absorbance, absorption coeffi cient, extinction coeffi cient, refractive index, imaginary and real dielectric constants and optical conductivity of (PVA–MgO) nanocomposites increase with an increase in Silicon carbide nanoparticles concentrations. The absorbance increases from 0.432 to 2.55 a.u while the transmittance decreases from 0.779 to 0.230 a.u. The energy gap decreases from 4.4 to 2.1 eV. The energy gap theoretically decreases from 7.07 to 3.04 eV. The experimental results of novel (PVA–MgO–SiC) nanocomposites applications showed that (PVA–MgO–SiC) nanocomposites have high sensitivity for relative humidity. The results obtained were compared with theoretic results obtained by using Gaussian 09 program and Gaussian view 5.0.8 program and using density functional theory (DFT) at B3LYP level with 6 - 31G basis set.

Analysis of Structural and Electronic Properties of Novel (PMMA/Al2O3 , PMMA/Al2O3 -Ag, PMMA/ZrO2, PMMA/ZrO2 -Ag, PMMA-Ag) Nanocomposites for Low Cost Electronics and Optics Applications

Angham Hazim,Hayder M. Abduljalil,Ahmed Hashim 한국전기전자재료학회 2020 Transactions on Electrical and Electronic Material Vol.21 No.1

In this paper, the eff ect of (Al2O3 , ZrO2 , Ag, Al2O3 -Ag, ZrO2 -Ag) nanoparticles on the optimized geometrical parameters and electronic properties of poly-methylmethacrylate has been investigated for first time. The optimization parameters included both bonds angles and bonds length. The electronic properties included the (lower unoccupied molecular orbital energy (E LUMO), high occupied molecular orbital energy (E HOMO), energy gap (Eg), ionization potential (IE), electron affinity (EA), electronegativity ( ), electrochemical hardness H, electronic softness S total energy, total dipole moment and Averagepolarizability). The results showed that the addition of nanoparticles has a direct impact on all the properties of the molecules studied. The increase in the number of atoms leads to decreased energy gap from 7.0329 to 2.7689 eV. The ionization potential and electron affi nity decrease with increasing of atoms number for structures. The produced nanocomposites have different applications in many fields such as: gas sensors, solar cells, diodes, UV shielding, lasers, optoelectronics, medical application, dental filling…etc.

Analysis of Structural, Optical and Electronic Properties of Polymeric Nanocomposites/Silicon Carbide for Humidity Sensors

Hind Ahmed,Hayder M. Abduljalil,Ahmed Hashim 한국전기전자재료학회 2019 Transactions on Electrical and Electronic Material Vol.20 No.3

The nanocomposites are really promising for industrial, environmental and medical applications. In this work, new types of nanocomposites have been prepared from (PVA–TiO 2 ) nanocomposites doped by SiC nanoparticles for humidity sensor with high sensitivity, fl exible, high corrosion resistance and low cost. The experimental and theoretical studies on structural and optical properties of (PVA–TiO 2 –SiC) nanocomposites have been investigated. The optical microscope and FTIR studies were examined. The optical properties of nanocomposites were examined in wavelength range (220–800) nm. The results showed that the optical absorbance of (PVA–TiO 2 ) nanocomposites increases with increasing of the SiC nanoparticles concentrations. The energy band gap of (PVA–TiO 2 ) nanocomposites decreases while the optical constants increase with the increase in SiC nanoparticles concentrations. The (PVA–TiO 2 –SiC) nanocomposites tested for humidity sensors at relative humidity range (40–80) RH.%. The experimental results showed that the electrical resistance for (PVA–TiO 2 –SiC) nanocomposites decreases with increase in relative humidity. The (PVA–TiO 2 –SiC) nanocomposites have highly sensitivity for relative humidity.