Iraqi Journal of Physics

The gas sensors were prepared using carbon quantum dots (CQDs) using an
electrochemical method after mixing the CQDs with Tris (8-hydroxyquinoline)
aluminum (III) (Alq3) polymer. A spin coating technique was used to deposit
CQDs/Alq3 composite film on glass substrates with a ratio of 1:1. The CQDs/Alq3
gas sensor showed a sensitivity of about 24 ٪at a temperature of 300 ℃, and this was
calculated after measuring the change in the resistance of the samples with a
response time of 2 and 8sec recovery time. The sensor showed a good response for
nitrogen dioxide (NO2) gas. However, the sensitivity, response time, and recovery
time for the CQDs gas sensor when exposed to NO2 gas at 300 °C were 78%, 4s, and
129s, respectively. The results showed that the best sensor CQDs/Alq3 led to a
reduction in the recovery time, which shows the importance of the Alq3 polymer in
improving the properties of the gas sensor.

Denture soft liners are specifically engineered to enhance patient
performance by altering the surfaces of prosthetics that come into touch with the
soft tissues within the oral cavity. Acrylic resin polymethyl methacrylate (PMMA)
and silicone elastomer-based are the two main types of denture soft liners.
Nanotechnology was employed as a means to enhance the mechanical qualities of
dentures. The primary objective of this investigation was to examine the impact of
cerium oxide (CeO2) nanoparticles (NPs) on the water sorption and solubility
characteristics of acrylic-based soft liners. The data was subjected to analysis of
variance (ANOVA). The surface characteristics were determined using scanning
electron microscopy (SEM). This in vitro study demonstrates that including CeO2
NPs at 2% and 3% concentrations does not impact acrylic-based soft lining
materials' water sorption and solubility. The solubility of CeO2 is well-recognized
to be very low. The results indicated that there were no statistically significant
differences between the groups.

Lithium-ion batteries (LIBs) are beginning to use solid polymer
electrolytes (SPEs) as a potentially useful replacement for liquid electrolytes.
However, incompatibility between the lithium metal anode and electrolyte, which
results in low ionic conductivity and reduced cycling performance of LIBs, is one
of the disadvantages of SPEs. Solution casting with glycerol as a plasticizer was
used to create electrolyte films consisting of 80% Poly (vinylidene fluoride)
(PVDF) and 20% poly (vinyl chloride) (PVC), undoped and doped with various
salts, including lithium carbonate (Li2CO3) and lithium chloride (LiCl) and various
metal oxides (CuO, WO3, and TiO2) nanoparticles (NPs). An investigation was
conducted to examine their impact on optical properties. The prepared SPEs were
characterized by UV-visible and Fourier transformer infrared spectroscopy (FTIR).
The results showed that the type of salt and doping greatly affected the energy gap.
The energy showed a blue shift after the addition of lithium carbonate, while it
showed a red shift after doping with metal oxides (WO3 and TiO2) NPs; the
minimum energy gap was 1.6 eV obtained from SPE (PVC/PVDF/Li2CO3) doped
with TiO2 NPs, while the energy gap showed red shift after adding LiCl. It changed
non-regularly after doping with metal oxide NPs, reaching the lowest value of 1.8
eV for samples doped with WO3 NPs. All optical constants were determined, and a
graph of their values vs. wavelength was created. The FTIR analysis confirmed the
presence of metal oxide NPs.

In this work, colloidal gold:lead (Au:Pb) core/shell nanoparticles (NPs)
were synthesized in liquid at 532 nm using the laser ablation method. An
investigation of the external magnetic field during the laser ablation process
affected the properties of the Au:Pb NP core and shell. The magnetic field
enhances the core shell’s crystallinity. The optical band gap energy increased from
2.067 to 2.086 eV in the presence of the magnetic field. It also led to an increase in
the concentration and a decrease in the size of nanoparticles, which led to increased
absorbance. A magnetic field strength of 250 mT resulted in a higher removal
efficiency. The external magnetic field significantly reduced NP agglomeration and
aggregation. We created and characterized an Au:Pb/porous silicon (PS)
heterojunction photodetector. The magnetic field greatly enhanced its properties.
The responsively (Rλ) of the photodetector increased from 0.093 to 0.551 A/W at λ
= 650 nm by increasing the magnetic field. On the other hand, the final Au:Pb/PS
material had the best photocurrent stability, demonstrating that adding Au:Pb NPs
can make PS's opto-electrical properties more stable. In the end, the Au:Pb NPs/PS
heterojunction photodetector results showed that the photodetector parameters got
much better when a magnetic field was present. By altering the preparation
conditions, we can produce high-performance core/shell photovoltaic devices.

In this study, Nd:YAG laser pulses with a wavelength of 1064 nm, a power
of 500 mJ, a pulse width of 9 ns, and a repetition frequency of 6 Hz were used to
hit a manganese oxide (MnO) target surface 300 times. Undoped and doped MnO
were prepared with different concentrations of Cu (0.03, 0.05, 0.07, and 0.09%)
prepared by PLD. Cu:MnO thin films were annealed at 473 K, and their
morphological, optical, and electrical characteristics were studied. The results of
the atomic force microscopic (AFM) investigation of morphological properties
showed that Cu dopant impacted the creation of roughness and particle size in
MnO2 films. The optical transmission was examined using a UV-Vis
spectrophotometer. The highest optical absorption was noted at 0.09 dopant
content. The dielectric constants' real (εr) and imaginary (εi) components, as well as
the extinction coefficient (k), refractive index (n), and other optical constants, were
studied. At an annealing temperature of (473 K), Hall effect studies demonstrate
that all produced films exhibit P-type conductivity.

This study presents a strategy to increase the efficiency of dye-sensitized solar
cells (DSSCs) by doping titanium dioxide (TiO2) with different magnesium (Mn)
concentrations (1, 3, 5, 7, and 9%) generated by the sol-gel process and effectively
employed as a photo-anode (the working electrode) for DSSCs. The Doctor Blade
method coated the indium-doped tin oxide (ITO) glass with a thin film layer. X-ray
diffraction (XRD) was used to evaluate the characteristics of undoped and
manganese-doped TiO2, and the results demonstrate that all of the thin films are
anatase. The samples were examined using XRD to assess grain size before and
after Mn doping. The spectrum of UV-Vis absorption changes; accordingly, as
doping increases, the energy gap decreases. The smallest energy gap's value (2.4
eV) is 7% manganese doping. AFM pictures show the average roughness and root
mean square of the weight percentage of films doped with 5%. Field effect
scanning electron microscope (FE-SEM) studies show that the particle size of thin
films gets smaller as more Mn is added, which happens at least as much as 7% Mn
doping. The optimal thickness for TiO2 paste over conductive glass is 15 μm, and
the cell's power conversion efficiency increased to 0.604074% with an Imax of
4.965 mA, a Vmax of 0.488 V, and a fill factor (FF) of 68.45954%.

This study aimed to investigate the structure and optical properties of Sn
nanostructures. Thin tin (Sn) films were deposited on glass substrates using the
pulsed laser deposition method. Nd:YAG laser with fundamental wavelengths of
532 nm and 1064 nm was used to create Sn nanostructures with varying energies of
400 mJ to 700 mJ and the same frequency of 6 Hz. The tin powder was compressed
into a disc with a one-centimetre diameter to serve as a sample. The X-ray
diffraction (XRD) pattern showed a crystalline structure with several Sn
nanostructures peaks at various energies (400–700 mJ). The results revealed a
crystalline size of 65.90 nm and 86.55 nm at 700 mJ, while the size was 40.19 nm
and 17.19 at 400 mJ for the given wavelengths (532nm and 1064 nm), respectively.
The appearance of Sn nanostructures and the aggregation of, particularly in the
form of cauliflower, were revealed in Field emission scanning electron microscopy
(FE-SEM) images. The results of the dispersive energy X-ray spectroscopy (EDS)
analysis showed that various amounts of tin, carbon, and oxygen were present.
Additionally, the optical characteristics were investigated of each film using
absorbance spectra, which covered a range of wavelengths from 190 to 1100 nm.
As the laser power increased, the band gap energy values in the optical properties
decreased, falling into the ranges of 3.06 to 1.65 eV and 3.22 to 1.82 eV at 1064nm
and 532nm, respectively.

The study focused on the thermodynamics characteristics such as (Gibbs
free energy, heat capacity, entropy and enthalpy) and spectroscopic properties like
(IR spectra, reduced masses, and force constant) of coronene (C24) and reduced
coronene oxide (C24OX) where X =1–5 as a function of number of oxygen atoms
and temperature from (298-398) oK. Density functional theory was used in the
methodology with the basis sets 6-311G** and the hybrid functional B3LYP
(Becke, 3-parameters, Lee-Yang-Parr), utilizing the Gaussian 09W program.
Gaussian view 05 was used as a complementary program to calculate the
geometrical structures. The Gibbs free energy and enthalpy decrease (negative
sign) with increased oxygen atoms and temperature, indicating an exergonic
reaction. The entropy and heat capacity increased with the number of oxygen
atoms and temperature. The spectroscopic characteristics were compared with
experimental results, particularly the longitudinal optical modes of vibration for
graphene and graphene oxide (1585 - 1582) cm-1, which were in good agreement.

In the current study, a novel conductive polymer poly 6-((4 acetylphenyl)
carbamoyl) cyclohex-3-ene-1-carboxylic acid (PACC) was created by polymerized
6-((4 acetylphenyl) carbamoyl) cyclohex-3-ene-1-carboxylic acid (ACC) monomer
using the electropolymerization process. The resulting polymer was characterized
using Fourier transform Infrared spectroscopy (FTIR). The ability of this polymer
to protect the alloy from corrosion was studied at temperatures ranging between
298 and 328 K. The ability of these coatings to stop corrosion on the surface was
assessed by measuring the corrosion potential (Ecorr) and the corrosion current (icorr)
using a potentiostat. Adding nanoscale metal oxides (zirconium dioxide (ZrO2) and
magnesium oxides (MgO)) enhanced the efficiency of this polymeric coating. The
protection efficiency of the polymer alone was 77.5%; this efficiency increased to
85.0% and 99.7% in the presence of nano ZrO2 and MgO, respectively. Kinetic and
thermodynamic parameters (Ea, H, and S) were calculated for uncoated and coated
LCS. An atomic force microscope (AFM) studied the coating surface morphology.
Electrochemical impedance spectroscopy (EIS) was used to evaluate the coating
resistance.

This study investigates the influence of silver oxide (Ag2O) concentration on the
optical characteristics of phosphate bioactive glasses (PBGs). PBGs have emerged as
promising alternatives to conventional silicate glasses in the medical field due to
their excellent bioactivity and chemical resistance. Samples with varying Ag2O
concentrations (0, 0.25, 0.5, and 0.75g) were sintered at 780°C for 2 hrs in an
electric furnace. The samples were subjected to Fourier transfer infrared
spectroscopy (FTIR), ultraviolet-visible (UV-Vis) spectroscopy, and
photoluminescence (PL) tests to assess their functional groups and optical properties.
By analyzing the FTIR spectrum of phosphate bioactive glass containing different
amounts of Ag2O, it is possible to identify changes in the vibrational modes
associated with Ag-O bonds and to gain insights into the structure and composition
of the material. Because Ag-O bonds exhibit infrared vibrational modes, introducing
Ag2O changed the FTIR spectrum. As Ag2O concentration increased, Ag-O
vibrational modes strengthened, indicating more Ag-O bonds. UV-Vis spectroscopy,
with increasing Ag2O concentration, the peak location shifted towards shorter
wavelengths. Optical spectra show distinct UV absorption in the prepared glass
spectrum, extending to near visible with increasing Ag2O content. The PL spectra
peaks and band gap energies revealed that Ag2O altered the glass's electrical
structure and optical activity. These discoveries help optimize metal-phosphate biactive glass for biomedical implants and UV-blocking coatings. The meltingannealing technique prepared glasses based on the base host Na2O-CaF2-P2O5
system with increasing Ag2O as additives or loading (0.2 to 1 wt%).

In this study, silver and iron nanoparticles were biosynthesized using the
garlic plant, an economical and environmentally friendly method. A blend of
chitosan (CS) and polyvinylalcohol (PVA) was prepared. The silver nanoparticles
(AgNPs), iron oxide nanoparticles (Fe2O3NPs), and the (CS/PVA) blend were
characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy
(FTIR), and Field Emission Scanning Electron Microscopy (FE-SEM) analyses.
The FE-SEM images revealed that Fe2O3NPs were cubical and hexagonal, and
AgNPs were spherical aggregates. AgNPs with blend (CS/PVA) and Fe2O3NPs
with blend (CS/PVA) and (Fe2O3NPs/blend (CS/PVA) /AgNPs) composite were
synthesized and tested for anticancer activity against cervical cancer cells (Hela)
using the MTT assay. Best kills and the highest inhibitory effect were observed in
(AgNPs/ blend (CS/PVA)) and (Fe2O3NPs/blend (CS/PVA)/AgNPs) composite.
These findings demonstrated the method's ability to synthesize nanocomposites
with desirable physical, chemical and biological properties. Therefore, these
findings demonstrate the new antibacterial and robust cytotoxicity features of the
nanocomposite material, which has promising medical applications.