Optical Characterization of Polyvinyl alcohol - Ammonium Nitrate Polymer Electrolytes Films

Polyvinyl alcohol – Ammonium Nitrate polymer electrolyte films were prepared by casting method. UV-Vis Double Beam Spectrophotometer in the wavelength range (190-1100) nm were used to investigate the optical properties. The optical constants such us, transmission spectra, refractive index, extinction coefficient, real and imaginary parts of the dielectric constant, optical band gaps, and optical conductance are found. It was found that the energy band gaps are decreased upon the increase of salts concentration. The values of the width of the tails of localized states in the forbidden gap of the films obtained from Urbach plots are varied from 0.64 to 1.16 eV. The real and imaginary part of dielectric constant of the polymer electrolyte films increases with increasing NH4NO3 concentration. The dielectric constant shows decreases abruptly in the wavelength (235-260) nm, and finally becomes constant with increase wavelength. Keywords: optical energy band gap; optical conductance; refractive index; extinction coefficient

Structural and optical characterization of pure and SnZrO3 doped PS based polymer nanocomposite

This report presents a straightforward, an efficient and a promising methodology for the preparation of nanocomposite polymer (NCP) systems composed of polystyrene (PS) as the host polymer with addition of SnZrO _3 filler. For structural study and optical properties determination of the prepared samples; x-ray diffraction (XRD), and ultraviolet-visible (UV–vis) spectroscopy was performed, respectively. From XRD pattern several new peaks of the composites appearance as an evidence of strong interaction between the polymer matrix and the filler. The crystalline size of nan-particles were estimated using Debye–Scherrer’s equation. The fundamental optical parameters, for instance refractive index ( n ), optical band gap energy ( E _g ), optical dielectric loss ( ε _i ), and optical dielectric constant ( ε _r ) have been determined in which the quantity of SnZrO _3 is effective. Tauc’s equation has been used in the specifying the direct and indirect band gap energy. The absorption edge (E _a ) shifting from4.42 to 3.74 eV is associated to the charge-transfer complexes creation within the composite films. There is an increasing in the n from 1.2 to 2.54 for pure PS upon addition of 12 wt.% doped that indicates the existence of few interaction between photons and electrons. The optical band gap and transition type are studied in detail. The exponent value ( $r$ ) has been identified from Tauc’s equation using the ε _i against photon energy to measure optical band gap energy and specify the electronic transition types. This doping of filler has considerably increased the ε _r from (1.5–6.4) for pure PS sample and doped SnZrO _3 nanoparticles

Optical Dielectric Loss as a Novel Approach to Specify the Types of Electron Transition: XRD and UV-vis as a Non-Destructive Techniques for Structural and Optical Characterization of PEO Based Nanocomposites

The structure and optical properties of polyethylene oxide (PEO) doped with tin titanate (SnTiO3) nano-filler were studied by X-ray diffraction (XRD) and UV-Vis spectroscopy as non-destructive techniques. PEO-based composed polymer electrolytes inserted with SnTiO3 nano-particles (NPs) were synthesized through the solution cast technique. The change from crystalline phase to amorphous phase of the host polymer was established by the lowering of the intensity and broadening of the crystalline peaks. The optical constants of PEO/SnTiO3 nano-composite (NC), such as, refractive index (n), optical absorption coefficient (α), dielectric loss (εi), as well as dielectric constant (εr) were determined for pure PEO and PEO/SnTiO3 NC. From these findings, the value of n of PEO altered from 2.13 to 2.47 upon the addition of 4 wt.% SnTiO3NPs. The value of εr also increased from 4.5 to 6.3, with addition of 4 wt.% SnTiO3. The fundamental optical absorption edge of the PEO shifted toward lower photon energy upon the addition of the SnTiO3 NPs, confirming a decrement in the optical band gap energy of PEO. The band gap shifted from 4.78 eV to 4.612 eV for PEO-doped with 4 wt.% SnTiO3. The nature of electronic transitions in the pure and the composite material were studied on the basis of Tauc’s model, while optical εi examination was also carried out to calculate the optical band gap

A Comprehensive Review on Optical Properties of Polymer Electrolytes and Composites

Polymer electrolytes and composites have prevailed in the high performance and mobile marketplace during recent years. Polymer-based solid electrolytes possess the benefits of low flammability, excellent flexibility, good thermal stability, as well as higher safety. Several researchers have paid attention to the optical properties of polymer electrolytes and their composites. In the present review paper, first, the characteristics, fundamentals, advantages and principles of various types of polymer electrolytes were discussed. Afterward, the characteristics and performance of various polymer hosts on the basis of specific essential and newly published works were described. New developments in various approaches to investigate the optical properties of polymer electrolytes were emphasized. The last part of the review devoted to the optical band gap study using two methods: Tauc’s model and optical dielectric loss parameter. Based on recently published literature sufficient quantum mechanical backgrounds were provided to support the applicability of the optical dielectric loss parameter for the band gap study. In this review paper, it was demonstrated that both Tauc’s model and optical dielectric loss should be studied to specify the type of electron transition and estimate the optical band gap accurately. Other parameters such as absorption coefficient, refractive index and optical dielectric constant were also explored

Polymer Composites with 0.98 Transparencies and Small Optical Energy Band Gap Using a Promising Green Methodology: Structural and Optical Properties

In this work, a green approach was implemented to prepare polymer composites using polyvinyl alcohol polymer and the extract of black tea leaves (polyphenols) in a complex form with Co2+ ions. A range of techniques was used to characterize the Co2+ complex and polymer composite, such as Ultraviolet–visible (UV-Visible) spectroscopy, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The optical parameters of absorption edge, refractive index (n), dielectric properties including real and imaginary parts (εr, and εi) were also investigated. The FRIR and XRD spectra were used to examine the compatibility between the PVA polymer and Co2+-polyphenol complex. The extent of interaction was evidenced from the shifts and change in the intensity of the peaks. The relatively wide amorphous phase in PVA polymer increased upon insertion of the Co2+-polyphenol complex. The amorphous character of the Co2+ complex was emphasized with the appearance of a hump in the XRD pattern. From UV-Visible spectroscopy, the optical properties, such as absorption edge, refractive index (n), (εr), (εi), and bandgap energy (Eg) of parent PVA and composite films were specified. The Eg of PVA was lowered from 5.8 to 1.82 eV upon addition of 45 mL of Co2+-polyphenol complex. The N/m* was calculated from the optical dielectric function. Ultimately, various types of electronic transitions within the polymer composites were specified using Tauc’s method. The direct bandgap (DBG) treatment of polymer composites with a developed amorphous phase is fundamental for commercialization in optoelectronic devices

Characteristics of Poly(vinyl Alcohol) (PVA) Based Composites Integrated with Green Synthesized Al3+-Metal Complex: Structural, Optical, and Localized Density of State Analysis

The influence of dispersing Al-metal complex on the optical properties of PVA was investigated using UV–visible spectroscopy. Polymer composite films with various Al3+-complex amounts in the PVA matrix were arranged by solution casting technique by means of distilled water as a widespread solvent. The formation of Al3+-metal complex was verified through Ultraviolet–visible (UV-Vis) and Fourier-transform infrared spectroscopy (FTIR) examinations. The addition of Al-complex into the polymer matrix led to the recovery of the optical parameters such as dielectric constant (εr and εi) and refractive index (n). The variations of real and imaginary parts of complex dielectric constant as a function of photon wavelength were studied to calculate localized charge density values (N/m*), high-frequency dielectric constant, relaxation time, optical mobility, optical resistivity, and plasma angular frequency (ωp) of electrons. In proportion with Al3+-complex content, the N/m* values were amplified from 3.68 × 1055 kg−1 m−3 to 109 × 1055 kg−1 m−3. The study of optical parameters may find applications within optical instrument manufacturing. The optical band gap was determined from Tauc’s equation, and the type of electronic transition was specified. A remarkable drop in the optical band gap was observed. The dispersion of static refractive index (no) of the prepared composites was analyzed using the theoretical Wemple–DiDomenico single oscillator model. The average oscillator energy (Eo) and oscillator dispersion energy (Ed) parameters were estimated

Synthesis of PVA/CeO2 Based Nanocomposites with Tuned Refractive Index and Reduced Absorption Edge: Structural and Optical Studies

In the current study, polymer nanocomposites (NCPs) based on poly (vinyl alcohol) (PVA) with altered refractive index and absorption edge were synthesized by means of a solution cast technique. The characterization techniques of UV–Vis spectroscopy and XRD were used to inspect the structural and optical properties of the prepared films. The XRD patterns of the doped samples have shown clear amendments in the structural properties of the PVA host polymer. Various optical parameters were studied to get more insights about the influence of CeO2 on optical properties of PVA. On the insertion of CeO2 nanoparticles (NPs) into the PVA matrix, the absorption edge was found to move to reduced photon energy sides. It was concluded that the CeO2 nanoparticles can be used to tune the refractive index (n) of the host polymer, and it reached up to 1.93 for 7 wt.% of CeO2 content. A detailed study of the bandgap (BG) was conducted using two approaches. The outcomes have confirmed the impact of the nanofiller on the BG reduction of the host polymer. The results of the optical BG study highlighted that it is crucial to address the ε” parameter during the BG analysis, and it is considered as a useful tool to specify the type of electronic transitions. Finally, the dispersion region of n is conferred in terms of the Wemple–DiDomenico single oscillator model

Characteristics of Glycerolized Chitosan: NH4NO3-Based Polymer Electrolyte for Energy Storage Devices with Extremely High Specific Capacitance and Energy Density Over 1000 Cycles

In this work, plasticized polymer electrolyte films consisting of chitosan, ammonium nitrate (NH4NO3) and glycerol for utilization in energy storage devices was presented. Various microscopic, spectroscopic and electrochemical techniques were used to characterize the concerned electrolyte and the electrical double-layer capacitor (EDLC) assembly. The nature of complexation between the polymer electrolyte components was examined via X-ray diffraction analysis. In the morphological study, field emission scanning electron microscopy (FESEM) was used to investigate the impact of glycerol as a plasticizer on the morphology of films. The polymer electrolyte (conducting membrane) was found to have a conductivity of 3.21 × 10−3 S/cm. It is indicated that the number density (n), mobility (μ) and diffusion coefficient (D) of ions are increased with the glycerol amount. The mechanism of charge storing was clarified, which implies a non-Faradaic process. The voltage window of the polymer electrolyte is 2.32 V. It was proved that the ion is responsible for charge-carrying via measuring the transference number (TNM). It was also determined that the internal resistance of the EDLC assembly lay between 39 and 50 Ω. The parameters associated with the EDLC assembly are of great importance and the specific capacitance (Cspe) was determined to be almost constant over 1 to 1000 cycles with an average of 124 F/g. Other decisive parameters were found: energy density (18 Wh/kg) and power density (2700 W/kg)

A brief review on optical properties of polymer Composites: Insights into Light-Matter interaction from classical to quantum transport point of view

In recent years, the optical capabilities of polymer composites have dominated the marketplace for applications in optoelectronic and energy devices. Supercapacitors, light-emitting displays, optical waveguide sensors, and organic photovoltaic cells are a few examples of the applications of the optical behavior of composites. Polymer composites are composed of nano/micro-sized inorganic particles (such as semiconductors, metal complexes, and synthetic nanoparticles) that are distributed within a polymer matrix. These materials have a significant role because they combine the optical properties of inorganic materials with the ease of processing of polymers, which utilizes the potential and performance of polymer-based optical systems. Optical features of polymer composites, such as indices of refraction, transparency, dispersion, and coefficients of absorption, influence their potential uses in optical systems and devices. The purpose of this research is to establish more insight into the optical characteristics of polymer composites and to understand the correlations between the structure and optoelectronic behavior of polymer composites. This review involves general concepts, scientific guidelines, and feasible mathematical sections. The unique optical characteristics of some common polymers (PEO, PMMA, PVA, and CS) and polymer composites are briefly reviewed. This review article establishes the fact that metal complexes are excellent over ceramic filler or nano-particles to improve optical absorption and decrease the optical band gap. An inspection of the fundamentals of light-matter interaction, ranging from classical (Drude-Lorentz model) to quantum methods for studying electron transition was exhibited. Furthermore, the applications of Tauc’s model and optical dielectric loss parameters to estimate the optical energy band gap of polymer composites are explained. Other fundamental optical parameters, such as absorption coefficient, optical dielectric constant, and refractive index are also explored. Finally, the Wemple-DiDomenico (WD) model is applied to investigate; the refractive index, optical dielectric constant, and optical spectra moments. The correlations between the optical dielectric function and several parameters such as ε∞, τ, N/m*, µopt, ρopt, ωp, and Eg are derived. Various models based on refractive index and absorption coefficient are discussed in detail to estimate crucial optical parameters