Polyvinyl Alcohol Films Research Articles

Activating Ultralong Room-Temperature Phosphorescence of Mono-Ring Arylboronic Acid by Hydrogen Bond for Tunable Afterglow Color and Stimulus Response.

Activating the ultralong room-temperature phosphorescence (RTP) of mono-ring arylboronic acid remains a great challenge, because the capacious free spaces shaped by a rubbery polymeric matrix allow the benzene ring skeleton to freely rotate. Herein, the ultralong RTP in mono-ring arylboronic acid derivatives embedded in a polyvinyl alcohol (PVA) matrix is activated, leveraging enhanced intermolecular and intramolecular hydrogen bonding and activating ultralong RTP. By incorporating diverse PBA derivatives into PVA via click chemistry, 3-aminophenylboronic acid (3A-PBA) doped PVA films showcase the most extended RTP lifetimes (2.24 s) and a high quantum yield (11.2%), alongside rapid and sensitive explosive vapor detection capabilities. These findings not only address the activation challenges of RTP in organic systems by highlighting the crucial role of hydrogen bonding and Förster resonance energy transfer in color tunability, but also mark a significant stride toward overcoming the limitations of current luminescent materials. This work heralds a new era in the development of organic phosphorescent materials, offering a promising strategy for broadening their practical applications and enhancing performance, particularly in environmental monitoring and security.

Reinforcing polyvinyl alcohol films with layered double hydroxide and tannic acid to enhance tensile strength, tribological performance, and corrosion resistance in biomedical coating applications

Abstract This study investigates the synergistic effects of incorporating layered double hydroxide (LDH) and tannic acid (TA) into polyvinyl alcohol (PVA) films to enhance their mechanical, tribological, and corrosion resistance properties for biomedical applications. Composite coating films were prepared by blending PVA with LDH and TA in various concentrations. The addition of LDH and TA significantly increased the crystallinity index of the composite films, with the highest crystallinity observed at 66.3% for the sample containing 1 wt% TA and 2 wt% LDH (PVA/TA1/LDH2). This enhancement in crystallinity contributed to improved mechanical performance, as demonstrated by tensile tests, where the PVA/TA1/LDH2 composite exhibited the highest tensile strength among all samples. Tribological testing revealed that the PVA/TA1/LDH2 composite also achieved the lowest coefficient of friction (COF), along with a minimal wear rate, indicating superior wear resistance. SEM analysis of the wear scars confirmed a narrow wear track and smoother surface morphology for this composite, which suggests effective load distribution and reduced surface degradation. The addition of TA was further shown to improve the corrosion resistance of the PVA composite films, with the PVA/TA1/LDH1 sample exhibiting the lowest corrosion current density (Icorr) of 0.36 µA cm⁻², representing a significant improvement over neat PVA. These findings highlight the potential of PVA/LDH/TA films for coating applications in biomedical devices, where enhanced mechanical strength, wear resistance, and corrosion protection are critical. The synergistic effects of LDH and TA provide a pathway for developing durable and functional coatings, expanding the practical utility of PVA films in demanding biomedical environments.

Polyvinyl alcohol and alginate bio-composite film containing titanium dioxide nanotubes for skin injury repair

This study explores the potential of polyvinyl alcohol (PVA) and alginate (SA) blend polymer films with embedded titanium dioxide nanotubes (TiO2NT) for wound healing applications. The nanocomposite film (PVA+SA@TiO2NT) was fabricated via a simple solvent casting process. The synergistic interaction between PVA and alginate significantly enhanced the film's stability in aqueous environments without compromising its weight. After 24 hours of immersion, the film exhibited a substantial swelling capacity (836±6%) and good WVTR ((282±4%). Scanning electron microscopy (SEM) revealed the formation of a smooth and random pore structure within the film. Fourier-transform infrared spectroscopy (FTIR) confirmed the successful formation of hydrogen bonds between PVA and alginate, along with the presence of Ti-O bonds, indicating successful incorporation of TiO2NT into the PVA+SA matrix. X-ray diffraction (XRD) analysis further corroborated the presence of TiO2NT. In vitro biocompatibility studies demonstrated the non-cytotoxic nature of the PVA+SA@TiO2NT bio-composite film. Additionally, in vitro wound healing studies suggest its potential as a promising biomaterial for wound dressing applications. These findings warrant further investigation to elucidate the complete mechanisms of action and optimize the nanocomposite's properties for clinical translation.

Effect of Pr6O11 rare-earth oxide on the structural characteristics and optical parameters of polyvinyl alcohol film

Effect of Pr6O11 rare-earth oxide on the structural characteristics and optical parameters of polyvinyl alcohol film

A Fluorescent Polyvinyl Alcohol Film with Efficient Photodynamic Antimicrobial Performance Enabled by Berberine/Phytic Acid Salt for Food Preservation

AbstractFood packaging that impedes microbial growth and can be safely used is critical to attenuate food spoilage. Herein, a green berberine/phytate salt (BPA) is successfully synthesized and aggregated in polyvinyl alcohol (PVA) film to impart fluorescent and photodynamic antimicrobial properties. Compared to berberine hydrochloride (BHL), BPA exhibited stronger fluorescence because intramolecular motions and intermolecular π–π accumulation of BHL are restricted by phytic acid (PA). Molecular dynamics simulation indicate that aggregation of BHL and PA formed through electrostatic interactions in the PVA matrix due to the change of the binding energy during the drying process. With increasing BPA content, the films exhibited increased ultraviolet, water vapor, and oxygen barriers and fluorescent properties, but reduced tensile strength and elongation at break. After radiated, PVA‐BPA9 film showed the highest antimicrobial rates against Staphylococcus aureus, Escherichia coli, P. citrinum, and Aspergillus niger reached 100%, 100%, 86.14%, and 66.24%, respectively, due to the increased reactive oxygen species production. The total number of microbial colonies in cooked chicken and oranges packaged by PVA‐BPA9 film with irradiation ARE 87.54% and 29.21% of those by PVA film. The findings indicate a new and feasible strategy to obtain a green photodynamic‐mediated film for safe and effective food packaging.

High-Performance Organic Field-Effect Transistors and Inverters with Good Flexibility and Low Operating Voltage.

Organic field-effect transistors (OFETs) with good flexibility and low operating voltage, are of great meaning for the low power stretchable and wearable electronic devices. The operating voltage and flexibility are easily affected by the dielectric layers in the OFETs. Bilayer dielectrics comprising both high- and low-permittivity (k) insulating polymers, have been reported. The flexible bilayer dielectrics can combine the advantages of both insulating polymers, which are high charge carriers from low-k polymers and low operating voltage from high-k polymers. However, the effect of film thicknesses in the bilayer dielectrics on the OFET performance is seldom investigated. Here, bilayer dielectrics comprising high-k polyvinyl alcohol (PVA) and low-k polymethylmethacrylate (PMMA) were fabricated. And PVA/PMMA bilayers with three different PVA film thicknesses are carefully investigated. The 300 nm PVA/100 nm PMMA bilayer dielectric makes the pentacene OFETs show the highest hole mobility of 1.24 cm2V-1s-1 and the corresponding inverters give a high voltage gain of 40 and a noise margin of 2.3 V (77% of 1/2 VDD) at low operating voltage of 6 V. Both the pentacene transistors and the inverters still work properly under bending radium of 5.85 mm, proving the good prospects of the PVA/PMMA bilayer dielectric in practical applications.

The effect of NaY‐zeolite on mechanical, thermal, and spectroscopic behavior of crosslinked polyvinyl alcohol films

AbstractThe effects of sodium y zeolite (NaY‐zeolite) on crosslinked Polyvinyl alcohol (CrPVA) composite films were investigated. The spectroscopic analysis showed that crosslinks were formed between PVA, Tartaric acid (TA), and NaY‐zeolite particles. The thermal stability of the CrPVA film was improved with the addition of zeolite. Optimum thermal stability was observed for 5 wt % zeolite content. It can be seen that the mechanical properties also improved for 5 wt % zeolite‐doped CrPVA composite films when compared with CrPVA. It was observed that Young's modulus increased 54.14 to 74.49 MPa. While the degree of crystallinity of the composite film decreased from 20.42 to 14.77% due to zeolite content. This is thought to be due to the increase in the structure's crosslinking rate. The utilization of TA and NaY zeolite in membrane applications may be considered an advantage for improving the mechanical characteristics and the recyclability of membrane technology.

The addition of Bi2WO6 nanoparticles to polyvinyl alcohol film: Improvements in optical, mechanical, and electrical properties

This study deals with the influence of adding Bi2WO6 (BWO) nanoparticles on the optical, structural, dielectric, and mechanical properties of polyvinyl alcohol (PVA). BWO nanoparticles synthesized by solvothermal method were characterized by X-Ray diffraction (XRD) and scanning electron microscope (SEM-EDS). The thick film nanocomposites were analyzed by Fourier Transformed Infrared (FTIR) spectrometer, XRD device, SEM, atomic force microscope (AFM), ultraviolet visible (UV–Vis) spectrophotometer, impedance analyzer, and tensile test machine. While FTIR analyses confirmed the formation of composite structure and the presence of BWO in the composites, AFM views indicated the reduced roughness for composites. Additionally, the UV–Vis light absorption spectra revealed a narrowed band gap in the composites. Moreover, with increasing BWO contribution, gradual increases were recorded in Young's modulus, toughness and % breaking strain parameters. The frequency dependent dielectric properties was also shown that the energy storage ability of the PVA matrix enhances 25 % and 50 % due to 2 % and 3 % BWO additives, respectively. However, the composite with higher ε′ and lower ε″ values than the pure PVA in the entire frequency range was the 2 % BWO-doped nanocomposite. Based on the serious and simultaneously improvements in electrical, optical and mechanical properties, it can be suggested that 2 % BWO additive provides the opportunity to expand the application area of PVA synergistically.

Diode Laser Irradiation Effects on Physical Properties of Titanium Dioxide Nano Fillers Doped Polyvinyl Alcohol Films

Study effect of diode laser (wavelength 650 nm) irradiation for different irradiant times (0.25, 0.5, 1.00, 3.00, and 4.00 hrs) on the physical properties of titanium dioxide (TiO2) possess particle size of 15.7 nm doped polyvinyl alcohol (PVA) films were experimentally investigated. The solution casting process has been utilized to create as-prepared TiO2/PVA nanocomposite films. Ultraviolet-Visible (UV-Vis) spectroscopy investigates the samples' optical characteristics by analyzing optical absorption spectra in a wavelength range of (200 - 900 nm) at room temperature (RT) of 300 K. The PVA matrix could be used to describe the influence. All optical constants produced artificially through laser radiation, like absorption, refraction index, extinction coefficient and complex dielectric constants, have decreased with increasing radiation times. On the contrary of optical energy gap they increased with increasing radiation times, according to the study's findings. TiO2 Nanoparticles (NPs) additions significantly impacted the PVA host's optical characteristics. When FTIR-spectrum regarding the TiO2/PVA nanocomposite films was examined in various ratios of irradiation times, the peak positions or bonds did not change; instead, they became smaller or larger as the irradiation time increased.

Effect of Morphology and Concentration of CeO2 Nanoceria on the Thermal Stability of Polyvinyl Alcohol Films

Objective: To determine the thermal stability of polyvinyl alcohol films under different concentrations of CeO2 nanoceria. Method: Cerium Oxide doped polyvinyl alcohol (PVA) nano-composites were synthesized by the traditional solution casting method for various concentrations of nano CeO2 by solution combustion method. The thermal properties of prepared PVA-2.5 wt% CeO2, PVA-7.5 wt% CeO2 , PVA-12.5 wt% CeO2, and PVA-25 wt% CeO2 composite films were elucidated by using techniques such as Differential Scanning Calorimetry, Thermogravimetry analysis and Differential Thermal analysis. Findings: The glass transition temperature of the pure PVA is found to be 114°C, whereas it varies between 110°C-120°C for composite films. The melting temperature of the composite films is the same as that of pure PVA except in the case of 7.5wt% CeO2 and 25wt% CeO2 composites. The reduced melting point of these composites elicits a decrease in crystallinity. A 12.5 wt % and 25 wt% CeO2-PVA nano-composite films exhibit an increase in the final degradation temperature, a high specific heat capacity, low mass loss, and a larger residual weight, indicating their potential applicability in thermal coating and thermal sensing applications. Polyvinyl alcohol (PVA) films are being used routinely as a dielectric layer for electrical applications due to the good physiochemical and dialectic properties of the material. An incorporation of CeO2 nanoceria improves not only the thermal but also the mechanical properties of PVA and extends its application for electrical and optical operation. Here in the present study, different concentrations of CeO2 were incorporated with the PVA and analysed for the thermal properties. The study showed that 12.5 wt % and 25 wt% CeO2-PVA nano-composite enhanced PVA film thermal stability. Keywords: PVA-CeO2 Nanocomposites; Differential Scanning Calorimetry; Thermogravimetry Analysis and Differential Thermal Analysis; Physical properties and thermal properties

Design of low-cost humidity sensor based on chipless RFID

It is of great significance to design a low-cost chipless radio frequency identification(RFID) sensor for environmental humidity monitoring. To this end, polyvinyl alcohol (PVA) film is used as a humidity sensitive material, and the overall size of the rectangular substrate is 18 mm × 18 mm ×0.5 mm. Through the humidity sensing principle and simulation analysis, the change of environmental humidity causes the change of the dielectric constant of the humidity sensitive material PVA, which in turn affects the resonant frequency offset of the entire sensor. The simulation results show that the relative humidity working range of the designed humidity sensor is 21.9% ∼ 52.5%, the corresponding sensor resonant frequency range is 2.76 ∼ 2.51GHz, the total offset reaches 250 MHz, and the average sensitivity at the maximum relative humidity is 23.08MHz/% . The designed humidity sensor has the advantages of miniaturization, simple structure and low cost, and can be used for humidity monitoring in various target environments. Keywords.low cost; chipless RFID humidity sensor; polyvinyl alcohol; humidity monitoring; humidity sensitive material.

Enhancing mechanical performance of hydroxyapatite-based bone implants via citric acid post-processing in binder jetting additive manufacturing

Binder jetting is a promising technology in the additive manufacturing of bone implants, particularly for printing brittle bioceramics that are susceptible to thermal residual stresses. However, challenges in this field include low strength and undesirable size changes due to post-sintering treatments, as well as the absence of necessary organic matter like Glycosaminoglycans, citric acid, etc. To address these issues, a novel approach was introduced using citric acid (CA) as a post-processing agent to enhance the mechanical performance of green samples and add organic matter, with boric acid (BA) as a control. A hydroxyapatite (HA) based powder mixed with 25 wt.% high-viscosity polyvinyl alcohol (PVA) was prepared and printed using a self-made printer with deionized water as the binder. The post-processing effects were analyzed in terms of mechanical properties and microstructure. The application of 5 wt.% CA solution increased the thickness of the PVA film between HA particles by 320.0%, leading to an increase in compressive strength (7.37 ± 0.28 MPa) and modulus (102.81 ± 6.74 MPa) by 840.7% and 1571.3%, respectively, achieving the mechanical standards for human trabecular bone. This work presents a simple and rapid room-temperature post-processing strategy for enhancing the mechanical properties of bone implants produced by binder jetting additive manufacturing.

Luminescent study of Eu(OOCC6H5)3·3(H2O) complex dispersed on polyvinyl alcohol films: Crystal structure, interaction and quenching effect

This study presents the preparation of a mononuclear complex of europium and benzoic acid and its interaction with polyvinyl alcohol films. The europium complex was prepared from europium (III) chloride hexahydrate (EuCl3 · 6H2O), and sodium benzoate (C7H5NaO2), and it was established that the ligand is attached to the metal ion through the carbonyl group anchored by bidentate interaction, obtaining a mononuclear complex powder with the formula Eu(OOCC6H5)3·3(H2O) (identified as EuBA3). First, the crystal structure solution for the complex powder was carried out, showing a monoclinic P2 space group with two molecules in the unit cell, the resulting crystal structure was deposited in the CCDC service with number 2370755. Afterward, the complex was deposited on polyvinyl alcohol films, to study the interactions between them, the morphological and luminescent properties were also evaluated. This work details the synthesis, of a complex made of europium and sodium benzoate and its luminescent properties as a complex deposited at different concentrations on polyvinyl alcohol films, the results obtained showed a shift in the excitation wavelength from the EuBA3 powder complex when incorporated into the PVA films. The concentration of the complex in the film increases until reaching a maximum followed by a decrease due to quenching.

Excellent facile fabrication of PVA and lignin nanoparticles from wheat straw after novel DES-THF pretreatment

The utilization of environmental friendly and renewable materials has received increasing attention recently. Lignin nanospheres (LNPs) prepared from recovered lignin and residual lignin after DESs and DESs-THF pretreatment were obtained by self-assembly in the present research. Then, films were prepared by incorporating them into polyvinyl alcohol (PVA) solution. The properties of various films were characterized and compared. Results showed that as the LNPs content increased, the UV blocking capacity of the films was gradually enhanced than PVA film. The DES-THF films showed better antioxidant properties up to 69 % due to higher phenolic hydroxyl content. The hydrophobicity of films incorporated with DESs-THF pretreated lignin was consistently better than that of DES pretreated. DES-THF-M films showed a higher Tmax than that of DES-M films, resulting in better thermal stability. Moreover, DES-THF-L films are lighter in color due to a lower degree of condensation, which is favorable to subsequent applications. The incorporation of LNPs improved mechanical and antioxidant properties, thermal stability, and UV shielding ability of PVA films, especially lignin after DES-THF pretreatment. In conclusion, the prepared PVA/LNPs composite films possessed good functional properties that make them potential for packaging materials.

Efficient synthesis of highly hydrophobic lignin nanoparticles and their application as nano fillers for multifunctional composite membranes

Controlling the hydrophobic behaviors of lignin nanoparticles (LNPs) is crucial and advantageous for their application as film Nano Fillers, yet it poses a significant challenge. Herein, we successfully developed a novel method for the preparation of LNPs with highly hydrophobic behaviors using ternary deep eutectic solution (DES)-H2O systems. The resulting LNPs exhibit a significantly reduced content of hydrophilic groups on their outer surface, leading to a zeta potential value of only −4.9 mV, and up to 140.0° of water contact angle (WCA). Afterwards, a “Dissolution-Restructuration” mechanism was proposed to explain the formation of the prepared LNPs. Firstly, DES demonstrates superior H-bonding capabilities, facilitating the complete disruption of inter- and intramolecular H-bonding in lignin, and resulting in the formation of a highly homogenized lignin network. Subsequently, the DES system undergoes compromise after adding water, triggering the reformation of both inter- and intramolecular H-bonding and π-π interactions. Consequently, lignin orderly self-assembles into LNPs with highly hydrophobic characteristics. Especially, using the as-prepared LNPs as Nano fillers, a series of LNPs-containing polyvinyl alcohol (PVA) films were successfully fabricated, exhibiting exceptional hydrophobic behaviors (with contact angles reaching up to 124.0°). Furthermore, the mechanical strength, UV-shielding capabilities, and biodegradability of the PVA films are significantly enhanced. This study introduces a sustainable and efficient approach for the synthesis of hydrophobic LNPs, thereby facilitating the broadening of applications for lignin-based functional composite film materials.

Unveiling the potential of PVA-Er2O3 films for superior optical, electrical, mechanical, and thermal applications

This study explores the enhancement of polyvinyl alcohol (PVA) films by incorporating erbium oxide (Er2O3) nanoparticles using the casting solution method. We investigated the structural, optical, electrical, dielectric, and mechanical properties of PVA-Er2O3 nanocomposite films with varying Er2O3 concentrations (2.5, 5, 7.5, and 10 wt%). Structural analyses confirmed successful nanoparticle integration. Optical measurements revealed reduced transparency and bandgap, alongside increased refractive index. Electrical conductivity showed significant improvement with Er2O3 inclusion. Dielectric properties demonstrated enhanced performance, with frequency-dependent studies and Argand plot analysis providing insights into charge transport and relaxation mechanisms. Mechanical testing indicated increased tensile strength and Young’s modulus, with the 10 wt% nanocomposite showing comparable performance to pure PVA. These findings highlight the potential of PVA-Er2O3 films for advanced applications in electronics, sensors, and energy storage systems.

Low-cost and durable polyvinyl alcohol modified polyethylene separator for vanadium redox flow battery

Porous separators are considered a viable alternative to the high cost Nafion membrane for vanadium redox flow battery (VRFB) commercialization. However, the porous separators suffer from high vanadium ion crossover due to the presence of large micron size pores, which leads to decay in capacity of the VRFB system. To tackle the same, a composite separator is synthesized wherein a cross-linked polyvinyl alcohol (PVA) layer is coated on to the porous polyethylene silica separator (PE separator) to mitigate the vanadium ion crossover rate and employed in the VRFB application. Scanning electron microscopy (SEM) analysis confirmed the successful coating of the PVA film on to the PE separator. Synthesized PE-PVA separator showed a significant decrease in the vanadium ion crossover by 31.44 times compared to the pristine PE separator. Consequently, the self-discharge time increases by 8 and 1.66 times compared to the pristine PE separator and the Nafion117 membrane, respectively. VRFB cell equipped with the synthesized separator showed better capacity retention with a capacity fade rate of 0.2 % Ah·cycle−1 than the Nafion117 membrane (0.5 % Ah·cycle−1). In-situ and ex-situ oxidative stability of the separator is explored in detail and a degradation mechanism of the cross-linked PVA membrane is proposed accordingly. The synthesized single side coated PE-PVA´ separator exhibits higher coulombic efficiency of 99 % and comparable energy efficiency of 71 % at a current density of 120 mA·cm−2 and demonstrated excellent lifetime durability tested up to 1600 charge-discharge cycles at 80 mA·cm−2.

Double-crosslinked polyvinyl alcohol/starch bioplastic with superior water-resistance and flame retardancy

The high water solubility and flammability of polyvinyl alcohol (PVA) limits its further widespread use in areas such as bioplastic and green packaging. In this study, double-crosslinked polyvinyl alcohol/starch bioplastics (named PDA) were fabricated using PVA, dialdehyde starch (DAS), and phytic acid (PA), resulting in a material with superior water resistance, flame retardancy, and excellent degradability. PA not only plays the role of catalyst for the chemical crosslinking but also as the physical crosslinker to form the intermolecular hydrogen bonds with PVA and DAS. This chemically and physically double cross-linked network structure results in PDA bioplastics with excellent toughness and water resistance. Specifically, the optimal formulation with 15 % PA content, designated as PDA15, exhibited a high toughness of 35.5 MJ/m3 and demonstrated prolonged shape retention in the boiling water. Additionally, PA also serves as a flame-retardant and antibacterial agent; the PDA15 achieved a high limit oxygen index (LOI) value of 40.0 % and passed the UL-94 V-0 rating without melt dripping, along with better degradability compared to pure PVA film. These outstanding performances make the PDA bioplastics highly promising for various applications, particularly in disposable plastics and laminated flexible packaging materials.

Development and application of visual fish freshness indicator film incorporated with anthocyanins encapsulation by whey protein-propylene glycol alginate nanoparticles

Intelligent indicator packaging has gained increased attention in meeting the demand for reducing food waste and mitigating the risk of food poisoning. This study focused on the preparation, characteristics, and application of freshness indicator films based on polyvinyl alcohol (PVA) and anthocyanins (ACNs)-encapsulated whey protein (WP)-propylene glycol alginate (PGA) nanoparticles. The successful encapsulation of ACNs by WP-PGA nanoparticles improved the stability of ACNs and their encapsulation efficiency (EE) reached 95.34 %. The incorporation of nanoparticles into the structure of the PVA films was justified by SEM, XRD, and ATR-FTIR, and resulted in a decrease in water vapor permeability (WVP) from 15.76 (×10−7 g·m−1·Pa−1·h−1) to 8.40 (×10−7 g·m−1·Pa−1·h−1) and an increase in scavenging rate of DPPH radical from 1.47 % to 18.92 %. The light-blocking property and mechanical properties of the films were also improved, and they showed visible color change in response to pH 2–12 and high color stability after 14 days of storage at 4 °C and 25 °C. Furthermore, the freshness indicator films underwent a noticeable transformation from rosy red to gray at bighead carp head spoilage. Therefore, the encapsulation of ACNs using WP-PGA nanoparticles provides a promising non-destructive and real-time freshness indication of aquatic products during both storage and transportation processes.

Polyvinyl alcohol dyed with methyl red as a radiochromic film dosimeter for gamma radiation

Abstract A Radiochromic film dosimeter for gamma radiation was prepared from polyvinyl alcohol (PVA) and methyl red (MR) by condensation polymerization. To confirm the reaction, the obtained PVA-MR film was characterized by Fourier-transform infrared spectroscopy (FTIR) and compared to PVA film. The result shows the appearance of new vibrational stretching at ~1700 cm−1, related to carbonyl groups, indicating that the reaction between PVA and MR has been successfully done. The effect of radiation on the color change characteristic of PVA-MR film and its possibility to be used as a radiochromic film dosimeter were investigated using ultraviolet (UV)-Vis spectrophotometry. The absorption spectrum of PVA-MR can be seen in the visible region at ~420 nm, which is characteristic of red, and the film undergoes decolorization gradually from red to transparent when exposed to gamma radiation up to 100 kGy. Moreover, the response of these dosimeters at different times after irradiation was tested and the energy band gap, Eg, was also calculated.