Properties Of Polyvinyl Alcohol Films Research Articles

Biotemplated fabrication of N/O co-doped porous carbon confined spinel NiFe2O4 heterostructured mimetics for triple-mode sensing of antioxidants and ameliorating packaging properties

In this work, shrimp shell-derived magnetic NiFe2O4/N, O co-doped porous carbon nanozyme with superior oxidase (OXD)-like activity was prepared and used for colorimetric/photothermal/smartphone dual-signal triple-mode detection of antioxidants in fruits and beverages. The magnetic NiFe2O4/N, O co-doped porous carbon (MNPC) material was triumphantly fabricated using a combined in-situ surface chelation and pyrolysis method. The resultant MNPC composite exhibits a superior OXD-like activity, which can effectively oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) for yielding colorimetric/temperature dual-signal (CTDS) in absence of H2O2. This CTDS output sensor was successfully used for the determination of ascorbic acid and tannic acid. The proposed CTDS sensor with good specificity and high sensitivity can satisfy different on-site analysis requirements. Interestingly, the MNPC as a sustainable filler was further used for improving packaging properties of polyvinyl alcohol film. In short, this work offers a large-scale and cheap method to fabricate magnetic carbon-based nanozyme for monitoring antioxidants and ameliorating packaging properties.

Enhancing the Properties of Polyvinyl Alcohol Films by Blending with Corn Stover-Derived Cellulose Nanocrystals and Beeswax.

Coating is a technique to surround a target substance with a thin layer to obtain desirable properties. Polyvinyl alcohols (PVAs) are biodegradable plastics and have shown good applicability as a coating or film material. Cellulose nanocrystals are a promising green nanomaterial that has been shown to enhance the properties of PVA after blending. However, these PVA/CNC films have concerns in a moist environment due to high hydrophilicity. To overcome this issue, the current study incorporated beeswax into PVA/CNC films and investigated the effect of CNC and beeswax on the properties of the coatings and films. Results showed that the addition of corn stover-derived CNCs to PVA films increased tensile strength (from 11 to 25 MPa) and Young's modulus (from 32 to 173 MPa) and reduced water vapor transmission rate (from 25 to 20 g h-1 m-2). Beeswax added to PVA/CNC films further improved water vapor barrier properties (from 20 to 9 g h-1 m-2) and maintained Young's modulus (from 173 to 160 MPa), though it caused a reduction in the tensile strength (from 25 to 11 MPa) of the films. This information can help to select materials for blending with PVAs by obtaining the desirable endmost properties depending on applications.

Lignin micro/nanoparticles: synthesis, properties, and application to endow polyvinyl alcohol film with multi-functionality

Lignin, as an abundant natural polymer, has great potential in the synthesis of multifunctional micro/nanoparticles. However, the synthesis methods and parameters during the preparation process impact the controllability of lignin micro/nanoparticles (LMNPs), thereby affecting the performance of composite materials containing LMNPs. In this study, a green, simple, and applicable method for organosolv lignin was proposed for the synthesis of LMNPs using recyclable γ-valerolactone and the parameters (lignin concentration, stirring speed, dropping speed, water/solvent ratio, and lignin structure) were systematically investigated. The tuning of multiple properties of the composites was investigated by mixing LMNPs with polyvinyl alcohol (PVA). Results indicated that synthesis parameters affected the LMNPs formation, leading to aggregation/fusion of LMNPs. The obtained spherical LMNPs were electrostatically stable in pH 4–12, uniform (0.09 PDI), and excellent in thermal stability and antioxidant activity. Based on diffusion-restricted cluster–cluster aggregation, LMNPs around 157–442 nm were fabricated through π-π interactions. The PVA/LMNPs composite films showed excellent properties in terms of mechanical properties, thermal stability, UV shielding capacity, and hydrophobicity. The LMNPs with different structures improved the properties of polyvinyl alcohol films, providing a controllable approach for the development of biodegradable food/medical packaging materials and UV-shielding biomaterials.

Lignocellulose Nanofibers Enhanced Mechanical and UV-Blocking Properties of Polyvinyl Alcohol Films

Lignin-containing cellulose nanofibers (LCNFs) from bamboo were prepared by choline chloride–lactic acid solvent treatment at 110–130∘C in combination with ultrasonication. Effects of LCNFs dosages on UV-blocking property, mechanical property, thermal stability and water vapor barrier property of LCNFs/PVA composite film were determined by UV spectrophotometer, universal mechanical testing machine, thermogravimetric analysis and weightlessness method, respectively. The results indicated that PVA film composited 10% LCNFs obtained from 120∘C showed best properties. As compared to pure PVA film, the UV-blocking property of composite film increased from 30% to 53%. LCNFs addition enhanced mechanical properties, resulting increment of tensile strength from 42[Formula: see text]MPa to 81[Formula: see text]MPa and elongation at break from 3% to 9%, respectively. LCNFs also introduced 2.4 times increment of water vapor barrier property of PVA film. The LCNFs/PVA composite films not only have excellent thermal stability and mechanical properties but also have UV-resistance and water vapor barrier properties. It provides a new idea for replacing some petroleum-based packaging materials and also shows the great potential of LCNFs materials.

Comparative studies of starch blends on the properties of PVA films

This research studied the effects of pregelatinized starch (PST) and hydrolyzed starch (HST) at various contents with 20 phr glycerol on the properties of polyvinyl alcohol (PVA) film. FTIR analysis showed that the increase of HST preferably interacted with the hydroxyl (OH) groups and CH molecules, while the interaction of hydrogen bonding with PST interacted with OH groups of PVA, but did not affect CH stretching molecules. The blend with HST possessed lower overall thermal degradation than the blend with PST. Tensile strength by blending with PST increased from 14 MPa to 30 MPa, while the elongation at break decreased by a factor of two. On the other hand, elongation at break of the blends with HST improved from 300 (when no HST) to 350%, and its tensile strength improved slightly only with 10 and 20% blending. Regarding the water-soluble properties, hydrogen bonding interaction of starch, PVA and glycerol showed hardly any effect on the rate of dissolving the blends. However, the chemical structure of starch and the size of molecules, especially in HST dramatically increased the rate of dissolving in water.

The Impact of Ammonium Fluoride on Structural, Absorbance Edge, and the Dielectric Properties of Polyvinyl Alcohol Films: Towards a Novel Analysis of the Optical Refractive Index, and CUT-OFF Laser Filters

The new proton-conducting composite electrolyte films (PCCEFs) consisting of polyvinyl alcohol (PVA) with varying ammonium fluoride salt concentrations were created using an expanded liquid casting process. The X-ray diffraction (XRD) study confirms the composite electrolyte films (CEFs) formation. The improvement in AMF02 salt doping compared to the PVA matrix film approach resulted in decreased variation in the crystalline size values, thus explaining how [NH4+] and polymer PVA matrix films interact. The band gaps decrease when the AMF02 salt filler concentration increases due to increased crystallite size. The suggested composites evaluated successful CUT-OFF laser filters and attenuation, as well as limiting laser power systems. For the 11.11 wt% AMF02 doping salt, the highest DC conductivity was 73.205 × 10−9 (siemens/m) at ambient temperature. Our dielectric results demonstrate that the CEFs are usually suitable for optoelectronic systems. There is a huge need to develop low dielectric permittivity composite electrolyte films (CEFs) for microelectronic devices and the high-frequency region.

Improved properties of polyvinyl alcohol films blended with aligned nanocellulose particles induced by a magnetic field

In this study, polyvinyl alcohol (PVA) films filled with nanocellulose particles were developed for food packaging. In particular, the effect of the weak magnetic field-induced alignment of the nanocellulose filler in PVA blended with rod-shaped cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) on the physicochemical properties of the respective blends was investigated. For the alignment of the nanocellulose particles (6% with respect to PVA), a film-forming solution of each blend was cast and a homogeneous magnetic field of the order of milli Tesla was applied during drying. Microscopic investigations were conducted to analyze the dispersion of the CNCs and CNFs in the PVA matrix. The influence of particle alignment was examined in terms of the microstructure, intermolecular interactions, crystallinity, and hydration state of the film, as well as water migration. The applied magnetic field induced the orientation of the nanocellulose fillers, leading to their improved dispersion in the PVA matrix. The uniform structure formed owing to the magnetically induced alignment of nanocellulose led to enhanced mechanical, barrier, and hydrophobic properties, as well as thermal stability of the two blends. The improvement was more evident for the CNC/PVA blend compared to the CNF/PVA one. The applied magnetic field decreased the fluidity of the film and increased the number of water molecules bound to PVA. When applied in the preservation of strawberries, the films exposed to a magnetic field facilitated better protection and firmness of the fruit.

SYNTHESIS AND WOUND HEALING PROPERTIES OF POLYVINYL ALCOHOL FILMS DOPED WITH METAL NANOPARTICLES OF Cu AND Ag

The skin recovery (wound healing) properties of materials based on polyvinyl alcohol (PVA) doped with metal nanoparticles (PVA-MNPs) and their chemical and physical characterization is reported. The synthesis of copper and silver metal nanoparticles supported in PVA was performed by Solvated Metal Atom Dispersed (SMAD) method using 2-ethoxyethanol as solvent. The average size of metal nanoclusters (PVA-Cu = 77 nm, PVA-Ag = 72 nm) was determined by TEM and the distribution of the inorganic phase in the hybrid material was analyzed by SEM-EDX. TGA performed in synthetic air atmosphere shows an improvement in the thermal stability by addition of nanometals to pure polymer, with the copper composite showing a higher thermo resistive capacity than the rest. Antibacterial activity against ATCC bacterial strains of Escherichia coli (E.C.), Staphylococcus aureus (S.A.), Staphylococcus epidermidis (S.E.) and Pseudomonas aeruginosa (P.A.) was determined. The silver compound showed antibacterial activity against all tested microorganisms, while the copper compound was active against S.E. Toxicological and wound healing tests were performed in Sprague Dawley rats with infested injuries on the back which were treated with PVA films doped with copper and silver. The recovery of injures infested with S. aureus is reported. This type of material could be used for biomedical applications, such as skin recovery processes in infected wounds or type I and II burns.

Influence of urea on polarization property and mechanical properties of polyvinyl alcohol films for the polarizers

Influence of urea on polarization property and mechanical properties of polyvinyl alcohol films for the polarizers

Properties of polyvinyl alcohol films reinforced by citric acid modified cellulose nanocrystals and silica aerogels

In this study, citric acid modified cellulose nanocrystals (MCNC) and silica aerogel (SA) were used as reinforcing agents and added to polyvinyl alcohol (PVA) in different proportions to prepare composite films with excellent mechanical and barrier properties. After modification with citric acid, MCNC successfully contained ester bonds. SEM and FTIR results showed that MCNC and SA were uniformly dispersed in the PVA matrix and formed a compact structure. XRD results showed that there were physical interactions between the reinforcing agents and PVA, which improved the thermal stability of the film. Meanwhile, the composite film obtained good barrier properties after adding 0.5 % MCNC and 1.5 % SA. The carbon dioxide permeability decreased by 66.01 % and the oxygen permeability decreased by 69.46 % (23 °C, 50 % RH) and 40.14 % (38 °C, 90 % RH). The tensile strength increased to 43.79 MPa. Therefore, the composite film can be widely used in the packaging of food, medicine, etc.

Absorption Properties of Polyvinyl Alcohol Films Filled with Nanoparticles Doped with Acridine Orange Dye

Polyvinyl Alcohol (PVA) polymer/ Acridine Orange (AO) dye films prepared via casting technique at room temperature. The effect of adding (Acridine Orange (AO) dye solution, Magnesium Oxide (MgO), and Aluminum Oxide (Al2O3) NPs) to the PVA polymer matrix were studied on the absorption spectra. The effect of AO addition on the absorption spectrum of PVA film is occurrence blue shift (5nm) from 280nm to 275 nm in the PVA and red shift (10nm) from 490nm to be 500 nm for AO maximum absorbance wavelength. The absorbance of AO dye decreases when adding PVA, but increases When the volume ratio of AO dye solution is increased to 0.49 for 18ml, the volume ratio of AO dye solution decreases for 24- and 30-ml volume ratios. Adding NPs led to enhancing the photophysical properties of polymer composite, noted that absorbance of adding alumina nanoparticles more than it is in the case of adding magnesia nanoparticles. Also, there is a 10 nm red shift in AO and a 5 nm blue shift in AO when they are added to the polymer matrix filled with MgO and Al2O3 NPs.

Role of rubrene additive for reinforcing the structural, optical, and dispersion properties of polyvinyl alcohol films towards optoelectronic applications

A conventional casting method was used to produce promoted polyvinyl alcohol (PVA) films via rubrene additive. The 1.2 g of PVA dissolved in 120 ml of distilled water and doped with various concentrations (0, 0.1, 0.3 and 0.4 wt%) of rubrene dye. The influence of rubrene dopants on the structural properties of PVA was studied using FTIR and XRD techniques. The semicrystalline nature of the PVA polymer was established by the XRD pattern. FT-IR analysis shows changes in peaks intensities of PVA and their widths are expanded in the presence of rubrene dopants which indicates the interactions between the functional groups of PVA and the rubrene dopants. XRD patterns exhibit the existence of rubrene inside the PVA structure leads to form cross-linking which enhances the amorphous nature within the doped PVA samples. The optical characteristics were investigated using spectrophotometric measurements of transmittance T(λ), reflectance R(λ), and absorbance A(λ) in the spectral range of 200–2500 nm. The indirect and direct optical band-gap values of PVA films decreased from 5.15 eV and 5.69 eV to 3.63 eV and 4.50 eV as rubrene doping ratio was increased from 0 to 0.4 wt%, respectively. The refractive index dispersion region was explained using the single oscillator (Wemple–DiDomenico) model. The extracted values of dispersion energy (Ed), dielectric constant at infinite frequency (ε∞) and lattice dielectric constant (εL) of PVA/rubrene composite films increased from 0.74 eV, 1.31 and 1.35 to 5.35 eV, 3.47 and 4.35; respectively, whereas oscillator energy (Eo) decreased from 2.41eV to 2.17 eV as rubrene contents increased from 0 to 0.4 wt%, respectively. Indeed, these changes in values of dispersion parameters is evidence to the cross-linking bonds between the host polymer and the rubrene dopants. The improvement of optical properties of PVA/rubrene films demonstrates their applicability as eco-friendly packaging materials, particularly in flexible optoelectronic and microelectronic devices.

Investigation of physico‐mechanical, thermal, morphological, optical and biodegradation properties of polyvinyl alcohol films reinforced with alkali treated Limonia acidissima shell powder

AbstractPolyvinyl alcohol (PVA) and various concentrations of (5–25 wt%) alkali treated Limonia acidissima shell powder (LASP) was utilized to develop bio composite packaging films by solution casting method. The alkali treatment (5%NaOH) of the LASP particles were carried out to improve the interface adhesion between filler and PVA matrix and also remove non cellulosic contents from LASP. The biofilms were characterized by Fourier‐transform infrared spectroscopy, X‐ray diffraction analysis, thermogravimetric analyzer, field emission scanning electron microscopy, Tensile test, UV–vis spectroscopy analysis, water uptake, water vapor permeability, and soil burial test. The bio composite films reinforced with alkali treated LASP particles and compatibilized matrix lead to notable increase in the mechanical, optical, and biodegradation properties when compared to the neat PVA film. The increase in thermal stability (13.49%) of (332.06°C) PVA/alkali‐treated LASP biofilm compared to that of pure PVA film (287.24°C). Tensile stress and young's modulus were enhanced to 57.03% and 83.35%, respectively, with the inclusion of alkali‐treated LASP (up to 20 wt%) in PVA film. Scanning electron microscope micrographs showed that, beyond the 20 wt% of the filler the irregularities emerged on the surface of the biofilms, consequently the mechanical and water barrier properties were diminished However, the PVA/alkali‐treated LASP biofilms absorb less water than pure PVA films. The increased water transport with in the films facilitated the biodegradation behavior (32.11% of weight loss in soil) of composite film. Hence the results suggested the composite films developed in the study to be an ideal material for packaging and cosmetics industries as well as adding the value to wood apple (Limonia acidissima) waste.

Structural, thermal, and optical properties of polyvinyl alcohol films doped with La2ZnOx nanoparticles

To investigate La2ZnOx nanoparticles, ZnO is partially substituted by lanthanum oxide (La2O3) using a tartaric acid precursor. The prepared nanoparticles were reinforced in the polyvinyl alcohol (PVA) with different content and the films were obtained by casting method. The impact of the nanoparticles in the polymer structure and the thermal stability of the films were studied by X-ray diffraction and TGA-DTA techniques. Optical parameters were investigated using the absorbance and transmittance spectra obtained from the UV–visible spectrophotometer. Optical bandgap decreases, whereas the refractive index and optical conductivity improved with the addition of La2ZnOx nanoparticles in the polymer matrix. PVA-La2ZnOx films with enhanced futures are promising for organic-electronic applications.

The influence of ZnO nanoparticles on the structural, optical and dielectric properties of Polyvinyl alcohol films

Polyvinyl alcohol/Zinc oxide (PVA/ZnO) nanocomposite films with various weight percentages of ZnO nanoparticles (0 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%) were prepared by solution casting method. The structural, optical and morphological properties of the synthesized samples were characterized by X-ray diffraction (XRD), UV–Visible spectroscopy, Fourier transform Infrared spectroscopy (FTIR) and Scanning electron microscope (SEM). X-ray diffraction studies confirms the formation of PVA/ZnO nanocomposites. From the UV–vis absorbance spectra, the band gap energy of the samples was calculated and its value decreases with increasing the wt% of ZnO into the PVA matrix. The transmittance of the nanocomposites in the visible region is decreased with increasing the concentration of ZnO into the PVA matrix and completely blocked in the UV region. These behaviours suggests that the nanocomposite materials could be used as UV shielding materials. The FTIR analysis indicates physical interaction between hydroxyl group of PVA and ZnO. SEM shows the dispersion of ZnO on the surface of PVA matrix. The dielectric properties and AC conductivity measurement in the frequency range 100 Hz to 1 MHz reveals the maximum dielectric constant at PVA/5 wt% ZnO nanocomposite.

Mechanical and Barrier Properties of Polyvinyl Alcohol Films Modified with Carbon Nanotubes and Zinc Oxide

A solution blending technique was employed to form a nanocomposite film of polyvinyl alcohol modified with carbon nanotube and zinc oxide (CNT/ZnO). The film was characterized using a tensile testing machine, X-ray diffraction, scanning electron microscopy, a contact angle device, and barrier property measurement. When the CNT/ZnO content was 1.2 phr, the results from mechanical property and water vapor permeation tests showed that the nanocomposite film had good tensile strength and water resistance. Moreover, CNT/ZnO improved the hydrophobicity of the film. CNT/ZnO/can improve the performance of PVA and is a good nanofiller of PVA. The results of this research might have the opportunity to be used as packaging film materials in the future.

Synthesis and structural of Cd0.5Zn0.5F2O4 nanoparticles and its influence on the structure and optical properties of polyvinyl alcohol films

This paper aims to synthesize cadmium-zinc ferrite (Cd0.5Zn0.5F2O4) nanoparticles and to fabrication of polyvinyl alcohol (PVA) films that host Cd0.5Zn0.5F2O4 nanoparticles in order to enhance structural and optical properties. Cd0.5Zn0.5F2O4 nanoparticles are prepared via sol–gel method and PVA–Cd0.5Zn0.5F2O4 films are prepared by solution casting. Characterization of Cd0.5Zn0.5F2O4 nanoparticles and the prepared nanocomposite films are investigated via X-ray diffraction (XRD), optical microscope, and UV–Vis spectrophotometry. XRD analyses are confirmed the formation of Cd0.5Zn0.5F2O4 nanoparticles and the crystal structure of polymer films are changed with the addition of Cd0.5Zn0.5F2O4 nanoparticles. The effect of Cd0.5Zn0.5F2O4 nanoparticles on the optical parameters is investigated. Urbach energy, refractive index, and extinction coefficient are increased, while the band gap decreases as the Cd0.5Zn0.5F2O4 concentration increases in the PVA matrix. Furthermore, optical dielectric constants and optical conductivity are enhanced as the Cd0.5Zn0.5F2O4 content rises in the polymer matrix.

Improving Physical Properties of Polyvinyl Alcohol Film through The Addition of Nanocellulose Prepared from Palm Oil Solid Waste

Cellulose from the palm oil solid waste (oil palm shells and stems) be isolated and used as a filler material in a biodegradable plastic, in order to improve its mechanical properties. Polyvinyl Alcohol (PVA) is a biodegradable polymer and compatible for nanocellulose fillers, where its mechanical properties can reach the same level as the conventional plastic. In this study, nanocellulose has been successfully prepared from the oil palm shells and stems with acid hydrolysis method and applied as a filler for PVA/nanocellulose film composite. The characterizations include Fourier Transform Infrared (FTIR), Differential Scanning Calorimetry (DSC) and mechanical properties (tensile and elongation). The FTIR and DSC analysis confirm the improvement of the mechanical properties after the addition of nanocellulose, where the tensile strength reaches 14.64 kgf/mm2 with the optimal thermal ratio at 203.5°C. Nevertheless, the addition of 20% nanocellulose reduces the value of tensile strength and elongation.

The instructive role of mechanical properties of polyvinyl alcohol film in the process of YSZ tape calendering

Aqueous tape calendering offers the advantage of a simple fabrication process, inexpensive equipment, and environmental friendliness. Polyvinyl alcohol (PVA), as a polymer, is a conventional binder for aqueous tape calendering. In this innovative work, we aim to achieve a suitable process for tape calendering, by studying mechanical properties of the PVA polymer film with a series of plasticizers. The results show that the elongation at break of the PVA film reaches a maximum of 828.26%, using a triple plasticizer of glycerol, polyethylene glycol (PEG) 200, and PEG 400. With an optimized ratio of the binder to the plasticizer, a YSZ sheet with a relative density of 98% and a conductivity of 0.043 S cm−1 at 800 °C is obtained by sintering at 1400 °C, demonstrating comparable performance to those of the YSZ electrolytes by dry pressing. SEM reveals that the sintered YSZ body is dense, and has no visible open and closed pores. The mechanical properties characterization of the PVA polymer film adopted in this paper has instructive significant instruction for tape calendering and tape casting methods.

Influence of pentaerythritol on the properties of polyvinyl alcohol films for the polarizers

Pentaerythritol was used as the plasticizer to prepare PVA films through solution casting method. The interaction between pentaerythritol and PVA was studied by FTIR. The crystallinity of raw PVA and modified PVA films was characterized by X-ray diffraction. The effect of the addition of pentaerythritol on the swelling properties, mechanical properties and optical properties of PVA films were investigated. The experimental results showed that the addition of pentaerythritol destroyed the hydrogen bonding in the PVA molecule and reduced the crystallinity of PVA. As the pentaerythritol content increased, the swelling property of the PVA films was significantly improved. The addition of pentaerythritol into PVA resulted in the increase of elongation at break, as well as the decrease of tensile strength. As the amount of pentaerythritol added, the optical performance of the PVA films was improved.