Solution Casting Research Articles

Harnessing the power of hollow Zein nanoparticles for enhanced antifouling and heavy metal removal of polyethersulfone membranes

This study explores the physicochemical characteristics of an innovative mixed matrix membrane made from polyethersulfone (PES) and hollow Zein nanoparticles (HZNs), which are derived from the corn storage protein, Zein. HZNs, with a mean diameter of 40 nm, were applied to address the challenges associated with metal and inorganic nanoparticles, such as their tendency to accumulate unevenly on the membrane surface. The membranes were fabricated by incorporating varying concentrations of HZNs into the PES casting solution through the nonsolvent phase separation method. The addition of HZNs enhanced the hydrophilicity and pure water flux of the membranes. It also modified the membrane structure, morphology, pore size, molecular weight cut-off (MWCO), and porosity. Increasing the HZN concentration up to 5 wt% proportionally improved the surface hydrophilicity and roughness of the membranes. Furthermore, the modified membranes exhibited excellent performance in rejecting heavy metals at an acidic pH of 4, with the 5 %-HZNs/PES membrane achieving a 100 % rejection rate without significantly affecting water flux due to Donnan exclusion. Additionally, the 5 %-HZNs/PES membrane showed a minimal irreversible fouling resistance (Rir) of 17.9 % and a fouling resistance ratio (FRR) of 82.1 %. These results indicate that the developed mixed matrix membrane holds significant promise for applications in water purification processes.

Fabrication of PZT/PVDF composite film and the influence of homogeneity to dielectric constant

AbstractThe Lead Zirconate Titanate/polyvinylidene fluoride (PZT/PVDF) piezoelectric composite with various volume fractions of PZT is successfully fabricated by the proposed solution casting and hot press methods. The aim of this study is to determine the quality of the composite material being fabricated by its homogeneity. Homogeneity can be determined by computing the free path space between particles based on the binary image of SEM, using dispersion and distribution quantitative methods, to gain a comprehensive understanding of the particles' scattering conditions. In comparison to several selected models providing adjustable factors that are highly related to the effect of homogeneity of the composite's internal structure, a suitable model is found.

Deep Eutectic Solvent-Based Polymer Electrolyte Films for an Electrochemical Double Layer Cell

Polymer electrolyte films based on DES were prepared with the solution cast technique. DES(ChCl-glycerol) was prepared with two different glycerols: one purchased from the industry and the other fabricated in the lab from waste vegetable oil. Two polymer electrolyte films were prepared with two different DES (industrial and from oil-based glycerol) were named D1 and D2, respectively. Fabricated polymer film (D1) with DES (prepared with industrial glycerol) shows excellent physical and thermochemical properties. The molecular and structural characteristics of the film were studied via FTIR and XRD. The surface morphology, thermal and electric properties of film were studied with SEM, TGA, and impedance spectroscopy techniques, respectively. The obtained films were flexible, strong, and transparent. Its properties are ascribed to a strong coherent hydrogen bond network with the matrix of the polymer. Polymer electrolyte film D1 exhibited good ionic conductivity of 1.25×10-3 Scm-1. The prepared polymer film was applied as solid electrolytes in symmetric solid-state supercapacitors. The fabricated EDLC cell exhibits specific capacitance of at voltage with scan rate. Moreover, the prepared electrolyte is biocompatible, environment safe and cost-effective that offers a new path for adaptable electronic devices. Keywords: Green electrolytes, Supercapacitor, Deep eutectic solvent, Hydrogen bond network, Choline chloride-glycerol.

Effect of Antigonon leptopus extract in corn starch-glycerol based film as colourimetric indicator film for monitoring fish freshness

A colourimetric indicator can be used to test the freshness of fish in a rapid, straightforward and non-destructive manner. Anthocyanin, a natural dye found in Antigonon leptopus flowers, has a sensitive colour reactivity to a wide range of pH levels and can be made into colourimetric indicator films on a laboratory scale, making it a viable replacement for artificial dyes. The study's purpose was to see how the concentration of A. leptopus extract affected the colourimetric assessment of fish freshness. Ethanol was used to extract anthocyanin from A. leptopus. FTIR and pHrespond spectroscopies were used to characterise the extracts. Colourimetric indicator films were developed to assess fish freshness by incorporating A. leptopus extract into a corn starch-glycerol matrix via the solution casting method, with concentrations of 10%, 30% and 50%, respectively. The effect of A. leptopus extract on visual aspects, thickness, morphology, FTIR spectra, UV-Vis spectra and colour responses was analysed. Microbial analysis, TVB-N contents, firmness, and pH of the fish samples were analysed after storage. The colour of the original films became darker as the extracted content increased. There was no significant (p>0.05) effect of A. leptopus extract on film thickness. SEM micrographs revealed that the composite films had homogeneous and whitish granules on the surface and that increasing the A. leptopus extract concentration caused the films to become rougher. FTIR and UV-Vis spectroscopies showed successful binding between A. leptopus extracts and corn starch-glycerol film. With increasing pH, the colour change of the films exposed to pH = 3-11 solutions was no significant difference due to improper storage. An increase in the microbial population, TVB-N content and pH was observed over the storage period as a result of fish deterioration. Colour changes were also identified in the film which became darker. Overall, colourimetric indicator film with 50% A. leptopus extract was found to be the optimal formulation since it had the highest values in ∆E* during progressive spoilage of fish.

Carboxymethyl hemicellulose/sorbitol/gallic acid green composite films for fresh fruit preservation

Fruits are prone to deterioration during transportation and preservation, while conventional packaging materials generally pose a persistent threat to the environment. In the present study, a multifunctional green composite film was developed using solution casting method through the interactions of hydrogen bonds among carboxymethyl hemicellulose, sorbitol, and gallic acid, which was subsequently employed as functional materials for fresh fruit preservation application. In particular, the influence of the degree of substitution (DS) of carboxymethyl hemicellulose on the properties of the composite films was investigated. The results indicated that as the DS increased, the carboxymethyl hemicellulose/sorbitol/gallic acid composite film demonstrated a notable improvement in transmittance, air barrier property, and antibacterial activity. Specifically, the composite film (DS = 0.59) showed a 42.54 % increase in transmittance and a 48.31 % decrease in air permeability compared to the composite film containing hemicellulose (control sample). Furthermore, the composite film (DS = 0.59) displayed a desired inhibition effect against Staphylococcus aureus. Based on the 9-day blueberry preservation test, the composite film (DS = 0.59) exhibited a weight loss rate of 15.36 %, whereas the blank group retained a value up to 20.34 %. In addition, the increased DS was found to lead to the decreased tensile strength but improved elongation at break. Overall, the carboxymethyl hemicellulose/sorbitol/gallic acid green composite films, derived from natural bio-materials and free of environmental concerns, could hold great promise as a novel packaging material for fresh fruit preservation.

Design and fabrication of PPTA-braid-reinforced PFA/GE hollow fiber composite membranes

Due to the effects of the rapid development of modern society and fresh water resource pollution, water shortage has further accelerated, which is becoming a very urgent problem. Herein, the poly (p-phenylene terephthalamide)-(PPTA-) braid-reinforced (PBR) poly(tetrafluoroethylene-co-perfluoropropylvinylether)/graphene (PFA/GE) hollow fiber composite membranes (HFCMs) were prepared by dipping coating-thermal sintering coupling technique with a green process. GE is an emerging type of two-dimensional functional nanoparticle with a tunable passageway for oil molecules. The influences of the GE concentration in the casting solution on the structure and performance of the PBR−PFA/GE HFCMs were investigated. The results showed that the addition of GE produced a finger-like pore structure suitable for oil channels. Meanwhile, the roughness and contact angle of the composite membrane increased accordingly, and the water contact angle increased from 115° to 120°. The permeation fluxes of kerosene also increased obviously with the increase of GE contents, and the maximum flux of M-3 reached as high as 217.66 L·m−2·h−1. The application of the lubricating oil flux test under working conditions of 60–150 °C has demonstrated the high-temperature oil permeability resistance of the composite membrane. Even after long-term use, its separation efficiency for water-in-oil emulsions still remains above 99.5 %. In addition, the membrane separation-efficiency both up to 99.9 % for activated carbon and silica dioxide (SiO2) in kerosene. Overall, the PBR-PFA/GE HFCMs with excellent lipophilicity presented great potential for oily wastewater treatment at high temperatures.

Enhanced thermal conductivity of reduced graphene oxide reinforced polymer films through a novel GO reduction mechanism

AbstractGraphene's remarkable thermal conductance characteristics makes it a very promising thermal interface material for polymeric composites. In this study, we propose an innovative approach aimed at augmenting the thermal conductivity of flexible composite films, employing reduced graphene oxide (rGO) and polyvinyl alcohol (PVA) as the constituent materials. The fabrication process involves the utilization of solution casting coupled with a low‐temperature chemical reduction method for graphene oxide (GO). Given that the high thermal conductivity of polymer nanocomposites typically correlates with increased crystallinity and reduced defects, our primary objective is to investigate the impact of reduction of GO in order to associate enhance crystallinity within the graphene oxide‐polymer system, with the overall increased thermal conductivity of the resulting GO/PVA films. The diethylene glycol‐GO/PVA films thus, generated through this methodology exhibit an exceptional thermal conductivity of approximately 5.1 W/mK, achieved with a mere 10 wt.% filler loading. This surpasses the thermal conductivity observed in films comprised solely of GO/PVA. The notable enhancement in thermal conductivity can be attributed to several factors, including improved crystallinity and reduced defects of GO with effective polymeric bridging facilitated by the rGO with PVA. Collectively, these advancements contribute to the overall thermal performance of the material, presenting a promising methodology for future developments in the field of thermal conductivity materials.Highlights Reduction of GO through a streamlined and facile methodology. Orchestrated a controlled reduction process at lower temperatures and simultaneously enhancing the crystallinity and decreasing the defects of GO. Fabricated reduced GO/PVA polymer films exhibited an exceptional thermal conductivity of approximately 5.1 W/mK with just a 10 wt.% filler loading.

The High-Performance Polymer Electrolytes Based on Agarose–Mg(ClO4)2 for Application in Electrochemical Energy Storage Devices

Electrochemical energy storage devices (EES) such as batteries and supercapacitors depend significantly on electrolytes, which have properties that significantly impact their energy capacity, rate performance, cyclability, and safety. Agarose–Mg(ClO4)2–based polymer electrolyte was prepared using the solution casting method by incorporating various amounts of Mg(ClO4)2 from 0 – 35 wt%. The presence of Mg(ClO4)2 as the dopant in agarose-matrix enhanced the ionic conductivity of the system from 1.796 × 10-8 S∙cm-1 to 6.247 × 10-4 S∙cm−1 in the composition of 30 wt% Mg(ClO4)2 due to the production of free ions. This system obeys the Arrhenius rule as it records the conductivity increment when temperature increases. This increment shows the amorphous nature of electrolytes, which XRD analyses by determining the crystallite size and degree of crystallinity of agarose–Mg(ClO4)2 polymer electrolyte. High ionic conductivity at room temperature has increased attention to this polymer electrolyte based on agarose–Mg(ClO4)2.

Mixed‐charge cellulose nanocrystal modified cellulose acetate membrane with endotoxin scavenging ability and antibacterial properties

AbstractBlending modification is used to improve the hemocompatibility of cellulose acetate (CA) dialysis membranes while endowing the CA membrane with endotoxin scavenging and antibacterial capabilities. First, polydopamine (PDA) and polyethylenimine (PEI) are used as negatively charged and positively charged moieties, respectively, together with cellulose nanocrystals (CNCs) to construct mixed charge CNCs (PEI‐PDA@CNCs). Then PEI‐PDA@CNCs is blended with the CA casting solution, and the modified CA dialysis membrane is prepared through a phase inversion process. Through biocompatibility, adsorption, antibacterial, and filtration experiments, various properties of PEI‐PDA@CNCs modified CA membrane (PDCA) are systematically tested. The results show that the PDCA membrane exhibited good blood compatibility and noncytotoxicity. At the same time, the PDCA membrane has antibacterial properties and excellent endotoxin adsorption capacity. Compared with the CA membrane, the clearance rates of PDCA membrane for Staphylococcus aureus and Escherichia coli reach 54.0% ± 1.5% and 52.9% ± 5.9% respectively. In the dynamic adsorption experiment, the adsorption capacity of PDCA membrane for endotoxin increases to 2322.1 ± 45.9 EU/g. The research results indicate that PEI‐PDA@CNC‐modified multifunctional CA membrane with endotoxin adsorption and antibacterial properties has potential application prospects in the fields of hemodialysis and blood purification.

The Development of Sustainable Biocomposite Materials Based on Poly(lactic acid) and Silverskin, a Coffee Industry By-Product, for Food Packaging Applications

Aligned with the principles of the circular economy and aiming at the production of environmentally friendly materials for food packaging applications, sustainable biocomposite films based on poly(lactic acid) (PLA) and coffee silverskin (SS), were developed. Coffee silverskin is a by-product of the coffee roasting process, while PLA is one of the most promising bio-based polymers. Several composites were prepared with different loadings of SS, ranging from 2.5 to 20 wt.%, via the solution casting method. The findings indicated that the effective dispersion of coffee silverskin in PLA was successfully accomplished and that a bleaching treatment of the filler leads to better interfacial interaction. The addition of silverskin, in any proportion, did not affect the melting point and glass transition temperature of the polymer matrix or the oxygen permeability of the film. Moreover, the degree of swelling was increased, more so for the films with modified particles, whereas the water vapor transmission rate and permeability increased only after the addition of high amounts (>10%) of surface-treated silverskin. A gradual decrease in color lightness was measured with the increasing concentration of silverskin, and the color was more intense in the untreated samples. The antioxidant activity of the films increased gradually with increasing additions of coffee silverskin due to the presence of compounds such as polyphenols. The chemical treatment of coffee silverskin resulted in the films having improved mechanical properties, as the chemical treatment facilitated stronger bonding between the base material and the additive. Therefore, sustainable composites with enhanced antioxidant activity can be produced by the incorporation of a food industry by-product into a PLA matrix.

Preparation, structural, morphological, optical, electrical, mechanical, and thermal properties of perovskite SrTiO3 nanoparticles boosted PVA/PEO blend for flexible optoelectronic and capacitor applications

Strontium titanate nanoparticles (SrTiO3 NPs) were produced via the solid-state reaction method. Then, they were used to enhance the structural, mechanical, electrical, and dielectric properties of polyvinyl alcohol (PVA)/polyethylene oxide (PEO) blend for energy storage applications. For this purpose, SrTiO3 NPs were dispersed in the polymer blend to fabricate nanocomposite films using a solution casting method. The nanocomposite films were then characterized using a variety of instruments, such as transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-Transform Infrared spectroscopy (FTIR), Ultraviolet/Visible spectroscopy (UV/visible), and impedance analyzers. Based on XRD and TEM measurements, the synthesized SrTiO3 NPs have a cubic perovskite phase and a diameter that varies between 70 and 160 nm. Additionally, according to XRD measurements, adding SrTiO3 NPs to PVA/PEO reduces the crystallinity of the resulting nanocomposites. In addition, the surface morphology and elemental composition were demonstrated through the utilization of scanning electron microscope.(SEM) and energy dispersive X-ray spectroscopic analysis (EDX) spectra, where PVA and PEO polymers formed a homogenous and rough surface, and the SrTiO3 NPs of low concentrations were spread out within the blend's structure. Analysis of the FTIR peaks revealed prominent characteristic peaks associated with vibrational groups that change randomly with the concentration of SrTiO3 NPs. With increasing SrTiO3 NPs concentration, the nanocomposite UV/visible absorbance, optical bandgap energies, and refractive index were calculated and discussed. Impedance studies conclude that the amount of SrTiO3 NPs in a mixture raises the mixture's AC electrical conductivity, dielectric loss, and dielectric constant. The mechanical characteristics, such as Young's modulus, yield strength, and strain at failure, were assessed by examining the tensile test of prepared films. The thermal stability of PVA/PEO-SrTiO3 nanocomposite films were studied by thermogravimetric analysis (TGA). These experimental results point to the potential for employing the produced nanocomposites in optoelectronic and capacitive energy storage systems.

Separation performance of cationic and anionic dyes from water using polyvinylidene fluoride-based ultrafiltration membrane incorporating polyethylene glycol

Membrane separation shows high performance in the dye’s removal at nanofiltration conditions. Pinpointing the problems accompanying using high pressure in the nanofiltration process sparks increased interest among investigators to tackle this important point. This work tackles the problem of using the nanofiltration process to remove intermediate molecular weight dyes by decorating new functionalized membranes working at ultrafiltration conditions. Flat sheet ultrafiltration membranes were successfully prepared by the phase inversion technique from polymeric solutions containing 16, 18, and 20 wt% of polyvinylidene fluoride (PVDF) and N, N-dimethyl formamide as a solvent. The prepared membranes were tested using rhodamine B (RhB) dye as a model pollutant at different transmembrane pressures of 1, 2, 3, and 4 bar. Optimistic permeability, permeate flux, and dye removal were obtained using 18 wt% of PVDF. This membrane was developed with different polyethylene glycol (PEG) contents of 3, 6, and 9 wt% to improve the hydrophilicity and permeability of the membrane surface at low pressure. The morphology analysis, elemental composition, and surface functional groups of the pure and modified membranes were examined. The effect of dye concentration and pH of the feed solution on the permeate flux and RhB removal was studied using an 18 wt% PVDF membrane containing 6 wt% of PEG. The results showed that incorporating 6 wt% of PEG in the 18 wt% PVDF casting solution reduced the CA from 78.85° for pure PVDF to 62.08° and enhanced the permeability from 7.16 L/m2.h for pure PVDF to 74.72 L/m2.h at 1 bar and initial RhB concentration of 10 mg/L. While RhB dye removal slightly decreased from 93.08 % for pure PVDF to 91.26 %. The results showcased the potential efficiency of the (6 wt%)PEG/(18 wt%)PVDF membrane for dye separation from water. Also, molecular weight cut-off was evaluated using RhB as a cationic dye, acid orange 10, and congo red as anionic dyes and it was 478 Da.

Effect of Sodium Ion Addition on Copper Selenide/Chitosan Film Towards Electrical and Shielding Efficiency Improvement

The operation of electronic devices can be disrupted by unwanted electromagnetic signals, affecting its operation. Deploying electromagnetic shielding is a viable solution to minimize the impact of electromagnetic interference (EMI). The conventional methods of electromagnetic shielding use metal gaskets to safeguard sensitive electronic components, which have drawbacks of cost and weight. Hence, electromagnetic shielding polymer can be an alternative to replace metal gaskets. This work investigates the effect of sodium ion (Na) addition to copper selenide/chitosan (CuSe/Ch) film for electromagnetic shielding applications. The shielding polymers were produced using solution casting methods, while the CuSe was synthesized using the chemical coprecipitation method. Impedance spectroscopy and two port waveguide methods were used to characterize the prepared polymer's electrical properties and shielding efficiency. The results indicate that Na incorporation in the CuSe/Ch film resulted in a 47 % decrease in bulk resistivity and increased DC conductivity from 6.07 × 10-6 S/cm to 3.69 × 10˗5 S/cm. The AC conductivity of films containing Na demonstrates a similar level of conductivity at lower frequencies, followed by a sharp increase at higher frequencies, indicating a more substantial influence of Na at higher frequencies. Higher absorption shielding efficiency (SEA) and lower reflection shielding efficiency (SER) were achieved by introducing Na into the CuSe chitosan film. The Na/CuSe/Ch film shows higher total shielding efficiency at an average of 20 dB, equivalent to 99 % of the EM power shield.

Molybdenum gallium carbide coated D-shape fiber for nanosecond dark pulse generation in erbium-doped fiber laser

Molybdenum gallium carbide (Mo2Ga2C), a material belongs to MAX phase group, has garnered significant interest in a wide range of scientific field, including material science, engineering, and laser physics. It is chemically and structurally promising since it exhibits a low shear modulus, superconducting behaviour, and high mechanical stability. Here, we prepared a saturable absorber (SA) based on Mo2Ga2C coated D-shape fiber using solution casting technique. It exhibits outstanding saturable absorption of 7.2%, allowing it to generate dark pulse laser in an erbium-doped fiber laser cavity. We analyzed the laser’s performance and obtained a dark pulse with a pulse energy, peak power, and average output power of 3.9 nJ, 27.5 mW, and 7.3 mW, respectively. This foundational work may introduce a new material as an alternative SA device in fiber laser cavity.

Performance improvement of polyethersulfone membranes with Ti3AlCN MAX phase in the treatment of organic and inorganic pollutants

In this work, the hydrophobic polyethersulfone (PES) membrane was modified by incorporating Ti3AlCN MAX phase. Synthesis of Ti3AlCN MAX phase was performed using the reactive sintering method. The scanning electron microscopy (SEM) images showed a 3D compressed layered morphology for the synthesized MAX phase. The Ti3AlCN MAX phase was added to the casting solution, and the mixed-matrix membranes were fabricated by the non-solvent induced phase inversion method. The performance and antifouling features of bare and modified membranes were explored by pure water flux, flux recovery ratio (FRR), and fouling resistance parameters. Through the modification of membranes by introducing the Ti3AlCN MAX phase, the enhancement of these features was observed, in which the membrane containing 1 wt% of MAX phase showed 17.7 L/m2.h.bar of permeability and 98.6% for FRR. Also, the separation efficiency of all membranes was evaluated by rejecting organic and inorganic pollutants. The Ti3AlCN MAX membranes could reject 96%, 95%, and 88% of reactive blue 50, Rose Bengal, and azithromycin antibiotics, respectively, as well as 98%, 80%, 86%, and 36% of Pb2+, As5+, Na2SO4, and NaCl, respectively. Finally, the outcomes indicated the Ti3AlCN MAX phase was an excellent and efficient novel additive for modifying the PES membrane.

Development of halochromic labels based on binary systems of cationic guar gum and κ-carrageenan loaded with alizarin red S for monitoring milk and seafood freshness

Monitoring of food quality, in particular, high-protein food quality, is an important component in ensuring food safety and human health. In this research, a feasible and easy solution casting and solvent evaporation strategy was adapted to fabricate alizarin red S (ARS)-loaded halochromic cationic guar gum (CGG) and κ-carrageenan (CAR) blend packaging labels to improve its good physical strength, multifunctional acid–base responsive characteristics, and water barrier properties. The findings indicated that incorporating CAR at 40% polymer solid mass achieved higher tensile strength (21.0 ± 1.77 MPa), water resistance (29.92 ± 6.61% solubility), and thermal stability, which can be attributed to good compatibility between CGG and CAR. The results obtained from FT-IR, XRD, and SEM analyses demonstrate that the incorporation of ARS exhibits non-covalent bonding with the polymer blend matrix through electrostatic interactions and hydrogen bonding, thus reducing its crystallinity and restructuring the CGG-CAR matrix disorderly. The prepared indicating label films presented visual recognition of ammonia and trimethylamine (TMA-N) at 0.008 mM in 6 min (the total color difference (ΔE) for TMA-N is＞11.89), and can be reused at least six times. Moreover, the color of ARS at different pH values remains persistent for at least 180 days. The practical applications show that the films, as indicator labels, can realize real-time, accurate, and visual dynamic monitoring of seafood (shrimp) and milk by engendering three chromatic stages discernible by the naked eye (fresh, spoiling, and spoiled). The ΔE for monitoring sub-fresh milk and shrimp reached as high as 14.91 and 13.32, respectively.

Biophysical studies of modified PVC sheet based on sunflower oil for antistatic and blood bags applications

In this work, the surface of polyvinyl chloride PVC sheet was modified by blending it with sunflower seed oil SSO to obtain PVC sheet/SSO films of ratios 100/0, 90/10, 80/20, 70/30, 60/40, and 50/50 (v/v)% using the solution casting method. Various techniques were used to characterize the prepared films, besides the use of hemolysis assays and blood clot formation tests. FTIR spectra revealed that there was a good interaction between the PVC sheet and the oil. The dielectric measurement indicated that SSO addition enhanced the dielectric properties of the sheet. The study of dielectric relaxation times confirmed the interaction between SSO and the sheet. DC conductivity increased to 6 × 10–6 S/m, so it could be applied in antistatic applications. Also, SSO addition increased the value of the thermal stability. According to SEM micrographs, the film was roughened at a ratio of 60/40 and smoothed out at 50/50. This behavior was confirmed with roughness and contact angle measurement results, in which the film of ratio 60/40 had the highest value equal to (72.03°) and then decreased at 50/50 to (59.62°). These results were confirmed by XRD measurement as the crystallinity increased at the film ratio of 60/40 and decreased again at 50/50. Also, the ratio of 60/40 demonstrated a large decrease in thrombus weights along with a slight increase in hemolysis, which is within the acceptable range and has a high degree of biocompatibility, so this concentration is recommended to be used in blood bags applications.

Development of antioxidant film based on gelatin and carboxymethylcellulose incorporated with Tecoma stans (L.) Juss. ex Kunth Petals extract for biodegradable food packaging

The aim of this research was to develop a novel combination of antioxidant blended film for use as biodegradable packaging in the food industry. The antioxidant film was prepared based on gelatin (G) and carboxymethyl cellulose (CMC) incorporated with Tecoma stans (L.) Juss. ex Kunth petals extract (TKE) at various concentrations (0.5, 1.0, and 2.0 mg∙L‒1) via solution casting method. The structural and surface morphology of G/CMC-TKE film were characterized using FTIR spectrometry technique and scanning electron microscopy (SEM), including determining antioxidant activity, water solubility, water vapor permeability, and biodegradability. According to FTIR analysis, the significant interaction between the gelatin and CMC chain is associated with hydrogen bonding. Adding TKE into the blended films significantly increased their roughness, thickness and antioxidant activity while decreasing their water solubility and water vapor transmission. Likewise, the biodegradability of the films containing antioxidants exhibited greater degradation values than the pure G/CMC film, and all of the biofilms was entirely degraded (>80%) in 14 days. The G/CMC-TKE 2.0 demonstrated the best antioxidant (74.47%), biodegradable activity (95.85% in 14 days), and the lowest water solubility (61.80%) and water vapor transmission rate (3.2483 g∙m‒2∙day‒1), which could be a feasible candidate for the food active packaging.

Inorganic metal oxide‐reinforced polymer‐based flexible inorganic nanocomposite for UV shielding applications

AbstractThis investigation reveals the successful incorporation of strontium‐doped thorium oxide (SrThO3) NPs into polyvinyl alcohol (PVA) polymer nanocomposites. The fabrication process of these PVA nanocomposites entails utilizing varying amounts (0.5, 1.0, 2.0, and 4.0 wt%) of SrThO3 nanofillers through a straightforward solution casting technique. The microstructure and overall structure of the resulting polymer nanocomposites were analyzed using powdered x‐ray diffraction for crystalline structure and Fourier transform infrared (FTIR) spectroscopy for molecular composition. The introduced SrThO3 nanofiller demonstrates a strong affinity for the hydroxyl groups present in the PVA polymer, a phenomenon validated through FTIR spectroscopy. In order to comprehend the impact of doping, the surface morphology of the PVA polymer nanocomposites underwent examination via scanning electron microscopy. The absorption and transmission of light were quantitatively assessed using UV–visible spectroscopy. The excitation and emission behaviors of electrons in both the PVA and SrThO3‐doped PVA nanocomposites were scrutinized through photoluminescence spectroscopy. Furthermore, the extent of UV light absorption was investigated by studying the degradation of methylene blue dye, a substance known for its sensitivity to UV light. Results indicate that the intentional incorporation of SrThO3 NPs significantly enhances UV stability.

Modification in the Optical and Dielectric Characteristics of Poly (Vinyl Alcohol)/Carboxymethyl Cellulose Blended Polymers Doped with Two Phases Nanocomposites for Application in Optoelectronic and Energy Storage Devices

Nanocomposite films comprised of poly (vinyl alcohol) (PVA) and carboxymethylcellulose (CMC) were fabricated via a solution casting procedure, with the incorporation of (1-x)CuCo2O4/xZnMn2O4. Our research described here was aimed to explore the impact of the (1-x)CuCo2O4/xZnMn2O4 on the structural, optical and electrical features of the PVA/CMC blended polymer, using various techniques. The different phases formed (CuCo2 O4 and/or ZnMn2O4) in (1-x) CuCo2O4/x ZnMn2O4 filler samples were identified applying Rietveld refinement analysis. The structures and morphologies of the PVA/CMC/(1-x)CuCo2O4/xZnMn2O4 blend composites were determined using X-ray diffraction and scanning electron microscopy techniques. Their various linear and nonlinear optical parameters were examined using the diffused reflectance technique. The blended polymer composite with x = 0.1 displayed the highest absorbance. The transmittance of the PVA/CMC blend declined from 91 to 69% when it was loaded with a nanocomposite containing 10% ZnMn2O4. The optical band gaps of the doped blend composites had their lowest values, 5.45 eV for direct transition and (4.83, 2.99, 2.31) eV for the indirect transition, as the blend was loaded with the fillers containing 10 and 15% ZnMn2O4. The study also explored the influence of the (1-x)CuCo2O4/x ZnMn2O4 on the fluorescence spectra and chromaticity diagram of the PVA/CMC blend. The effect of the filler on the complex dielectric constant, complex electric modulus, ac conductivity and electrical storage energy of the host blend was examined. The obtained characteristics imply potential utility of the doped blends in photocatalytic, UV-blocking, UV-filtering, optoelectronic, electrical storage, nonlinear optical and photonic applications.