Polymer Bulletin最新文献

Semiconducting polymers, especially polyindole, have become a significant area of research due to their superior electrical, optical, and electrochemical properties. These properties qualify it for a wide range of potential applications, including transistors, Schottky diodes, light-emitting diodes, and rechargeable batteries. Semiconducting poly(2-amino-5-(1H-indolyl)-5H-thiazolo[4,3-b]-1,3,4-thiadiazole) (PAITTD) and its N-substituted indole derivatives, which include a side chain containing chlorobenzene (PACBITTD) and bromobenzene (PABBSITTD), have been prepared by the radical polymerization process. Characterization techniques, such as XRD, SEM, and TGA/DSC, have been employed to investigate the structural, morphological, and thermal properties of the prepared compounds. The optical properties were investigated by measuring absorbance using a UV-visible spectrophotometer in the range of 200–1200 nm. Several optical parameters, including the refractive index n(λ), optical conductivity (σopt), extinction coefficient (k), dissipation factor (tan δ), and relaxation time (τ), are calculated from the absorpance spectrum A(λ). A PAITTD and PACBSITTD depict three semi-sharp absorption peaks at (212 -352- 412 nm) and (212–478–700 nm), respectively. These three absorption peaks of PAITTD increase to five (212–352 – 412–498–700 nm) for PABBITTID. The absorption spectra are analyzed using multiple peak analysis techniques. The lowest evaluated optical gaps for PACBSITTD (Eg = 1.53–2.05 ± 0.05 eV) are confirmed through various methods. First, it was calculated from the intersections of the linear plot (αhν)² with the hν-axis. Second, it was determined from the extrapolation of the straight line of the ε’ and ε” curves to the hν-axis. Third, the intercept of the dielectric relaxation time with hν was used as a disjunctive method. Finally, it was ascertained from the cross-point between the curves of σ_opt and σ_e. PACBITTD, with the lowest band gap, broad spectral coverage and high photon harvesting efficiency, is a very promising material for solar cells, photodiodes, and other cutting-edge light-harvesting technologies.

A new method to find the optimum composition of ternary copolymers for pressure-sensitive adhesives (PSAs) using molecular dynamics simulations was investigated. Since tack, peel and shear properties, being the main characteristics to assess the performance of PSAs, are difficult to evaluate directly by microscopic simulations, and glass transition temperature, adhesive-substrate interaction energy, and shear modulus were chosen as the corresponding simulation parameters. For this purpose, the well-known PSAs, such as ternary copolymers based on 2-ethyl hexyl acrylate (2-EHA), methyl methacrylate (MMA), acrylic acid (AA), were simulated. Then, the copolymers with similar adhesive properties were simulated to set target values for 2-EHA/MMA/AA ternary PSA to meet. Next, the simulations were carried out to maximize the target properties of the adhesive by varying the MMA content from 0 to 40 wt% in the 2-EHA/MMA binary system and subsequently, repeated the simulation to further improve the properties of the adhesive, adjusting the AA content to 10 wt% in the 2-EHA/MMA/AA ternary system. As a result, the optimum compositions in the 2-EHA/MMA binary system and in the 2-EHA/MMA/AA ternary system were 80/20 and 80/16/4, respectively. Unlike previous studies that were limited to simulating the adhesion properties of copolymers of a specified composition, in this paper the optimum composition was determined by simulating the adhesion properties of different compositions of adhesives and balancing them to achieve good performance.

The following work intends to show the investigation of silver salt incorporated polymer electrolyte with the addition of Titanium dioxide (TiO₂) nanofiller. A traditional solution casting method has been followed to synthesize the Nanocomposite polymer electrolyte (NPE) using Poly (vinyl alcohol) (PVA) as polymer with the addition of Silver tetrafluoroborate (AgBF₄) and TiO₂. The NPE investigated through structural and functional analysis to confirm the complex mixture of PVA: AgBF₄:TiO₂. The TiO₂ dispersion and the effect of Ag-ion in the NPE is examined from surface morphology of NPE and thermal stability of the material has been studied and known that the NPE can withstand around 100 °C. Further NPE’s ionic conductivity is investigated that achieved up to 1.45 × 10^− 4 S.cm^− 1. The dielectric analysis shows NPE’s dielectric properties and the dipole relaxation in NPE taking place in the time of 6.05 × 10^− 7 s. The NPE subjected to test in a two-electrode cell where the electrodes are prepared by activated carbon (AC). The cell’s performance is studied through electrochemical impedance spectroscopy (EIS) analysis and through equivalent electrical circuit modeling (EEC). Dielectric characteristics and complex capacitance of the cell are examined to study the performance of the cell. A real-time testing of the cell has been carried out, which analyses the charging and discharging of the cell.

Fouling of the membranes is the biggest challenge while removing emulsified oil from water due to the high adhesive properties of oil with membranes. Therefore, zwitterionic surface on the membranes were achieved by polymer coating along metal deposition to impart anti-fouling properties to the membranes. In this study, the surface of polyvinylidene fluoride (PVDF) membrane was modified with zwitterionic surface to enhance its resistance to early fouling. Surface modification was achieved by applying a uniform layer of copper metal by electroless deposition and then coating a layer of polyethyleneimine (PEI). The removal efficiency of the surface modified PVDF membrane was determined by studying the separation of emulsified diesel oil from water and comparing the product water obtained from both the pure and modified PVDF membranes. The results of removal percentage and water flux applying modified PVDF membrane were observed as 98.2% and 1564 Lm^− 2h⁻bar⁻ respectively. The permeate flux decline ratio and flux ratio of recovery of the pure membrane were determined as 84.2% and 55.8% respectively and the modified membrane as 69.6% and 85.1% respectively. This study concludes that the PVDF membranes modified by electroless deposited copper with PEI coating have better anti-fouling properties than the pure PVDF membrane and it has greater potential to remove emulsified diesel oil from water.

The current study describes the preparation and characterization of a new curcumin-loaded chitosan/silk fibroin/α-Fe₂O₃ nanocomposite (Cs-SF-Fe₂O₃-Cur) for the selective delivery of curcumin to breast cancer cells. The nanocomposite exhibited a hydrodynamic size of 301 nm, a zeta potential of 40 mV, and an encapsulation efficiency of 87%. The drug release assay showed a pH-sensitive release profile of 82% at pH 5.4, simulating the tumor microenvironment. In vitro cytotoxicity assays on MCF-7 breast cancer cells showed that, compared to free curcumin, the cell viability remarkably decreased to 44%. In comparison, apoptotic rates reached up to 30% in the treatment of the nanocomposite. Therefore, the present results confirm Cs-SF-Fe₂O₃-Cur as a potential drug delivery system, which may enhance the stability, bioavailability, and thus the therapeutic efficiency of curcumin.

In this study, a stable macromolecular oil-in-water emulsion based on gelatin and pectin incorporating argan oil was first developed and characterized. This emulsion served as the basis for preparing composite films, to which a plasticizer was added to improve flexibility and swelling behavior, while the incorporation of oxidized pectin reduced the water-absorption capacity of the matrices. The films obtained showed a good pro-coagulant effect and marked antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa (MIC = 20 mg/mL). However, they had no antifungal activity, unlike the reference drug, which showed clear inhibition. With regard to wound healing, in vivo results on wounds in Wistar rats showed almost complete retraction (99%) after 8 days of treatment, which was significantly better than that obtained with the commercial dressing, whose retraction rate at the same stage was around 70%. In addition, the antioxidant activity demonstrated a remarkable synergy in formulations containing argan oil. Finally, a questionnaire distributed to healthcare professionals (doctors, pharmacists, dentists, chemists, etc.) enabled us to gain a better understanding of their perception of this type of oil-enriched biomaterial. Respondents expressed a strong interest, highlighting antimicrobial potential as the main perceived advantage, ahead of coagulation effects and anti-inflammatory properties. Statistical analyses (Chi-square tests) supported the interpretation of the survey responses, revealing profession-dependent differences in certain perceptions.

In this study, chitosan CS: PVP blend polymer electrolytes were synthesized via the solution casting method, incorporating lithium nitrate (LiNO₃) as an ionic source at varying concentrations. The effects of LiNO₃ concentration on the electrical properties of the CS: PVP system were systematically investigated using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, and electrical impedance spectroscopy (EIS). XRD analysis demonstrated that increasing LiNO₃ concentrations led to reduce in crystallinity, as evidenced by the broadening of diffraction peaks around 20° (2θ). This reduction is advantageous for ionic conductivity, facilitating greater segmental mobility within the polymer matrix. FTIR spectroscopy confirmed the formation of polymer-salt complexes, indicated by shifts in characteristic vibrational bands, suggesting successful interactions between LiNO₃ and the polymer blend. Enhanced hydrogen bonding and polymer chain interactions were evidenced by increased intensities of O-H and C-H vibrational bands upon salt addition. EIS analysis revealed that the DC conductivity increased from 9.66(times {10^{ - 10}})S/cm to 1.19(times {10^{ - 6}}) S/cm with increasing LiNO₃ content. Frequency-dependent dielectric parameters, including the dielectric constant ((varepsilon ')) and dielectric loss ((varepsilon '')), exhibited higher values at elevated salt concentrations in the low-frequency region, while stabilizing at higher frequencies. This behavior indicates that LiNO₃ enhances ion conductivity and polarization within the CS: PVP films. Electrical modulus analysis further suggested that LiNO₃ incorporation significantly enhances the flexibility and ion mobility of the polymer electrolytes, rendering them suitable for advanced applications in electrochemical devices.

Black seed (Nigella sativa) contains diverse active compounds that offer remarkable therapeutic benefits. Electrospinning is a technique that employs a high-voltage electrical source to manipulate polymer solutions, resulting in the production of nanofibers. microporous materials were used to electrospin nanofibers of polyvinyl alcohol (PVA) and chitosan (CS) infused with NS(mension full name first) extract. The characterisation of the nanofibers included an examination of their structure, porosity, and physical properties using gas chromatography-mass spectrometry (GC-MS), water contact angle assessments, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR). SEM demonstrated consistent and defect-free morphologies of the synthesized nanofibers, with an average diameter of 463.8 ± 5.85 nm. Measurements of fiber wettability and water contact angle were conducted. The findings showed that the electrospun PVA/CS/NS nanofiber mats exhibited enhanced wettability and a higher contact angle in comparison to PVA/CS and PVA nanofibers, corroborated by DPPH antioxidant activity and antibacterial efficacy against Escherichia coli and Staphylococcus aureus, in addition to their application in wound dressing. The study concluded that the PVA/CS nanofiber mats infused with Nigella sativa extract (NS) exhibit favorable biological applications and biocompatibility. Further research is recommended to examine the effects of this compound in medical applications.

In the search for sustainable packaging solutions, biodegradable polymers have emerged as promising candidates for the food industry. This review explores the potential of biopolymers in food packaging, specifically highlighting their tailorable capabilities when doped with nanoparticles and essential oils. Through a comprehensive analysis, we present that the incorporation of additives imparts biodegradable polymers with the essential attributes required for excellence in packaging. Our study demonstrates that the synergy between biopolymers, nanoparticles, and essential oils results in packaging materials that exhibit improved barrier properties, tensile strength, antimicrobial nature and enhanced shelf-life being biodegradable in nature. This study not only sheds light on the scientific advancements in the field but also portrays the practical relevance of biodegradable polymer-based packaging materials in shaping the future of the food industry. As we head towards a more sustainable tomorrow, these improved materials promise to be an eco-friendly alternative for reducing environmental impact while ensuring the safety and freshness of our food products.

Bio particle composites are superior to conventional synthetics due to their biodegradability and high strength-to-weight ratio. The novelty of this study lies in the successful incorporation and characterization of Terminalia Arjuna Seed (TAS) particles as a reinforcing bio-filler in a vinylester (VE) matrix. The approximate composition of TA seeds is 1.95% moisture, 7.2% ash, 339.07 µg/g cellulose, and 208.66 µg/g lignin, confirming the biowaste’s potential as a filler. The hammer mill was used to pulverize the spotless dry TAS, and a particle size range of 80 μm to 180 μm was maintained throughout the analysis. It was favored for composite construction to use filler proportions ranging from 0% to 30% by weight with a (VE) matrix. We used the hand layup molding technique to make the samples. The findings indicate that a composite incorporating a filler loading of 15 weight% can attain a flexural strength of 86 MPa and a peak tensile strength of 62 MPa.The highest shore D hardness value observed in a sample loaded with 20 weight% filler was 78. The thermal properties of the prepared material are also improved while increasing filler weight%. The morphological properties of the prepared sample were examined using a scanning electron microscope (SEM). This proves that the manufactured composite material may be used for a variety of automotive purposes.