Polymers最新文献

Solid polymer electrolytes (SPEs) for symmetrical supercapacitors are proposed herein with activated carbon as electrodes and optimized solid polymer electrolyte membranes, which serve as the separators and electrolytes. We propose the design of a low-cost solid polymer electrolyte consisting of guanidinium nitrate (GuN) and poly(ethylene oxide) (PEO) with poly(vinylpyrrolidone) (PVP). Using the solution casting approach, blended polymer electrolytes with varying GuN weight percentage ratios of PVP and PEO are prepared. On the blended polymer electrolytes, structural, morphological, vibrational, and ionic conductivity are investigated. The solid polymer electrolytes' morphology and level of roughness are examined using an FESEM. The interlinking bond formation between the blended polymers and the GuN salt is verified by FTIR measurements, indicating that the ligands are chemically complex. We found that, up to 20 wt.% GuN, the conductivity value increased (1.84 × 10^-6 S/cm) with an increase in mobile charge carriers. Notably, the optimized PVP/PEO/20 wt.% solid polymer electrolyte was fabricated into a solid-state symmetrical supercapacitor device, which delivered a potential window of 0 to 2 V, a superior energy density of 3.88 Wh kg^-1, and a power density of 1132 W kg^-1.

Vat photopolymerization (VPP) is an additive manufacturing method that requires the design of photocurable resins to act as feedstock and binder for the printing of parts, both monolithic and composite. The design of a suitable photoresin is costly and time-consuming. The development of one formulation requires the consumption of kilograms of costly materials, weeks of printing and performance testing, as well as the need to have developers with the expertise and knowledge of the materials used, making the development process cost thousands. This paper presents a new characterization methodology for acrylates that allows for the computerization of the photoresin formulation development process, reducing the timescale to less than a week. Okoruwa Maximum Saturation Potential (OMSP) is a methodology that uses attenuated total reflection (ATR-FTIR) to study the functional group of acrylates, assigning numerical outputs to characterize monomers, oligomers and formulations, allowing for more precise distinguishment between materials. It utilizes the principles of Gaussian normal distribution for the storage, recall, and computerization of acrylate data and formulation design without the need to database numerous files of spectral data to an average coefficient of determination (R²) of 0.97. The same characterization method can be used to define the potential reactivity of acrylate formulations without knowing the formulation components, something not possible when using properties such as functionality. This allows for modifications to be made to unknown formulations without prior knowledge of their contents. Validation studies were performed to define the boundaries of the operation of OMSP and assess the methodology's reliability as a characterization tool. OMSP can confidently detect changes caused by the presence of various acrylates made to the photoresin system and distinguish between acrylates of the same viscosity and functionality. OMSP can compare digitally mixed formulations to physically mixed formulations and provides a high degree of accuracy (R² of 0.9406 to 0.9964), highlighting the future potential for building foundations for artificial intelligence in VPP; the streamlining of photoresin formulation design; and transforming the way acrylates are characterized, selected, and used.

This study investigated silicone composites with distributed boron nitride platelets and carbon microfibers that are oriented electrically. The process involved homogenizing and dispersing nano/microparticles in the liquid polymer, aligning the particles with DC and AC electric fields, and curing the composite with IR radiation to trap particles within chains. This innovative concept utilized two fields to align particles, improving the even distribution of carbon microfibers among BN in the chains. Based on SEM images, the chains are uniformly distributed on the surface of the sample, fully formed and mature, but their architecture critically depends on composition. The physical and electrical characteristics of composites were extensively studied with regard to the composition and orientation of particles. The higher the concentration of BN platelets, the greater the enhancement of dielectric permittivity, but the effect decreases gradually after reaching a concentration of 15%. The impact of incorporating carbon microfibers into the dielectric permittivity of composites is clearly beneficial, especially when the BN content surpasses 12%. Thermal conductivity showed a significant improvement in all samples with aligned particles, regardless of their composition. For homogeneous materials, the thermal conductivity is significantly enhanced by the inclusion of carbon microfibers, particularly when the boron nitride content exceeds 12%. The biggest increase happened when carbon microfibers were added at a rate of 2%, while the BN content surpassed 15.5%. The thermal conductivity of composites is greatly improved by adding carbon microfibers when oriented particles are present, even at BN content over 12%. When the BN content surpasses 15.5%, the effect diminishes as the fibers within chains are only partly vertically oriented, with BN platelets prioritizing vertical alignment. The outcomes of this study showed improved results for composites with BN platelets and carbon microfibers compared to prior findings in the literature, all while utilizing a more straightforward approach for processing the polymer matrix and aligning particles. In contrast to current technologies, utilizing homologous materials with uniformly dispersed particles, the presented technology reduces ingredient consumption by 5-10 times due to the arrangement in chains, which enhances heat transfer efficiency in the desired direction. The present technology can be used in a variety of industrial settings, accommodating different ingredients and film thicknesses, and can be customized for various applications in electronics thermal management.

This study explores the development and evaluation of a novel series of aromatic co-polyamides featuring diverse pendant groups, including phenyl and pyridinyl derivatives, designed for water desalination membrane applications. These co-polyamides, synthesized with a combination of hexafluoroisopropyl, oxyether, phenyl, and amide groups, exhibited excellent solubility in polar aprotic solvents, thermal stability exceeding 350 °C, and the ability to form robust, flexible films. Membranes prepared via phase inversion demonstrated variable water permeability and NaCl rejection rates, significantly influenced by the pendant group chemistry. Notably, pyridinyl-substituted membranes achieved water fluxes up to 17.7 L m^-2 h^-1 and a NaCl rejection of 37.3%, while phenyl-substituted variants provided insights into the interplay of hydrophobicity and porosity. These findings highlight the critical role of pendant group functionality in tailoring membrane performance, offering a foundation for further structural modifications to enhance efficiency in water treatment technologies.

Light-polymerizing reline materials offer improved chairside workability compared to conventional auto-polymerizing reline materials, addressing the partial denture (RPD) incompatibility caused by residual ridge resorption owing to long-term use. This study evaluates the fitting accuracy of relined materials by combining conventional fitting tests with three-dimensional (3D) measurements for detailed analysis. Light-polymerizing reline material (HikariLiner^®, Tokuyama, Tokyo, Japan, LP) and auto-polymerizing material (Rebase III^®, Tokuyama, AP) were used. The gaps formed between the relined denture base and the simplified edentulous model were evaluated. The displacement and deviation of the experimentally relined RPDs on the partially edentulous models were analyzed using 3D data superimposition. In the edentulous model, the gaps at all measurement points were significantly smaller for the AP than in the LP. Moreover, the alveolar ridge crest gap was significantly larger than that at other sites. In the partial denture model, the RMS values at the residual ridge crest were significantly lower for the AP. The evaluation method using 3D scanning and comparison was suitable for a detailed fit analysis. Further improvements in the scanning accuracy may enhance future assessments. Therefore, the evaluation method using 3D scanning and comparison was suitable for effectively analyzing the fit of relines, necessitating further accuracy improvements.

Bone tissue engineering aims to develop biomaterials that are capable of effectively repairing and regenerating damaged bone tissue. Among the various polymers used in this field, polycaprolactone (PCL) is one of the most widely utilized. As a biocompatible polymer, PCL is easy to fabricate, cost-effective, and offers consistent quality control, making it a popular choice for biomedical applications. However, PCL lacks inherent antibacterial properties, making it susceptible to bacterial adhesion and biofilm formation, which can lead to implant failure. To address this issue, this study aims to enhance the antibacterial properties of PCL by incorporating calcium phosphate composite (PCL_CaP) nanostructures onto its surface via hydrothermal synthesis. The resulting "PCL_CaP" nanostructured surfaces exhibited improved wettability and demonstrated mechano-bactericidal potential against Escherichia coli and Bacillus subtilis. The flake-like morphology of the fabricated CaP nanostructures effectively disrupted bacteria membranes, inhibiting bacterial growth. Furthermore, the "PCL_CaP" surfaces supported the adhesion, proliferation, and differentiation of pre-osteoblasts, indicating their potential for bone tissue engineering applications. This study demonstrates the promise of calcium phosphate composite nanostructures as an effective antibacterial coating for implants and medical devices, with further research required to evaluate their long-term stability and in vivo performance.

Rapid heating cycle molding technology has recently emerged as a novel injection molding technique, with the uniformity of temperature distribution on the mold cavity surface being a critical factor influencing product quality. A numerical simulation method is employed to investigate the rapid heating process of molds and optimize heating power, with the positions of heating rods as variables. The temperature uniformity coefficient is an indicator used to assess the uniformity of temperature distribution within a system or process, while the thermal response rate plays a crucial role in evaluating the heating efficiency of a heating system. The thermal response rate of the cavity and the temperature uniformity coefficient are set as optimization objectives to define parameter ranges for orthogonal experiments. The findings indicate that the optimal range for the lateral distance L₁ is 20-30 mm, for L₂ it is 50-70 mm, and for the vertical distance (h) it is 3-8 mm. The response surface multiple regression equation derived from the orthogonal experiment data demonstrates a model prediction error rate of 1.8% and 2.4%. Additionally, by applying particle swarm optimization to the regression equation, the study identifies an optimal scheme that reduces system energy consumption by 12.5%, achieves a thermal response rate of 0.75 k/s, decreases the temperature uniformity coefficient by 44.6%, and lowers the temperature difference by 52.17%. This optimization ensures efficient heating of the mold cavity, reduces energy consumption, and enhances the uniformity of the surface temperature distribution, ultimately improving the surface quality of the products.

Sphingan is a crucial exopolysaccharide (EPS) produced by Sphingomonas genus bacteria with wide-ranging applications in fields such as food, medicine, and petroleum. In this study, a novel sphingan, named MT gum, was overproduced from the wild-type strain Sphingomonas sp. MT01 at a yield of 25.6 g/L in a 5 L fermenter for 52 h at 35 °C. The MT gum was mainly composed of D-glucose (65.91%) and L-guluronic acid (30.69%), as confirmed by RP-HPLC, with Mw 7.24 × 10⁵ Da. The MT gum exhibited excellent rheology and pseudoplasticity characteristics while maintaining function in high-temperature and high-salinity environments. The viscosity retention rates of MT gum (0.1%, w/v) were 54.06% (80 °C, 50,000 mg/L salinity) and 34.78% (90 °C, 50,000 mg/L salinity), respectively. The apparent viscosity of MT solutions (0.1%, w/v) was much higher than that of welan solutions under the same conditions. The MT gum also had the property of instant dissolution and completely swelled in 40 min. Meanwhile, the MT gum was resistant to 3-10 mg/L Fe²⁺ in the reservoir conditions, ensuring its application in offshore oil fields. These findings suggested that the biopolymer MT gum produced by the strain MT01 had significant potential in enhanced oil recovery (EOR) of high-temperature and high-salinity oil reservoirs.

Graphene's incorporation into polymers has enabled the development of advanced polymer/graphene nanocomposites with superior properties. This study focuses on the use of a microcellular foamed polystyrene (PS)/graphene (GP) nanocomposite (3 wt%) for nickel (II) ion removal from aqueous solutions. Adsorption behavior was evaluated through FTIR, TEM, SEM, TGA, and XRD analyses. Key factors, including initial ion concentration, pH, temperature, and sorbent dosage, were examined. Results showed optimal nickel removal at specific pH levels with removal efficiency decreasing from 91 to 80% as Ni (II) concentrations increased from 10 to 100 mg/L. The adsorption capacity improved from 11 to 130 mg/g. Equilibrium data aligned with Langmuir and Freundlich isotherm models, while adsorption kinetics followed a second-order kinetic model. These findings highlight the potential of PS/GP nanocomposites for nickel ion removal, offering a promising solution for small-scale industrial applications.

Ligament tears can strongly influence an individual's daily life and ability to engage in physical activities. It is essential to develop artificial scaffolds for ligament repairs in order to effectively restore damaged ligaments. In this experiment, the objective was to evaluate fibrous membranes as scaffolds for ligament repair. These membranes were created through electrospinning using piezoelectric polyvinylidene fluoride (PVDF) composites, which contained 1 wt.% and 3 wt.% of copper-impregnated nanohydroxyapatite (Cu-nHA). The proposed electrospun membrane would feature an aligned fiber structure achieved through high-speed roller stretching, which mimics the properties of biomimetic ligaments. Nanoparticles of Cu-nHA had been composited into PVDF to enhance the pirzoelectric β-phase of the PVDF crystallines. The study assessed the physicochemical properties, antibacterial activity, and biocompatibility of the membranes in vitro. A microstructure analysis revealed that the composite membrane exhibited a bionic structure with aligned fibers resembling human ligaments. The piezoelectric performance of the experimental group containing 3 wt.% Cu-nHA was significantly improved to 25.02 ± 0.68 V/g·m^-2 compared with that of the pure PVDF group at 18.98 ± 1.18 V/g·m^-2. Further enhancement in piezoelectric performance by 31.8% was achieved by manipulating the semicrystalline structures. Antibacterial and cytotoxicity tests showed that the composite membrane inherited the antibacterial properties of Cu-nHA nanoparticles without causing cytotoxic reactions. Tensile tests revealed that the membrane's flexibility of strain was adequate for use as artificial scaffolds for ligaments. In particular, the mechanical properties of the two experimental groups containing Cu-nHA were significantly enhanced compared with those of the pure PVDF group. The favorable piezoelectric and flexible properties are highly beneficial for ligament tissue regeneration. This study successfully developed PVDF/Cu-nHA piezoelectric fibers for a biocompatible, unidirectional piezoelectric membrane with potential applications as ligament repair scaffolds.