Polymer Bulletin最新文献

Magnetic superabsorbents have been successfully synthesized through aqueous solution polymerization, employing sodium alginate as the backbone material, acrylic acid and acrylamide as the polymeric monomers, Fe₃O₄ nano-particles as the magnetic component, N,N’-methylenebisacrylamide as the crosslinking agent, and ammonium persulfate serving as the initiator. The micro-morphology and thermal stability of these superabsorbents were thoroughly characterized using scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA), respectively. A comprehensive investigation was undertaken to examine the swelling capacity, water retention properties, magnetic responsiveness, and reusability of the magnetic superabsorbents. The findings reveal that these superabsorbents possess an impressive maximum water absorption capacity of 302.7 g/g in distilled water. Notably, their swelling ratios maintain high levels within a pH range of 5–10. Featuring a porous structure, the magnetic superabsorbents demonstrate rapid swelling kinetics, attaining swelling equilibrium within 30 min in a 1 wt% NaCl solution. Furthermore, the superabsorbents exhibit excellent magnetic responsiveness, characterized by a maximum saturation magnetization of 7.91 emu/g, allowing for swift separation under an external magnetic field. Lastly, the magnetic superabsorbents display outstanding reusability, with their water absorption capacity in distilled water still exceeding 90% of the initial swelling ratio after seven reuse cycles.

The study aimed to develop a highly efficient, biodegradable polymer-coated urea to minimize nitrogen (N) losses and facilitate sustained release. The study included four treatments: T₁: uncoated urea (UCU); T₂: palm stearin-coated urea (PSCU) 10%; T₃: pine oleoresin-coated urea (POCU) 6%; and T₄: humic acid-coated urea (HACU) 15%. The bio polymer-based urea coatings were compared for their N content and their dissolution rate in water against UCU as a control. Results from high throughput instrumentation revealed that the coating materials had great compatibility with urea fertilizer. In a laboratory study of urea release in water over a 5-h interval, PSCU 10% (0.54–2.38 mol L⁻¹) exhibited a sustained release of urea. This performance was superior to POCU 6% (0.59–2.50 mol L⁻¹) and HACU 15% (0.71–2.69 mol L⁻¹). In contrast, UCU released (1.61–2.47 mol L⁻¹) almost all its urea within 2-h interval. Additionally, PSCU 10% had excellent synergy in surface morphology, interaction and crystal structure through scanning electron microscope (SEM), Fourier transform infrared spectroscopy analysis (FTIR) and X-ray diffraction (XRD), respectively. The PSCU 10% fertilizer could be a good competitor for other coated urea fertilizers. However, this fertilizer must be field validated to prove its effectiveness on crops before commercialization.

Robust adhesion is crucial for ionic hydrogels in flexible electronic pressure and strain sensors. Herein, we design a transparent and strong adhesion electronic pressure and strain sensor based on a multifunctional ionic hydrogel with double network using polyacrylamide (PAM) and gum arabic (GA). First, the effect of ionic type on the mechanical properties of hydrogels was measured. The GA/PAM–Fe³⁺ hydrogel with high extensibility (1835%) and toughness (left( {{1}.{text{47 MJ}}/{text{m}}^{{3}} } right)) was selected as the best sensor material. Moreover, the GA/PAM–Fe³⁺ hydrogel has good adhesion property with various substrates, and the maximum peel strength of the hydrogel to skin could reach up to 123.9 N/m. Furthermore, the resistance of GA/PAM–Fe³⁺ hydrogel is sensitive to a wide strain window and the gauge factor shows stable and reliable change during deformation. Due to its compliant and excellent adhesive properties, strain sensors based on this hydrogel can be well fixed on the epidermis without adhesive tape, and can perceive large and gentle body movements. These characteristics demonstrate that GA/PAM–Fe³⁺ hydrogel is promising for a broad range of practical applications in wearable sensors.

Dielectric elastomers with conducting inorganic fillers offer a wide range of uses, including capacitive energy storage, elastomer sensors, actuators, and many more. In this approach, low dielectric loss and high dielectric constant may be made possible by ternary composites that use metal alloy components as reinforcing fillers. Here, Cu-based alloy was added to acrylonitrile-butadiene rubber (NBR) to produce ternary rubber composites. Unfortunately, the Cu–Al–Zn alloy’s material incompatibility with the rubber matrix typically leads to phase separation, void formation, and particle aggregation, all of which have a dramatic negative impact on performance. Using 3-(trimethoxysilyl)propyl methacrylate as a coupling agent, Cu–Al–Zn alloy particles were uniformly dispersed onto the NBR rubber matrix through surface modification. By using scanning electron microscopy, the appropriate reinforcement of modified Cu-based alloy particles into NBR was carefully examined. The effect of modified Cu–Al–Zn alloy loading on the swelling behavior of the composite was also investigated. The findings show that the shape and dispersion state of modified Cu–Al–Zn alloy were important for the dielectric characteristics of the NBR compounds. By adding reinforced modified Cu-based alloy to the NBR matrix, mechanical characteristics were significantly improved. The uniform dispersion of modified Cu–Al–Zn alloy particles and strong interfacial compatibility with rubber matrix are the reasons for the outstanding performance of NBR composites, which suggests high-performance dielectric composite.

Textile dyeing releases over 80% of industrial effluents without proper treatment. Dye discharged into effluents typically needs degradation before release into aquatic environments. In this regard, the present paper reports the nanocomposite copper oxide/polyaniline (CuO/PANI) is successfully synthesized by in situ chemical oxidative polymerization method and investigates their catalytic activity against organic dyes and nitro compounds. CuO is synthesized by colloidal sol–gel method using oxalic acid as capping agent to obtained desired morphology. The elemental composition, unit cell and lattice parameters of nanocomposite are characterized by using XRD. The XRD revealed that nanoparticles are extremely crystalline, but nanocomposite is amorphous because of the presence of polymer. The structural and elemental analysis of CuO and CuO/PANI is confirmed by SEM and EDX analysis. FTIR spectra of CuO showed bending vibration, while CuO/PANI showed the presence of benzenoid and quinoid rings. Catalytic productivity of the CuO and CuO/PANI as catalysts in degradation of dyes and reduction of nitro compounds is also studied. The degradation and reduction processes are monitored through the utilization of UV–Vis spectrophotometer. The catalytic activity of both catalysts is evaluated by several parameters including k_app, degradation/reduction time, % degradation/reduction, degraded/reduced concentration and half-life. Among all substrates, highest k_app is 0.0653 min⁻¹ for CV by CuO, while 0.0502 min⁻¹ for EBT by CuO/PANI due to large surface area. On degradation and reduction rate of substrates, the impact of functional group type and orientation, bond type and steric hindrance is also investigated.

In this study, MOF-74 nanocarriers were coated with sodium alginate (SALG) to enhance physicochemical properties and biocompatibility. Spectroscopic and microscopic analyses showed MOF-74 particle size below 100 nm. Zinc-based MOF-74 nanocarriers (Zn-MOF-74) were developed for doxorubicin (DOX) delivery, achieving high drug loading efficiency (DLE) and drug loading capacity (DLC) as measured by UV–visible spectrometry. Nanocarriers synthesized using zinc acetate (R_A-MOF-74) achieved a DLE of 96.5% and a DLC of 19.6%, outperforming those prepared with zinc nitrate (R_N-MOF-74) with a DLE of 88.8% and a DLC of 18.3%. Uncoated samples released cargo rapidly at pH 1.5 and significantly at pH 8. In contrast, SALG-coated samples showed reduced release at pH 1.5 and reached 54.2% release at pH 8 due to alginate’s physicochemical properties. Drug release from DOX@R_A-MOF-74/ALG was significantly slower and more sustained than from uncoated samples. This study demonstrates the potential of SALG-coated R_A-MOF-74 as a controlled drug release system for biomedical applications.

The utilization of natural fibers obtained from leather industrial wastes contributes to a circular economy and aids to the reduction in the usually high loadings of mineral flame-retardant additives employed to impart the flame retardancy in polymer systems. The present work investigates the relationship between viscoelastic properties and flame retardancy of thermoplastic starch multicomponent systems loaded with leather waste, aluminum trihydroxide used as flame-retardant additive, and bentonite clay. Different blending temperatures and rotational speeds during extrusion process are tested for the multicomponent systems. Rheological, morphological, flammability, thermal analysis, and tensile mechanical test are also used to characterize the obtained multicomponent systems. A detailed investigation of the viscoelastic properties through Han, Cole–Cole, and van Gurp–Palmen diagrams indicated that the fibers have to be well dispersed in the polymer matrix forming a network structure and that the material has to exhibit viscoelasticity to a moderate level, i.e., not too viscous and not too elastic as observed in the VGP diagram in order to impart the flame retardancy effect in the multicomponent system. These multicomponent systems with enhanced properties are a promising and sustainable alternative to traditional high-loaded flame-retardant systems taking advantage of the landfill disposal in local areas where leather wastes are a problem the great attention contributing to a circular economy.

There is a growing threat of wastewater pollution impacting human access to clean water. The surge in pharmaceuticals and personal care products (PPCPs) in such water has reached alarming levels, posing an unprecedented threat to aquatic ecosystems and human health. Conventional wastewater treatment is not specifically tailored to address the presence of PPCPs. This paper examines the possibility of using nano-chitin and chitosan as effective and sustainable adsorbents for the removal of PPCPs from wastewater. The recent progress in functionalized nano-chitin or chitosan composites is reviewed with attention to enhanced adsorption capacity and selectivity toward different classes of PPCPs. Unique features of nano-chitin and chitosan, such as their large surface areas and biocompatibility making them a good choice for PPCP adsorption, are also discussed. Critical evaluation is given about how these nanomaterials absorb PPCPs by looking at various mechanisms like electrostatic interactions, hydrogen bonding, hydrophobic interaction, among others. Finally, future research directions provided for improving performance and scalability of such bio-based adsorbents are discussed.

Graphical Abstract

Acidic conditions affect the archaeological bone in the burial and in uncontrolled display and storage environment or due to improper restoration processes. Accordingly, bones become weak and fragile. This study aims to evaluate nano calcium propionate and nano styrene butyl acrylate (used for the first time in the treatment of bones) at different concentrations for deacidification and consolidation of fragile bones. New bone samples were prepared. Artificial accelerated aging (acid and heat) was applied to prepare aged untreated samples. Deacidification and consolidation processes using the materials mentioned above were applied. The analytical techniques used were transmission electron microscope (TEM) and thermal gravimetric analysis (TGA) were used for morphological and thermal stability investigation for the prepared nano styrene butyl acrylate copolymer and its calcium propionate nonocomposites, a digital microscope and scanning electron microscope (SEM) for investigation of the surface morphology, pH value measurement, change of color measurement, attenuated total reflection—Fourier transform infrared spectroscopy (ATR/FTIR), contact angle (wettability), and X-ray diffraction analysis for measurement of bone crystallinity. The results proved that acid-heat aging affected bone properties such as changes in surface morphology and color, decrease in pH value, and contact angle. Bone samples became more crystalline, and the chemical composition of bone was also affected. The treatment of aged untreated bone samples with the materials used in this study improved their properties, such as increasing the pH value and contact angle. The surface morphology, color change, and crystallinity of bone improved and became more stable.