Journal of Polymers and the Environment最新文献

Utilizing xanthan gum, a biodegradable polymer, in enhanced oil recovery (EOR) is imperative wherever there is a need for innovation in oil production that is both cost-effective and environmentally friendly. Xanthan, chosen for its natural sourcing, availability, controllability, eco-friendliness, and biodegradability, proves resilient against harsh reservoir conditions owing to its rigid structure and elongated polysaccharide chains. This study investigates two modified xanthan gum composites, achieved by grafting with synthetic vinyl monomers through emulsified polymerization. Spectroscopic characterization using FTIR and ¹H-NMR, along with surface morphology analysis via atomic force microscopy (AFM) and thermal behavior screening through TGA analysis, elucidates the properties of these modified composites. Rheological behavior under reservoir conditions, including stress scanning and viscosity/shear rate dependency, was evaluated. Material modeling with the Materials Studio program simulated the equilibrium adsorption of xanthan and modified biopolymer chains on SiO₂-quartz crystal to assess wettability alteration. Simulation results indicate that XG-g-AM, MMA&TEVS exhibit greater stability and surface coverage with more negative electrostatic energies compared to XG and XG-g-AM&MMA. The laboratory runs on a sandstone-packed model to identify the disclosed XG-g-AM&MMA and XG-g-AM, MMA&TEVS biopolymers as promising EOR candidates and wettability modifiers in challenging sandstone reservoirs, as per experimental outcomes.

This work reported two types of photocatalysts in polymeric sheets derived from recycled high-density polyethylene (HDPEr): anatase TiO₂ and Ag-decorated anatase TiO₂ (TiO₂-Ag). The Ag nanoparticles were deposited on the TiO₂ nanoparticles via chemical reduction using formaldehyde as the reducing agent, although XPS analysis indicated that anatase was also reduced during Ag deposition. The sheets were prepared using two methods: extrusion and a plasma immersion process. In the first one, nanoparticles were introduced during extrusion, resulting in photocatalyst/HDPEr composites. On the other hand, the plasma method involved depositing photocatalyst nanoparticles into the polymer sheet surface through a two-step process of air plasma treatment followed by immersion in an aqueous photocatalyst suspension. The composites obtained through extrusion exhibited a higher Young’s modulus compared to neat HDPEr, attributed to the reinforcing effect of the nanoparticles, which was more significant with the incorporation of TiO₂ nanoparticles. Photocatalytic activity assessment revealed that sheets obtained by extrusion showed poor performance, whereas photocatalyst deposition on sheets significantly enhanced NOx photodegradation. Notably, TiO₂-Ag nanoparticles exhibited superior photocatalytic activity, with the polymeric sheet containing TiO₂-Ag nanoparticles on the surface achieving the highest activity (~ 23.67% NOx photodegradation). The detailed methodology and robust experimental data provided offer valuable insights into optimizing nanoparticle incorporation techniques to enhance the functional properties of recycled polymeric materials for environmental applications. Overall, although the plasma treatment did not affect the mechanical properties of the sheets significantly, it allows an outstanding advance in NO_X abatement. Especially for the TiO₂-Ag-modified sheets. Based on this background, this research addresses a double environmental approach by developing self-cleaning building panels from HDPEr.

Soybean oil is one of the most widely produced and consumed vegetable oils globally. Known for its rich fatty acid composition, including linoleic, oleic, and alpha-linolenic acids, soybean oil offers substantial nutritional and health benefits. It is not only a dietary staple but also a versatile component in industrial and biomedical applications. This review paper offers a comprehensive discussion on the emerging role of functionalized soybean oil (SO) in the development of sustainable polymers for tissue engineering (TE) and drug delivery systems (DDS). Plant oils, particularly soybean oil, offer significant environmental benefits, making them an excellent substitute for petroleum-based polymers and biomedical applications due to their biodegradability and low ecological footprint. Despite the burgeoning potential of soybean oil-derived polymers in revolutionizing natural-based biomaterials, there is a critical need for an in-depth review to thoroughly comprehend their capabilities and steer forthcoming innovations.This review aims to address the scientific gap by offering a comprehensive analysis of recent advancements in the biomedical application of soybean oil derivatives. The impact of this paper lies in its systematic collation of research on the design, fabrication, and utility of soybean oil-derived biomaterials, highlighting their significance in various medical applications, including therapeutic patches, wound care, and scaffolding in regenerative medicine. The review suggests future research directions and sets the stage for future innovations in soybean oil-based biomaterials, positioning these materials as crucial components in the pursuit of sustainable and effective biomedical solutions.

In this study, we are interested in preparing novel hydrogel and hydrogel nanocomposite-based adsorbents for removing methylene blue (MB) dye based on grafted locust bean gum (LBG). LBG hydrogel and hydrogel nanocomposite were synthesized using a radical polymerization technique in the absence and presence of TiO₂ with LBG-cl-(acrylic acid (AA)-co-acrylamide (AAm)). Various analytical instruments Fourier transform infrared (FTIR), X-Ray diffraction (XRD), Scanning electron microscopy (SEM), and High-resolution transmission electron microscopy (HRTEM) were used to elucidate the chemical structure and surface morphology of the prepared samples. Using a batch adsorption experiment, the Langmuir isotherm model showed that LBG-cl-p(AA-co-AAm) hydrogel had a maximum adsorption capacity of 1540.9 mg/g and LBG-cl-(AA-co-AAm)/TiO₂ hydrogel nanocomposites had a maximum adsorption capacity of 1273.4 mg/g at neutral pH. The thermodynamic data demonstrated that MB dye was removed via spontaneous adsorption. Furthermore, the regeneration study showed good recyclability for the obtained hydrogel nanocomposites through six consecutive reusable cycles. Therefore, the hydrogel nanocomposites are an effective adsorbent for the removal of MB dye from aqueous solutions.

Although adding flocculants is an essential step in wastewater treatment and maintaining the stability of the solid-state in solution to produce a loose cell-like structure, in some instances, polymeric material fails to support this due to specific surface charges. Therefore, the current study aimed to develop a cationic form (CBS) obtained from unripe waste bananas as native starch and characterize it as a flocculating agent. The starch from unripe waste banana fruit peel was extracted and synthesized to CBS using an etherification reaction via grafting a cationic moiety such as 3-chloro-2-hydroxypropyl trimethylammonium chloride (CHPTAC). In addition, the synthesis process was optimized using quality by design (QBD). The utilization of QBD led to the attainment of the maximum degree of substitution (DS) value of 0.623 under optimal circumstances, which involved reacting moieties such as CHPTAC (0.007 moL) and NaOH (30% w/v) with a reaction duration of 18 h at a temperature of 50 °C. Moreover, elemental, structural, x-ray diffraction, thermal analysis, and surface morphology indicated that a significant cationic fraction was integrated within the BS. In addition, the biocompatibility study showed that both native BS and CBS were > 95% biocompatible against CaCO-2 and HeK-293 cells. Furthermore, the flocculation performance of CBS showed that the transmittance of the supernatant fluid augmented in direct correlation to the sedimentation and flocculation time for CBS. Thus, the modified CBS can be utilized as an economical, safe, and potential substitute against available flocculating agents.

Graphical Abstract

In this work, short oil palm fibre-reinforced bio-epoxy matrix composites were fabricated using the hand-lay-up technique. The effects of oil palm fibre composites on mechanical, physical, and thermal behaviours were examined. This work aimed to identify the optimal fibre loading that enables the oil palm/bio-epoxy composite to have superior thermal and mechanical properties. Fibre loading varied from 30 to 60 wt%. A maximum Young’s modulus of 5.76 GPa was obtained at 60 wt% while a maximum flexural modulus of 5.2 GPa and impact strength of 5.55 kJ/m² was obtained at 50 wt%. However, tensile and flexural strength were not much improved. Regarding the moisture absorption and thickness swelling, the composites followed a similar order: bio-epoxy matrix < 30 wt% < 40 wt% <50 wt% < 60 wt%. The fickian diffusion model was used to describe the thickness swelling behaviour. The major inference from the thermal characterization was that as the fibre loading was increased, there was a substantial improvement in thermal stability evident from the lower damping factor (0.21 at 60 wt.%), better dimensional stability and higher residue % (22.22% at 50 wt%) at elevated temperatures. Besides, scanning electron microscopy (SEM) was examined for tested samples to understand the fibre-to-matrix bonding phenomenon. Based on these results, the short oil palm fibre composites can be suggested for some potential applications such as automotive components (e.g., door trims, interior panels), aerospace (e.g., tray tables, overhead bins) and construction materials (e.g., cladding, roofing).

Chitin is the second most abundant biopolymer in the world after cellulose and commonly found in crustaceans. It is also the most abundant natural nitrogen-containing polysaccharide. The challenge in separation of chitin directly from snow crab (Chionoecetes opilio) shells is that the solvent used must be versatile in removing calcium carbonate and protein while also being efficient, environmentally friendly, and cost-effective. In this study, chitin was extracted from snow crab shells using a DES consisting of TEBAC and lactic acid. DES successfully removed minerals and proteins, with a deproteinization rate of 95.51% and a decalcification rate of 96.41%, while the purity of chitin was 91.15% and the yield was 21.31%. Furthermore, the extracted chitin has large pores on its surface, making it an ideal matrix for biomedical materials. This study provides an environmentally friendly and cost-effective solution for the utilization of crustacean waste using multifunctional DES.

Green synthesis of nanoparticles is an effective, cost-effective, and environmentally friendly approach to produce biocompatible nanoparticles with broad-spectrum bioactivities. In the current study, lactic acid bacterium-derived exopolysaccharide (EPS) was explored to biologically synthesize green silver nanoparticles (EPS-AgNPs). The antibacterial and antioxidant activities of EPS-AgNPs were investigated by agar well diffusion and DPPH tests, respectively. Subsequently, EPS-AgNPs and chemical AgNPs were characterized, and their physicochemical properties were compared. According to 16 S rRNA gene sequencing, the EPS-producing lactic acid bacterium showed 97.77% similarity to Enterococcus faecium. EPS-AgNPs exhibited inhibitory effects on Gram-positive and Gram-negative bacterial pathogens. Additionally, EPS-AgNPs showed considerable ability (84%) to quench DPPH free radicals. Fourier-transform infrared spectroscopy (FT-IR) showed the involvement of EPS’s functional groups, including hydroxyl, carbonyl, and aldehyde groups, in synthesizing nanoparticles. Scanning electron microscopy revealed a quasi-spherical morphology for both the EPS-AgNPs and chemically synthesized AgNPs, while X-ray diffraction (XRD) analysis confirmed their crystalline nature. The high metal content of chemical Ag-NPs (89.79%) was in good agreement with its high thermal stability in TGA results. Additionally, lower thermal stability and less Ag content (65.93%) of EPS-AgNPs, along with their smooth surfaces, indicated the capping role of EPS. EPS-AgNPs showed Z-average size, PI value, and zeta potential of 158.31 nm, 0.29, and − 17.75 mV, respectively. Collectively, the present study revealed that Enterococcus faecium-derived EPS acted as reducing, capping, and stabilizing agents in green synthesizing EPS-AgNPs with potential applications in medical and food-packaging industries.

Plasticizers are core components utilized in plastics processing. They are additives applied to improve and, in some cases, make possible the processing of a polymer. Thus, plasticizers have an impact on lowering production costs, improving productivity, and other properties of the polymer. Yet, there are issues related to the toxicity of phthalic-based components used in traditional plasticizers. One of the emerging alternatives consists of using raw materials from bio-renewable sources that have low toxicity, are more readily available, and are mostly biodegradable. Such starting raw materials can be used for the synthesis of bio-plasticizers which can serve as a feasible alternative to traditional ones. The large number of raw materials from renewable sources along with their chemical versatility offers a broad variety of reactions that can be performed to obtain various bio-plasticizers that can present efficiencies that are comparable to or even surpass those of petrochemical-based ones. Following that, this review is divided into five parts. First, the introduction provides the main concepts, importance, and progress of the development of bio-plasticizers. The second part covers the main types of plasticizers, compounds utilized, and commercially available bio-plasticizers. The third part discusses the mechanism involved with plasticization and how that process can be improved based on the plasticizer’s chemical structure. The fourth part covers the main advantages of bio-plasticizers and the benefits they can offer for manufacturing. Lastly, the future perspectives and challenges within the field are discussed. Through that, this review provides detailed discussions covering the main aspects related to bio-plasticizers to facilitate the readers’ understanding of the main concepts while also providing a vast number of reports from the recent literature to aid them in the generation of novel ideas. In this way, readers can potentially have novel insights to tackle the main current challenges related to the use of plasticizers in polymers.