Abstract: We combined atomistic simulations and experiments to assess the photocatalytic potential of the rutile phase of TiO2 combined with phenyl-modified carbon nitride (PhCN). Density Functional Tight Binding calculations are employed to investigate the electronic properties, band alignment, and adsorption behavior of TiO2/PhCN heterostructures. The results show a favorable adhesion and band alignment indicating strong potential for photocatalytic applications. XRD measurements, optical characterization, and photocatalytic degradation experiments provide insight on the beneficial integration of the organic and inorganic components, identifying the PhCN/rutile heterostructure as a promising green photocatalyst.

Abstract: Nylons 6,7, 8,7 and 10,7 have been synthesized by interfacial polycondensation and characterized. Thermal properties and thermally induced structural transitions have been evaluated to complement the reported data on nylon 4,7. Therefore, the complete even-odd series derived from pimelic acid is fully characterized to insist in their peculiar structural polymorphism. Real time WAXD synchrotron experiments were acquired during heating, cooling and reheating processes. Basically, three structures were involved: a modified α-form, a distorted pseudohexagonal form and a pseudohexagonal form. The modified α-form was stable up to relatively low temperatures (i.e., lower than 140 °C), was mainly produced by solution crystallization and was progressively disfavored when the number of methylene groups of the diamine moiety increased. A progressive transition from the modified α-form to the distorted pseudohexagonal structure was observed during heating. Also, a continuous reverse transition was detected on cooling, although the yield on the modified α-form was low. A Brill transition towards a pseudohexagonal structure was observed in all cases. This transition was reversible, although with some hysteresis degree. Oriented fiber patterns corresponding to the distorted pseudohexagonal structure were obtained by melt stretching. In all cases, the 00l reflections appeared with a meridional orientation and indicated a shortening close to 0.05 nm/amide group with respect to the expected values for fully extended conformations.

Abstract: Lignin, a complex aromatic biopolymer abundant as waste in biorefineries and the pulp and paper industry, holds significant potential for valorization. This study presents the oxidative depolymerization of Lignoboost lignin (LB) using H2O2 under mild, solvent- and catalyst-free, inherently acidic conditions at temperatures from 50-70°C. The depolymerized LB was rich in aromatic dimers-trimers (68.6 wt.%) with high functionalization (2.75 mmol/g OHphen, 3.58 mmol/g OHcarb, 19.5 wt.% of H in -CH=CH-), and aliphatic dicarboxylic acids (53.4 wt.% of the monomers). Acidic conditions provided higher depolymerization and functionalization than alkaline conditions, alongside simplified product recovery. The process was also successfully applied to Kraft lignin (KL) from black liquor, demonstrating its versatility and robustness. The optimized conditions were scaled up (×25), improving efficiency and yielding a Mw and Đ of 464 g/mol and 1.3, respectively. As proof of concept, the scaled-up product underwent radical crosslinking, resulting in a new biopolymer with higher thermal stability than LB (54.2 wt.% residual mass at 600°C versus 36.1 wt.%). This green, scalable depolymerization process enhances lignin valorization, producing two high-value compounds—low molecular weight functionalized aromatics and dicarboxylic acids—that can be used independently or together, owing to their inherent capacity to form crosslinked networks.

Abstract: Using a digital oscilloscope, the primary harmonics resulting from applying different frequencies and power levels of ultrasonic waves during the polymer extrusion process were identified. The primary harmonics are located between 10 and 60 kHz and exhibit unique characteristics such as shape, crest, and trough, the latter being associated with voltage and current. The crest-to trough distance (height) observed during processing at 34 kHz and 375 W shows the highest value, correlating with the highest melt flow index and the lowest apparent viscosity. It is well known that ultrasonic waves can randomly break C-C bonds in hydrocarbon compounds, leading to a decrease in molecular weight. However, applying ultrasonic waves at different frequencies and power levels can promote chain scission in both high and medium molecular weight chains, increasing molecular weight distribution. This phenomenon can lead to chain disentanglement along with chain scission as molecular weight decreases at medium power and frequency intensities. Finally, a schematic representation of the interaction between polymer chains and ultrasonic waves is proposed.

Abstract: This study explored the innovative foaming behavior of a novel biodegradable polymer blend consisting of PLA/PBS/PBAT enhanced with nanohydroxyapatite (nHA), using supercritical carbon dioxide (SCCO₂) as an environmentally friendly physical foaming agent. The aim was to investigate the effects of various foaming strategies on the resulting cell structure, aiming for potential applications in tissue engineering. Eight foaming strategies were examined, starting with a basic saturation process at high temperature and pressure, followed by rapid decompression to ambient conditions, referred to as the (1T-1P) strategy. Intermediate temperature and pressure variations were introduced before the final decompression to evaluate the impact of operating parameters further. These strategies included intermediate-temperature cooling (2T-1P), intermediate-temperature cooling with rapid intermediate decompression (2T-2P), and intermediate-temperature cooling with gradual intermediate decompression (2T-2P, stepwise ΔP). SEM imaging revealed that the (2T-2P, stepwise ΔP) strategy produced a bimodal cell structure, featuring small cells ranging from 105 to 164 μm and large cells between 476 and 889 μm. This study demonstrated that cell size was influenced by the regulation of intermediate pressure reduction and the change in intermediate temperature. The results were interpreted based on classical nucleation theory, the gas solubility principle, and the effect of polymer melt strength. Foaming results of average cell size, cell density, expansion ratio, porosity, and opening cell content are reported. The hydrophilicity of various foamed polymer blends was evaluated by measuring the water contact angle. Typical compressive stress-strain curves obtained using DMA showed a consistent trend reflecting the effect of foam stiffness.

Abstract: Block copolymers of N-vinyl pyrrolidone, NVP and either n-hexyl methacrylate, HMA, PNVP-b-PHMA or stearyl methacrylate, SMA, PNVP-b-PSMA, were prepared by RAFT polymerization techniques and sequential addition of monomers starting from the polymerization of NVP and using two different CTAs. The synthesis of the copolymers was monitored by Size Exclusion Chromatography, SEC and NMR spectroscopy. The thermal properties of both types of copolymers were studied by Differential Scanning Calorimetry, DSC, Thermogravimetric Analysis, TGA and Differential Thermogravimetry, DTG. The self-assembly behavior in THF, which is a selective solvent for the polymethacrylates blocks, and in aqueous solutions, where PNVP is soluble was examined by static, SLS and dynamic light scattering, DLS, techniques. The effect of the side ester moiety of the polymethacrylate chain on the micellization behavior was traced. The hydrophobic compound curcumin was efficiently encapsulated within the micellar core of the supramolecular structures in aqueous solutions, as was demonstrated by UV-Vis spectroscopy.

Abstract: Integrating thermochromic pigments (TP) into food packaging offers significant benefits for monitoring temperature variations, improving food safety, and reducing waste. However, the recyclability of such materials remains underexplored, particularly regarding the retention of their optical and mechanical properties after repeated recycling. Addressing this gap, this research aims to evaluate how mechanical recycling affects key properties of polypropylene (PP) blends containing varying TP concentrations. Three formulations—PP100/TP0 (0% TP), PP98/TP2 (2% TP), and PP92/TP8 (8% TP) were subjected to five recycling cycles, with changes in thermal stability, color transition behavior, mechanical integrity, and surface morphology analyzed. Results indicate that PP100/TP0 maintains its mechanical integrity with minimal degradation across recycling cycles. However, blends containing TP exhibited progressive deterioration, with PP98/TP2 displaying moderate reductions in mechanical strength and thermochromic efficiency, while PP92/TP8 showed significant degradation, including increased activation temperatures and color vibrancy loss. These effects were attributed to polymer breakdown, pigment aggregation, and altered crystallinity. Despite the limitations of recyclability, this study provides critical insights into the feasibility of TP in sustainable intelligent food packaging. Further research is required to enhance TP stability during reprocessing, ensuring long-term functionality in circular packaging systems.

Abstract: Arising from Zhang et al. Nature https://doi.org/10.1038/s41586-024-08387-9 The authors present a multi-layer-stacked crystalline 2D Polyaniline (PAni) structure with metallic out-of-plane electrical conductivity.[1] They claim this out-of-plane metallic conductivity (15 S/cm) to be the highest conductivity of this type ever published. The PAni structure presented would in fact be unique and a new structure principle for conductive polymers as their model involves single chains as network strings in a 2D layer. While this publication offers some interesting prospects, there are too many unsupported statements, hence having found a new principle may be least premature.

Abstract: Calcium lignosulfonate was incorporated into rubber compounds based on styrene-butadiene rubber (SBR) and acrylonitrile-butadiene rubber (NBR) in the amount ranging from 10 to 60 phr. Sulfur based curing system and peroxide curing system consisting of dicumyl peroxide in combination with methacrylic acid zinc salt were used for cross-linking of rubber compounds. The aim of the work was to investigate the influence of lignosulfonate and curing system composition of curing process, cross-link density, morphology, physical-mechanical and dynamic-mechanical properties of composites. The achieved results showed that peroxide cured composites demonstrated higher cross-link density, which was found not to be influenced by the content of lignosulfonate. The cross-link density of sulfur cured composites was lower and showed a decreasing trend with increasing amount of the biopolymer. Lower cross-linking degree was reflected in higher elongation at break and higher increase of elongation at break of the corresponding composites. On the other hand, peroxide cured composites exhibited higher modulus M100 and higher hardness. The microscopic analysis revealed that co-agent in peroxide vulcanization contributed to the improvement of adhesion between the biopolymer and the rubber resulting in higher tensile strength of the equivalent composites. Higher cross-link density of peroxide cured composites caused higher restriction of the chains segments' mobility due to which these composites exhibited higher glass transition temperature.

Abstract: This study focuses on the development and characterization of biodegradable polymer composite materials with a polypropylene (PP) matrix and hybrid fillers. The fillers incorporated into these composites consisted of a blend of fibers and particles derived from natural, biodegradable materials, such as flax fibers (FF) and wood flour (WF) particles. The compositions of polymer material were expressed as PP/FF/WF weight ratios of 100/0/0, 70/5/25, and 70/10/20. The polymer materials were prepared using conventional plastic processing methods like extrusion to produce composite mixtures, followed by melt injection to manufacture the samples needed for characterization. The structural characterization of the polymer materials was conducted using optical microscopy and X-ray diffraction (XRD) analyses, while thermal, mechanical, and dielectric properties were also evaluated. Additionally, their biodegradation behavior under mould exposure was assessed over six months. The results were analyzed comparatively, and the optimal composition was identified as the polymer composite containing the highest flax fiber content, namely PP + 10% flax fiber + 20% wood flour.

Abstract: Polycarboxylate superplasticizers (PCEs) are the most important polymer admixtures in cement and concrete. Developing novel, green, and efficient synthesis methods is essential to lowering energy consumption. Here, a mechanochemical internal mixing polymerization was used to synthesize high-concentration PCEs (INPCEs) for the first time. The optimum reaction temperature, reaction rotating speed, and reaction time were determined using the orthogonal method. The optimum acid-ether ratio (i.e. the molar ratio of acrylic acid (AA) to isopentenyl polyoxyethylene ether (TPEG)) and concentrations of ammonium persulfate (APS) and sodium methacrylate sulfonate (MAS) were also determined. Finally, the molecular structures of the INPCEs were characterized using Fourier transform infrared spectroscopy (FT-IR) and gel permeation chromatography (GPC), and their performance and energy consumption were compared with PCE synthesized via an aqueous solution polymerization (TPCE). The results showed that the optimum reaction temperature, rotating speed, and time were 60 °C, 70 R/min, and 60 min, respectively. In addition, the acid-ether ratio, concentrations of MAS and APS, and the polymerization method affected the molecular weight and PDI of INPCEs but did not alter the functional groups. At an AA:TPEG:MAS molar of 3.5:1:0.12 and an APS concentration of 1 wt% (relative to TPEG), the initial fluidity of cement paste with INPCE was 312.5 mm at an INPCE dosage of 0.20 wt% and a water-cement ratio of 0.35. Further, the concentrations of the INPCEs were＞99.00 wt%, which is much higher than the TPCE concentration of 39.73 wt%, the dispersion and dispersion retention of INPCE was almost as good as that of TPCE, while requiring much less energy for synthesis. These findings can contribute to the reduction of energy consumption in the concrete industry.

Abstract: Exposure of organisms to nanoplastics (NPs) is inevitable given their global abundance and environmental persistence. Polyethylene terephthalate (PET) is a common plastic used in a wide range of products, including clothing and food and beverage packaging. Recent studies suggest that NPs can cross the blood-brain barrier and cause potential neurotoxicity. It is widely known that aggregation of amyloid beta (Aβ) peptides in the brain is a pathological hallmark of Alzheimer's disease (AD). While the impact of nanoplastics such as polystyrene (PS) on amyloid aggregation has been studied, the effects of PET NPs remain unexplored. In this study, we examined the effect of PET NPs of different sizes (PET50 nm and PET140 nm) and concentrations (0, 10, 50 and 100 ppm) on the fibrillation of Aβ1-40. Our results showed that the presence of PET50 nm as well as PET140 nm decreased the lag phase of the fibrillation processes in a dose- and size-dependent manner from 6.7 ± 0.08 h for Aβ in the absence of PET (Aβcontrol) to 3.1 ± 0.03 h for PET50 nm and 3.8 ± 0.06 h for PET140 nm. CD spectroscopy showed that PET50nm significantly impacts the structural composition of Aβ aggregates. A significant rise in antiparallel β-sheet content and β-turn structure and a substantial reduction in other structures were observed in presence of 100 ppm PET50 nm. These changes indicate that higher concentrations (100 ppm) of PET50 nm promote more rigid and uniform peptide aggregats. Although PET50 nm NPs influence the kinetics of aggregation and secondary structure, the overall morphology of the resulting fibrils remains largely unaltered, as seen by transmission electron microscopy. Also the local cross-β structure of the fibrils was not affected by the presence of PET50 nm NPs during fibrillation, as confirmed by 13C solid-state NMR spectroscopy. Overall, these findings show that PET NPs accelerate amyloid fibril formation and alter the secondary structure of Aβ fibrils. These results also indicate that the accumulation of PET-NPs in the brain may facilitate the progression of various neurodegenerative diseases, including Alzheimer's disease.

Abstract: This study investigates the development and characterization of PBS/EA cellulose and PCL/EA cellulose biocomposites in order to understand their structural, morphological, and thermal properties for sustainable applications. Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) were used to analyze these properties. FTIR analysis of PBS/EA cellulose composites showed increased hydroxyl peak intensities, suggesting possible interactions, whereas PCL/EA cellulose composites exhibited no significant interactions. XRD results revealed improved crystallinity in both composites with increased EA cellulose content. SEM images indicated enhanced surface morphology and good interaction in PBS/EA cellulose composites while PCL/EA cellulose composites showed a sea-island morphology, implying poor compatibility. DSC analysis showed that EA cellulose lowered the melting temperature of PBS, while minimal effects were observed in PCL composites. TGA results demonstrated improved thermal stability at lower EA cellulose contents in both PBS and PCL composites. These findings provide valuable insights into the potential of PBS/EA cellulose and PCL/EA cellulose biocomposites as biocompatible and sustainable materials, especially for applications in biomedical and environmentally friendly packaging sectors.

Abstract: The COVID-19 pandemic significantly impacted material sciences, particularly polymer composites, which played a crucial role in personal protective equipment (PPE), medical devices, and packaging. This study explores the modifications and advancements in polymer materials developed to meet the urgent demands of the pandemic. Key innovations include enhanced filtration efficiency in PPE, integration of antimicrobial nanoparticles, and the development of biopolymer alternatives to address environmental concerns. The incorporation of silver, copper oxide, zinc oxide, and titanium dioxide nanoparticles improved antiviral and antibacterial properties, while polymer modifications enhanced durability, thermal resistance, and recyclability. Additionally, research into biodegradable polymers such as polylactic acid (PLA) and polyhydroxyalkanoates (PHAs) gained momentum as sustainable alternatives to fossil-based plastics. The findings underscore the necessity of material innovation during global crises and highlight the future potential of modified polymer composites in healthcare and environmental sustainability.

Abstract: This study explores the development of polypropylene (PP) compound recipes using analytical models (AM) combined with genetic algorithms (GA). A talcum-filled PP compound, commonly utilised in injection moulding for packaging applications, served as a reference material, with shear viscosity, tensile modulus, and impact strength selected as target properties for replication. The AM were adapted and fitted to a dataset of 52 compounds, achieving high predictive accuracy for shear viscosity and tensile modulus, while impact strength proved more challenging due to its inherent variability. Three recipes were generated using GA under predefined material constraints. Recipe 1 aimed to replicate all three target properties, achieving a balanced compromise with maximum deviations of 13.14% for tensile modulus and 12.37% for impact strength while closely matching shear viscosity (maximum 9.8% deviation). Recipes 2 and 3, focused solely on matching shear viscosity and impact strength, demonstrated exceptional accuracy for shear viscosity, with Recipe 2 achieving near-perfect alignment (2.5% deviation). However, neither recipe approached the tensile modulus target due to material limitations. The findings demonstrate the effectiveness of combining AM with GA for designing alternative formulations, emphasising the importance of realistic targets and material constraints. This methodology is highly adaptable, allowing for the inclusion of additional optimisation criteria such as cost or sustainability. Future work will explore broader material sets and properties, extending the framework’s applicability to technical polymers and diverse industrial applications.

Abstract: The mesoscopic phase separation in two- and three-dimensional gels has been studied by computer simulation of a bead-spring model of Lennard-Jones particles. The formation of complex networks of high density phase (HDP) has been investigated and partially explained with competing short- and long-range energies. HDP network formation was found to occur at certain combinations of temperature and spring coefficient, given sufficient particle density. The morphology of the HDP networks changed with these three parameters. HDP networks became more faceted with higher spring coefficients, wider but less dense at higher temperatures and more voluminous and compact at larger densities. HDP network formation was preceded by a stage of HDP precipitation and followed by a stage of surface minimization.

Abstract:

The development of effective drug delivery systems is a major challenge in cancer therapy, gene therapy, and infectious disease treatment because of its low bioavailability, rapid clearance, and toxicity towards non-targeted healthy tissues. This review discusses how PEGylation, the covalent attachment of poly(ethylene glycol) (PEG), enhances the pharmacokinetic profiles of the drug-containing nanosystems through the "stealth effect" that avoids immune system detection and improves circulation times in different nano-delivery systems. The review provides an overview of the synthetic methods of PEG derivatives, their conjugation with nanoparticles, proteins, and drugs, and their characterization using modern analytical tools. The paper explores various PEGylation strategies, including covalent conjugation and self-assembly, and discusses the influence of PEG chain length, density, and conformation on drug delivery efficiency. Despite its advantages, there are several challenges associated with PEGylation such as the immunogenicity of anti-PEG responses, the potential for accelerated clearance of PEGylated drugs, reduced therapeutic efficacy, and the possibility of allergic reactions. Consequently, the balance between the benefits of PEGylation and its immunogenic risks remains a critical area of investigation.

Abstract:

Polyetheretherketone (PEEK) is widely used across various industries because of its high thermal stability, chemical resistance, and superior mechanical properties. This paper introduces an optimized method for dispersing functionalized graphene to improve the frictional and electrical resistance properties of PEEK. The influence of graphene, recognized as an effective additive, on the melt behavior, thermal stability, and tribological and electrical properties of PEEK–graphene nanocomposites was assessed for different filler contents. Results show that graphene acts as a nucleating agent, enhancing crystallinity in PEEK–graphene nanocomposites. A nanocomposite containing 1.0 wt.% graphene exhibited optimal frictional performance and surface resistance. Additionally, the study reveals that the integration of hybrid additives with varied shapes fosters the formation of three-dimensional particle networks more effectively than graphene additives alone.

Abstract: The increasing demand for sustainable materials in automotive applications, coupled with the critical need to address marine plastic pollution, presents an opportunity for innovative material development. This study explores composites made from recycled polyamide 6 (PA6) fishing nets reinforced with switchgrass fibers (0–30 wt%). The composite with 30 wt% switchgrass fibers increased tensile strength by 23% and Young’s modulus by 126% compared to unreinforced recycled PA6, achieving 93% of the tensile strength of commercial automotive-grade neat PA6 and surpassing another grade by 22%. However, higher fiber loading hindered processability, as evidenced by incomplete mold filling and reflected by a decrease in melt flow rate from 19.35 to 8.63 g/10 min. Thermal analysis revealed reduced crystallinity and crystallization temperatures with fiber addition, attributed to restricted polymer chain mobility. While dynamic mechanical analysis demonstrated improved stiffness below the glass transition temperature, scanning electron microscopy indicated optimal fiber-matrix adhesion at up to 20 wt% fiber loading, with aggregation at higher concentrations. These findings establish recycled fishing net-derived PA6/switchgrass fiber composites as a viable alternative to virgin materials in automotive applications, with mechanical properties comparable to commercial grades. Although the composites demonstrate enhanced mechanical strength and modulus, the significant reduction in ductility restricts their use to rigid, semi-structural components where flexibility is not critical. Future research should address processing challenges to enhance fiber dispersion and interfacial adhesion at higher loadings.

Abstract: Chemical conversion of plastic waste has been considered as important subject in terms of circular economy, and chemical recycling and upcycling of poly(ethylene terephthalate) (PET) has been considered as one of the important subjects. In this study, depolymerization of PET with n-hexylamine, n-octylamine, and with 3-amino-1-propanol have been explored in the presence of Cp*TiCl3 (Cp* = C5Me5). The reactions of PET with n-hexylamine, n-octylamine at 130 ºC afforded the corresponding di(n-alkyl) terephthalamides in high yields (>90 %), and Cp*TiCl3 plays a role as the catalyst to facilitate the conversion in the exclusive selectivity. The reaction of PET with 3-amino-1-propanol proceeded at 100 ºC even in the absence of Ti catalyst, affording bis(3-hydroxy) terephthalamide in high yields. Unique contrast in the depolymerization of PET between by transesterification with alcohol and by aminolysis has been demonstrated.