Developing a green, efficient, and robust route for fabricating silver nanoparticle (Ag-NP) composites remains a crucial challenge, particularly in achieving uniform particle size and high Ag-NP loading. In this study, a simple in-situ strategy was employed to synthesize and immobilize Ag-NPs (1–15 wt%) onto a bio-derived hydroxyapatite-curcumin (HAP-curcumin) nanocomposite. HAP was sustainably extracted from Black Tilapia fish scales, while curcumin functioned as both a natural reducing and stabilizing agent, enabling an environmentally friendly synthesis process. Structural and physicochemical analyses, XRD, FTIR, BET, XPS, and HRTEM, confirmed the successful formation and uniform dispersion of spherical Ag-NPs (∼15.7 nm) on the HAP-curcumin surface. The nanocomposites exhibited outstanding catalytic performance, efficiently reducing various organic pollutants, including 4-nitrophenol, Congo red, methylene blue, and rhodamine B, in the presence of NaBH₄. Remarkably, the 15% Ag/HAP-curcumin sample achieved rapid degradation of 4-nitrophenol within 5 s (k = 2.3297 min⁻¹) and demonstrated strong catalytic activity even in real sample matrices (milk, juice, and soap-containing wastewater). The 15% Ag/HAP-curcumin nanocomposite showed excellent stability over repeated cycles with negligible Ag leaching, indicating strong potential for practical applications. Beyond catalysis, the nanocomposites displayed potent antimicrobial activity against Bacillus cereus, Staphylococcus aureus, Staphylococcus hominis, and Candida albicans. The 15% Ag/HAP-curcumin nanocomposite achieved complete (100%) inhibition at 150 μg/mL, highlighting its dual functionality as a green catalyst and antimicrobial agent. This work presents a sustainable route for designing multifunctional Ag-based nanocomposites with promising applications in environmental remediation and biomedical fields.

Mitigating the co-existence of environmental stresses on crop plants necessitates the development of integrated, eco-friendly, and sustainable approaches to alleviate plant stress responses. This study represents the first attempt to mitigate the toxic impact of prevalent pollutant (salinity) and an emergent plastic manufacturing pollutants (bisphenol A, BPA) using the polyamine (cadaverine).Tomato plants, treated with or without cadaverine, were subjected to NaCl salinity (120 mM), BPA (375 mg kg soil), and their combinations compared to non-stressed control plants examining morphological, physiological, metabolic, and molecular responses. After 10 days of transplanting, tomato plants under combined stress were unable to survive without cadaverine application. However, cadaverine spraying mitigated the damaging effects of both single and combined stresses under short- and long-term exposure, enabling stressed plants to endure the conditions and complete their life cycles. Cadaverine efficiently restrained the reduction in chlorophylls, carotenoids, and cytosolutes under applied stresses compared to the stressed plants. Cadaverine also increased α-tocopherol content (by 171 and 53 %) and enhanced the activity of polyphenol oxidase (by 26 and 32 %), glutathione s-transferases (by 18 and 39 %), superoxide dismutase (by 23 and 46 %), and phenylalanine ammonia-lyase (by 9 and 25 %), under BPA and salinity stress, respectively. Thus, cadaverine ameliorated the oxidative and nitrosative burst induced by BPA or salinity, respectively by declining hydroxyl radical (by 28 % and 20 %), superoxide anion (by 73 % and 74 %), nitric oxide (by 60 and 65 %), lipid peroxidation (by 35 % and 54 %), and lipoxygenase activity (by 74 and 68 %). Moreover, cadaverine enhanced the expression of defence-related genes, including polyphenol oxidase, tubulin, and thaumatin-like protein, and reduced the uptake of BPA in the tomato’s roots while promoting its metabolism in leaves and fruits. This ensured the safety of the harvested fruits. By mitigating stress, improving plant resilience, and limiting pollutant accumulation, cadaverine presents significant potential for sustainable agricultural practices and food safety. These findings offer valuable insights into the role of cadaverine in managing abiotic stress and safeguarding crop health in environmentally challenging conditions.

Two novel luminescent main-chain polybenzoxazine polymers, (Poly1)main and (Poly2)x main, were synthesized and characterized to explore their structural, thermal, morphological and photophysical properties. Polymer (Poly1)main was obtained via a Mannich condensation reaction without a catalyst, followed by thermal polymerization to produce the crosslinked polymer (Poly2)x main. Structural analyses using Fourier transform infrared spectroscopy and X-ray diffraction confirmed the successful formation of the polymers, with (Poly2)x main exhibiting a higher degree of crosslinking and partial ordering in an otherwise amorphous structure. Scanning electron microscopy imaging revealed that thermal polymerization significantly altered the morphology, transforming the porous structure of (Poly1)main into a denser, layered morphology in (Poly2)x main. Thermogravimetric analysis and differential scanning calorimetry highlighted the improved thermal stability of (Poly2)x main due to extensive crosslinking. Photophysical studies showed that (Poly1)main in solution exhibited yellow-green luminescence with a broad emission maximum at 522 nm and CIE coordinates (0.39, 0.48). In contrast, the powders of both polymers displayed sharp red luminescence with an emission peak at 658 nm and CIE coordinates (0.72, 0.27), attributed to molecular packing effects and exciton coupling in the solid state. These results underscore the interplay among structural, morphological and photophysical properties, highlighting the potential of these polymers in optoelectronics, sensing and luminescent materials.
© 2025 Society of Chemical Industry.
Keywords: luminescent polymers; main chain; polybenzoxazines; photophysical properties; catalyst-free synthesis

α-Aminophosphonate and their related derivatives have garnered significant attention as a result of their use in many
biological and industrial applications, particularly in the fields of materials science. This research described synthesis and characterization of novel α-aminophosphonate derivatives (ES1-ES4) based on poly(p-hydroxystyrene). The synthesis was achieved by chemically modification of poly(p-hydroxystyrene) (PHS) with triphenylphosphite and various aldehydes (vanillin, N,N'-dimethylaminobenzaldhyde, p-chlorobenzaldhyde, and 3,4,5-trimethoxybenzaldhyde). The chemical structures were confirmed using FT-IR, 1H, 13C and 31P-NMR besides the thermal analysis techniques. A significant increase in molecular weight and radius of gyration were observed following functionalization, as evidenced by static laser light dispersion. The degree of functionalization (DoF) ranged from 71.5 to 80.06. The electronic properties and physical characteristics of these derivatives were elucidated through computational studies that employed DFT simulations. These studies revealed significant changes in the electron density distribution, electrostatic potential, and key polymeric properties, such as optical characteristics, mechanical strength, and glass transition temperature. Based on antimicrobial investigation, ES1 and ES4 showed potent inhibition against gram-positive bacteria and Candida albicans, indicating broad-spectrum activity. With a selectivity index of 1.50–1.72, cytotoxicity evaluations demonstrated that derivatives coded ES2, ES3, and ES4 exhibited reduced toxicity towards normal lung fibroblasts, recording IC50 of 181.37, 193.38 and 203.95 μg/ mL, respectively. On the other hand, higher selective toxicity against HepG2 liver cancer cells with IC50 values: 118.27, 121.75 and 121.18 μg/mL. These results demonstrated that α-aminophosphonate hybrid polymers have great promise as antibacterial and preliminary anticancer potential against HepG2 cells, while maintaining moderate safety toward normal fibroblasts at lower concentrations.

Abstract
Clustering-triggered emission (CTE) luminophores are novel luminescence compounds lacking extensive conjugation and receiving considerable interest. Two novel fluorescent polyketones (PKs) with a styrene unit as a pendant group in their backbone have been successfully synthesized. They are distinguished by the groups that separate the attached repeating monomeric units diacetyl cyclohexanone styrene (DAcSt), polyketone ether styrene (PKESt) with two benzene rings separated by an aliphatic ether or polyketone styrene (PKSt) with a single benzene ring. Using different techniques to investigate the structural, thermal stabilities, and morphological analyses of the polymers (PKSt, PKESt), their photophysical luminescence behavior is examined, and it appears that they are novel CTE compounds as a result of numerous n-π*, π-π* transitions and hydrogen-bonding interaction, displaying aggregation-induced emission (AIE) phenomena. PKESt has excitation-independent emission and generates blue light at different excitation wavelengths even at a short wavelength of 256 nm, while PKSt emits white light at 256 nm and blue emission at 325 nm, showing excitation-dependent wavelength. These unique luminous phenomena will bring light to the mechanism of clusteroluminescence (CL) and provide new approaches to the rational design of innovative luminescent materials. This study not only discloses new properties of PKs clustering emission but also gives novel perspectives on how to use PKs clustering emission to build novel types of luminescence systems. This system’s potential is metal ion sensors for transition metals ( Zn2+, Ni2+, Co2+, Cu2+, Fe3+) with outstanding selective fluorescence response to Fe3+ ions. These polymers may be useful photocatalytic materials with ferric ions since Fe3+ ions quench these Pks.
Keywords Clustering-triggered emission (CTE) · Nonconjugated polymer · 

Clusteroluminescence (CL) fluorescent polyketone · Aggregation-induced emission (AIE) · Metal sensors Extended author

Abstract
A series of novel Poly(ether-ketone)s (PEK-6, PEK-8, and PEK-10) were successfully synthesized via a Friedel–Crafts
polyacylation reaction using bisphenoxyalkane-based monomers with varying methylene spacer lengths (m = 6, 8, 10) and azobenzene-4,4’-dicarbonyl dichloride as the comonomer. The chemical structures of the monomers were confirmed by ¹H-NMR, ¹³C-NMR, FTIR, and mass spectrometry, while the polymers were characterized by FTIR, thermogravimetric
analysis (TGA), scanning electron microscopy (SEM), and X-ray diffraction (XRD). FTIR spectra confirmed the successful
incorporation of carbonyl and ether groups into the polymer backbone. TGA analysis revealed that all polymers
exhibited good thermal stability, though PEK-10 showed a lower onset degradation (Td5 = 195 °C) compared to PEK-6
and PEK-8 (both with Td5 = 307 °C). SEM images indicated significant morphological differences among the samples,
with surface roughness increasing with longer alkyl chains. XRD analysis showed a predominantly amorphous nature. The dye adsorption potential of the synthesized PEKs was explored using methylene blue as a model dye. Time-dependent UV–Vis spectroscopic studies indicated significant differences in adsorption behavior between the polymers. PEK-10 exhibited excellent and sustained adsorption performance, with absorbance decreasing from 0.56 to 0.09 at 664 nm after 24 h, highlighting strong dye-polymer interaction and retention. In contrast, PEK-8 initially showed rapid adsorption (to 0.35 in 10 min) but was followed by gradual desorption over time, returning to 0.55 after 24 h. These findings underscore the impact of alkyl spacer length on the structural, thermal, and adsorption properties of PEKs and suggest PEK-10 as a promising candidate in environmental remediation, particularly for dye removal from aqueous systems.
Keywords Poly(ether-ketone)s · Friedel–Crafts polyacylation · Azobenzene · Dye adsorption · Thermal stability.

A new polyimide, poly(1,3-thiazine imide) (PTzI), together with two co-polyimides (CoPTz-DsI and
CoPTz-HaI), were synthesized from the monomer named 4,4’-(1,4-phenylene)bis(6-(benzene-2-
yl)-6 H-1,3-thiazine-2-amine) (PTA), which has a di-1,3-thiazine heterocyclic structure. The structure of
PTA was confirmed with FT-IR, along with NMR spectra and mass spectroscopy. A thermal imidization
process was used to prepare PTzI from the corresponding polyamic acid (PAA), which was obtained by
polycondensation of PTA with 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA). Similarly,
the copolymers were synthesized via thermal imidization of PAAs derived from the polycondensation
of PTA with 4,4′-diaminodiphenyl sulfone (DDS) or 1,6-hexane diamine (HAD), in addition to BTDA.
The structure and imidization of each polymer were verified at various curing temperatures using
Fourier transform infrared FT-IR spectroscopy. X-ray diffraction verified their amorphous nature,
while scanning electron microscopy (SEM) morphological investigation indicated different levels of
homogeneity and compactness. The rigid aromatic backbones and imide linkages provide exceptional
thermal stability and chemical resistance, demonstrating their high performance. Thermogravimetric
study (TGA and derivative TGA) showed that the materials had outstanding thermal stability, with
high degradation initiation and initial decomposition temperatures (Td5%) in the range of 294–418 °C,
and char yields of 52–63% at 800 °C. In acidic environments, the synthesized polymers have shown
exceptional corrosion prevention performance for mild steel MS, according to electrochemical
evaluations. Due to its structural composition rich in 1,3-thiazine structure, PTzI exhibited the
highest inhibition efficiency (99.4%). Additionally, CoPTz-HaI and CoPTz-DsI demonstrated excellent
efficiencies of 95.2% and 96.4%, respectively. The inhibitory performance was shown to be improved as
the PTA concentration increased, suggesting that it may be used to create more sophisticated coatings
that resist corrosion.
Keywords Polyimides, Co-polyimides, Coating, Anti-corrosion, Thermal imidization, Polythiazine.