The amalgamation of natural polysaccharides with synthetic polymers often produces fruitful results in the area of drug delivery due to their biodegradable and biocompatible nature. In this study, a series of blend films composed of chitosan (CS)/poly(allylamine hydrochloride) (PAH) in different compositions were prepared as smart drug delivery matrices. The properties of these polymeric films were then explored. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) analysis confirmed an intermolecular hydrogen bonding between CS and PAH. Atomic force microscopy (AFM) revealed improvements in surface morphology as the percentage of PAH in the blend films increased up to 60% (w/w). Water contact angle (WCA) ranged between 97° to 115°, exhibiting the hydrophobic nature of the films. Two films were selected, CTH-1 (90% CS and 10% PAH) and CTH-2 (80% CS and 20% PAH), to test for in vitro cumulative drug release (%) at 37 ± 0.5 °C as a function of time. It was revealed that for simulated gastric fluid (SGF) with pH 1.2, the cumulative drug release (CDR) for CTH-1 and CTH-2 was around 88% and 85% in 50 min, respectively. Both films converted into gel-like material after 30 min. On the other hand, in pH 7.4 phosphate buffer saline (PBS) solution, the maximum CDR for CTH-1 and CTH-2 was 93% in 90 min and 98% in 120 min, respectively. After 120 min, these films became fragments. Sustained drug release was observed in PBS, as compared to SGF, because of the poor stability of the films in the latter. These results demonstrate the excellent potential of blend films in sustained-release drug delivery systems for hydrophilic or unstable drugs.

Syzygium aromaticum L. is an aromatic plant with a significant amount of essential oil (EO), which is used in food, medicine, for flavoring, and in the fragrance industry. The purpose of this study was to comparatively evaluate the chemical composition, yield, and antioxidant and antifungal activities of Syzygium aromaticum essential oils extracted by the conventional hydro-distillation, steam distillation, and the emerging superheated steam distillation methods. It was noticed that the extraction methods significantly influenced the yield, chemical composition, and antioxidant and antimicrobial activities of essential oils. The maximum yield was obtained using superheated steam distillation, followed by hydro-distillation and steam distillation. The antioxidant potential of EO extracts was evaluated following the scavenging of 2,2-dipenyl-1-picrylhydrazyl radicals, hydrogen peroxide scavenging activity and ferric reducing power assays. Results revealed that EO extracted superheated steam distillation exhibited the highest antioxidant activity. GC-MS analysis depicted eugenol (47.94–26.50%) and caryophyllene (20.24–9.25%) as the major compounds of Syzygium aromaticum EOs. The antimicrobial activity of EO extracts was evaluated, via the resazurin microtiter plate assay, microdilution broth assay, and disc diffusion methods, against normal and food pathogenic bacterial and fungal strains. After comparative evaluation, it was observed that superheated steam extracted EO exhibited the highest antimicrobial potential. Overall, methodical evaluation disclosed that superheated steam distillation is an effective method to extract EOs from plant sources, with greater yield and promising biological activities.

Conjugated microporous polymers (CMPs) have conjugated skeleton and permanent porosity, and exhibit huge potential in developing novel functional materials for resolving the challenging energy and environment issues. Metal-containing CMPs often exhibited unique properties. In the present manuscript, ferrocene-based conjugated microporous polymers (FcCMPs) were designed and synthesized with 1,1′-dibromoferrocene and 5,10,15,20-Tetrakis(4- bromophenyl) porphyrin (FcCMP-1) or Tetra (p-bromophenyl) methane (FcCMP-2) as building units via Yamamoto coupling. FcCMPs were amorphous, and exhibited excellent thermal and physicochemical stability. The BET surface area of FcCMP-1 and FcCMP-2 was 638 m²/g and 422 m²/g, respectively. In comparison with FcCMP-2, FcCMP-1 displayed better gas storage capacity due to higher porosity. FcCMPs were also used as an adsorbent for removal of methyl violet from aqueous solution, and exhibited excellent adsorption properties due to the interaction between electron-rich conjugated structure of the polymers and methyl violet with cationic groups. Moreover, FcCMPs could be extracted and regenerated by an eluent and then re-used for high efficient removal of methyl violet.

This study focuses on the removal of uranium ions from nuclear wastewater by fabricating inorganic–organic hybrid cyclic and linear polyphosphazene based polymers. Synthesized HCP-A and HCP-B had BET surface areas of 497.06 m² g⁻¹ and 410.75 m² g⁻¹, respectively, while the pore size distribution (PSD) was in the range of 1–20 nm. The maximum removal efficiency of uranium by HCP-A and HCP-B for a lab prepared sample was found to be 97.6% and 95.2%, respectively, at pH 6, a contact period of 80 minutes, an adsorbent weight of 0.6 g, and a temperature of 25 °C, while for a nuclear wastewater sample, it was 83.9% and 79.8%, respectively. Lone pair–cation interactions, metal ligand complexation, hydrogen bonding, cation–pi interactions and electrostatic interactions were responsible for adsorption. The point of zero charge (PZC) for both HCPs was at pH 4.6. The optimal uranium uptake capacities of HCP-A and HCP-B were found to be 714.28 mg g⁻¹ and 555.56 mg g⁻¹, respectively. The Freundlich model was the best match for uranium adsorption by both HCPs, with R² values of 0.9775 and 0.9931, respectively. Adsorption kinetics study exhibited that it fitted a pseudo 2nd order kinetic model with R² values of 0.9446 for HCP-A and 0.9882 for HCP-B. The uranium uptake process was found to be spontaneous and exothermic in nature. For HCP-A and HCP-B, a Gibbs free energy (ΔG) of −1.516 kJ mol⁻¹ and −0.27 kJ mol⁻¹, enthalpy change (ΔH) of −41.59 kJ mol⁻¹ and −40.65 kJ mol⁻¹, and entropy change (ΔS) of −0.134 kJ mol⁻¹ K⁻¹ and −0.136 kJ mol⁻¹ K⁻¹, respectively, were observed. The reusability of HCPs with a minor decrease (2% and 1%) in their adsorption capability suggests that they can be used in industrial level applications.