Bactericidal and biocatalytic temperature responsive microgel based self-cleaning membranes for water purification

The present study focuses on creating an antimicrobial and biocatalytic smart gating membrane by synthesizing unique core-shell microgels. The core-shell microgels are synthesized by grafting short chains of poly(ethylenimine) (PEI) onto a poly((N-isopropyl acrylamide)-co-glycidyl methacrylate)) (P(NIPAm-co-GMA)) core. Subsequently, the produced microgels are utilized as a substrate for synthesizing and stabilizing silver nanoparticles (Ag NPs) through an in-situ approach. These Ag NPs immobilized microgels are then suction filtered over a polyethylene terephthalate (PET) track-etched support to create cross-linked composite microgel membranes (CMMs). After structural and permeation characterization of the prepared CMMs, the laccase enzyme is then covalently grafted to the surface of the membrane and tested for its effectiveness in degrading Reactive red-120 dye. The laccase immobilized biocatalytic CMMs show effective degradation of the Reactive red-120 by 71%, 48%, and 34% at pH 3, 4, and 5, respectively. Furthermore, the immobilized laccase enzyme showed better activity and stability in terms of thermal, pH, and storage compared to the free laccase, leading to increased reusability. The unique combination of Ag NPs and laccase on a thermoresponsive microgel support resulted in a responsive self-cleaning membrane with excellent antimicrobial and dye degradation capabilities for environmentally friendly separation technology.

Ag2CO3 containing magnetic nanocomposite as a powerful and recoverable catalyst for Knoevenagel condensation

In this paper, the synthesis, characterization and catalytic application of a novel magnetic silica-supported Ag2CO3 (MS/Ag2CO3) with core-shell structure are developed. The MS/Ag2CO3 nanocomposite was prepared through chemical modification of magnetic MS nanoparticles with AgNO3 under alkaline conditions. The structure, chemical composition and magnetic properties of MS/Ag2CO3 were investigated by using VSM, PXRD, FT-IR, EDX and SEM techniques. The MS/Ag2CO3 nanocomposite was used as an effective catalyst for the Knoevenagel condensation under solvent-free conditions at 60 °C in an ultrasonic bath. The recovery and leaching tests were performed to study the nature of the MS/Ag2CO3 catalyst under applied conditions.

Microporous poly(glycidyl methacrylate-co-ethylene glycol dimethyl acrylate) microspheres: synthesis, functionalization and applications

As a new kind of functional material, micron-sized porous polymer microspheres are a hot research topic in the field of polymer materials.

"2-Amino glucose" as a substrate for synthesis of magnetically recoverable nanocatalyst NiFe2O4@SiO2@amino glucose for the green synthesis of novel bis (1,2-dihydro-4-hydroxy-2-oxoquinolin-3-yl)methanes

2-Amino glucose ((2S,3R,4S,5S,6R)-2-amino-6-(hydroxymethyl)tetrahydro-2H-pyran-3,4,5-triol) as a substrate for the synthesis of NiFe₂O₄@SiO₂@amino glucose supply an environmentally friendly procedure for the synthesis of bis(1,2-dihydro-4-hydroxy-2-oxoquinolin-3-yl)methanes through one-pot condensation of aldehyde or pyrazolo carbaldehyde and two equivalents of 4-hydroxyquinolin-2(1H)-ones in aqueous media. Eco-friendliness, high purity of the desired products, short reaction time and easy workup procedure can be mentioned as the other advantages of this method. The structures of the synthesized 4-hydroxy-2(1H)-quinolone compounds were confirmed by ¹H, ¹³C NMR and FTIR spectral data and elemental analyses.

Advances in Magnetic Nanoparticles-Supported Palladium Complexes for Coupling Reactions

Carbon‒carbon (C‒C) and carbon‒heteroatom (C‒X) bonds that form via transition-metal-catalyzed processes have been extensively used in the organic synthesis and preparation of natural products and important compounds such as heterocycles, biologically active molecules, and dendrimers. Among the most significant catalysts, magnetic nanoparticles-supported palladium complexes are very effective, versatile, and heterogeneous catalysts for a wide range of C‒C and C‒X coupling reactions due to their reusability, thermal stability, and excellent catalytic performance. In this review, recent advances to develop magnetic nanoparticles supported palladium complexes, including their preparation, characterization, catalytic application, and reusability in the formation of both C‒C and C‒X bonds, by authors such as Sonogashira, Heck, Suzuki‒Miyaura, and Stille, and a few examples concerning N-arylation, S-arylation, and Csp2-P coupling reactions are discussed.

Cage and linear structured polysiloxane/epoxy hybrids for coatings: Surface property and film permeability

Three polysiloxane/epoxy hybrids obtained by evolving cage- or linear-structured polysiloxane into poly glycidyl methacrylate (PGMA) matrix are compared used as coatings. One is the cage-structured hybrid of P(GMA/MA-POSS) copolymer obtained by GMA and methacrylisobutyl polyhedral oligomeric silsesquioxane (MA-POSS) via free radical polymerization, the other two are PGMA/NH₂-POSS and PGMA/NH₂-PDMS hybrids by cage-structured aminopropyllsobutyl POSS (NH₂-POSS) or linear-structured diamino terminated poly(dimethylsiloxane) (NH₂-PDMS) to cure PGMA. The effect of MA-POSS, NH₂-POSS and NH₂-PDMS on polysiloxane/epoxy hybrid films is characterized according to their surface morphology, transparency, permeability, adhesive strength and thermo-mechanical properties. Due to caged POSS tending to agglomerate onto the film surface, P(GMA/MA-POSS) and PGMA/NH₂-POSS films exhibit much more heterogeneous surfaces than PGMA/NH₂-PDMS film, but the well-compatibility between epoxy matrix and MA-POSS has provided P(GMA/MA-POSS) film with much higher transmittance (98%) than PGMA/NH₂-POSS film (24%), PGMA/NH₂-PDMS film (27%) and traditional epoxy resin film (5%). The introduction of polysiloxane into epoxy matrix is confirmed to create hybrids with strong adhesive strength (526-1113N) and high thermos-stability (T_g=262-282°C), especially the cage-structured P(GMA/MA-POSS) hybrid (1113N and 282°C), but the flexible PDMS improves PGMA/NH₂-PDMS hybrid with much higher storage modulus (519MPa) than PGMA/NH₂-POSS (271MPa), which suggests that PDMS is advantage in improving the film stiffness than POSS cages. However, cage-structured P(GMA/MA-POSS) and PGMA/NH₂-POSS indicate higher permeability than PGMA/NH₂-PDMS and traditional epoxy resin. Comparatively, the cage-structured P(GMA/MA-POSS) hybrid is the best coating in transparency, permeability, adhesive strength and thermostability, but linear-structured PGMA/NH₂-PDMS hybrid behaviors the best coating in mechanical property.

Introduction of Fe3O4@SiO2–ZrCl2-MNPs for the efficient promotion of some multi-component reactions under solvent-free conditions

In the work, the preparation, characterization and use of Fe₃O₄@SiO₂–ZrCl₂-MNPs as nano magnetic reagents in the promotion of some multi-component reactions is reported.

Diazoresin modified monodisperse porous poly(glycidylmethacrylate-co-divinylbenzene) microspheres as the stationary phase for high performance liquid chromatography

Diazoresin modified monodisperse porous PGMA–DVB microspheres were used as a novel tool for the separation and purification of the N-vinyl-1,2,4-triazole product from its by-product was developed.

PEPPSI-SONO-SP2: a new highly efficient ligand-free catalyst system for the synthesis of tri-substituted triazine derivatives via Suzuki–Miyaura and Sonogashira coupling reactions under a green approach

Consecutive Suzuki–Miyaura and Sonogashira cross coupling reactions catalyzed by a new competent palladium catalyst PEPPSI-SONO-SP² under mild and green reaction conditions.