The preparation, characterization and catalytic activity of Ni NPs supported on porous alginate-g-poly(p-styrene sulfonamide-co-acrylamide)

Structural and optical properties of alginate-based antibacterial dressing with calcium phosphate and zinc oxide for biodegradable wound painting applications

The skin is the outermost part of the body. Although susceptible to damage, the skin is in direct contact with the external environment. Wound dressing is a clinical method that plays a vital role in wound healing. Herein, we developed an antibacterial wound dressing using alginate as the basic material. The dressing was prepared using the solvent casting method, which was used to analyze the effects of adding CaP and ZnO on its structural, optical, and antibacterial properties. Adding CaP exhibited strong but stiff mechanical properties, unlike the CaP/ZnO, which possessed high strength and elasticity. The optical properties of sample S2 did not have a considerable impact. By contrast, the addition of ZnO to sample S3 notably increases the wavelength and absorption value. The diameter of the inhibition zone for S. aureus bacteria exhibited a successive increase in its antibacterial properties, and sample S3 exhibited the highest value. Thus, sample S3 is the most promising wound dressing concerning speeding up the wound healing process because it possesses the most optimal mechanical, optical, and antibacterial properties. The main limitation to be addressed is that sample S3 cannot be easily digested in the environment.

Enhanced reduction of nitrobenzene derivatives using reusable Ni nanoparticles supported on multi-layered poly(1,2-phenylenediamine)-coated layered double hydroxides

Recently, nanomaterials with layered double hydroxide (LDH) cores have been the subject of intense research regarding their promising applications in organic synthesis. In this study, nitrobenzene reduction is investigated by designing and synthesizing a novel LDH-based heterogeneous catalyst containing a nickel-1,2-phenylenediamine complex. The Cu–Zn–Al LDH was functionalized with copolymer bearing a glycidyl methacrylate (GMA) linkage that makes it suitable for grafting with 1,2-phenylenediamine. Overall, the synthesized LDH@MPS-GMA-PDA-Ni was found to be a highly efficient heterogeneous nanocatalyst that can catalyze nitroarene reduction with high yields under mild conditions.

Preparation of a reusable and pore size controllable porous polymer monolith and its catalysis of biodiesel synthesis

A sulfonated porous polymer monolith (PPM-SO₃H) has been prepared via the polymerisation of styrene (St) and divinyl benzene (DVB) with organic microspheres as pore-forming agents, followed by sulfonation with concentrated sulfuric acid. It was characterized by acid–base titration in order to determine its acid density, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, mercury intrusion porosimetry (MIP) and thermogravimetric analysis (TG). The PPM-SO₃H showed an acid density of 1.89 mmol g⁻¹ and pore cavities with an average diameter of 870 nm. The catalytic activity of PPM-SO₃H in practical biodiesel synthesis from waste fatty acids was investigated and the main reaction parameters were optimized through orthogonal experiment. The best reaction conditions obtained for the optimization of methanol to oil ratio, catalyst concentration, reaction temperature and reaction time were 1 : 1, 20%, 80 °C and 8 h, respectively. PPM-SO₃H showed excellent catalytic activity. In biodiesel synthesis, the esterification rate of PPM-SO₃H is 96.9%, which is much higher than that of commercial poly(sodium-p-styrenesulfonate) (esterification rate 29.0%). The PPM-SO₃H can be reused several times without significant loss of catalytic activity; the esterification rate was still 90.8% after 6 cycles. The pore size of this porous polymer monolith can be controlled. The dimension and shape of this porous polymer monolith were also adjustable by choosing a suitable polymerisation container.

A novel pore size controllable sulfonated porous polymer monolith was fabricated using organic microspheres as pore-forming agents. The monolith exhibited excellent catalytic activity in the synthesis of biodiesel.

Synthesis of calixresorcarenes using magnetic poly triazine-benzene sulfonamide-SO3H

The purpose of this work is to develop a magnetically recyclable immobilized base catalyst for the green synthesis of calixresorcarenes. To achieve this, poly triazine-benzene sulfonamide (PTBSA) has been coated on magnetic Fe₃O₄ nanoparticles and subsequently chlorosulfonic acid has been supported to obtain Fe₃O₄@PTBSA-SO₃H. The structure of nano-Fe₃O₄@PTBSA-SO₃H was characterized by TEM, XRD, FT-IR, VSM, WDX, EDX, TGA/DSC and FE-SEM. The catalytic efficiency of this catalyst was also investigated in the synthesis of novel calixresorcarene derivatives. The advantages of heterogeneous nature, catalytic activity and the recyclability of the polymer support were also strengthened by advanced surface treatment. These key factors (basic sites, acidic sites and heterogeneity) play essential roles in the catalyst performance. This procedure has some advantages such as short reaction time, clean and fast work-up and easy separation of the catalyst by an external magnet.

Magnetic poly triazine-benzene sulfonamide-SO₃H was investigated for the synthesis of calixresorcarenes.