Magnetic colloidal polymeric ionic liquid synthesis and use in hydrogen production

Drug delivery systems of CoFe2O4/chitosan and MnFe2O4/chitosan magnetic composites

The study consists of three parts. In the first part, synthesis and characterization of core-shell magnetic composite beads based on chitosan and containing two different magnetic nanoparticles were carried out. The beads were formed from CoFe₂O₄/chitosan and MnFe₂O₄/chitosan. TGA and SEM were used for the characterization of core-shell materials. In the second part, swelling experiments of magnetic beads were performed. In the third part, 5-Fluorouracil was encapsulated at different rates in two different magnetic materials, release experiments were carried out at pH 7.4, pH 6.8, and pH 1.2, and the model of drug release was determined. Korsmeyer-Peppas, Higuchi, first-order, and zero-order models were used for mathematical modeling. Both prepared systems were found to be suitable for controlled release for 5-Fluorouracil.

Design, characterization and catalytic evaluation of halometallic ionic liquid incorporated Nd2O3 nanoparticles ([smim][FeCl4]-@Nd2O3) for the synthesis of N-aryl indeno pyrrole derivatives

Silica modified imidazolium [smim] based halometallic ionic liquids, [smim][MCl₄] (M = Fe, Cu and Zn), were synthesized for the evaluation of acidic and catalytic properties. Among these ILs, [smim][FeCl₄]⁻ was used for the preparation of heterogeneous catalyst ([smim][FeCl₄]⁻@Nd₂O₃) by simple immobilization of IL on Nd₂O₃ nanoparticles. The structure of [smim][FeCl₄]⁻@Nd₂O₃ was established by various techniques including FTIR, Raman, UV-vis DRS, powder XRD, SEM/EDX, elemental mapping, TEM, TGA, EPR and XPS analyses. The stability of nano-catalyst, [smim][ FeCl₄]⁻@Nd₂O₃, was established with the help of zeta potential analysis which showed a value of −40.32 mV lying under the stability range. Potentiometric titration with n-butyl amine was used to evaluate the acidic properties of [smim][MCl₄] as well as [smim][FeCl₄]⁻@Nd₂O₃. The catalytic potential of the material was probed through the one pot synthesis of N-aryl indeno pyrrole derivatives. The results showed excellent performance of the material by producing a high yield (98%) of indeno pyrrole derivatives. A recyclability experiment revealed that the catalyst was efficient in up to five cycles with insignificant loss in catalytic activity. The evaluation of green metrics indicated the sustainability of the present protocol in terms of high atom economy and low E-factor.

Silica modified imidazolium based halometallic ionic liquids, [smim][MCl₄] and [smim][FeCl₄]⁻@Nd₂O₃ were synthesized for the evaluation of acidic and catalytic properties.

System for Living ROMP of a Paramagnetic FeCl4--Based Ionic Liquid Monomer: Direct Synthesis of Magnetically Responsive Block Copolymers

Direct, living ring-opening metathesis polymerization of a highly paramagnetic, norbornene-based imidazolium FeCl₄^- ionic liquid monomer was achieved using the Grubbs third-generation catalyst and starting the polymerization off with an uncharged, nonparamagnetic norbornene monomer in a sequential block copolymerization. Preparing the paramagnetic norbornene imidazolium FeCl₄^- monomer in high purity was found to be crucial for enabling living polymerization behavior and generating paramagnetic diblock copolymers with predictable block lengths and compositions.

An amphiphilic manganese porphyrin-paired ionic copolymer: a highly efficient biphasic transfer catalyst for the selective oxidation of olefins with O2 and TBHP

A novel amphiphilic manganese porphyrin-paired ionic copolymer, {ADA-INA-[Mn(TPPS)(OAc)]}_n, was prepared by the self-assembly process of non-cross-linked amphiphilic polymeric ligands with inorganic species.

Enhanced catalytic activity of the nanostructured Co-W-B film catalysts for hydrogen evolution from the hydrolysis of ammonia borane

In this work, nanostructured Co-W-B films are successfully synthesized on the foam sponge by electroless plating method and employed as the catalysts with enhanced catalytic activity towards hydrogen evolution from the hydrolysis of ammonia borane (NH₃BH₃, AB) at room temperature. The particle size of the as-prepared Co-W-B film catalysts is varied by adjusting the depositional pH value to identify the most suitable particle size for hydrogen evolution of AB hydrolysis. The Co-W-B film catalyst with the particle size of about 67.3 nm shows the highest catalytic activity and can reach a hydrogen generation rate of 3327.7 mL min^-1 g_cat^-1 at 298 K. The activation energy of the hydrolysis reaction of AB is determined to be 32.2 kJ mol^-1. Remarkably, the as-obtained Co-W-B film is also a reusable catalyst preserving 78.4% of their initial catalytic activity even after 5 cycles in hydrolysis of AB at room temperature. Thus, the enhanced catalytic activity illustrates that the Co-W-B film is a promising catalyst for AB hydrolytic dehydrogenation in fuel cells and the related fields.

Synthesis and characterization of ureido-derivatized UCST-type poly(ionic liquid) microgels

Ureido-derivatized poly(ionic liquid) microgels, which possess an upper critical solution temperature and can be used in catalytic esterification, are synthesized.

Synthesis and characterization of CO2-sensitive temperature-responsive catalytic poly(ionic liquid) microgels

A class of poly(ionic liquid) microgels exhibiting CO₂-switchable temperature-responsive volume phase transition behavior have been synthesized and used for CO₂ fixation.

Preparation of Poly(ionic liquid) Hollow Particles with Switchable Permeability

Poly(ionic liquid) (PIL) particles with a single-hollow structure are prepared by suspension polymerization from monomer droplets consisting of the hydrophobic ionic liquid monomer [2-(methacryloyloxy)ethyl]trimethylammonium bis(trifluoromethanesulfonyl)amide, ethylene glycol dimethacrylate, and n-butyl acetate containing dissolved poly(n-butyl methacrylate). The obtained PIL hollow particles' shells can be changed from hydrophobic to hydrophilic by anion exchange using a LiBr/ethanol solution. In the case of hydrophilic PIL hollow particles, the water-soluble fluorescent materials can penetrate into the hollow structure, whereas in the case of hydrophobic PIL hollow particles, penetration of the fluorescent materials is restricted. In addition, the encapsulated water-soluble materials can be preserved into the hollow part by changing the shell property of the PIL particle encapsulated with the water-soluble materials from hydrophilic to hydrophobic.

Fast removal of high quantities of toxic arsenate via cationic p(APTMACl) microgels

Hydrogels are resourceful materials and can be prepared in different morphology, size, surface charge and porosity adopting different polymerization techniques and reaction conditions. The cationic poly(3-acrylamidopropyl)trimethylammonium chloride (p(APTMACl)) microgels were synthesized by photo-initiated inverse suspension polymerization technique. These microgels were utilized as absorbents for the removal of toxic arsenate (As) from different aqueous environments. The experimental parameters affecting absorption efficiency were investigated, and it was demonstrated that these types of microgels are highly efficient in removing arsenate anions from different aqueous environments compared to the previously reported bulk hydrogel, and cryogel of the same material. A removal efficiency of approximately 97.25% was obtained by immersing 0.5 g microgel in 250 ppm 100 mL solution of arsenate anions for 60 min. Both Langmuir and Freundlich adsorption isotherms were applied to adsorption of arsenate anions by p(APTMACl) microgels, and the Langmuir isotherm was a better representation of the adsorption of arsenate with a high value of R(2) (0.9982). Furthermore, mag-p(APTMACl) microgels were synthesized for the adsorption of arsenate anions to provide easy removal of the microgel composite by using an externally applied magnetic field. Furthermore, re-usability of the p(APTMACl) microgels was also investigated for the adsorption of arsenate anions.

Synthesis and characterization of responsive poly(anionic liquid) microgels

Responsive poly(anionic liquid) microgels are synthesized by polymerization of tetrabutylphosphonium 4-styrenesulfonate, which can be further functionalized to harness catalytic properties.

Preparation of poly(ionic liquid) composite particles and function modification with anion exchange

Detailed investigation on the synthesis of poly(ionic liquid) composite particles by seeded (dispersion) polymerization and property modification using anion exchange.

The use of superporous p(3-acrylamidopropyl)trimethyl ammonium chloride cryogels for removal of toxic arsenate anions

Poly((3-Acrylamidopropyl)trimethylammonium chloride) (p(APTMACl)) cryogels were used as a superporous polymer network for the removal of toxic arsenate anions from an aqueous medium. The fast swelling in water, in about 7 s, was shown to be very useful leading to fast arsenate adsorption by p(APTMACl) cryogels within 30 min in comparison to 12 h for bulk common p(APTMACl) hydrogels. A maximum adsorption capacity of about 120 (mg/g) arsenate was obtained for p(APTMACl) cryogels. Both the Langmuir and Freundlich adsorption isotherms were applied for adsorption of arsenate anions by p(APTMACl) cryogels, and it was observed that the adsorption of arsenate anions by p(APTMACl) cryogels are represented better via Langmuir adsorption isotherm providing the R(2) value of 0.998. Furthermore, mag-p(APTMACl) cryogels were synthesized, and shown to be very useful in the fast removal of toxic arsenate anions. The mag-p(APTMACl) cryogels including the adsorbed arsenate were removed by an externally applied magnetic field, with some reduction in the arsenate ion adsorption capacity. It was also further demonstrated that p(APTMACl) cryogels can be reused in the adsorption of arsenate 5 times from aqueous environments without significant loss of adsorption capacity, from 113.47 ± 9 to 102.67 ± 6 mg/g.

Very fast catalytic reduction of 4-nitrophenol, methylene blue and eosin Y in natural waters using green chemistry: p(tannic acid)–Cu ionic liquid composites

Using tannic acid (TA) as a biopolymer, poly(tannic Acid) (p(TA)) microgels were obtained by cross-linking TA with trimethylolpropane triglycidyl ether (TMPGDE) as cross-linker in a water-in-oil micro emulsion system.

Highly versatile p(MAc)–M (M: Cu, Co, Ni) microgel composite catalyst for individual and simultaneous catalytic reduction of nitro compounds and dyes

Poly(methacrylic acid) (p(MAc)) microgels were synthesized by inverse suspension polymerization and used as a template for copper, nickel, and cobalt nanoparticle preparation.

Magnetic ionic liquids: synthesis, properties and applications

Magnetic ionic liquids are room temperature ionic liquids, which have paramagnetic properties by themselves without the need of adding magnetic particles.