Preparation and catalytic application of sulfonated PVA-Zr-pillared clay nanocomposite materials towards one pot synthesis of hexahydropyrimidines
TL;DR: In this article, a series of sulfonated polyvinyl alcohol-Zr-pillared clay nanocomposites were synthesized and characterized using XRD, FTIR, Raman, UV-vis and FE-SEM analytical techniques.
Abstract: A series of sulfonated polyvinyl alcohol-Zr-pillared clay nanocomposites were synthesized. A low molecular weight polyvinyl alcohol (PVA) was sulfonated using chlorosulfonic acid. The sulfonated PVA was intercalated inside the parent clay and Zr-pillared clay (Zr-P) matrix. In an alternative approach, the polyvinyl alcohol was initially intercalated into the clay and Zr-P structure followed by in-situ sulfonation inside the clay matrix. The composite materials were characterized using XRD, FTIR, Raman, UV–vis and FE-SEM analytical techniques. Expansion in clay interlayer due to insertion of the polymeric species and the Zr-pillars was observed from XRD study. FTIR and UV–vis study revealed presence of hydrated sulfonic acid clusters in the composite materials. The clay sheets were largely present in an exfoliated state in the clay-polymer composite materials. Insertion of the Zr-pillar imparts structural rigidity and consequent changes in the morphological features. The catalytic activity of the Zr-pillared clay-sulfonated polyvinyl alcohol composite materials has been investigated for synthesis of hexahydropyrimidines by multicomponent condensation of substituted aniline, formaldehyde and β-dicarbonyl compounds. The composite materials were found to be highly active for synthesis of structurally diverse hexahydropyrimidines in high yield and purity.
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TL;DR: In this article, the phosphorylated fullerene/sulfonated polyvinyl alcohol (PFSP) cation exchange membrane was prepared, characterized and its applications were studied in microbial fuel cell for copper removal along with the power generation.
Abstract: The phosphorylated fullerene/sulfonated polyvinyl alcohol (PFSP) cation exchange membrane was prepared, characterized and its applications were studied in microbial fuel cell (MFC) for copper removal along with the power generation. The phosphorylation of fullerene was confirmed by UV and Fourier Transform Infrared Spectroscopy (FTIR). The composite membrane was prepared by solution casting method and characterized by FTIR, Scanning Electron Microscopy (SEM) and Thermo Gravimetric Analysis (TGA) methods. The proton conductivity, water uptake and ion exchange capacity (IEC) of the prepared membrane were observed to be 11.7 × 10−2 S/cm, 120% and 1.67 meq/g respectively. Open circuit voltage (OCV) and power density obtained were 801 mV and 499.1 mW/m2 respectively for the composite membrane. The maximum Cu++ removal was 73.2% as compared to 63.2% for Ultrex CMI 7000; a commercial membrane. This prepared membrane is expected to offer vital and constructive properties for its application in fuel cell technology and to remove copper ions from wastewater.
25 citations
TL;DR: In this article, a new polymer anchored complex, PSMo has been prepared by reacting H 2 MoO 4 and 30% H 2 O 2 with macromolecular ligand, poly(sodium vinyl sulfonate).
Abstract: Peroxomolybdenum(VI) species immobilized on linear water soluble polymers formulated as, [MoO(O 2 ) 2 (sulfonate)]–PS [ PS = poly(sodium vinyl sulfonate)] ( PSM o) and[Mo 2 O 2 (O 2 ) 4 (carboxylate)]–PA [ PA = poly(sodium acrylate)]( PAMo ) served as efficient and recyclable catalysts for selective oxidation of organic sulfides to sulfoxide in water with 30% H 2 O 2 . The new polymer anchored complex, PSMo has been prepared by reacting H 2 MoO 4 and 30% H 2 O 2 with macromolecular ligand, poly(sodium vinyl sulfonate) and characterized by elemental analysis, spectral studies (FTIR, Raman, 13 C NMR, 95 Mo NMR, UV–vis), SEM, EDX and TGA-DTG analysis. The catalytic protocol effects clean and facile oxidation of a wide range of sulfides to afford pure sulfoxides with high TOF and excellent chemoselectivity at ambient temperature,with an easy work-up procedure. The catalysts can be regenerated in-situ and recycled at least up to ten consecutive reaction cycles without significant loss of activity and are amenable for ready scalability. The catalytic procedure thus provides an ecologically sustainable alternative as it involves water as solvent, H 2 O 2 as green oxidant, a recyclable non-polluting catalyst, and is absolutely free from halide, organic co-solvent or co-catalyst. This is the first catalytic protocol for selective aqueous oxidation of sulfides using a catalytic system based on peroxometal species supported on water soluble polymers.
21 citations
TL;DR: In this article, a series of pyrimidinone derivatives were efficiently synthesized using PEG-SANM nanocomposite as the solid acid nanocatalyst under mild and solvent-free conditions.
Abstract: A series of pyrimidinone derivatives were efficiently synthesized using PEG-SANM nanocomposite as the solid acid nanocatalyst under mild and solvent-free conditions. The generality of the process was successfully demonstrated by variation of the starting materials. Also, large-scale synthesis of products occurred readily in the presence of this nanocatalyst. This new method eliminated the use of organic solvents and the products were obtained in good to excellent yields and high purities after a simple workup in short reaction times. No chromatographic separation is needed for isolation of the obtained products. The nanocatalyst was recovered and reused for up to five times without a noticeable decrease in the catalytic activity.
21 citations
TL;DR: In this article, a layered α-zirconium phosphate (α-ZrP) was prepared by reflux method using ZrOCl2.8H2O and H3PO4 as precursor.
Abstract: Layered α-zirconium phosphate (α-ZrP) was prepared by reflux method using ZrOCl2.8H2O and H3PO4 as precursor. The α-ZrP material was pillared with Zr-oxyhydroxy nanoclusters to prepare Zr-pillared α-zirconium phosphate (ZZP). An enhancement in interlayer spacing, surface area and porosity was noticed as a result of Zr-pillaring. The cesium exchanged phosphotungstic acid (CsxH3-xPW12O40) nanoparticles were dispersed in the porous matrix of ZZP material to prepare CsxH3-xPW12O40-ZZP nanocomposite systems. The nanocomposites were characterized using XRD, FTIR, UV–vis-DRS, TGA-DTA, XPS, N2 sorption, TPD, FESEM and HRTEM techniques. The expansion in layer structure of α-ZrP upon pillaring and its subsequent retention in the composite material was noticed from XRD. UV–vis and FTIR study indicated structural integrity of the CsxH3-xPW12O40 nanoclusters in the ZZP interlayer. The surface area of the composite materials was in the range of 80–130 m2 g−1. The composite materials contained significantly higher amount of medium and strong acidic sites compared to the ZP and ZZP materials. Microscopic study suggested the presence of hierarchical nanospheres with diameter between 150 and 200 nm. The presence of well dispersed CsxH3-xPW12O40 nanoparticles with size between 8 and 15 nm was confirmed from HRTEM study. The nanocomposite materials were used as efficient heterogeneous catalyst for synthesis of spirooxindoles by multicomponent one pot condensation of isatin, malononitrile, naphthol/1,3-diketones. Structurally diverse spirooxindole derivatives were synthesized in high yield and purity in short span of time using the CsxH3-xPW12O40-ZZP nanocomposites as catalyst under mild conditions.
19 citations
TL;DR: In this paper , the authors summarized the studies on the interactions between water-soluble polymers and layered clay minerals and clarified the structure-property relationship in these hybrids for the reported application from the viewpoint of the uniqueness over other nanocomposites of water soluble polymer and various nanoparticles.
Abstract: Functional materials based on the hybrids of layered clay minerals and water-soluble polymers have been reported extensively. Here, the studies on the interactions between water-soluble polymers and layered clay minerals are summarized to clarify the structure-property relationship in these hybrids for the reported application from the viewpoint of the uniqueness over other nanocomposites of water-soluble polymers and various nanoparticles. The reported application of hybrids of layered clay minerals and water-soluble polymers includes solid-electrolyte and gas barrier film for packaging and such characteristics as stabilities and self-healing were also examined as associating characteristics necessary for the practical application. These functions/characters have been designed by the structure, which is controlled by the choices of layered clay minerals, polymers and their composition (polymer/clay ratio) as well as the processing.
10 citations
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TL;DR: A review of the academic and industrial aspects of the preparation, characterization, materials properties, crystallization behavior, melt rheology, and processing of polymer/layered silicate nanocomposites is given in this article.
Abstract: A review is given of the academic and industrial aspects of the preparation, characterization, materials properties, crystallization behavior, melt rheology, and processing of polymer/layered silicate nanocomposites. These materials are attracting considerable interest in polymer science research. Hectorite and montmorillonite are among the most commonly used smectite-type layered silicates for the preparation of nanocomposites. Smectites are a valuable mineral class for industrial applications because of their high cation exchange capacities, surface area, surface reactivity, adsorptive properties, and, in the case of hectorite, high viscosity and transparency in solution. In their pristine form they are hydrophilic in nature, and this property makes them very difficult to disperse into a polymer matrix. The most common way to remove this difficulty is to replace interlayer cations with quarternized ammonium or phosphonium cations, preferably with long alkyl chains. A wide range of polymer matrices is covered in this review, with special emphasis on biodegradable polymers. In general, polymer/layered silicate nanocomposites are of three different types, namely (1) intercalated nanocomposites , for which insertion of polymer chains into a layered silicate structure occurs in a crystallographically regular fashion, with a repeat distance of few nanometers, regardless of polymer to clay ratio, (2) flocculated nanocomposites , for which intercalated and stacked silicate layers flocculated to some extent due to the hydroxylated edge–edge interactions of the silicate layers, and (3) exfoliated nanocomposites , for which the individual silicate layers are separated in the polymer matrix by average distances that depend only on the clay loading. This new family of composite materials frequently exhibits remarkable improvements of material properties when compared with the matrix polymers alone or conventional micro- and macro-composite materials. Improvements can include a high storage modulus, both in solid and melt states, increased tensile and flexural properties, a decrease in gas permeability and flammability, increased heat distortion temperature, an increase in the biodegradability rate of biodegradable polymers, and so forth.
6,343 citations
TL;DR: In this paper, the structure, preparation and properties of polymer-layered silicate nanocomposites are discussed in general, and detailed examples are also drawn from the scientific literature.
Abstract: This review reports recent advances in the field of polymer–layered silicate nanocomposites. These materials have attracted both academic and industrial attention because they exhibit dramatic improvement in properties at very low filler contents. Herein, the structure, preparation and properties of polymer–layered silicate nanocomposites are discussed in general, and detailed examples are also drawn from the scientific literature.
2,277 citations
TL;DR: Solid catalysts provide numerous opportunities for recovering and recycling catalysts from reaction environments, which can lead to improved processing steps, better process economics, and environmentally friendly industrial manufacturing.
Abstract: Solid catalysts provide numerous opportunities for
recovering and recycling catalysts from reaction
environments. These features can lead to improved
processing steps, better process economics, and environmentally
friendly industrial manufacturing.
Thus, the motivating factors for creating recoverable
catalysts are large.
1,164 citations
TL;DR: The area of periodic mesoporous materials prepared by cooperative assembly in the presence of amphiphile molecules underwent dramatic growth as discussed by the authors, and many types may be regrouped in the future.
Abstract: The area of periodic mesoporous materials prepared by cooperative assembly in the presence of amphiphile molecules underwent dramatic growth. Among the silica-based materials, many types may be reg...
810 citations
TL;DR: In this paper, a mesoporous molecular sieve of MCM-41 type with polyethylenimine (PEI) was used for the preparation of CO2 adsorbents.
Abstract: Novel CO2 “molecular basket” adsorbents were prepared by synthesizing and modifying the mesoporous molecular sieve of MCM-41 type with polyethylenimine (PEI) The MCM-41-PEI adsorbents were characterized by X-ray powder diffraction (XRD), N2 adsorption/desorption, thermal gravimetric analysis (TGA) as well as the CO2 adsorption/desorption performance This paper reports on the effects of preparation conditions (PEI loadings, preparation methods, PEI loading procedures, types of solvents, solvent/MCM-41 ratios, addition of additive, and Si/Al ratios of MCM-41) on the CO2 adsorption/desorption performance of MCM-41-PEI With the increase in PEI loading, the surface area, pore size and pore volume of the PEI-loaded MCM-41 adsorbent decreased When the PEI loading was higher than 30 wt%, the mesoporous pores began to be filled with PEI and the mesoporous molecular sieve MCM-41 showed a synergetic effect on the adsorption of CO2 by PEI At PEI loading of 50 wt% in MCM-41-PEI, the highest CO2 adsorption capacity of 246 mg/g-PEI was obtained, which is 30 times higher than that of the MCM-41 and is about 23 times that of the pure PEI Impregnation was found to be a better method for the preparation of MCM-41-PEI adsorbents than mechanical mixing method The adsorbent prepared by a one-step impregnation method had a higher CO2 adsorption capacity than that of prepared by a two-step impregnation method The higher the Si/Al ratio of MCM-41 or the solvent/MCM-41 ratio, the higher the CO2 adsorption capacity Using polyethylene glycol as additive into the MCM-41-PEI adsorbent increased not only the CO2 adsorption capacity, but also the rates of CO2 adsorption/desorption A simple model was proposed to account for the synergetic effect of MCM-41 on the adsorption of CO2 by PEI
713 citations