Polystyrene Resin Beads Research Articles

Cationic Polystyrene Resin Bound Silver Nanocomposites Assisted Fourier Transform Infrared Spectroscopy for Enhanced Catalytic Reduction of 4-Nitrophenol in Aqueous Medium

The present work reported a novel strategy to construct supported cationic-polystyrene-resin-bound silver nanocomposites for enhanced catalytic reduction of 4-nitrophenol in an aqueous medium. The Fourier transform infrared spectroscopy (FTIR) was used as a model instrument for the study of catalytic reduction of 4-nitrophenol using cationic-polystyrene-resin-bound silver nanocomposite materials. The mechanism is based on the reduction of 4-nitrophenol to 4-aminophenol due to the electron transfer process that occurred between donor borohydride (BH4−) and acceptor 4-nitrophenol. The polystyrene resin provides support and surface area to increase the catalytic activity of silver nanoparticles. The diffused reflectance-Fourier transform infrared spectroscopy revealed the binding of silver particles onto the surface of cationic polystyrene resin beads. Furthermore, the catalyst was easily separated by the filtration and drying process and was able to reuse. A quantitative analysis of this work has also been performed. The linearity range, the limit of detection, and the limit of quantification obtained for the present method were 0.1 × 10−4 to 1.0 M, 0.6 M, and 2.1 M, respectively. Moreover, a good catalytic efficiency was found to be 96.8%. The advantages of the current method are its simplicity, sensitivity, rapidity, low cost, ease of preparation, and excellent catalytic efficiency to reduce 4-nitrophenol from an aqueous solution.

Immobilization and Characterization of Pectinase onto the Cationic Polystyrene Resin.

In the present study, the immobilization of free pectinase onto polystyrene resin beads via crosslinking with glutaraldehyde was investigated. The immobilized pectinase was characterized by Fourier transform infrared spectroscopy and confocal laser scanning microscopy. After optimizing the immobilization conditions, the optimum pH of immobilized pectinase shifted from 8.0 to 8.5 and the optimum temperature shifted from 45 to 60 °C, showing its improved stability to temperature and pH compared with the free pectinase. The Michaelis–Menten constant Km value of free and immobilized pectinase was determined to be 1.95 and 5.36 mM, respectively. The storage stability of immobilized pectinase was demonstrated with 36.8% of the initial activity preserved after 30 days at 25 °C. The reusability of the immobilized pectinase activity was 54.6% of its initial activity after being recycled six times. Therefore, based on the findings mentioned above, it can be inferred that this simple immobilization technique for pectinase appears to be promising for industrial applications.

Application of Lost-foam casting Technology in Grate of Hot blast stove and Solution of Defects

Lost-foam casting Technology has been applied in Manufacturing the grate of hot blast stove. According to the requirements of structure and tolerance dimension, the lost-foam unit of grate is prepared with expandable polystyrene resin beads. RTCr2 is used as the material of grate, which is poured at 1360-1380°C by Top post system. And the negative pressure range is 0.04-0.05MPa. The results show that the surface of the casting is relatively complete, and the internal structure of the casting is dense. Through inspection, the quality performance, structure dimension and manufacturing precision of casting products can meet the requirements well. But there are also some disadvantages, such as inner hole sticking sand, surface sand hole, shrinkage cavity, air hole, sand inclusion, slag inclusion, mechanical processing edge breaking. Then some corresponding effective repair methods are used to solve the defects, which guarantee the quality of the products. Some lost-foam casting data and control measures have been accumulated, which are beneficial to continuously improve the lost-foam casting process and master the key casting technologies such as lost-foam casting and hot metal casting.

Preparation of dicyandiamide modified polystyrene resin beads decorated with nano‐Fe3O4 for removing Hg(II) from aqueous solution

In this study, dicyandiamide (DCDA) modified polystyrene (PS) resin beads decorated with nano‐Fe3O4 (Fe3O4‐PS‐DCDA hybrids) were prepared by co‐precipitation method. The Fe3O4‐PS‐DCDA hybrids were characterized by scanning electron microscopy (SEM), Fourier transform‐infrared (FT‐IR) spectroscopy, X‐ray diffraction (XRD) spectroscopy, X‐ray photoelectron spectroscopy (XPS), nitrogen adsorption/desorption isotherms, and vibrating sample magnetometer (VSM). Meanwhile, the adsorption property of Fe3O4‐PS‐DCDA hybrids for Hg(II) in aqueous solution was investigated by batch methods. The results show that the nano‐Fe3O4 decorated on the outer surface and interior of DCDA modified PS resin beads (PS‐DCDA) is nanoparticles and nanorods, respectively. The saturation magnetization (Ms) of the Fe3O4‐PS‐DCDA hybrids is 0.70 emu/g, which is enough to ensure the convenient magnetic separation. The adsorption kinetics of the hybrids for Hg(II) accorded with the pseudo‐second‐order model and the adsorption isotherms followed the Freundlich equation. POLYM. COMPOS., 39:2232–2240, 2018. © 2016 Society of Plastics Engineers

Styrene production from a biomass-derived carbon source using a coculture system of phenylalanine ammonia lyase and phenylacrylic acid decarboxylase-expressing Streptomyces lividans transformants

To produce styrene from a biomass-derived carbon source, Streptomyces lividans was adopted as a host strain. The gene encoding ferulic acid decarboxylase from Saccharomyces cerevisiae (FDC1) was introduced into S.lividans, and the resulting S.lividans transformant successfully expressed FDC1 and converted trans-cinnamic acid (CA) to styrene. A key factor in styrene production using microbes is the recovery of volatile styrene. In the present study, we selected polystyrene resin beads XRD-4 as the absorbent agent to recover styrene produced using S.lividans transformants, which enabled recovery of styrene from the culture broth. For styrene production from biomass-derived carbon sources, S.lividans/FDC1 was cultured together with S.lividans/p-encP, which we previously reported as a CA-producing S.lividans strain. This coculture system combined with the recovery of styrene using XAD-4 allowed the production of styrene from glucose, cellobiose, or xylo-oligosaccharide, respectively.

Rapid Synthesis of a Functional Resin‐Supported Scorpionate and Its Copper(I, II), Rhodium(I), and Chromium(III) Complexes

Boron‐scorpionates are readily prepared by microwave (MW) assisted methods. Such a method is described here, leading to the rapid preparation of a heterogeneous resin‐supported scorpionate as its sodium salt, BdPhTpNa [BdPhTp = phenyltris(1‐pyrazolyl)borate covalently bound through the phenyl ring to commercial cross‐linked polystyrene resin beads]. Formation of a functional heterogeneous scorpionate was confirmed from the subsequent reactions of several metal complexes. This supported ligand system coordinates a variety of transition metal ions including copper(I and II), chromium(III) and rhodium(I). Chromium(III) provided definitive electronic spectral evidence for supported–TpCrIII coordination spheres, including reversible ligand‐substitution reactions. The copper(I) case exhibited typical scorpionate CuI reactivity including spectroscopically characterized (IR and 31P NMR) complexes with CO, PPh3, and HCCH. Copper(II) provided EPR evidence for heterogeneous scorpionates. The supported rhodium(I) complex was demonstrated to be a recyclable heterogeneous rhodium–scorpionate catalyst. These results all support the conclusion that the immobilized chelate forms coordinatively unsaturated half‐sandwich metal complexes (LMn+) capable of efficient ligand‐substitution reactions or catalytic activity.

Production of novel "functional oil" rich in diglycerides and phytosterol esters with "one-pot" enzymatic transesterification.

Diglycerides and phytosterol esters are two important functional lipids. Phytosterol esters mixed with dietary diglyceride could not only influence body weight but also prevent or reverse insulin resistance and hyperlipidemia. In this study, a kind of novel "functional oil" rich in both diglycerides and phytosterol esters was prepared with "one-pot" enzymatic transesterification. First, lipase AYS (Candida rugosa) was immobilized on the porous cross-linked polystyrene resin beads (NKA) via hydrophobic interaction. The resulting immobilized AYS showed much better transesterification activity and thermal stability to freeways. On the basis of the excellent biocatalyst prepared, a method for high-efficiency enzymatic esterification of phytosterols with different triglycerides to produce corresponding functional oils rich in both diglycerides and phytosterol esters was developed. Four functional oils rich in both diglycerides and phytosterol esters with conversions >92.1% and controllable fatty acid composition were obtained under the optimized conditions: 80 mmol/L phytosterols, 160 mmol/L triglycerides, and 25 mg/mL AYS@NKA at 180 rpm and 50 °C for 12 h in hexane. The prepared functional oil possessed low acid value (≤1.0 mgKOH/g), peroxide value (≤2.1 mmol/kg), and conjugated diene value (≤1.96 mmol/kg) and high diglyceride and phytosterol ester contents (≥10.4 and ≥20.2%, respectively). All of the characteristics favored the wide application of the functional oil in different fields of functional food.

Solid-Phase Synthesis of 2-Aminoethyl Glucosamine Sulfoforms

Mono- and disaccharides of sulfonated glucosamines (GlcN sulfoforms) conjugated to 2-aminoethyl linkers were generated by solid-phase synthesis. Orthogonally protected intermediates were tethered onto tritylated polystyrene resin beads, subjected to a modular sequence of deprotection and sulfonation steps, then cleaved from solid support without degradation of N- or O-sulfate esters using solvolytic conditions, and finally purified by reverse-phase HPLC to afford the title compounds.

Synthesis of the positron-emitting radiotracer [18F]-2-fluoro-2-deoxy-d-glucose from resin-bound perfluoroalkylsulfonates

A new approach to the synthesis of 2-fluoro-2-deoxy-d-glucose (FDG, [(19/18)F]-) is described, which employs supported perfluoroalkylsulfonate precursors , where the support consists of insoluble polystyrene resin beads. Treatment of these resins with [(19)F]fluoride ion afforded protected FDG [(19)F]- as the major product, and the identities of the main byproducts were determined. Acidic removal of the acetal protecting groups from [(19)F]- was shown to produce [(19)F]FDG. The method has been applied to the efficient radiosynthesis of the imaging agent [(18)F]FDG, and was shown to produce the radiochemical tracer in good radiochemical yield (average 73%, decay corrected).

α‐PW12O40]3− Immobilized on Ionic Liquid–Modified Polymer as a Heterogeneous Catalyst for Alcohol Oxidation with Hydrogen Peroxide

Ionic liquid–modified polystyrene resin beads were demonstrated to be an appropriate support for polyoxometalate. In this heterogeneous catalytic system, alcohols can be efficiently oxidized to corresponding carbonyl groups with H2O2 in CH3CN. The catalyst can be easily recovered by filtration and recycled without apparent loss of catalytic performance.

Lytic Antimicrobial Activity of Hen Egg White Lysozyme Immobilized to Polystyrene Beads

Lysozyme [EC 3.2.1.17] was covalently attached to polystyrene resin beads by the sole histidine residue (His-15) through peptide spacers of various lengths. The spacers were amino acid chains composed of 6-aminocaproic acid synthesized with the solid phase peptide synthesis method. Immobilized lysozyme with a spacer length of three 6-aminocaproic acid units (2736 U/g resin with a protein load of 2.21 mg/g resin) displayed the greatest degree of hydrolytic activity against lyophilized Micrococcus lysodeikticus cell wall preparations. Enzymatic activity of immobilized lysozyme was 14.2% of that of the free enzyme. Preparations with longer spacers yielded higher total activity yet the retained activity was constant at about 14% level. A control that consisted of randomly coupled lysozyme to polystyrene beads without an amino acid spacer gave an enzyme activity of 158 U/g with a protein load of 1.24 mg/g resin which equated to 1.4% retained activity. Properties of the immobilized lysozyme system were studied, including stability and activity against soluble compared with insoluble substrates. A kinetics study of the immobilized lysozyme using Eadie-Hofstee plot parameters suggested significant external diffusion effects indicative of deviation from classic Michaelis-Menten kinetic behavior.

Air and Water Free Solid-Phase Synthesis of Thiol Stabilized Au Nanoparticles with Anchored, Recyclable Dendrimer Templates

Solid-phase synthetic templates for Au nanoparticles were developed using Merrifield resins and polyamidoamine (PAMAM) dendrimers. This synthetic scheme affords the opportunity to prepare metal nanoparticles in the absence of air and water, and it does not necessitate phase transfer agents that can be difficult to remove in subsequent steps. Amine-terminated generation 5 PAMAM (G5NH2) dendrimers were grafted to anhydride functionalized polystyrene resin beads and alkylated with 1,2-epoxydodecane to produce G5C12anch. The anchored dendrimers bound both CoII and AuIII salts from toluene solutions at ratios comparable to those of solution phase alkyl-terminated PAMAM dendrimers. The encapsulated AuIII salts could be reduced with NaBH4 to produce anchored dendrimer encapsulated nanoparticles (DENs). Treatment of the anchored DENs with decanethiol in toluene extracted the Au nanoparticles from the dendrimers as monolayer protected clusters (MPCs). After a brief NaCN etch, the anchored dendrimers were readily recycled and a subsequent synthesis of decanethiol Au MPCs was performed with comparable MPC yield and particle size distribution.

Vibrational spectroscopic encoding of polystyrene-based resin beads: Converting the encoding peaks into barcodes

A detailed approach is described for the vibrational spectroscopic encoding of polystyrene-based resin beads by converting the infrared absorption peaks suitable for encoding (encoding peaks) into barcodes. Based on combining the FT-IR measurements and the quantum-chemical computations, the vibrational characteristics of p-tert-butylstyrene monomer, polystyrene and poly( p- tert-butylstyrene) resin beads are analyzed, which are helpful for the selection of encoding peaks. The vibrational spectroscopic encoding of polystyrene-based resin beads could be obtained by converting the wavenumber, intensity and full width at half maximum (FWHM) of the encoding peaks into barcodes automatically through a computer program designed in our laboratory.

Microscopic Infrared Mapping of Chloromethylated Polystyrene Resin Beads

In solid-phase combinatorial chemistry, analyses are performed using a wide range of analytical techniques ranging from gel-phase nuclear magnetic resonance (NMR) to colorimetric tests to elemental analysis. However, these techniques cannot be used to interrogate functional group distribution at the single-bead level. This paper explores the feasibility of using Fourier transform infrared (FT-IR) microscopy to examine site distribution on chloromethylated polystyrene resin beads and to quantify the loading after coupling with 4-cyanophenol, an IR tagging agent. FT-IR microscopy also provides a unique opportunity to better understand the reactivity of highly cross-linked polymer beads under a range of chemical conditions.

Covalent adhesion; organic reactivity at a solid–solid interface through an inter-bead Diels–Alder reaction†

Polystyrene resin beads carrying respectively maleimide and anthracene groups attached to extended side-chains adhere to one another in a manner consistent with an inter-bead cycloaddition reaction.

Effect of inert particle concentration on mass transfer between particles and liquid in solid-liquid two-phase upflow through vertical tubes and in stirred tanks.

Mass transfer coefficients between particles and liquid in the region of high particle concentration were obtained by the use of both active and inert particles suspended in solid-liquid two-phase upflow through vertical tubes and in stirred tanks. When adding inert particles of low density such as polystyrene and anion-exchange resin beads, mass transfer coefficients decreased with increasing particle concentration, remarkably above concentrations from 20 to 30%. Meanwhile, the coefficients increased in two-phase tube flow and decreased in stirred tanks when using glass beads. The experimental results were correlated with parameters including (1) the kinematic viscosity of slurry and (2) the effective energy dissipation rate, based on the concept that only a part of the energy supplied contributes to the mass transfer. The first method was successfully applied only to the system containing low-density particles, and the second to systems having either high- or low-density particles. The effectiveness of energy dissipation on mass transfer at high particle concentration is discussed in some detail.