Use of nanomaterials in the pretreatment of water samples for environmental analysis

The challenge of providing clean drinking water is of enormous relevance in today’s human civilization, being essential for human consumption, but also for agriculture, livestock and several industrial applications. In addition to remediation strategies, the accurate monitoring of pollutants in water sup-plies, which most of the times are present at low concentrations, is a critical challenge. The usual low concentration of target analytes, the presence of in-terferents and the incompatibility of the sample matrix with instrumental techniques and detectors are the main reasons that renders sample preparation a relevant part of environmental monitoring strategies. The discovery and ap-plication of new nanomaterials allowed improvements on the pretreatment of water samples, with benefits in terms of speed, reliability and sensitivity in analysis. In this chapter, the use of nanomaterials in solid-phase extraction (SPE) protocols for water samples pretreatment for environmental monitoring is addressed. The most used nanomaterials, including metallic nanoparticles, metal organic frameworks, molecularly imprinted polymers, carbon-based nanomaterials, silica-based nanoparticles and nanocomposites are described, and their applications and advantages overviewed. Main gaps are identified and new directions on the field are suggested.publishe

Synthesis and characterization of oligosalicylaldehyde-based epoxy resins

WOS: 000237134100012The synthesis of a new epoxy resin of oligosalicylaldehyde by the reaction with epichlorohydrin is reported. New resin's epoxy value and chlorine content were determined and found to be 25 % and 1 %, respectively. The characterization of the new resin was instrumented by FTIR, H-1 NMR, scanning electron microscopy, and thermal gravimetric analyses. TGA results showed that the cured epoxy resin has a good resistance to thermal decomposition. The mass losses of cured epoxy resin were found to be 5 %, 10 %, 50 % at 175 degrees C, 240 degrees C and 400 degrees C, respectively. On the curing procedure the resin was cured with polyethylenepolyamine at 25 degrees C for 8 h and 100 degrees C for 1.5 h. The FTIR spectrum of new epoxy resin gave the peak of oxirane ring a (nu) over bar = 918 cm(-1)

Environmentally friendly enzyme-catalyzed polymerization of a novel phenoxy-ketimine

The monomer with ketimine side group, 2-(l-(benzylimino)ethyl)phenol (2-BEP), was synthesized from the condensation of 2-hydroxyacetophenone and benzyl amine. The enzymatic oxidative polymerization of 2-BEP was performed in the presence of hydrogen peroxide using horseradish peroxidase (HRP) as catalyst. The oxidation reaction was carried out in various solvents and phosphate buffers at room temperature. These studies have shown that a dark brown polymer was successfully synthesized by utilizing aqueous methanol as the cosolvent at pH 7.0. Poly(2-BEP) shows good solubility in DMF and DMSO, but it is insoluble in THF, methanol, water, acetone and chloroform. Characterization of poly(2-BEP) was carried out via UV-vis, FT-IR,1H-NMR,13C-NMR and GPC techniques. The number-average molecular weight (Mn), weight-average molecular weight (Mw) and polydispersity index (PDI) of the polymer were determined to be 1157.4 g mol-1, 2039.6 g mol-1 and 1.76, respectively. FT-IR and1H-NMR studies confirmed the presence of phenylene and oxyphenylene units within the polymer backbone. The optical band gaps (Eg) of 2-BEP and poly (2-BEP) were calculated as4.10 eV and 3.86 eV, respectively. © 2017, Gh. Asachi Technical University of Iasi. All rights reserved

Synthesis and characterization of poly{2-[3-(1H-pyrrol-2-yl)phenyl]-1H- pyrrole} and its copolymer with EDOT1

A pyrrole-functionalized monomer 2-[3-(1H-pyrrol-2-yl)phenyl]-1H-pyrrole (PyPhPy) was synthesized. The structure of monomer was investigated by Nuclear Magnetic Resonance ( 1H NMR) and Fourier Transform Infrared (FTIR) spectroscopy. The chemical polymerization of PyPhPy (CPyPhPy) was realized using FeCl3 as the oxidant. The electrochemical oxidative polymerization of polymer P(PyPhPy) and its copolymer with 3,4-ethylenedioxythiophene poly(2-[3-(1H- pyrrol-2-yl)phenyl]-1H-pyrrole-co-3,4- ethylenedioxythiophene) [P(PyPhPy-co-EDOT)] were achieved via potentiodynamic method by using NaClO 4/ LiClO 4 as the supporting electrolyte in CH 3CN. Characterizations of the resulting polymers were performed by cyclic voltammetry (CV), FTIR, scanning electron microscopy (SEM), UV-Visible spectrophotometry (UV- Vis) and thermogravimetry analyses (TGA). Electrical conductivity of CPyPhPy, P(PyPhPy), and P(PyPhPyco- EDOT) were measured by four-probe technique. © Pleiades Publishing, Ltd., 2011

Immobilization of invertase and glucose oxidase in conducting copolymers of thiophene functionalized poly(vinyl alcohol) with pyrrole

WOS: 000236451300007In this study, immobilizations of invertase and glucose oxidase were achieved in conducting thiophene functionalized copolymers of vinyl alcohol with thiophene side groups and pyrrole (PVATh/PPy) via electrochemical polymerization. The kinetic parameters, V-max (maximum reaction rate) and K-m (substrate affinity), of both free and immobilized enzymes were determined. The effect of supporting electrolytes, p-toluene sulfonic acid and sodium dodecyl sulfate, on the enzyme activity and film morphologies was examined. The optimum temperature, operational and storage stabilities of immobilized enzymes were determined. PVATh/PPy copolymer was found to exhibit significantly enhanced properties compared to pristine polypyrrole. (c) 2005 Elsevier B.V. All rights reserved

Electrochromic properties of poly (1-(phenyl)-2,5-di(2-thienyl)-1H-pyrrole-co-3,4-ethylenedioxy thiophene) and its application in electrochromic devices

Electrochemical copolymerization of 1-(phenyl)-2,5-di(2-thienyl)-1H-pyrrole (PTP) with 3,4-ethylenedioxy thiophene (EDOT) was carried out in acetonitrile (AN)/NaClO4/LiClO4 (0.1 M) solvent-electrolyte couple via potentiodynamic electrolysis. Characterizations of the resulting copolymer were performed via cyclic voltammetry (CV), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and spectroelectrochemical analysis. Spectroelectrochemical analyses show that the copolymer of PTP with EDOT has an electronic band gap (due to ? to ?* transition) of 1.9 eV at 480 nm, with a claret red in the fully reduced form and a blue color in the fully oxidized form. Via kinetic studies, the optical contrast (?T %) was found to be 8% for P(PTP-co-EDOT). Results showed that the time required to reach 95% of the ultimate transmittance was 1.7 s for the copolymer. The P(PTP-co-EDOT) film was used to construct a dual type polymer electrochromic device (ECDs) with poly(3,4-ethylenedioxy thiophene) (PEDOT). Spectroelectrochemistry, electrochromic switching and open circuit memory of the device were investigated. © 2007 Elsevier B.V. All rights reserved

Synthesis and characterization of conducting copolymers of poly(vinyl alcohol) with thiophene side-groups and pyrrole

WOS: 000225347700033Graft copolymers of poly(vinyl alcohol) with thiophene side-groups and pyrrole were synthesized by electrochemical polymerization methods. Poly(vinyl alcohol) with thiophene side-groups (PVATh) was obtained from the reaction between poly(vinyl alcohol) (PVA) and thiophene-3-acetic acid. The syntheses of copolymers Of PVATh and pyrrole were achieved electrochemically by using three different supporting electrolytes, p-toluene sulfonic acid (PTSA), sodium dodecyl sulfate (SDS) and tetrabutylammonium tetrafluoroborate (TBAFB). Characterization of PVATh and graft copolymers was performed by a combination of techniques including cyclic voltammetry, scanning electron microscopy, thermal gravimetry, differential scanning calorimetry, size-exclusion chromatography, H-1 NMR and FT-IR. The conductivities were measured by the four-probe technique. (C) 2004 Society of Chemical Industry

Synthesis and characterization of water-soluble oligosalicylaldehyde- sulfanilic acid and its Cu(II), Co(II), Pb(II) complexes

This work presents the synthesis and characterization of a new water-soluble oligophenol derivative, 4-(2-hydroxybenzylideneamino) benzenesulfanilic acid (OSAL-SA) and its metal complexes. The chemical structure of the water-soluble polymer was characterized by nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FTIR) spectroscopies and thermogravimetric analyses (TGAs). Pb(II), Cu(II), Co(II) complexes of the polymer were also synthesized in methanol. Characteriza tions of water insoluble polymer-metal complexes were performed by FTIR, flame atomic absorption spectroscopy, and TGA. The conductivity measurements of OSAL-SA and polymer-metal complexes were carried out by the four-probe technique. © 2008 Wiley Periodicals, Inc

A soluble conducting polymer: 1-phenyl-2,5-di(2-thienyl)-1H-pyrrole and its electrochromic application

WOS: 000240026500023A thiophene-functionalized monomer 1-phenyl-2,5-di(2-thienyl)-1H-pyrrole (PTP) was synthesized. The chemical polymerization of PTP (CPTP) was realized by using FeCl3 as the oxidant. The structures of both the monomer and the soluble polymer (CPTP) were investigated by Nuclear Magnetic Resonance (H-1 and C-13 NMR) and Fourier Transform Infrared (FTIR). The average molecular weight of the chemically synthesized polymer was determined by gel permeation chromatography (GPC) as Mn = 7.2 x 10(3). The electrochemical oxidative polymerization of PTP was carried out via constant-potential electrolysis. Characterizations of the resulting polymer were done by cyclic voltammetry (CV), FTIR, Scanning Electron Microscopy (SEM) and UV-vis Spectroscopy. The conductivity of sample was measured by four-probe technique. Moreover, the spectroelectrochemical and electrochromic properties of the polymer film were investigated. Spectroelectrochemical analysis of P(PTP) revealed electronic transitions at 413, 577 and 884 mn corresponding to pi-pi* transition, polaron, and bipolaron band formations, respectively. Kinetic studies evaluated the switching ability of the P(PTP); the percent transmittance T% was found as 27%. The homopolymer of PTP was used to construct dual-type polymer electrochromic devices (ECDs) against poly(3,4-ethylenedioxythiophene) (PEDOT). Spectroelectrochemistry, electrochromic switching and open circuit stability of the devices were investigated. (c) 2006 Elsevier Ltd. All rights reserved

Raman spectroscopy: A novel experimental approach to evaluating cisplatin induced tissue damage

The aim of this work is to clarify the effect of curcumin and beta-carotene on cisplatin-induced tissue damage and to demonstrate the potential of Raman spectroscopy to detect tissue changes consistent with liver and kidney histopathology as a potential diagnostic adjunct. In the study, 56 Wistar albino female rats were used and randomly divided into 7 groups (n:8). Sham group received only sesame oil; Cisplatin group, received a single dose injection of cisplatin; Beta-carotene group, treated with beta-carotene orally; Cisplatin + Beta-carotene group, pretreated with beta-carotene 30 min prior to the cisplatin injection, then received cisplatin; Curcumin group, orally treated with curcumin; Cisplatin + Curcumin group, pretreated with curcumin 30min prior to the cisplatin injection, then received cisplatin. The second application was performed 1 week after the first application. One of the liver and kidney tissues was taken to 10% form for histopathological examinations and the others were taken to -80 degrees C for raman spectroscopy. Received sections were hematoxylin-eosin stained. The avidin-biotin peroxidase method was used for to investigate anti-TNF-alpha and IL1-beta activities. TUNEL method was applied to determine apoptotic cells