Spectroscopic investigation of PVA-TIO2 membranes gamma irradiated

Todicǎ, M.; Udrescu, Luciana; Damian, Grigore; Aştilean, Simion

doi:10.1016/j.molstruc.2012.12.006

Cited by 6 publications

(7 citation statements)

References 14 publications

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“…This signal is determined by the unpaired electron on the substrate 2p of the oxygen of the OH − ion resulting from the breaking of -C-O-H bonds, or the unpaired electrons of the free radicals produced by the mechanism presented above. Previous work reported by the authors showed the increase of the amplitude of this signal with the dose of radiation [27]. Similar ESR investigations were made on samples with TiO 2 .…”

Section: Resultssupporting

confidence: 85%

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ESR and XRD investigation of effects induced by gamma radiation on PVA-TiO2 membranes

et al. 2013

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Abstract:The effects of gamma radiation on the local structure of PVA membranes containing TiO 2 were investigated by ESR and XRD methods. An intense ESR signal is observed after irradiation at 16 KGy dose. This signal appears only for irradiated samples and it is associated with the breaking of the polymeric chain, followed by local reorganization of the polymeric segments and the apparition of the unpaired electrons and free radicals. The intensity of the signal decreases with the concentration of TiO 2 , indicating a shielding effect of the dopand. That the modification of local order of the polymeric chains has been modified after irradiation is confirmed by XRD method. PACS

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Section: Resultssupporting

confidence: 85%

“…We observed a reduction of the amplitude of the ESR signal after this period of time. For pure PVA this behavior has been reported previously, [27]. Similar behavior is observed for the samples with TiO 2 , but the effect is less pronounced especially at high concentration of TiO 2 .…”

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confidence: 88%

ESR and XRD investigation of effects induced by gamma radiation on PVA-TiO2 membranes

et al. 2013

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“…In the last decade, PNC materials based on poly(vinyl alcohol) (PVA) and titanium dioxide (i.e., titania or TiO 2 ) have made considerable academic and technological progress because of their wide range of applications in various fields . PVA is a hydrophilic, nontoxic, and biocompatible polymer, and it is completely soluble in hot water.…”

Section: Introductionmentioning

confidence: 99%

“…It is one of the most practical inorganic nanomaterials and offers high‐performance catalysis, photocatalysis, and electrocatalysis applications. Therefore, it is frequently used in the performance development of polymeric membranes . Chemical bonding between PVA and TiO 2 nanoparticles is considered to be the most efficient process in the alteration of useful properties in their nanocomposites.…”

Section: Introductionmentioning

confidence: 99%

Anomalous behavior of the dielectric and electrical properties of polymeric nanodielectric poly(vinyl alcohol)–titanium dioxide films

Choudhary

Sengwa

2016

J of Applied Polymer Sci

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The complex dielectric permittivity, alternating-current electrical conductivity, electric modulus, and impedance spectra of polymeric nanocomposite (PNC) films consisting of a poly(vinyl alcohol) (PVA) matrix dispersed with nanosize particles of titanium dioxide (TiO 2 ); (i.e., PVA-x wt % TiO 2 , where x is 0, 1, 3, or 5) were investigated in the frequency range 20 Hz to 1 MHz at ambient temperature. A detailed analysis of the results showed that the values of the dielectric and electrical parameters of these PNC-based nanodielectric films varied anomalously with increasing TiO 2 concentration. The temperature-dependent dielectric characterization of the PVA-3 wt % TiO 2 film revealed that the dielectric polarization at a fixed frequency increased nonlinearly with increasing temperature. The temperature-dependent electric modulus relaxation time values of the nanodielectric film obeyed Arrhenius behavior. The X-ray diffraction study confirmed that the crystalline phase of the PVA matrix decreased with increasing TiO 2 concentration; this suggested that the interaction of the TiO 2 nanoparticles caused some destruction of the hydroxyl group dipolar ordering in the hydrogen-bonded crystalline structure of the pristine PVA matrix. The intensities of the diffraction peaks of the TiO 2 nanofiller were enhanced as its concentration increased in these nanodielectrics; this confirmed the existence of TiO 2 nanoparticles inside the crystalline phases of the PVA matrix. The surface morphology of the films was examined by the study of their scanning electron micrographs. The feasibility of using these flexible polymeric nanodielectric films as electrical insulators and dielectric substrates in lowpower microelectronic devices operated at audio-and radio-frequency electric fields was explored. V C 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44568.

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“…Adding TiO 2 nanoparticles improves the hydrophilic proper-ties of the composite nanofluid and increases the hydrogen bonding among TiO 2 nanoparticles, PVA, and water. Hydrogen bond formation brings rigidity to the polymeric lattice and reduces the mobility of the chain that influences the rheological characteristics of the composite nanofluid [33][34][35][36][37][38]. Figure 5 presents the average of the main and two-way interactive effects on Herschel-Bulkley flow index, indicating that the flow index increases with the rise in temperature ( Fig.…”

Section: The Analysis Of Variance For the Herschel-bulkley Flow Indexmentioning

confidence: 99%

Effect of TiO₂ nanoparticle on rheological behavior of poly(vinyl alcohol) solution

Shakouri

Ahmari

Hojjat

et al. 2015

J Vinyl Addit Technol

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In recent years, addition of nanoparticles to fluids and polymers has been used as a way of modifying rheological properties. Poly(vinyl alcohol) (PVA) and titanium dioxide (TiO2) nanoparticles aqueous composite nanofluids were prepared through the use of ultrasonic vibration. In fact, ultrasonic vibration is an advantageous method for nanoparticle dispersion. The preparation method prevents reduction of the polymer's molecular weight. TiO2 nanoparticles with different concentrations were employed to investigate the rheological characteristics of composite nanofluids. Rheological characteristics of base fluids and composite nanofluids were measured at different temperatures. Based on the results, all composite nanofluids, as well as base fluids, exhibited non‐Newtonian behavior and rheological characteristics of composite nanofluids, following the Herschel‐Bulkley model. In addition, model parameters are functions of temperature, PVA, and TiO2 nanoparticle concentrations. Also, two‐way interactions among temperature, PVA, and TiO2 nanoparticle concentrations affect flow index and consistency index of the Herschel‐Bulkley model. J. VINYL ADDIT. TECHNOL., 23:234–240, 2017. © 2015 Society of Plastics Engineers

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Spectroscopic investigation of PVA-TIO2 membranes gamma irradiated

Cited by 6 publications

References 14 publications

ESR and XRD investigation of effects induced by gamma radiation on PVA-TiO2 membranes

ESR and XRD investigation of effects induced by gamma radiation on PVA-TiO2 membranes

Anomalous behavior of the dielectric and electrical properties of polymeric nanodielectric poly(vinyl alcohol)–titanium dioxide films

Effect of TiO₂ nanoparticle on rheological behavior of poly(vinyl alcohol) solution

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Spectroscopic investigation of PVA-TIO2 membranes gamma irradiated

Cited by 6 publications

References 14 publications

ESR and XRD investigation of effects induced by gamma radiation on PVA-TiO2 membranes

ESR and XRD investigation of effects induced by gamma radiation on PVA-TiO2 membranes

Anomalous behavior of the dielectric and electrical properties of polymeric nanodielectric poly(vinyl alcohol)–titanium dioxide films

Effect of TiO2 nanoparticle on rheological behavior of poly(vinyl alcohol) solution

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Effect of TiO₂ nanoparticle on rheological behavior of poly(vinyl alcohol) solution