Investigation in to Properties of Polyurethane Closed Cell by High Loading of SiO 2 Nanoparticles

Abstract In this research the composition of polyurethane closed cell (PUCC

Determination of Nonlinear Optical Properties of MgO Nanoparticles Doped in Poly (Ether) Urethane

The third-order optical nonlinearities of poly (ether) urethane open cell (PEUOC)/MgO nanocomposites, dissolved in dimethylformamide are characterized by Z-scan technique with CW Nd:YAG laser at its second harmonic frequency of 532 nm with TEM00 Gaussian profile. The synthesized samples are also characterized by optical microscopy and scanning electron microscopy imaging. The nonlinear refractive indices and nonlinear absorption coefficients of the synthesized samples are obtained in the order of $10^{-8} cm^{2}//W$ with negative sign and $10^{-5} cm//W$, respectively. The origin of optical nonlinearity in this case may be attributed due to the presence of strong saturable absorption effect. All the results suggest that the nonlinear coefficients of the synthesized samples can be controlled by nanoparticles content into PEUOC. Furthermore, the results show that PEUOC/MgO may be promising candidate for the application to optical limiting in the visible region

Optical and Physical Properties of SiO2 Nanoparticles and Tetra Ortho Silicate

In this article optical and physical property of the composition of polyurethane open cell (PUOC) with two different concentrations of SiO2 nanoparticles (1 and 2wt. %) will be reported. Tetra ortho silicate (TEOS) as an organic agent with different concentrations trations (0.05, 0.1, 0.15 and 0.2 Vol./Vol.) was added to polyurethane composition. Optical microscopy imaging, watering uptake, FTIR and Raman spectroscopy of the synthesized samples were measured. The cell size of samples by adding SiO2 NPs and TEOS was decreased. The PUOC/1wt. % SiO2 was recognized as a best specimen for absorbing water. By focusing on the recorded Raman spectra, it is revealed that PUOC/1wt. % SiO2 and PUOC/200µl TEOS have more covalent bonds than others. The degree of phase separation, DPS, and the hydrogen bonding index, R, in samples were evaluated in terms of their FTIR spectroscopy data. Two samples, PUOC/1wt. % SiO2 and PUOC/800µl TEOS, have the highest R and DPS factors among the synthesized samples. By adding SiO2 NPs and TEOS into to PUOC, the apparent density of foams was increased. This is similar to the behavior of real density in SiO2 NPs into PUOC but by adding TEOS into PUOC, the real density of samples were decreased. The total porosity, open porosity and closed porosity of the synthesized samples were calculated. By adding SiO2 NPs and TEOS into PUOC, the open porosity of samples was increased

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this work are E7 doped with small compositional percentage o

The influence of γ-irradiation on molecular structure and mass attenuation coefficients of γ-Al2O3 nanoparticles

In this research, γ-Al2O3 nanoparticles (NPs) were synthesized by using the sol–gel process. The photon attenuation properties of these NPs were obtained by measuring the linear and mass attenuation coefficients (μl, μm) at different photon energies. In addition, the theoretical values of μm for γ-Al2O3 micro-particles were calculated using the WinXCom computer program and compared with the experimental values of μm for NPs of γ-Al2O3. Furthermore, in order to evaluate the impact of γ-irradiation on these NPs, the experimental values of μl and μm for γ-Al2O3 NPs, before and after receiving 20 kGy dose of γ-irradiation, were investigated. It was observed that μm of γ-Al2O3 NPs decreases after receiving γ-irradiation because of increasing the photon’s energy, which indicates the changes in the molecular structure of NPs after γ-irradiation. Moreover, the structural properties of NPs were evaluated by UV–Vis spectroscopy, x-ray diffraction patterns, and scanning electron microscopy images. UV–Vis spectroscopy showed an absorption peak at 212.5 nm before γ-irradiation, and the absorption peak of NPs disappeared when γ-irradiation was started. The average crystalline size was determined to be 3.65 nm in the sample before γ-irradiation and 9.29 nm in the sample with the maximum dose of 20 kGy. The results of scanning electron microscopy show an increase in particle size from 6.5 nm in a non-irradiated sample up to 9 nm in a sample with the highest γ-irradiation dose

Structural, optical and dielectric studies of Ag nanoparticles decorated by herceptin

Silver nanoparticles (AgNPs) were synthesized (with 17�31 nm sizes) by reduction of AgNO3 by NaBH4 solution and covered by anti-HER2 monoclonal antibody (Herceptin). The morphology, structure, optical and dielectric properties of the prepared AgNPs have been characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), UV�Vis system and Fourier transform infrared (FTIR) spectroscopy. The complex index of refraction and the dielectric coefficient Herceptin and AgNPs covered by Herceptin were measured over the spectral region of 400�4000 cm�1. The XRD patterns showed the formation of face-centered cubic lattice structure of AgNPs and according to the TEM image AgNPs had spherical shape with an average diameter size of about 25 nm. By using Kramers�Kronig (KK) dispersion relations analysis, these measurements allow the determination of the real and imaginary parts of refractive index and dielectric coefficient over the entire wavelength intervals. By covering AgNPs with antibody, the intensity of n and k peaks were decreased. After decoration with AgNPs, the real and imaginary parts of permittivity in samples were also decreased. In addition, the resonance frequency of decorated samples with AgNPs have red shifts in comparison with the pure samples. These results are applicable in development of methods for detection of airborne pathogenic agent. © 2019 Elsevier B.V

Third-Order Nonlinear Optical Behavior of an Amide-Tricarboxylate Zinc(II) Metal-Organic Framework with Two-Fold 3D+3D Interpenetration

A new metal-organic framework (MOF), [Zn4(μ4-O)(μ6-L)2(H2O)2]n·nDMF (ZSTU-10), was assembled from zinc(II) nitrate and N,N′,N″-bis(4-carboxylate)trimesicamide linkers and fully characterized. Its crystal structure discloses an intricate two-fold 3D+3D interpenetrated MOF driven by the [Zn4(μ4-O)]-based tetragonal secondary building units and the C3-symmetric tris-amide-tricarboxylate linkers (μ6-L3-). Topological analysis of ZSTU-10 reveals two interpenetrated 3,6-connected nets with an rtl (rutile) topology. Z-Scan analysis at 532 nm was conducted to study a nonlinear optical (NLO) behavior of ZSTU-10. The nonlinear responses of ZSTU-10 were explored under various laser intensities, revealing notable third-order NLO properties in the visible region. A large two-photon absorption at lower incident intensities highlights the fact that ZSTU-10 can be applied in optical limiting devices as well as optical modulators. Moreover, a nonlinear refractive index (n2) is indicative of a self-defocusing behavior. This work thus expands a family of novel MOF materials with remarkable optical properties. © 2021 American Chemical Society

Third-order nonlinear optical behavior of an amide-tricarboxylate zinc(II) metal–organic framework with two-fold 3D+3D interpenetration:Inorganic Chemistry

A new metal–organic framework (MOF), [Zn4(μ4-O)(μ6-L)2(H2O)2]n·nDMF (ZSTU-10), was assembled from zinc(II) nitrate and N,N′,N″-bis(4-carboxylate)trimesicamide linkers and fully characterized. Its crystal structure discloses an intricate two-fold 3D+3D interpenetrated MOF driven by the [Zn4(μ4-O)]-based tetragonal secondary building units and the C3-symmetric tris-amide-tricarboxylate linkers (μ6-L3–). Topological analysis of ZSTU-10 reveals two interpenetrated 3,6-connected nets with an rtl (rutile) topology. Z-Scan analysis at 532 nm was conducted to study a nonlinear optical (NLO) behavior of ZSTU-10. The nonlinear responses of ZSTU-10 were explored under various laser intensities, revealing notable third-order NLO properties in the visible region. A large two-photon absorption at lower incident intensities highlights the fact that ZSTU-10 can be applied in optical limiting devices as well as optical modulators. Moreover, a nonlinear refractive index (n2) is indicative of a self-defocusing behavior. This work thus expands a family of novel MOF materials with remarkable optical properties.</p

Third-order nonlinear optical behavior of an amide-tricarboxylate zinc(II) metal–organic framework with two-fold 3D+3D interpenetration:Inorganic Chemistry

A new metal–organic framework (MOF), [Zn4(μ4-O)(μ6-L)2(H2O)2]n·nDMF (ZSTU-10), was assembled from zinc(II) nitrate and N,N′,N″-bis(4-carboxylate)trimesicamide linkers and fully characterized. Its crystal structure discloses an intricate two-fold 3D+3D interpenetrated MOF driven by the [Zn4(μ4-O)]-based tetragonal secondary building units and the C3-symmetric tris-amide-tricarboxylate linkers (μ6-L3–). Topological analysis of ZSTU-10 reveals two interpenetrated 3,6-connected nets with an rtl (rutile) topology. Z-Scan analysis at 532 nm was conducted to study a nonlinear optical (NLO) behavior of ZSTU-10. The nonlinear responses of ZSTU-10 were explored under various laser intensities, revealing notable third-order NLO properties in the visible region. A large two-photon absorption at lower incident intensities highlights the fact that ZSTU-10 can be applied in optical limiting devices as well as optical modulators. Moreover, a nonlinear refractive index (n2) is indicative of a self-defocusing behavior. This work thus expands a family of novel MOF materials with remarkable optical properties.</p