Assessment of γ-sterilization and/or cross linking effects on orthopedic biomaterial using optical diffuse reflectance spectroscopy

Mehmood, Malik Sajjad; Siddiqui, Nasir; Maqbool, Syed Asad; Baluch, M. A. A.; Mukhtar, Saqlain Saqib; Yasin, Tariq

doi:10.1016/j.ijleo.2017.06.127

Cited by 8 publications

(8 citation statements)

References 30 publications

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“…ese structural imperfections arise due to the formation of localized energy states close to the boundaries of the energy gap. Urbach energy is also inversely proportional to the optical band gap energy [18,19]. e values of Urbach energies of Pyrope-Almandine garnet, Quartz, Black tourmaline, and Amethyst are 0.52 eV, 0.21 eV, 0.46 eV, and 0.43 eV, respectively.…”

Section: Resultsmentioning

confidence: 98%

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Spectroscopic Analysis for Harnessing the Quality and Potential of Gemstones for Small and Medium-Sized Enterprises (SMEs)

Ahmad

Serbaya

Rizwan

et al. 2021

Journal of Spectroscopy

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Introduction of modern technologies and methods and quality analysis for the gemstone industry are the main strategic initiatives of the Small and Medium Development Authority (SMEDA) of Pakistan. In this regard, four natural gemstones Quartz, Pyrope-Almandine Garnet, Black tourmaline, and Amethyst brought from Hunza valley Pakistan were analyzed by state-of-the-art spectroscopic techniques including EDX, UV-VIS, and FTIR spectroscopy. EDX revealed the traces of Fe, Mg, and Ca in Pyrope-Almandine garnet, Mg and Fe in Black tourmaline, Au and Ca in Amethyst. UV-VIS data revealed the values of Urbach energies 520, 210, 460, and 430 meV, and the values of direct bandgap energies 5.14, 6.12, 5.54, 5.74 eV, respectively. The higher structural disorder due to the presence of Fe and other impurities in stones except Quartz was attributed to the higher values of Urbach energies and decrease in band gaps: FTIR data Fe-O and Si-O stretching vibration in Pyrope-Almandine garnet, Si-O bending vibrations and O-H stretching vibration in Quartz, Si-O-Si bending and stretching vibrations and C=O stretching vibrations in Black tourmaline, Ca-O stretching vibrations and Si-OH weak-vibrations in Amethyst. Photoluminescence results also showed useful information in investigating the properties of gemstones.

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Section: Resultsmentioning

confidence: 98%

“…e slope of the ln (a) vs. h] plot in the lower photon energy region is used for the calculation of Eu of each sample. For the calculation of bandgap energies direct and/ or indirect, modified Mott and Davis as reported in the literature [19,20] is used.…”

Section: Uv-vis Testingmentioning

confidence: 99%

Spectroscopic Analysis for Harnessing the Quality and Potential of Gemstones for Small and Medium-Sized Enterprises (SMEs)

Ahmad

Serbaya

Rizwan

et al. 2021

Journal of Spectroscopy

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“…The band gap is determined by the extrapolation of linear portion of the curve on the hv axis to (αhv) 2 = 0. [46][47][48] The band gaps of pure Fe 3 O 4 , pristine PPy and Fe 3 O 4 @PPy nanocomposite are found to be 1.5 eV, 1.3 eV, and 0.4 eV, respectively. The values of band gaps for Fe 3 O 4 NPs and pristine PPy are close to the values given in literature.…”

Section: Characterizationmentioning

confidence: 97%

“…[42][43][44] (Figure 1a) using Tauc's equation (Equation (4)). [45][46][47] In the equation, α is the absorption coefficient, v is the frequency of light, h is Planck's constant, hv is the photon energy, E g is optical band gap energy, K is a constant, and t is an index and ½ for direct transitions.…”

Section: Characterizationmentioning

confidence: 99%

NIR‐responsive Fe₃O₄@PPy nanocomposite for efficient potential use in photothermal therapy

Getiren

Çıplak

Gökalp

et al. 2020

J of Applied Polymer Sci

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In this work, superparamagnetic Fe3O4@PPy nanocomposite with core‐shell structure having strong near‐infrared (NIR) absorption is synthesized via a facile two‐step modified procedure. The prepared nanocomposite samples are characterized by UV–vis, FTIR, SEM, TEM, VSM, and XRD. The effects of laser power density (1.5–2.5 W cm−2) and aqueous concentration (0.01–0.2 mg ml−1) of the nanocomposite on the photothermal performance are investigated in the NIR region (808 nm). At 0.1 mg ml−1 concentration, the temperature reaches up to 50.1°C, 64.1°C, and 78.4°C within 10 min, under 1.5 W cm−2, 2.0 W cm−2, and 2.5 W cm−2 NIR laser power density values, respectively. Photothermal conservation efficiency is calculated as 43.9% and the nanocomposite exhibits excellent photothermal stability. In summary, the core‐shell Fe3O4@PPy nanocomposite is a promising candidate for photothermal therapy and simultaneous magnetic field‐guided treatments.

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“…In another study, Asif et al [ 27 ] concluded the anisotropic nature of UHMWPE in the UV-VIS region and confirmed the forwarded scattering nature of UHMWPE for UV-VIS light. Furthermore, the literature reveals a linear dependence between direct Urbach energy (E u ) band gaps and absorbed dose [ 28 ]. More recently, Noor Us Saba et al [ 29 ] studied the light distribution in UHMWPE for 300 nm and 800 nm and found that photons with low energy/higher wavelengths penetrate by a greater distance.…”

Section: Introductionmentioning

confidence: 99%

Simulation of Light Distribution in Gamma Irradiated UHMWPE Using Monte Carlo Model for Light (MCML) Transport in Turbid Media: Analysis for Industrial Scale Biomaterial Modifications

et al. 2021

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(1) Background: This study investigated the miscibility of carbon-based fillers within industrial scale polymers for the preparation of superior quality polymer composites. It focuses on finding the light distribution in gamma irradiated ultra-high molecular weight polyethylene (UHMWPE). (2) Methods: The Kubleka–Munk model (KMM) was used to extract the optical properties, i.e., absorption coefficients (μa) and scattering coefficients (μs). Samples amounting to 30 kGy and 100 kGy of irradiated (in the open air) UHMWPE from 630 nm to 800 nm were used for this purpose. Moreover, theoretical validation of experimental results was performed while using extracted optical properties as inputs for the Monte Carlo model of light transport (MCML) code. (3) Conclusions: The investigations revealed that there was a significant decrease in absorption and scattering coefficient (μa & μs) values with irradiation, and 30 kGy irradiated samples suffered more compared to 100 kGy irradiated samples. Furthermore, the simulation of light transport for 800 nm showed an increase in penetration depth for UHMWPE after gamma irradiation. The decrease in dimensionless transport albedo μs(μa+μs) from 0.95 to 0.93 was considered responsible for this increase in photon absorption per unit area with irradiation. The report results are of particular importance when considering the light radiation (from 600 nm to 899 nm) for polyethylene modification and/or stabilization via enhancing the polyethylene chain mobility.

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Assessment of γ-sterilization and/or cross linking effects on orthopedic biomaterial using optical diffuse reflectance spectroscopy

Cited by 8 publications

References 30 publications

Spectroscopic Analysis for Harnessing the Quality and Potential of Gemstones for Small and Medium-Sized Enterprises (SMEs)

Spectroscopic Analysis for Harnessing the Quality and Potential of Gemstones for Small and Medium-Sized Enterprises (SMEs)

NIR‐responsive Fe₃O₄@PPy nanocomposite for efficient potential use in photothermal therapy

Simulation of Light Distribution in Gamma Irradiated UHMWPE Using Monte Carlo Model for Light (MCML) Transport in Turbid Media: Analysis for Industrial Scale Biomaterial Modifications

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Assessment of γ-sterilization and/or cross linking effects on orthopedic biomaterial using optical diffuse reflectance spectroscopy

Cited by 8 publications

References 30 publications

Spectroscopic Analysis for Harnessing the Quality and Potential of Gemstones for Small and Medium-Sized Enterprises (SMEs)

Spectroscopic Analysis for Harnessing the Quality and Potential of Gemstones for Small and Medium-Sized Enterprises (SMEs)

NIR‐responsive Fe3O4@PPy nanocomposite for efficient potential use in photothermal therapy

Simulation of Light Distribution in Gamma Irradiated UHMWPE Using Monte Carlo Model for Light (MCML) Transport in Turbid Media: Analysis for Industrial Scale Biomaterial Modifications

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Product

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NIR‐responsive Fe₃O₄@PPy nanocomposite for efficient potential use in photothermal therapy