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The Hydrophilic-Hydrophobic Correlations in Water Systems
Published in Fausto Martelli, Properties of Water from Numerical and Experimental Perspectives, 2022
Francesco Mallamace, Carmelo Corsaro, Paola Lanzafame, Georgia Papanikolaou, Domenico Mallamace
In this local order frame, experimental techniques must be considered like NMR (Abragam 1961, Bloembergen et al. 1948, Kubo and Tomita 1954), neutron scattering (e.g., elastic and deep-in elastic) (Egelstaff 1971, van Hove 1954), X-ray, Raman, IR, light-fast spectroscopy (Bernie and Pecora 1976, Fabelinskii 1969), strongly sensitive to system atomic and molecular properties and confutations. In these terms, the pair distribution function ghh(r) of the hydrophobic molecules can be measured, by means of a small angle neutron scattering.
Impact of Factors on Remediation of Anions (Fluoride, Nitrate, Perchlorate, and Sulfate) Via Batch Adsorption Processes
Published in Deepak Gusain, Faizal Bux, Batch Adsorption Process of Metals and Anions for Remediation of Contaminated Water, 2021
Deepak Gusain, Shikha Dubey, Yogesh Chandra Sharma, Faizal Bux
There are a number of techniques used to determine the mechanism of sulfate adsorption such as EXAFS, differential atomic pair distribution function analysis (d-PDF), (Zhu et al. 2013) and Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FT-IR) (Johnston and Chrysochoou 2016). The EXAFS spectrum is used for the mechanism of adsorption of sulfate (pH = 4) on ferrihydrite (Zhu et al. 2013). The EXAFS spectra of the sample after adsorption on ferrihydrite showed a weak peak at 8.5 Å−1 similar to that of jarosite; this feature was not shown by liquid sulfate solution. This suggests that fewer than three Fe atoms on average surround the sulfur atom of the surface-bound sulfate ion.
Perovskites Thin Films for Photovoltaic Applications
Published in Kunwu Fu, Anita Wing Yi Ho-Baillie, Hemant Kumar Mulmudi, Pham Thi Thu Trang, Perovskite Solar Cells, 2019
Kunwu Fu, Anita Wing Yi Ho-Baillie, Hemant Kumar Mulmudi, Pham Thi Thu Trang
Another phase which should be noted is the amorphous phase. Pair distribution function analysis of X-ray scattering showed that after annealing at 100°C for 30 min, the MAPbI3 in mesoporous TiO2 has about 30 atom% in medium range crystalline order and the other 70 atom% in a disordered state with a coherence length of 1.4 nm.33 The poor crystallization of the MAPbI3 in mesoporous TiO2 was studied by high-resolution transmission electron microscopy.34 Quartz crystal microbalance measurements suggest that during sequential method only half of PbI2 is converted to MAPbI3 instantly, while the other half is involved in reversible transformation with MAPbI3. Additionally, the amorphous character with a very small average crystallite size may be present after the transformation.35 MAPbI3 is a direct bandgap (1.55 eV) material (Figure 1.3c) with an absorption coefficient in the order of 1.5 × 104cm−1 at 550 nm.36
Structural characterizations of fly ash-based geopolymer after adsorption of various metal ions
Published in Environmental Technology, 2021
Pair distribution function (PDF) is proven to be a powerful technique for revealing the local atomic structure of complex materials such as disordered substance [27,28]. The reduced PDF, G(r), can be obtained from the Fourier sine transformation of the reduced structure function F(Q) = Q[S(Q) −1], as shown in Equation (1), where the definition of Q is given in Equation (2), with θ being the scattering angle and λ the wavelength of the light source.