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Critical Factors Affecting the Synthesis of Bionanomaterials and Biocomposites
Published in Naveen Dwivedi, Shubha Dwivedi, Bionanotechnology Towards Sustainable Management of Environmental Pollution, 2023
Rachita Sharma, Priya Singh, Ved Kumar Mishra, Naveen Dwivedi, Nikita Singhal
Ultraviolet-visible spectroscopy (UV-Vis) is based on the absorption of radiation in the range of ultraviolet and visible light. UV-Vis is a technique that is used to measure the absorbance or scattering of light (UV or visible) from the sample with the help of the absorption spectrum. In this technique, light is emitted from a source, whose wavelength will be selected by a wavelength selector, and passed into a liquid sample. When the light is passed through the sample, it will absorb a certain amount of energy to excite its electrons from the ground-state to the excitation state. The absorbance of a certain wavelength of light will help us find the difference in the wavelength of light compared to the control. The analysis of the amount of absorbance at different wavelengths will help us to draw a graph called “absorption-spectra,” having absorbance on its y-axis and wavelength on its x-axis. Some metal nanoparticles, like gold or silver, show absorbance on the surface. Plasmon uses UV-Vis spectra for the characterization of the size and shape of nanoparticles. High absorption peaks obtained at certain wavelengths tell us the high size distribution, small size, particular shape, etc.
Borate Phosphor
Published in S. K. Omanwar, R. P. Sonekar, N. S. Bajaj, Borate Phosphors, 2022
Raman spectroscopy is an analytical technique, in which scattered light is used to measure the vibrational energy modes of a sample. This phenomenon was first observed by K. S. Krishnan in 1928. After that, Indian scientist C. V. Raman worked with K. S. Krishnan [121]. Raman spectroscopy provides chemical and structural information of material, in addition to the identification of substances through their characteristic Raman ‘fingerprint’ [122].
Spectroscopic Analysis of Polymer Coatings
Published in Sanjay Mavinkere Rangappa, Jyotishkumar Parameswaranpillai, Suchart Siengchin, Polymer Coatings, 2020
Jyoti Sharma, Manju Rawat, Daisy Sharma, Sanjeev Kumar Ahuja, Avinash Chandra, Sanghamitra Barman, Raj Kumar Arya
Nuclear magnetic resonance (NMR) spectroscopy is a spectroscopic technique used to observe local magnetic fields around atomic nuclei. The sample is placed in a magnetic field, and the NMR signal is produced by the excitation of the nuclei of the sample with radio waves into nuclear magnetic resonance, which is detected with sensitive radio receivers. The schematic representation of the instrumentation is shown in Figure 6.9 (Zia et al., 2019).
Study on Mechanism of Influence of Microstructure on Combustion Characteristics of Mine Conveyor Belt
Published in Combustion Science and Technology, 2023
Wei Wang, Yun-Tao Liang, Qian-Kun Zhao, Peng Li, Wei-Dong Wang
Infrared spectroscopy is an effective method to determine the molecular structure and chemical bond of materials. Different chemical bonds or functional groups have different absorption frequencies for infrared light, so the positions of characteristic peaks in infrared spectra are different. On the contrary, the positions of infrared absorption bands of the same chemical bonds or functional groups will be within a certain wavenumber range, and have certain characteristics. Therefore, various chemical bonds or functional groups contained in different types of conveyor belts can be tested by infrared spectrum, and the corresponding spectrogram of characteristic absorption peak can be given. Then, the corresponding position and attribution of absorption peak can be determined by comparing with the standard spectrogram, and the types of chemical bonds and functional groups can be defined. At the same time, the absorption peak can be fitted, and the change rule of the content of each active functional group can be quantitatively analyzed, so as to understand the special active groups of different conveyor belts and lay a foundation for subsequent research (Gao et al. 2022; Yan et al. 2016; Zhao et al. 2018).
A double perovskite BiLaCoMnO6: synthesis, microstructural, dielectric and optical properties
Published in Phase Transitions, 2023
S. K. Parida, Tanushree Satapathy, S. Mishra, R. N. P. Choudhary
Raman spectroscopy is a very important tool; where the scattered light is used to measure the vibrational energy modes of the material under study. It gives detailed information on molecular composition and structure. Figure 3 shows the Raman spectrum of the BiLaCoMnO6 ceramic. In this present study, the active Raman modes are observed at 201, 263, 382, 498, 636, 746, 850, and 946 cm−1 respectively. The assignment of the strongest Raman peak in the double perovskite is observed at 636 cm−1 corresponding to Ag while the peak at 498 cm−1 corresponds to T2g Raman active mode [35]. The strongest peak at 636 cm−1 is the frequency range of anti-stretching and bending vibrations of (Mn/Co) octahedra and also Raman active in #P4bm structure [36–38]. Again, the presence of weak Raman lines corresponding to modes at respective frequency bands supports the monoclinic crystal symmetry (#C/2c). Therefore, the presence of all Raman line corresponding to modes confirms the presence of all atomic vibration of constituent elements and support the tetragonal crystal symmetry in the prepared stable double perovskite.
Nickel oxide nanoparticles: biosynthesized, characterization and photocatalytic application in degradation of methylene blue dye
Published in Inorganic and Nano-Metal Chemistry, 2022
Abdolhossein Miri, Fatemah Mahabbati, Ahmad Najafidoust, Mohammad Javad Miri, Mina Sarani
Raman spectroscopy is a molecular spectroscopy technique that is based on the interaction between light and matter. In this method, each material contains its own peak that is called the fingerprint of that certain material. In regards to the excited states of pure NiO, Raman scattering has exhibited one phonon (TO and LO) and two phonons (2TO, TO + LO and 2LO), as well as one, two, and four excited states of magnon (Figure 6). The Raman spectra of single-crystal NiO has displayed several bands above the point of 400 cm−1. It should be noted that the origin of first four bands was the vibrational origin including TO and LO modes of one-phonon (1 P) (within the range of 561 cm−1), 2TO modes of two-phonon (2 P) (in range of 710 cm−1), and TO + LO (855 cm−1) and 2LO (1009 cm−1) modes. Meanwhile, the last strong band observed at 1392 cm−1 has been apparently caused by two-magnon (2 M) scattering. This mode can be clearly perceived at room temperature due to the available high Nile temperatures. However, the 1 P band has been more evident owing to the defect or surface effect of powders, while the three bands of 2 P had appeared to be more extended and the 855 cm−1 band has virtually disappeared.[61] According to the peak location comparison between bulk nickel oxide and NiO NPs, the occurrence of a reduction in the size of nanoparticles can affect their magnetic behaviors and alter their peak location.