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Holographic Recording Materials
Published in Raymond K. Kostuk, Holography, 2019
The basic chemistry of bleach solutions consists of: (i) an oxidizing agent; (ii) an alkali halide such as potassium bromide (KBr); and (iii) a buffer such as H2SO4 [1]. This prescription can generally be used for both direct (develop-fix-bleach) and develop-bleach-rehalogenate techniques. In the direct bleaching process, the emulsion is developed, undergoes a fixation step to remove unexposed silver halide grains, and then bleached as illustrated in Figure 8.2. As noted, there will be some emulsion thickness shrinkage during the fixing step that can change the highest efficiency reconstruction wavelength and angle for slanted gratings and introduce aberrations into the reconstructed image. Kodak D-19 in combination with the bleach proposed by Lehmann [24] provides high efficiency and acceptable scatter levels for transmission holograms where shrinkage is not as critical as for reflection holograms. It was found by Pennington and Harper [23] that most of the scatter in the direct bleaching process is due to reticulation of the emulsion surface and to larger grain growth and size variation during rehalogenation.
Applied Chemistry and Physics
Published in Robert A. Burke, Applied Chemistry and Physics, 2020
The next example combines the metal calcium and the nonmetal phosphorous resulting in the compound calcium phosphide. It is a dangerous fire risk. The compound name ends in “ide.” Therefore, this is also a binary salt. Lithium fluoride is a strong irritant to the eyes and skin. Potassium bromide is toxic by ingestion and inhalation. Sodium chloride is table salt, a medical concern when ingested in excess, but certainly of no significant hazard to emergency responders. However, if sodium chloride is washed into a farmer’s field from an incident, the farmer may not be able to grow crops in that field for many years!
Physical Properties of Crystalline Infrared Optical Materials
Published in Paul Klocek, Handbook of Infrared Optical Materials, 2017
James Steve Browder, Stanley S. Ballard, Paul Klocek
Notes: Potassium bromide is grown in the same manner as sodium chloride and is hygroscopic. It is soluble in alcohol and glycerin. Potassium bromide is used in IR prisms and windows and in laser windows. Diameters as large as 8 in. are available.
Trapping synthetic dye molecules using modified lemon grass adsorbent
Published in Journal of Dispersion Science and Technology, 2022
Mohd Azmier Ahmad, Nur ‘Adilah Ahmed, Kayode Adesina Adegoke, Olugbenga Solomon Bello
Surface functional groups were investigated using an FTIR spectrophotometer (Shimadzu model IRPrestige-21). The spectroscopic investigation enables the study of the surface chemistries of LLAC before and after adsorption. The spectra reveal the characteristics’ details of the functional groups present in LLAC before and after adsorption. The samples are encapsulated in the potassium bromide pellet. They are measured from 4000 to 400 cm−1. The analysis is done automatically by software which attached to the system (Spectrum version 5.0.2). The pore volume, average pore diameter, and surface area were determined using Micromeritics ASAP2020 volumetric adsorption analyzer while the Brunauer-Emmett-Teller (BET) was used to measure the surface area of the adsorbent. The total pore volume was determined in liquid N2 volume at 0.98 relative pressure.[50]
Effects of drying temperature on hygroscopicity and mechanical performance of resin-impregnated wood
Published in Drying Technology, 2021
Kang Xu, Yulei Gao, Xiaomeng Zhang, Zhonghao Li, Shasha Song, Yiqiang Wu, Xianjun Li, Jianxiong Lu
Wood flour with 200 mesh was prepared from RI60, RI80, RI100, RI120, RI140, and CK100 samples, and RS60, RS80, RS100, RS120, and RS140 were ground to powder for infrared spectroscopic analysis (Nicolet iS50, Thermo Fisher Scientific). Potassium bromide was the tableting matrix, and the amount of wood flour or resin powder to potassium bromide was 1:100. The scanning range was 4000 cm−1–400 cm−1 and the scanning times were 64. In the meantime, using a Bruker-400 Solid State Nuclear Magnetic Resonance (AVANCE III, Bruker Germany) with cross polarization/magic angle spinning (CP/MAS), the samples were continuously tested. Resonance frequency = 100.6 MHz, pulse delay = 2 s, pulse width = 10 μs, sampling spectrum width = 30.2 kHz, sampling time = 24.93 ms, sampling interval = 16.533 μs, and scanning times = 512.
HDCO radical dissociation thresholds by velocity map imaging
Published in Molecular Physics, 2021
C. D. Foley, G. A. Cooper, J. Tu, M. Harmata, A. G. Suits
Synthesis of paraformaldehyde-d1 was adapted from a previously described method, which is detailed below [52]. CDBr3 (50 g) was added to an oven-dried 200 ml round bottom flask, attached to a reflux condenser and an argon-filled balloon, and then Bu3SnH (57 g) was added dropwise carefully. After addition and waiting for 10 min, the reaction mixture was heated to reflux for 25 h. The mixture then was distilled to give pure CDHBr2. CDHBr2 (15 g) was placed in a 200 mL round bottom flask. Glacial acetic acid (54 ml) and acetic anhydride (6 ml) were added. Potassium acetate (26 g) was then added in one portion and the reflux condenser and an argon-filled balloon were quickly attached to the round bottom flask. The reaction mixture was heated at reflux for 40 h. The mixture was then allowed to cool to room temperature and 150 ml of diethyl ether were added. White precipitated potassium bromide was filtered off several times and more diethyl ether was added until there was no precipitated potassium bromide formed. The filtrates were combined and the solvent was removed by a rotary evaporator to afford the pure d-methylene diacetate in 78% yield. d-Methylene diacetate (9 g) was placed in a 25 mL round bottom flask and HPLC grade water (1 ml) and conc. HCl (1 ml) were added. The reaction mixture was then heated to reflux for 24 h. The solvent was removed by oil pump and paraformaldehyde-d1 was formed as a white powder.