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Sample Preparation Techniques to Isolate and Recover Organics and Inorganics
Published in Paul R. Loconto, Trace Environmental Quantitative Analysis, 2020
QUECHERS is an abbreviation for the phrase: Quick, Easy, Cheap, Rugged, Effective, Safe whose origins go back to pioneer work done at a United States Department of Agriculture (USDA) laboratory.130 This author unknowingly applied what came to be known as QUECHERS when he developed a LLE approach while attempting to find a way to extract three polar organic compounds: 2-aminoethanol, N-methyl-2-aminoethanol and N,N’-dimethyl-2-aminoethanol from an aqueous solution. He was advised to add enough Na2SO4(s) to 4 mL of a deep-blue liquid (copper (II) hydroxide complexed 2-aminoethanol) to saturate the solution followed by adding 2 mL of 2-propanol (isopropyl alcohol). After shaking this mixture and allowing it to settle, an upper phase developed!131 The schematic shown in Figure 3.60 which describes the first step in implementing the QUECHERS sample prep technique. When the ionic strength of an aqueous solution is significantly increased, the degree to which a polar molecule such as 2-propanol interacts intermolecularly with water is significantly reduced. The reader would do well at this point to go back and review Figures 3.44 and 3.45.
Chemical Modification of Cellulose
Published in David N.-S. Hon, Chemical Modification of Lignocellulosic Materials, 2017
Cellulose can be modified with organostannane chlorides, such as dibutyl or triphenyl derivatives [91,92], or with organotin halides in the presence of bisethylenediamine copper(II) hydroxide [93], Epoxy-activated cellulose was prepared by reacting cellulose acetate fibers with sodium methoxide, followed by reacting it with epichlorohydrin in DMSO. This epoxy-activated cellulose has proved to be a useful intermediate to react with substances containing active hydrogen, such as amine, amino acid, or carboxylic acids [94], as shown in Fig. 3. Epoxidized cellulose has also been converted to a thiol derivative via reduction of a thiosulfate intermediate [95], and sulfoethylcellulose has been obtained from sodium chloroethanesulfonate [96]. Cellulose monoresorcinol ether can be made by refluxing a mixture of powdered cellulose and benzene, with phosphorous tribromide followed by refluxing of the cellulose bromide in alcohol with an excess of sodium m-hydroxyphenoxide (monosodium salt of resorcinol) [97,98].
Properties of the Elements and Inorganic Compounds
Published in W. M. Haynes, David R. Lide, Thomas J. Bruno, CRC Handbook of Chemistry and Physics, 2016
W. M. Haynes, David R. Lide, Thomas J. Bruno
Copper(II) ferrocyanide Copper(II) ferrous sulfide Copper(I) fluoride Copper(II) fluoride Copper(II) fluoride dihydrate Copper(II) formate Copper(II) formate tetrahydrate Copper(II) gluconate Copper(II) hexafluoro-2,4-pentanedioate Copper(II) hexafluorosilicate tetrahydrate Copper(I) hydride Copper(II) hydroxide Copper(II) iodate Copper(II) iodate monohydrate Copper(I) iodide Copper(I) mercury iodide Copper(II) molybdate Copper(II) nitrate Copper(II) nitrate hexahydrate Copper(II) nitrate trihydrate Copper nitride Copper(II) oleate Copper(II) oxalate Copper(II) oxalate hemihydrate Copper(I) oxide Copper(II) oxide Copper(II) oxychloride hemiheptahydrate Copper(II) 2,4-pentanedioate Copper(II) perchlorate
Comparative study on cupric oxide nanoparticles synthesis in saline buffer versus basic water by Spondias mombin peel extract for biocatalysis
Published in Inorganic and Nano-Metal Chemistry, 2023
Md. Rajibul Akanda, Umme Habiba Ema, M. Aminul Haque, Md. Mehedi Hasan
It can be assumed that S. mombin extract contain significant amount of ascorbic acid with other phytochemicals.[53] Here it is observed that peel extract mediated CuO NPs synthesis manifests stepwise color changes from greenish to brownish (Scheme 1B). The stepwise color changes are explained in Figure 1 as follows: firstly, the bluish color of CuSO4.5H2O solution in the basic medium is due to the formation of copper(II) hydroxide (Eq. (1)). Upon reaction of the above solution with ascorbic acid of S. mombin peel extract gives dehydroascorbic acid and copper (I) oxide and turned the solution color greenish (Eq. (2)). Copper (I) oxide in the basic aqueous solution is actually a mixture of copper (II) hydroxide and copper (I) hydroxide (Eq. (3)). Finally, upon increasing reaction time to 60 minutes with boiling the solution turned brownish in color and confirms the formation of copper (II) oxide CuO NPs (Eqs. (4) and (5), respectively).[58] This probable mechanism proposed for CuO NPs synthesis is well supported by the literature.[56] The conversion of nanoparticles to bulk was barred due to the action of flavonoids and other phytochemicals (polyphenol, flavonoid, tannin etc) present in peel extract as a stabilizer. Except for ascorbic acid, the presence of other typical phytochemicals in S. mombin peel extract was screened and quantified in recently published literature by Akanda et al.[40]
Laser-Assisted coating techniques and surface modifications: a short review
Published in Particulate Science and Technology, 2021
Behzad Fotovvati, Amir Dehghanghadikolaei, Navid Namdari
Using the laser-assisted direct material deposition method, Mansour et al. (Mansur, Wang, and Berndt 2013) developed a composite coating of hydroxyapatite (HA) and Ti-6Al-4V, which had two distinct layers including a top hard ceramic layer on a heat-affected zone, in which Ti diffuses into Fe. They found that a combination of the laser power and traverse speed, i.e., energy density, controls important coating features such as mechanical properties, microstructure, and chemistry. With the energy density of 167 J/mm2, they could obtain a Ca/P ratio of less than 1.67 (nearest to human bone), which is favorable for cell apoptosis and clinical practice. Rytlewski (Rytlewski 2014) compared two different coating compositions of 5 wt.% of Cu(acac)2 and 15 wt.% of copper(II) oxide (CuO) or copper(II) hydroxide (Cu(OH)2). They used various numbers of laser pulses at a constant fluence of 100 mJ/cm2 to irradiate the coatings followed by electroless metalization with copper. More efficient laser ablation and formation of metallic copper on the coating surface containing CuO allowed the copper to be plated at a higher energy dose of laser radiation compared to the coatings containing Cu(OH)2. The authors observed less porosity in the coating containing CuO rather than in Cu(OH)2, and they attributed this observation to the formation of water, which results in the thermal decomposition of Cu(OH)2.
Upcycling of waste textiles into regenerated cellulose fibres: impact of pretreatments
Published in The Journal of The Textile Institute, 2020
Yibo Ma, Lucas Rosson, Xungai Wang, Nolene Byrne
Once the pretreated cotton pulp was prepared, the degree of polymerisation (DP) was measured through dissolution in Bis(ethylenediamine)copper(II) hydroxide solution (CED) according to standard (ASTM D1795 – 13). The pretreated cotton pulp was dissolved in a binary solvent 1-butyl-3-methylimidazolium acetate ([Bmim]OAc) and DMSO. The solvent system consisted of 20 wt%. [Bmim] OAc and 80 wt% DMSO at a polymer concentration of 6 wt%. The DMSO was first added and manually stirred until the pulp was well dispersed. The IL was then added, and the solution was again stirred manually for approximately 3–5 minutes. In order to properly dissolve the pretreated waste cotton pulp in the solvents, the solution was mixed in a Thinky Conditioning Mixer for approximately 30 minutes.