Polyethylene glycols impregnation

Ohkoshi, M. (2002). FTIR-PAS study of light-induced changes in the surface of acetylated or polyethylene glycol-impregnated wood. Journal of Wood Science, 48(5), 394-401. 

That none of the above methods is completely satisfactory as a conservation procedure is generally agreed. One interesting recent development involves the application of freeze-drying technology (24,25) combined with polyethylene glycol impregnation. 

Black L (1989), Selective permeation of aromatic hydrocarbons through polyethylene glycol impregnated regenerated cellulose or cellulose acetate membrane,... 

The reagent can be employed on silica gel, kieselguhr and Si 50 000 layers (also when they are impregnated with polyethylene glycol [1]) and on cellulose layers. 

TLC plates Silica gel 60 (Merck) impregnated by dipping once in a 10% solution of polyethylene glycol 1000 in methanol. 

Figure 2.7—Structure of polysiloxanes (silicones) and polyethylene glycols. An inventory of all the compositions of these phases that can be used for impregnation or bonding would be lengthy. The surface of the silica column can be treated with tetradimethylsiloxane in order to obtain the bound phase, which is polymerised and then cross-linked.

Figure 2 Creep-recovery tests of chemically treated woods. U, untreated wood Fs, vapor phase formalization F, liquid phase formalization A, acetylation PO, etherification with propylene oxide MG, treatment with maleic acid and glycerol PFl, impregnation with low molecular weight phenol-formaldehyde resin PEG-ICP, impregnation with polyethylene glycol (PEG-IOOO) WPC, formation of a wood- polymer composite (PMMA) WIC, formation of a wood-inorganic material composite.

A good separation was obtained on a packed column of 30 % polyethylene glycol 4000 on silica gel impregnated with 20 % potassium hydroxide. Potassium hydroxide was used to reduce adsorption to the solid support. The results are given in Table 6.1. 

Examples presented describe the separation and purification of naphthalene from its associated impurities, alkylated mono- and dicyclic aromatics. Supercritical pentane at 42 atm and 215 °C and a chromatography adsorbent of baked brick impregnated with polyethylene glycol (6000 molecular weight) are used to separate a 95% naphthalene-5 % alkylated aromatics mixture into a 99.5% naphthalene fraction of 70% yield and a concentrated impurities fraction of 10% of the feed. Approximately 20% of the product is recycled. 

Various reagents have been used for subtracting aldehydes and ketones. Thus, to remove aldehydes and ketones from a mixture with alcohols and epoxides, Osokin et al. [66] used a packing containing diatomite impregnated with an aqueous solution of sodium hydroxide (6%) and a solution of hydroxylammonium chloride in polyethylene glycol (20%). Aldehydes and ketones were converted into oximes and retained by the stationary phase, whereas alcohols and epoxides were not retained by this packing. 

As an alternative to the conventional polyethylene glycol (PEG) treatment of waterlogged wood see Chapter 8), attempts were made in 1966-1967 to apply a radiation-curing process (i, 2). The aim was to reduce treatment time and achieve more stability for treated objects subjected to interior climatic changes. The impregnation of waterlogged wood by immersion involves a liquid-liquid exchange process. Dry wood was directly bulked by monomers by a vacuum-pressure process. 

Removal of PCBs from a contaminated water stream can be achieved by adsorption with chitosan [9012-76-4] and activated charcoal (Thome and Van Daele 1986). Chitosan from Procambarus clarkii coated on diatomaceous earth such as Cellite partially removed PCBs from waste streams (Portier 1988). Decontamination of transformer oil consists of immobilization of PCBs and halogenated organic compounds on alkali- or alkaline-metal carbonates and bicarbonates impregnated with polyethylene glycol and Ci to Ce alcoholates of alkali- and alkaline-earth metals (Tumiatti et al. 1989). 

In 1955, Rajka et al. demonstrated the ability of ascorbic acid to protect guinea pigs from the skin irritation caused by a 20% dichromate solution. In 1958, Samitz and Pomerantz showed that ascorbic acid (1% solution in polyethylene glycol) blocked the effect of a 0.25% dichromate solution on the skin of patients subject to chromate dermatitis. In an extension of this work, in 1962, Samitz et al. found that rats administered a lethal dose of potassium dichromate (130 mg/kg) via gastric intubation, followed within two hours by ascorbic acid, led to a 93% survival rate in the 28 rats tested. This and other work led to the use of ascorbic acid in the treatment of, and protection from, the toxic effects of chromate in industrial situations. This included the use of ascorbic acid impregnation of the material used in the respiratory masks of workers exposed to chromic acid mists ... 

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