Sodium hydroxide aqueous solution

To the reaction mixture, 125.7 g of a 15% sodium hydroxide aqueous solution was dropwise added to make the reaction mixture strongly alkaline. Then, undissolved inorganic salts were separated by filtration, and the inorganic... 

Preparation of Solutions. Tetraethoxysilane is used as a silica source. By adding tetraethoxysilane to a tetramethylammonium or a (2-hydroxyethyl)trimethylammonium hydroxide aqueous solution, two kinds of mixtures in which a N/Si ratio was 1.0 and a Si02 concentration was 2.22 mol kg-1 were prepared. For comparison, another mixture consisting of tetraethoxysilane and a sodium hydroxide aqueous solution with a Na/Si molar ratio of 1.0 and a Si02 concentration of 2.22 mol kg-1 was prepared. 

Sodium Hydroxide-Tetraethoxysilane Mixture. The exothermal reaction in the mixture of sodium hydroxide aqueous solution and... 

Organic gels were prepared by polycondensation of resorcinol with formaldehyde in water as a solvent. Three series of carbon samples were prepared one without addition of metal the two others containing nickel and palladium (about 1% weight) respectively. The incorporation of metal was achieved by dissolution of a metal salt nickel acetate (tetrahydrate) and palladium acetate were used. As resorcinol plays the role of nickel complexant, nickel is easily soluble in resorcinol-formaldehyde aqueous solutions. On the contrary, significant amounts of palladium cannot be dissolved without using an additional complexant. Diethylenetrinitrilopentaacetic acid (DTPA) was then added to the solution. No sodium carbonate as polymerisation catalyst was used. In this work, the pH was adjusted to a chosen value by the use of sodium hydroxide (aqueous solution) and measured by a pH-meter. 

Mercerization. The purified cotton fibers were mercerized in 20 sodium hydroxide aqueous solution for 5b at 20 C. Then the samples were washed with distilled water, immersed in 0.1 acetic acid, washed with distilled water until acetic acid was throughly removed and then air-dried. 

Open-tubular column Soda-lime glass capillaries were treated with a sodium hydroxide aqueous solution at 45-50 "C for 2 days and washed with methanol until the effluent became neutral. The capillaries were then dried under helium at 120 "C for a few hours and washed with methanollc 0.01 H hydrochloric acid, water and methanol. Finally, the capillaries were dried mder helium at 120 °C for a few hours. Chemically and physically stable silica gel layer was formed on the glass surface with above pretreatments. An orgwic solution of octadecyltriethoxysilane was filled into the pretreated capillaries and the reaction weis carried out at elevated temperature. After the reaction, columns were washed with orgcuiic solvents and the mobile phase. Both ends of columns were inserted into narrow-bore(ca. 0.2 mm i.d.) PTFE tubing for small dead-volume connection. 

SBAS reinforcing fibers were fabricated via the ACI s viscous suspension spinning process (VSSP) °. In this process, cellulose is digested in a sodium hydroxide aqueous solution in the form of a viscous liquid (viscose) that is mixed with the SBAS powder dispersed in a water slurry (Figure 2a). It should be noted that the lower amount of HTE, compared to the matrix composition, was used in the mixture for fibers to increase their sintering temperature and prevent strong fiber-to-matrix bonding. 

Figure 8.3 depicts a special electrolytic cell, called a Hoffmann voltameter, which demonstrates the famous electrolysis of water experiment. Note that pure water (a covalent compound - see Chapter 4) does not conduct electricity, so cannot be readily electrolysed. In the demonstration an electrolyte, such as sulfuric acid or a sodium hydroxide aqueous solution, is added to the water to allow electrolysis to occur at an observable rate. The oxygen and hydrogen evolved can be tested in the usual ways. The observations from this experiment provide data that support many chemical models, such as the composition of water and its H2O formula. 

Scheme 17.32). Mechanistic investigation revealed the intervention of a highly stereoselective retro aldol reaction, which could be minimised by using a catalytic amount of 1% sodium hydroxide aqueous solution and ammonium chloride, leading to the establishment of a general and practical chemical process for the synthesis of optically active arati-p-hydroiq -a-amino esters. 

Several studies have been made to optimize the properties of natural fiber-reinforced PLA composites from the point of view of fiber-matrix adhesion. Pretreatment of fibers, such as chemical modification, seems to be the most promising approach, in which covalent bonds are formed between the fiber and matrix. One of the most common and efficient methods is alkali treatment (for example, with 2% sodium hydroxide aqueous solution) of fibers, which has been used to... 

To an aqueous solution containing 16.8 g of cyanamide, 16 g of sodium hydroxide and 200 ml of water was added dropwise 25.0 g of MDI dissolved in dioxane over an hour period at a temperature between 10 to 15 C. A 2N sodium hydroxide aqueous solution (200 ml) was also added slowly at a speed to finish addition at the same time as the addition of MDI solution. The aqueous solution was stirred at room temperature for an additional hour after the addition of reactants. 

Preparation by adding m-cresol to a mixture of bis(4-tri-chloromethylphenoxy)ketone and aluminium chloride in methylene chloride at 0° for 1.5 h, then at 20° for 3 h. Then, hydrolysis of the intermediate product so obtained with 20% sodium hydroxide aqueous solution at 20° for 7 h (40%) [901]. 

Also prepared by treatment of 5-(pivaloyloxy)-2-methoxy-acetophenone in DMF with a 2 M sodium hydroxide aqueous solution at 100° for 12 h (83%) [3818]. 

According to the literature [1], phosphonate or phosphinate salts could be generally synthesized by the reaction of the corresponding phosphonate or phosphinate esters with inorganic alkalis or salts. For example, as shown in Scheme 3.6, Baillie reported that sodium (9-methyl acetylphosphonate 1-1 could be obtained by demethylation of (9, (9-dimethyl acetylphosphonate 1-la with sodium iodide in butanone [1,5]. The phosphinate 2a could be hydrolyzed to give the corresponding salts 2 in 2 M sodium hydroxide aqueous solution [1]. 

Resistances to chemicals are shown in Figure 5.21. Figure 5.21a shows retention of elongation at break of the membrane after dipping in an oxidant (0.5% sodium h5q)ochlorite aqueous solution) for 2 months, and Figure 5.21b shows that after dipping in an alkah (4% sodium hydroxide aqueous solution) for 2 months. Even after contact with chemicals for a long period, no mechanical deterioration is observed. 

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