Effect of NaOH

Liden, K., Takahasi, C. and Nelson, D.E. 1995 The effects of lipids in stable carbon isotope analysis and the effects of NaOH treatment on the composition of extracted bone collagen. Journal ofArchaeological Science 22 321-326. 

Fig. 8 Effect of NaOH upon reaction of 2,4-dinitrochlorobenzene with the hydro-phobic ammonium salts, (C H17)3NCH2CH2OH.X. Solid points in 80 vol% H2Oj open points in 70 vol% H20. Ammonium salt concentrations , 0.008 M, X = Br O, 0.05 M, X = Br , 0.05 M, X = OMs V, 0.1 M, X = OMs. The lines are theoretical. (Reprinted with permission of the American Chemical Society)...

Fig. 9.2.15 Effect of NaOH concentration on the copper powders obtained from the reduction of CuO in a sorbitol-ethylene glycol solution (A) no NaOH (B) [NaOH] = 10-2 mol L l. (C) [NaOH] = 5 X 1(T2 mol L I (D) [NaOH] = 10-1 mol L-1. (From Ref. 17.)...

Following treatment of barley straw with 5% NaOH, Israel-sen, t al. (56) observed a decrease in NDF of 14.6 percentage units, while Braman and Abe (57) found the ADF fraction of wheat straw decreased by 5.7 units following NaOH treatment. Rexen (58) showed a substantial decrease in ADF of barley straw following NaOH treatment, but no effect of NaOH on rice straw. Itoh, et al. (59) observed significant decreases in NDF of ammoniated... 

Since NaOH and NaA102 had no apparent effect on cobalt solubility, it seemed likely that cobalt sorption was increased by these components due to effects they had on the sediment minerals. Studies of the effects of NaOH and NaA102 on the sediment minerals are required to identify possible new mineral phases which might cause increased cobalt sorption. 

Neptunium and plutonium sorption behaviors were remarkably similar, implying that they had similar sorption reactions and solution species. Both NaOH and NaA102 decreased neptunium and plutonium sorption. Several explanations can be offered to rationalize this behavior. First, NaOH and NaAlO, may have reacted with the sediment minerals to yield solids of lower sorptive capacity. Aluminate ion, as an anionic species, also may have competed with the similar neptunate and plutonate anions for sorption sites. Finally, sodium hydroxide may have stabilized the hydrolyzed Np02(0H) and Pu02(0H)2" species in solution, as was shown in the solubility tests, and prevented sorption. Explanation of the effect of NaOH and NaA102 on neptunium and plutonium sorption will require further investigation. 

The present paper reports on a study which was conducted to investigate the effect of NaOH on the in vitro release profiles of microspheres prepared with polylactides (2) Since these polyesters degrade by hydrolysis (4), it is possible that the molecular weight of the polymers can be decreased by the alkaline pH of the sodium oleate emulsifier solution (pH 10) during fabrication. This in turn could affect the release kinetics of the microspheres. 

Drug release may be affected by a number of process parameters such as drug loading, polymer molecular weight, polymer composition, initial concentration of the polymer in the organic phase of the emulsion, amount of emulsifier, stirring speed, vacuum pressure, solvent evaporation time and temperature. These parameters were kept constant and only the amount of NaOH was varied. Therefore, changes in the in vitro release curves should reflect only the effect of NaOH in various concentrations. ... 

The effect of NaOH on drug release was examined with microspheres prepared with thioridazine and two biodegradable polymers. The wall-forming polymers were poly(DL-lactide) and poly(L-lactide). Sodium oleate was used as the emulsifier, with the exception of one set of experiments where the emulsions were stabilized with polyvinyl alcohol. 

Figure 1. Effect of NaOH on thioridazine release from poly(DL-lactide) microspheres. Key (0) no NaOH, 15-85 pm (A) 0.045 mole NaOH/mole lactic acid, 10-75 pm ( ) 0.14 mole NaOH/mole lactic acid, 10-75 pm. Drug loading, 43%. Emulsifier, sodium oleate.

In order to determine whether the effect of NaOH was specific to the use of sodium oleate as the emulsifier, microspheres were also prepared using polyvinyl alcohol to stabilize the emulsion. Figure 3 indicates that there was only a moderate increase in drug release by the addition of NaOH to the emulsion. 

The time for 50% release was 8 days for the 50% thioridazine-loaded microspheres prepared without NaOH. It was decreased to 5 days for those prepared with NaOH. The effect of NaOH was more pronounced when the drug loading was increased to 58%, as shown in Figure 4. The time for 50% release was significantly reduced from 7 days (without NaOH) to 1 day (with NaOH). 

The release data for the posttreated microspheres follow closely the solid line which represents the original microspheres prepared without NaOH. The data for the posttreated microspheres differ significantly from those for microspheres prepared in the usual manner with NaOH. If there was any interaction between NaOH and the drug-loaded microspheres, it was not sufficient to cause any measurable increase in drug release. This indicates that the effect of NaOH occurred prior to completion of solvent evaporation. It was not caused by any subsequent interaction between the drug-loaded microspheres and NaOH. 

Figure 6. Effect of NaOH posttreatment on thioridazine release from poly(DL-lactide) microspheres. Key (o) before NaOH posttreatment,...

The data also suggest that the effect of NaOH occurred during the solvent evaporation step, rather than before or after this step. 

The significant effect of NaOH/phenol ratio on gel time is plotted in Figure 5. The fastest gelation rate occurred between NaOH/phenol molar ratios... 

Table III. Effect of NaOH Content on Content of High Molecular Weight Fraction and Average Molecular Weight...

Figure 5. Effect of NaOH/phenol ratio on gel time of phenolic resins.

Photocatalytic Decomposition of Liquid Water on a NiO-SrTiCh Catalyst. As in Entry 7 but for liquid water. Effect of NaOH film (see Entry 6) reproduced for NiO-SrTiCh powder. 400... 

Water Photolysis over Metallized SrTiCh Catalysts. Promoting effect of NaOH not so pronounced as for Ti02. 406... 

The rate of compound 2 formation increased dramatically on going from LiOH to NaOH and further to KOH and LiOH-CsF. However, vinylation in the presence of LiOH did not occur at all, but the reaction proceeded quite fast with NaOH, KOH and CsOH. The effect of NaOH-CsF turned out to be unexpected the selectivity of pyrrole 2 formation increased and the vinylation was suppressed. 

The aminolysis and methanolysis of ionized phenyl salicylate (189) have been examined under micellar conditions. The effect of CTABr on the rates of aminolysis of (189) by -butylamine, piperidine, and pyrrolidine is to bring about a rate decrease (up to 17-fold with pyrrolidine). The results are interpreted in terms of binding constants for the amines with CTABr and the pseudo-phase model.The effects of mixed surfactants SDS and CTABr on the methanolysis of (189) and the alkaline hydrolysis of phenyl benzoate suggest that micellar aggregates are involved in the processes.The effects of NaOH and KBr on the intramolecular general base-catalysed methanolysis of (189) in the presence of CTABr has been investigated. Pseudo-first-order rate constants were not affected by either additive but other changes were noted. The effect of mixed MeCN-water solvents on the same reaction has also been probed. 

Figure 7. The effect of NaOH concentration on extraction of Eu (III) (1) and Am(III) (2) from 10 4M DTP A by 0.04M DOF toluene solution extraction time,...

This paper reports results on one phase of a program of study of concentrated oil-in-water emulsions, namely the effect of several composition variables on the apparent viscosity of concentrated (60 volume percent) crude oil-in-water emulsions. In particular, the effects of NaOH content, NaCl content, emulsion preparation technique, crude oil viscosity and aging of emulsion were studied. 

A. The Effect of NaOH Concentration on Shell Crude Emulsion Properties... 

Figure 1. Effect of NaOH Content and Aging on pH Values for 607. Shell Crude Emulsions.

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