Sodium dispersion chemistry

Dr. Bill Coleman, for several chemical steps in Syntex s synthesis of the oral contraceptive chlormadinone. With Haldor Christensen, sodium dispersion chemistry led to a superior process for the manufacture of the Eh Lilly herbicide, diphenamid. We devised novel patented chemistry, with the inspiration of Dr. Martin Hultquist, for the manufacture of DDQ. The list could go on and on, but the essence is that in Arapahoe we became chemical process development chemists. We learned that there were no such chemists as steroid chemists, organometallic chemists, heterocyclic chemists, and so on. There are only process development chemists, capable of synthesizing anything. Being scientists in a small company we also learned to accommodate other disciplines and business requirements in creating our chemical processes. 

S. Stankovich, R.D. Piner, X. Chen, N. Wu, S.T. Nguyen, R.S. Ruoff, Stable aqueous dispersions of graphitic nanoplatelets via the reduction of exfoliated graphite oxide in the presence of poly(sodium 4-styrenesulfonate), Journal of Materials Chemistry, 16 (2006) 155. 

Colloid Chemistry of Sodium Polyacrylate Dispersed Calcium Carbonate Slurries... 

Basic studies on diazonium-CNT chemistry led to two very efficient techniques for SWCNT derivatization solvent-free functionalization [176] and functionalization of individual (unbundled) nanotubes [175], With the solvent-free functionalization (Scheme 1.26), heavily functionalized and soluble material is obtained and the nanotubes disperse in polymer more efficiently than pristine SWCNTs [176], With the second method, aryldiazonium salts react efficiently with the individual (unbundled) HiPCO produced and sodium dodecyl sulfate (SDS)-coated SWCNTs in water. The resulting functionalized tubes (one addend in nine tube carbons) remained unbundled throughout their entire lengths and were incapable of reroping. [175],... 

In order to control the mechanism by which nickel is loaded onto sodium titanate and to control the degree of nickel dispersion, we need to understand the ion-exchange properties of the sodium titanate support, the hydrolysis chemistry of the dissolved nickel, and how the different nickel species are expected to interact with the titanate support. 

Discussions of chiroptical properties of corresponding compounds in this series of The Chemistry of Functional Groups generally refer to the spectral range 589-190 nm, i.e. the emphasis is on optical (molar) rotations [O] J in the transparent region (optical rotatory dispersion, ORD) and rotations [0]J measured at the wavelength of the sodium-D-line (X = 589 nm) as well as electronic circular dichroism A e (CD) in the near ultraviolet region (X 190 nm) ... 

Figure 8.5. Plot of the system constants (solvation parameter model) against composition for a mixed micelle electrolyte solution containing 50 mM sodium N-dodeconyl-N-methyltaurine and different amounts of the non-ionic surfactant Brij 35 (polyoxyethylene [23] dodecyl ether) (Left). Plot of the system constants for a mixed micelle buffer containing 50 mM sodium N-dodecanoyl-N-methyltaurine and 20 mM Brij 35 against the volume fraction of acetonitrile added to the electrolyte solution (Right). System constants m = difference in cavity formation and dispersion interactions r = difference in electron lone pair interactions s = difference in dipole-type interactions a = difference in hydrogen-bond basicity and b = difference in hydrogen-bond acidity. (From ref. [218] Royal Society of Chemistry).

Rose et al. (1996) described the development of a SCP characterisation for oil and coal fuel-types, using particle chemistries determined by energy dispersive X-ray spectroscopy (EDS). This technique is described as semi-quantitative as the results are expressed as a percentage of the total of elements selected for analysis. Additionally, the EDS detector used was unable to determine elements lighter than sodium, and thus carbon and oxygen, most probably the major constituents in SCPs (c.f. traffic-derived soot Fruhstorfer Niessner, 1994), were not measurable and do not appear in the total. However, rather than being a drawback, this had a positive effect as the 17 trace elements analysed consequently appeared to be much more important to the particle composition than in reality, and it was these, rather than the carbon content, which were used in differentiating between the fuel-types. 

In the manufacture of an acylated ketone, dimethylformamide was charged into a 2.2 m Pfaudler glass-lined reactor, blanketed with nitrogen. A quantity of sodium hydride dispersed in oil was added, together with diethyl-carbonate. When the mix recorded a temperature of 323 K, ketone and methylace-tylpyridine were added. In the incident, an exothermic reaction occurred before the addition of the ketone. The investigation revealed that the chemistry of the process had not been properly investigated and was not fully understood. 

To inhibit microbial growth in blood samples taken for the determination of ethanol, sodium fluoride is added. As a volatile organic analyte is measured, the sample containers should prevent evaporation. Clinical chemistry samples have a variety of preservatives depending on the specific analysis, e.g., heparin or citrate to prevent clotting of a whole blood sample. In this instance the tube already has the preservative in place before the sample is added all that is required is that the container is gently mixed to disperse the preservative throughout the sample. 

Dispersive erosion depends on the mineralogy and chemistry of soil on the one hand, and the dissolved salts in the pore and eroding water on the other. The presence of exchangeable sodium is the main chemical factor contributing towards dispersive clay behaviour. This is expressed in terms of the exchangeable sodium percentage, ESP ... 

Ruiz, C.C., L. Diaz-Lopez, and J. Aguiar. 2008. Micellization of sodium dodecyl sulfate in glycerol aqueous mixtures. Journal of Dispersion Science and Technology 29(2) 266-273. Santos, A., J.A. Toledo-Femandez, R. Mendoza-Sema, L. Gago-Duport, N. de la Rosa-Fox, M. Pinero, and L. Esquivias. 2006. Chemically active silica aerogel— wollastonite composites for CO2 fixation by carbonation reactions. Industrial and Engineering Chemistry Research 46(1) 103-107. 

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