Abstract: A free chlorine measurement system and sensor are provided. In accordance with one aspect of the invention, the sensor has a porous working electrode disposed in an electrolyte proximate a porous membrane. The membrane allows free chlorine therethrough where it is reduced and generates a current. The current is related to the free chlorine concentration. The internal electrolyte solution is pH stabilized with a long-term pH stabilizer that has a solubility in water at room temperature between about 1.2 moles/liter and about 0.001 moles/liter. The stabilizer can be an acid or a base depending on whether the pH is to be stabilized at a relatively low value or a relatively high value respectively.

Abstract: Hydrophilic diamond surfaces comprise surface oxygen bonded onto diamond surface only through oxygen/carbon single bond. The hydrophilic diamond surfaces are treated with strong reductant (e.g., lithium aluminum hydride) to reduce oxygen/carbon double bonds to oxygen/carbon single bond. The hydrophilic diamond surfaces can be used as stationary phase for liquid chromatography.

Abstract: A free chlorine measurement system and sensor are provided. In accordance with one aspect of the invention, the sensor has a porous working electrode disposed in an electrolyte proximate a porous membrane. The membrane allows free chlorine therethrough where it is reduced and generates a current. The current is related to the free chlorine concentration. The internal electrolyte solution is pH stabilized with a long-term pH stabilizer that has a solubility in water at room temperature between about 1.2 moles/liter and about 0.001 moles/liter. The stabilizer can be an acid or a base depending on whether the pH is to be stabilized at a relatively low value or a relatively high value respectively.

Abstract: The invention sets forth a method to connect diamond powders with other diamond powders or to connect diamond powders with substrates by cycloaddition reactions. The diamond powders are pretreated to desorb non-carbon surface atoms. The cycloaddition reactions are between clean diamond surfaces and C—C double bonds in the cross-linking molecules, which are either conjugated or not. The reactions are performed at temperatures <200 Celsius degree. The cross-linking molecules are covalently bonded to diamond powders through C—C single bonds. The method produces diamond structures with big sizes. The diamond structures produced by the method can be chemically stable. The diamond structures produced by connecting diamond powders are porous.

Abstract: Packing materials useful in applications such as liquid chromatography and solid phase extraction, as well as processes for producing such packing materials are described. The packing materials are based on chemically modified diamond powders. The surfaces of the diamond powders are attached with hydrocarbon, amino, carboxylic acid, or sulfonic acid groups through C—C, C—N, or C—S single bonds. The residual groups can be solely hydroxyl groups or solely hydrogen atoms. The stability of the packing materials allows regeneration of columns at pH>14 for protein separation. With hydrogen atoms as the residual groups for reverse phase diamond packings, the non-specific interaction associated with silica, polymeric, or graphitic packings can be largely eliminated. With hydroxyl groups as the residual groups for ion exchangers based on diamond powders, the non-specific interaction associated with hydrophobic sites can be largely eliminated.