The Ca2+ concentration and hydrolysis degree [-COO-] dependence of the self-complexation of partially hydrolyzed poly(acrylamide) (HPAM) chains in CaCl2 aqueous solution was systematically investigated by a combination of static and dynamic laser light scattering. We have, for the first time, revealed a transition between the intrachain and interchain complexations. For each given HPAM sample, ...

A flow injection SPR spectrometer is used to detect DNA hybridization via amplification by an enzyme-catalyzed precipitation reaction. Hybridization of an oligodeoxynucleotide (ODN) target with a surface-confined ODN probe, followed by hybridization between the overhang on the resultant duplex and a biotin-tagged ODN, yields a "sandwich" complex (a three-component double-stranded). A streptavid...

The shape, porosity, and surface hydrophilicity of hematite particles formed from a forced hydrolysis reaction of acidic FeCl3 solution were controlled by using a trace of polymers (0.001 and 0.003 wt%). The spherical particles were produced on the systems with polyvinyl alcohol (PVA) and polyaspartic acid (PAS). In the case of polyacryl amide (PAAm), slightly small spherical particles were pre...

The sorption of uranyl onto hydrous ferric oxide (HFO) or hematite was measured by discontinuously titrating the suspensions with uranyl at pH 5.9, 6.8, and 7.8 under Pco2 = 10(-35)atm (sorption isotherms). Batch reactors were used with equilibration times up to 48 days. Sorption of 1 microM uranyl onto HFO was also measured versus pH (sorption edge). A diffuse double layer surface complexation...

Eight quaternary ammonium compounds were tested for their ability to induce contact dermatitis in guinea pigs by using a modified Freund's complete adjuvant test together with the guinea pig maximization test. Only two quaternary ammonium salts of the eight tested could be designated as strong allergens. These two active substances were shown to be capable of stable association with membrane li...

Complexation of thiazorylazododecylphenol (TADP) with Ni2+ at the surface of sodium dodecylsulfate (SDS) micelles has been spectrophotometrically studied. Complicated spectral changes are analyzed by a factor and multivariate analysis, which implies the formation of [TDAP(OH-)Ni]0 as well as a simple 1:1 complex of Ni2+ with TDAP at the micellar interface. All of the equilibrium constants requi...

The complexation reaction between iodine and 1,10-Diaza-18-Crown-6 (DA18C6) has been studied in acetonitrile by spectrophotometric, biamperometric and conductometric techniques. The results are indicative of the formation of [(CH3CH)nI+.I¯3] from iodine and acetonitrile, and the formation of DA18C6 I+. I¯ from DA18C6 and [(CH...

A supramolecular approach for the specific detection of sarcosine, recently linked to the occurrence of aggressive prostate cancer forms, has been developed. A hybrid active surface was prepared by the covalent anchoring on Si substrates of a tetraphosphonate cavitand as supramolecular receptor and it was proven able to recognize sarcosine from its nonmethylated precursor, glycine, in water and...