Incorporation Of Alkyl Groups Research Articles

Properties of modified surface for biosensing interface.

Properties of modified surface, behavior against salting-out effect, suppressive effect for protein nonspecific adsorption, and wettability were examined using various mercapto compounds bearing methyloligoethylene glycol, oligoethylene glycol, alkyl oligoethylene glycol, alkyl phosphoryl choline, alkyl inverse phosphoryl choline, and alkyl sulfobetaine moieties. The behavior against salting-out effect was examined using gold nanoparticle with PBS and NaCl aqueous solution. The suppressive effect for protein nonspecific adsorption was evaluated by SPR, and the wettability was measured on the SPR chip. The gold nanoparticle modified with 8C3EG, 12C4EG, 12CPC, 6CCP, and 12CCP showed excellent behavior against salting-out effect. The suppression of protein nonspecific adsorption was effective with 6EG, 12C4EG, 12CPC, and 12CS. On the other hand, the modified surface possessed high wettability except for the surface modified with M6EG. The results indicate that incorporation of alkyl group into surface modification materials is effective for the enhancement of behavior against salting-out effect and suppressive effect for protein nonspecific adsorption regardless of wettability. Among the zwitter ionic derivatives, inverse phosphoryl choline derivatives showed intriguing properties, high behavior against salting-out effect with high wettability but low suppressive effect for protein nonspecific adsorption.

Adsorption Kinetics of Anilines on Macroporous Kaolin

Macroporous kaolin is studied as a convenient substrate for adsorption of petroleum heavy ends in relation to feasible upgrading processes. Understanding the parameters that control adsorption of polar molecules over different adsorption media is important for process optimization. In these regards, adsorption kinetics of small molecular mass anilines (<205 g/mol) over macroporous kaolin was studied. The results indicate that the dynamic and levels of adsorption of these molecules is not controlled by differences in molecular size. The nature of substituents on the aniline ring plays an important role on the adsorption. The incorporation of oxygen as a methoxy group in the ortho or para position enhances the adsorption, while the incorporation of alkyl groups has mixed effects on this phenomenon, decreasing the adsorptivity when the group in placed in the ortho position. The presence of two aromatic rings attached to the aniline molecule such as 1-amino anthracene increases the adsorption uptake. Moreover, the presence of sulfur in the form of methylthio groups reduces the adsorption particularly when the group is located in the ortho position. Finally, thermodynamics of the adsorption of these anilines over macroporous kaolin are studied and found primarily governed by the type of substituent present on the aromatic ring.

Surfactant-free artificial latexes from modified styrene–maleic anhydride (SMA) copolymers

We describe the preparation of surfactant-free artificial latexes on the basis of poly(styrene- alt-maleic anhydride) (SMA) copolymers. The SMA copolymers were first partially alkyl-imidized and then partially ammonolyzed in acetone. Upon adding to water and after the removal of acetone, the modified copolymers formed stable latexes, with a diameter of ∼150 nm and a PDI < 0.2. In the absence of alkyl groups the particles became completely soluble in water after a few days. The latexes from the partially alkyl-imidized polymer were found to remain stable at pH > 2. The incorporation of alkyl groups into the copolymers significantly lowered the T g of the polymer from 150 to 75 °C, depending on the amount of alkylamines added. It was found that the molecular weight as well as the molar mass distribution of the SMA polymers did not show major effects on the properties of the artificial latexes.