Global optimization reveals that aggregation is enhanced for coronene substituted with carboxylic and amine groups, which due to the influence of weak hydrogen bonds stronger electrostatic contributions.

Here, we report a facile and straight-forward approach to incorporate amphoteric groups inside the single conical nanochannels. This was realized by direct chemical modification of the surface carboxyl groups with L-lysine chains whose positive and negative charges are very sensitive to the external pH. The chemically functionalised channels were characterized both theoretically and experimenta...

Chemical properties of cationic biosorbents, the orange peel and the lemon peel, have been studied. ATR and Raman spectra indicated that the functional groups in the peels structure responsible for dye sorption are carboxyl groups (COOH and COOM, M=Na,K,Ca,Mg) and hydroxyl groups (OH). Increasing the mass of the peels in water suspensions a decrease in dissociation of both, the –COOH and –COOM ...

A method for the rapid modification under mild conditions of carboxyl groups in proteins has been developed. The method involves the activation of the carboxyl group by a water-soluble carbodiimide and the subsequent reaction of the activated carboxyl group with a nucleophile such as glycine methyl ester. The kinetics of the reaction indicates that there are limits to the variation of carbodiim...

Carboxyl groups i n porcine pepsin were chemically modified "by the carbodiimide reaction using waterrsoluble l-ethyl-3-(3-dimethylaminopropyl) carbodiimide and amino acid esters as nucleophiles. The modification resulted in profound changes in the a c t i v i t i e s , specificity and.some physicochemical properties of the enzyme. These include* (1) significant decrease in milk clotting activi...

We have used pHLIP® [pH (low) insertion peptide] to study the roles of carboxyl groups in transmembrane (TM) peptide insertion. pHLIP binds to the surface of a lipid bilayer as a disordered peptide at neutral pH; when the pH is lowered, it inserts across the membrane to form a TM helix. Peptide insertion is reversed when the pH is raised above the characteristic pK(a) (6.0). A key event that fa...

Few-layer nitrogen doped graphene was synthesized originating from graphene oxide functionalized by selective oxygenic functional groups (hydroxyl, carbonyl, carboxyl etc.) under hydrothermal conditions, respectively. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) observation evidenced few-layer feature of the graphene oxide. X-ray diffraction (XRD) pattern confirmed p...