Surface properties of aqueous amino acid solutions II. Leucine-leucine hydrochloride and leucine-sodium leucinate mixtures.
To understand the distinction between the effects of zwitterionic, anionic, and cationic l-leucine upon adsorption and lateral interactions at air/water surface, the surface tensions of aqueous solutions of l-leucine-l-leucine hydrochloride and l-leucine-sodium l-leucinate mixtures were measured as a function of concentration and composition at 25 degrees C. The surface activity decreases in the order l-leucine >l-leucine hydrochloride > sodium l-leucinate. Both l-leucine hydrochloride and sodium l-leucinate form gaseous adsorbed films through the experimentally accessible concentration range, while the adsorbed film of zwitterionic l-leucine shows a transition between gaseous and expanded film.
Matubayasi
Norihiro
N
Faculty of Fisheries, Nagasaki University, 1-14 Bunkyou-machi, Nagasaki 852-8521, Japan. norihiro@net.nagasaki-u.ac.jp
Matsuyama
Shohei
S
Akizuki
Ryosuke
R
D000327:Adsorption; D000388:Air; D000596:Amino Acids / Q000737:chemistry*; D006851:Hydrochloric Acid / Q000737:chemistry*; D007930:Leucine / Q000737:chemistry*; D012964:Sodium / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry; D013499:Surface Properties; D013500:Surface Tension; D014867:Water / Q000737:chemistry
D000596:Amino Acids; D012996:Solutions; D014867:Water; D012964:Sodium; D007930:Leucine; D006851:Hydrochloric Acid