Synthesis and photochemical surface fixation of hydroxylated cascade molecules

✍ Scribed by Takashi Sugawara; Takehisa Matsuda

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 210 KB
• Volume: 35
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19970115)35:1<137::aid-pola14>3.0.co;2-l

✦ Synopsis

A novel supramolecularly assembled surface architectural method was developed, which involved a self-assembling process of amphiphilic molecules and a subsequent photochemical process. The specially designed molecules were cascade ''tree'' molecules composed of a phenylazido group as root, an aliphatic hydrocarbon chain as stem, and two or three tris(hydroxymethyl)aminomethane groups as leaves. Using a horizontal lifting method, unimolecular assemblies which formed at an air/water interface were transferred to polyethylene (PE) surfaces. Upon ultraviolet irradiation, these molecules were covalently fixed on the surfaces due to the photochemical reactivity of the phenylazido group. Treated surfaces became wettable with water, indicating that hydrophilic hemispheres were located at the outer surface region of the PE surfaces. Bimolecular assemblies composed of cascade molecules and noncascade molecules with a hydroxyl group at a terminus exhibited lower advancing and receding contact angles and reduced hysteresis than those of unimolecular ones, indicating that these bimolecular assemblies have a well-structured molecular organization with a high degree of packing. ᭧