Contrast viscosity changes upon photoirradiation for mixtures of poly(acrylic acid)-based alpha-cyclodextrin and azobenzene polymers.
Polymer-polymer interactions were investigated for mixtures of a poly(acrylic acid) (pAA) carrying azobenzene (pC12Azo) and two kinds of pAA carrying alpha-cyclodextrin (CD), in which CDs are attached to the main chain through the 3- and 6-positions in CD (p3alphaCD and p6alphaCD, respectively), using several techniques, such as viscosity and NMR measurements. Viscosity data exhibited contrast changes upon UV irradiation: thinning (p3alphaCD/pC12Azo) and thickening (p6alphaCD/pC12Azo). NOESY spectra confirmed that the contrast viscosity changes were ascribable to differences in how CD moieties interact with pC12Azo after photoisomerization of azobenzene moieties from trans to cis: dissociation of inclusion complexes (p3alphaCD/pC12Azo) and formation of interlocked complexes (p6alphaCD/pC12Azo).
Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
Itsuro
I
Tomatsu
Akihito
A
Hashidzume
Akira
A
Harada
D000180:Acrylic Resins / Q000737:chemistry* / Q000528:radiation effects*; D001391:Azo Compounds / Q000737:chemistry* / Q000528:radiation effects*; D004548:Elasticity; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D014783:Viscosity; D047391:alpha-Cyclodextrins / Q000737:chemistry* / Q000528:radiation effects*
D000180:Acrylic Resins; D001391:Azo Compounds; D047391:alpha-Cyclodextrins; C006903:carbopol 940; C009850:azobenzene