| Abstract: | The Langmuir film balance and the Davies surface-film viscous traction apparatus have been used with films of cellulose triacetate alone and in presence of two different disperse dyes; these were C.I. Disperse Red 13, an azo dye having both proton-donating and proton-accepting groups in its molecule, and C.I. Disperse Yellow 13 (methoxybenzanthrone), which has only proton-accepting groups. The results show that a 1:1 complex is formed between either dye molecule and a hexa-acetylcellobiose unit of the cellulose triacetate molecule, and possibly also a complex with an aggregate of the yellow dye. This indicates a face-to-face association of the dye molecules (which are planar) with cellulose acetate. The association is probably a hydrogen-bonding interaction. |
