Study of assembly of arachidic acid/LDHs hybrid films containing photoactive dyes.
Hybrid monolayers formed with an floating arachidic acid (AA) anions monolayer binding with a densely packed layered double hydroxides (LDHs) monolayer at an air/LDHs suspension interface has been studied by pi-A isotherms and TEM images. An ordered multilayer film of AA/LDHs has been fabricated by Langmuir-Blodgett technique on various substrates. The photoactive dyes (methyl orange, MO, and Congo red, CR) can be incorporated into the galleries of LDHs in the AA/LDHs hybrid LB film by an ion intercalation method. The results of FTIR and UV-vis absorption spectra can approve the formation of AA/LDHs/dyes composite films. In addition, UV-vis absorption spectra and LAXRD analyses also provide evidence for the good vertical uniformity and stable layered periodic structure of AA/LDHs/dyes films. More interestingly, it was found that the dye molecules intercalated can be induced by a positively charged LDHs sheet to align in a special orientation and form different aggregates: MO molecules form sandwich H-type aggregates, while CR molecules form head-to-tail J-type aggregates. On the basis of these data, a possible model of the AA/LDHs/dyes composite films was proposed. Also, the dye molecules incorporated into AA/LDHs films exhibit excellent configuration stability under the irradiation of UV light because the LDHs matrix offers a more rigid and constrained environment for them.
Key Laboratory for Colloid & Interface Chemistry of Education Ministry, Shandong University, Jinan, Shandong 250100, People's Republic of China.
Jun
J
Wang
Xuemei
X
Ren
Xusheng
X
Feng
Shangying
S
Liu
Dejun
D
Sun
D000388:Air; D001391:Azo Compounds / Q000737:chemistry; D004396:Coloring Agents / Q000737:chemistry*; D003224:Congo Red / Q000737:chemistry; D004537:Eicosanoic Acids / Q000737:chemistry*; D006878:Hydroxides / Q000737:chemistry*; D008567:Membranes, Artificial; D008854:Microscopy, Electron; D015394:Molecular Structure; D010316:Particle Size; D013499:Surface Properties; D013535:Suspensions / Q000737:chemistry
D001391:Azo Compounds; D004396:Coloring Agents; D004537:Eicosanoic Acids; D006878:Hydroxides; D008567:Membranes, Artificial; D013535:Suspensions; D003224:Congo Red; C100258:methyl orange