Controlled Fabrication Of Single Charge Small Organic Molecular Multilayers Film And The Research Of The Function Of Film

Self-assembly method with the advantage of versatility, simplicity and easyoperation was widely applied. The current research interest lies on the fabrication ofmultilayers film using low molecular weight organic materials. Since these organicmaterials offer many interesting electronic and optical properties. Although manymethods on fabricating functionalized multilayers film have been established, it stillremains challenge on how to controllably introduce abundant single chargedfunctional molecules into multilayers systems. In this dissertation we mainly focus onthe method which we can introduce single charged molecules into multilayerssystems. Development the related applications of the small-molecules multilayersfilm based on their characteristics.We found a new method, so-called "pre-mixing self-assembly", by which we canintroduce single charged molecules into multilayers systems. This method isdescribed as follows: first, we mix single charged molecules as molecular templateswith chitosan solution to form pre-mixing assemblies; second, we deposit thesepre-mixing assemblies alternatively with anion polyelectrolyte at solid/liquidinterface to fabricate multilayers film. The single charged molecules can beintroduced into multilayers film through this method abundantly and controllably. Atthe same time the releasing time of small-molecules dye in the film is delayed. Theorganic dye like neutral red (NR), safranine T (ST), methylene blue (MB) andacridine orange (AO) all can be assembled by this method. Their loading was foundto be controlled by changing the concentration of small-molecules dye and film layers.Their release was affected by the change of pH and ionic strength. Applyingheat-treatment after film formation can delay the release time.A self-assembled multilayers film was prepared containing two small-molecules.MB was chosen as the model to study the load and release behavior when anothersmall-molecule coexisted in the film. The load and the existing form of MB inself-assembled multilayers film can be regulated by changing the concentration of thesame charge dye AO in pre-mixing assemblies. The stability of MB in the film can greatly improve when the negative charge titan yellow (TY) was added to pre-mixingassemblies. The loading and releasing mechanism was discussed.Another method of assembly of small-molecules was researched. First, weprepared a-NH2terminated self-assembled monolayer（SAM） on the substrate; then,a small fluorescent molecules with activity group was bond to the SAM. The filmprepared by this method has a good stability. Therefore, a series of novel fluorescentfilm sensors have been developed. We prepared1-naphthylamine acetate fluorescentsensing film to detect Mn2+in aqueous phase, dansyl chloride fluorescence sensingfilm to detect moisture content in the ethanol and fluorescein isothiocyanate sensingfilm to detect the pH of the solution.