Study On The Aggregation Behavior And Adsorption Of Surfactants On Solutions And Minerals In The Presence Of Melon Rings

Cucurbit[n] uril(Q[n]), a macrocyclic cage compound, consists of methylene-bridged glycoluril units. It possesses a hydrophobic cavity and polar carbonyl groups surrounding the portals.The investigation of the interaction between Cucurbit[n] urils and surfactants is very important in many fields such as molecular recognition, biological process analysis, biochemical reaction, drug delivery and fluorescence induction. In this paper, the aggregation behavior and adsorption of surfactants in the presence of Cucurbit[n] urils have been studied.In the first section, Cucurbit[n] urils and surfactants have been introduced.In the second section,we preparated a 4, 4'-dipyridy surfactant. The intermediate product was obtained by the reaction between 4, 4'-dipyridine and methyl iodide,followed by the reaction between the intermediate and 1-Bromooctane. The total yield was 57%. The structure of the surfactant was identified by IR and 1H NMR.In the third section, a Gemini surfactant was prepared as following method. We used N, N, N, N- tetramethyl ethylene diamine and bromo dodecane as the main raw materials to prepare the Gemini surfactant by one step reaction. The total yield was87.5%. The structure of the surfactant was identified by IR and 1H NMR.In the fourth section, we investigated the interaction between the surfactants and the Cucurbit[n] urils using nuclear magnetic resonance spectroscopy, UV spectroscopy and isothermal titration calorimetry. The interaction between the 4,4'-dipyridy surfactant and Cucurbit[8] uril(Q[8]) and interaction between DTAB and Q[7] or Q[8] were investigated.In the fifth section, we studied the interaction between the Gemini surfactant and the Q[7] or Q[8] using the nuclear magnetic resonance spectroscopy and the isothermal titration calorimetry. The hydrophobic chain of the Gemini surfactant could enter the cavity of the Cucurbit[n] uril(Q[7] or Q[8]). As a result, formation of1:2 supramolecular system spontaneously happened and its driving force was the enthalpy and entropy change, but the enthalpy change was the main driving force.In the sixth section, we studied the influence of cucurbiturils on the surfaceproperties of the surfactant solution using surface tension method and fluorescence probe. It showed that Q[7] or Q[8] could decrease the aggregation number of the Gemini surfactant and Q[7] could reduce the foaming ability and foam stability of the Gemini surfactant.In the seventh section, the wetting properties of the surfactant in the presence of the cucurbit urils were studied using DTAB and the Gemini surfactant as the model compounds. It showed that withoud Q[7] or Q[8], the adsorption of surfactants on the quartz surface could be divided into three processes. But in the present of the Q[7] or Q[8], the adsorption of surfactants on the quartz surface could be divided into four processes.