Preparation, surface-activities and dispersion of nano-particle aqueous solution of modified Gemini surfactants.

• Main Authors: Min-yan Dong, 董泯言
• Other Authors: Chung-Feng Jeffrey Kuo
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/7af3fv

博士 === 國立臺灣科技大學 === 材料科學與工程系 === 99 === In this study, the Gemini surfactant was appended to maleic anhydride through condensation with polyoxyethylenated stearyl ether; anionic hydrophilic moieties were obtained after modifying the spacer units with sodium hydrogen sulfite groups to form a series of modified Gemini surfactants. The molecular structures of these surfactants were confirmed by 1H-NMR and FT-IR. The surface activities were evaluated by surface tension, contact angel, foaming properties, and compared with traditional single-molecule surfactants. The pH buffer capacities, emulsion, dispersibilities, scouring and dye-surfactant interactions were also investigated. Surface tension results exhibited that surfactants have lower surface tension, cmc, surface excess concentration and occupied area per molecule, moreover, these compounds own better wetting and lower foaming than traditional surfactants due to the molecular structures of surfactants are Gemini structure. From emulsion results, the lower value of occupied area per molecule indicated that molecules packed close on oil surface and resulted in better emulsion stability. We have also studied the dispersing abilities of these surfactants toward commercial disperse dyes at elevated temperature. From measurements of the particle sizes and the dispersibilities of the dye solutions, we found that the surfactants exhibited good surface activities and dispersibilities. We used spectrophotometry to investigate the interactions between the dyes and the surfactants in the dye bath. In the case of each of the three kinds of disperse dyes and three kinds of direct dyes, the absorbance of the dye solutions in the presence of the surfactants were higher than those in its absence because of the dispersion, dissolution and forming complex. The difference mainly results from TiO2 dispersion adding surfactants which could provide accuracy in controlling size and offer a simple production procedure. Meanwhile, the research also discusses how different parameters affect the particle size distribution. The study uses Taguchi Experimental Design Method so that the most adequate parameters could be predicted and applied to coating process using TiO2 dispersion solution.