Fabrication and application of TiO2 foams with hierarchical pore structures

• Main Authors: Chih-Yu Chuang, 莊志宇
• Other Authors: Wen-Jea Tseng
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/32788361186799480938

碩士 === 國立中興大學 === 材料科學與工程學系所 === 104 === This research aims to prepare macroporous TiO2 foams with hierarchical pore structures via particle-stabilized direct foaming. Mesoporous TiO2 particles with a submicrometer particle size were first synthesized by a solvothermal route; in which, anatase TiO2 with a wormhole-like pore structure and a BET surface area of 142.5 m2/g resulted. Different surfactants were used to modify the surface of TiO2 particles in solvent. By selective adsorption of non-ionic 1-hxadecylamine (HDA) molecules on the as-prepared, mesoporous TiO2 particles, an initially hydrophilic surface became partly hydrophobic. The contact angle increased from ca. 5o to greater than 70o with the HDA adsorption. Stable foams were then prepared by a simple mechanical frothing of aqueous suspensions consisting of the hydrophobic TiO2 particles as the filler phase. The hydrophobic particles tended to reside at the air-water interface so that the bubbles were protected from coalescence, drainage and disproportionation to occur between the neighboring bubbles. Finally, macroporous TiO2 foams with hierarchical pore structures ranging from nanopores to micron-sized pore size and a high porosity could be prepared after calcination at moderate temperatures. The TiO2 foams prepared at calcination temperature of 1000oC showed the best oil-absorption capability. The macroporous TiO2 foams exhibit absorption capacities ranging from 10 to 15 times of their own weight for a variety of oils. Then, the macroporous TiO2 foams also showed good recyclability in the oil-absorption.