A detailed investigation of the microwave assisted phenylphosphonic acid modification of P25 TiO2

• Published in: Advanced powder technology : the international journal of the Society of Powder Technology, Japan Vol. 28; no. 1; pp. 236 - 243
• Main Authors: Tassi, Marco, Roevens, Annelore, Reekmans, Gunter, Vanhamel, Martine, Meynen, Vera, D’Haen, Jan, Adriaensens, Peter, Carleer, Robert
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-01-2017
• Subjects: 31P solid state NMR; ATR-FTIR; Phosphonic acid; TEM; TiO2 surface modification; Titaniumphenylphosphonate; Phosphonic acid; Titaniumphenylphosphonate; 31P solid state NMR; ATR-FTIR; TEM; TiO2 surface modification
• ISSN: 0921-8831; 1568-5527
• DOI: 10.1016/j.apt.2016.09.020

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•Formation of titaniumphosphonate starts around 45°C.•The water is crucial for the formation of titaniumphenylphosphonate.•The absence of water results only in the surface modification of the P25 TiO2.•The correlation between the amorphous TiO2 and titaniumphenylphosphonate formation.
The microwave assisted reaction between P25 titanium dioxide (TiO2) and phenylphosphonic acid (PPA) is explored thoroughly and the influence of the reaction conditions on the grafting mechanism and formed products is presented. While the surface grafting is observed at low temperatures and water free conditions, the formation of titaniumphosphonate is favored in water and high reaction temperatures. For the first time the correlation between the amorphous TiO2 phase and the formation of titaniumphenylphosphonate is reported. Materials are fully characterized by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), solid-state 31P Nuclear Magnetic Resonance (31P NMR) spectroscopy, energy dispersive X-ray (EDX) spectroscopy and transmission electron microscopy (TEM).