Metal fluoride materials with complex pore structure and organic functionality

Evaluation of novel nanoscaled metal fluorides on their ability to remineralize enamel caries lesions

“…The tested NMF are small in size but have a large surface ranging from 229 m 2 g −1 ± 64 m 2 g −1 to even more than 300 m 2 g −1 and possess a great level of Lewis acidity 25–27 . Therefore, these metal fluorides present a higher reactivity than their macroscaled chemical equivalences.…”

“…Consequently, it becomes more accessible for ions to permeate into the enamel structure 12,28 . The tested NMF are smaller than <15 nm, the reduced size enables the NMF to penetrate the enamel matrix and to form a reservoir within the enamel lesion 27 . Thus, a constant contribution to the enamel’s remineralization process is possible.…”

“…Notably, clogging of enamel pores may inhibit further dissolution and subsequent demineralization of enamel. Early caries lesion in enamel possesses a pore size of 50–200 nm, the investigated NMF are similarly produced as the metal fluorides, with a size between 10–15 nm 27,36 . Therefore, these NMF should easily penetrate the enamel structure without clogging of superficial pores due to their limited amount of free reactive fluoride ions and thus can provide a fluoride reservoir within the lesion.…”

Nanoscale metal fluorides: a new class of heterogeneous catalysts

“…7) that has been proven in the meantime to be a general synthesis approach for nanoscopic metal fluorides. [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] For deeper insights into the mechanism of the fluorolytic sol-gel approach, see ref. 10.…”

Rational design of MgF2catalysts with long-term stability for the dehydrofluorination of 1,1-difluoroethane (HFC-152a)

“…This can be explained by the Tanabe model where the surface acidity of MgF 2 is generated from the excessive positive charge caused by the coordinated unsaturated Mg 2+ ions on the surface; 14 the generation of high surface area is oen accompanied by the production of large amount of acid sites; 15 therefore, signicant research efforts have been focused on the synthesis of highsurface area MgF 2 (HS-MgF 2 ). [16][17][18][19][20][21][22][23] Kemnitz et al 17 have successfully synthesized amorphous nano-sized MgF 2 with the high surface area of 150-350 m 2 g À1 via a non-aqueous uorolytic sol-gel method. The results of the analysis of temperature-programmed desorption of ammonia (NH 3 -TPD) showed that the strong acid sites disappeared when the catalysts were pre-treated at 300 C, and above this temperature, the structure of HS-MgF 2 would probably be affected.…”