Study on chemical structures of poly (tetrafluoroethylene-co-perfluoroalkylvinylether) by soft-EB irradiation in solid and molten state

Kakigi, Tomoyuki; Oshima, Akira; Miyoshi, Nozomi; Murata, Kei; Fujii, Kazuki; Mitani, Naohiro; Urakawa, Tatsuya; Sato, Yukiko; Matsuura, Akio; Li, Jingye; Miura, Takaharu; Katoh, Etsuko; Washio, Masakazu

doi:10.1016/j.nimb.2007.08.036

Cited by 4 publications

(1 citation statement)

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“…Because of the long T 1 time of KF, polytetrafluoroethylene (PTFE) was used as an external reference for pulse and chemical-shift calibration (d ¼ À124 ppm with respect to CFCl 3 (ref. 44)). Proton decoupled 29 Si MAS NMR spectra were recorded by use of a 4 mm MAS probe head and a sample-rotation rate of 5 kHz.…”

Section: Characterizationmentioning

confidence: 99%

Facile synthesis of the DD3R zeolite: performance in the adsorptive separation of buta-1,3-diene and but-2-ene isomers

et al. 2011

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Small pore size and hydrophobic nature of DD3R make this material a unique zeolite with high potential in industrial separation applications. However, the reproducible rapid synthesis of this zeolite is still a problem. In this work, a thorough assessment of different synthetic methods revealed that synthesis reproducibility relies on two main pillars: the use of properly cleaned autoclave liners and the synthesis composition. High quality DD3R crystals are obtained when KOH is used as a cleaning agent, eliminating memory effects, and when KF is used in the synthesis as a mineralizing agent. H NMR reveals that template molecules accommodated within the cages are sticking to these 8-ring windows through their amine group. High quality DD3R crystals are applied in the adsorptive separation of buta-1,3-diene and but-2-ene isomers, one of the most energy intensive separations in chemical industry. Mixture separation experiments revealed that the 8-ring apertures of the DD3R cages are only accessible to trans-but-2-ene and buta-1,3-diene, while excluding but-1-ene and cis-but-2-ene molecules, resulting in shape-selective separation in the presence of C4 mixtures.

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Section: Characterizationmentioning

confidence: 99%