Dynamic properties of water in silicalite-1 powder

Interplay between hydrophilicity and surface barriers on water transport in zeolite membranes

“…Results show that D is sensible to both defect concentration and silanol hydrophilicity at low hydration values (that is, ϑ M <0.5). The diffusivity decreased as the crystal hydrophilicity increased and the trend agreed with previous experiments27484950. However, at higher values of the pore hydration (that is, ϑ M >0.5), D becomes independent of the defect density.…”

“…However, the experimentally measured diffusivity of water is also strongly correlated to the distance over which measures are performed19. When the experimental measurements probe diffusivities over distances on the order of nanometres (that is, neutron scattering), the results show a reasonable (that is, within an order of magnitude) agreement with those measurements calculated from MD simulations484953. However, other measurement techniques (for example, gravimetric uptake quantify or pulsed field gradient nuclear magnetic resonance) evaluate water transport over much larger distances (∼1–100 μm) and these measured diffusivities are generally three to six orders of magnitude lower than those found by molecular simulations or neutron scattering275455.…”

Modification of commercial NaY zeolite to give high water diffusivity and adsorb a large amount of water

“…In zeolite beta, the presence of the mesopores is found to enhance the rate of molecular diffusion by a factor of 3. Filippov et al discussed dynamic properties of water in silicalite-1 by 2H NMR with bipolar field gradient pulses and longitudinal Eddy-current-delay [7]. Ogura et al [8,9] reported ZSM-5 zeolite having a SiO 2 /Al 2 O 3 molar ratio of 39.4 (NH 4 -form) was treated in a NaOH alkali solution and mesopores with a uniform size were formed on the zeolite.…”

Study of the Distribution of Organic Molecules in the Porous Space of Vycor Glasses

“…This method provides important information such as characteristics of porous materials and the properties of the adsorbed fluid by measuring the nuclear magnetic relaxation times. It should be mentioned that in most papers properties of adsorbed liquids in such porous B. Gizatullin (&) Á G. Pimenov Institute of Physics, Kazan Federal University, 18 Kremlyovskaya St.,, Kazan 420008, Republic of Tatarstan, Russian Federation e-mail: bulat_giz@mail.ru materials as zeolites, porous glass and aerogels are being discussed under conditions of the completely filled pore volume [3][4][5]. When talking about partially filled pores, more detailed information about the interaction between the adsorbed liquid and surface of the porous material can be obtained by means of NMR [6,7].…”