Layer-by-layer aqueous rapid synthesis of ZIF-8 films on a reactive surface

Abstract

The synthesis of zeolitic imidazolate framework-8 (ZIF-8) films in an aqueous system was achieved. ZIF-8 films with controllable thickness were successfully grown on a modified substrate at room temperature. The 3-(2-imidazolin-1-yl)propyltriethoxysilane (IPTES) was used to first form a pseudo-surface of ZIF-8 on a glass substrate, followed by layer-by-layer growth. The film thickness of ZIF-8 was controlled within the range from 220 to 640 nm per growth cycle by changing the reactivity of the zinc source. Notably, the use of a preorganized zinc source led to drastic changes in the formation rate of ZIF-8. The use of a low-reactivity growth solution containing zinc acetate thus allowed the preparation of dense ZIF-8 films.

Zeolitic Imidazolate Frameworks (ZIF): A Potential Membrane for CO2/CH4Separation

“…The ZIF membrane is formed when ZIF crystals grow as film on the inert porous support. Several approaches have been demonstrated in synthesizing ZIF membranes, including in-situ (69,87), layer-by-layer growth (88,89), microwave-assisted (31,34,90), electrospinning (91), and secondary seeded growth (3,33,35). Generally, ZIF membranes are synthesized through in situ growth and secondary or seeded growth methods (37), which will be discussed in the following section.…”

An innovative approach for the preparation of confined ZIF-8 membranes by conversion of ZnO ALD layers

“…It is recognized in the literature [18] that the ZIF-8 formation classically occurs via a coordination reaction between Zn 2 þ cations and imidazolium anions (mim À ). Although high rate of heterogeneous nucleation can be expected from the ALD nanolayers [27], the zinc source is not easily dissociated to Zn 2 þ in the considered reaction conditions and relatively low ZIF-8 formation rates are expected.…”

“…On the other hand, support modifications with relevant species such as organo-silane compounds (e.g. 3-(2-imidasolin-1-yl)propyltriethoxysilane) [18] polydopamine [7] revealed attractive for controlling the growth of uniform ZIF-8 thin layers on various types of supports. Unlike insitu methods, secondary growth is considered to allow for better control of the membrane design and microstructure, provided a uniform layer of seeds can be reproducibly deposited on the support.…”

Secondary growth of ZIF-8 films onto copper-based foils. Insight into surface interactions

“…Other supports on which ZIF-8 films have been synthesized include glass slide [30], polysulfone membrane [31], carbon nanotube bucky-paper [32], nylon membrane [33], silicon [34] and polymide [35]. Our interest is to synthesize MOF films on appropriate substrates so as to allow their utilization as structured catalysts in processes with a high demand of heat transfer.…”