Zeolite- and Carbon Membranes
For this purpose zeolite and carbon membranes are combined with catalysts and designed as membrane reactors. In cooperation with other working groups at Fraunhofer IKTS, membrane production can be …
Growth of Uniformly Oriented Silica MFI and BEA Zeolite Films …
Zeolites are aluminosilicates with angstrom-scale pores and channels in their crystal lattice. When grown as continuous films on various substrates, they function as molecular sieve membranes (1–13) and platforms for second-order nonlinear optical (2-NLO) mixing (14–16), among other applications (17–20).In these contexts, optimal …
Ultrathin ZSM-5 zeolite nanosheet laminated …
Abstract. The tremendous potential of zeolite membranes for efficient molecular separation via size-exclusion effects is highly desired by the energy and chemical industries, but its practical realization has …
Unit-cell-thick zeolitic imidazolate framework films for membrane …
The ZIF films were synthesized by immersing a substrate in an ultradilute precursor solution (≤2 mM Zn 2+ and ≤16 mM 2-methylimidazole (2-mIm)) for a few minutes (Fig. 1a).The use of such ...
Preparation, mechanism and applications of oriented MFI zeolite
It is well known that in the structure of MFI zeolite membranes, the sinusoidal channel (0.51 × 0.55 nm, approximately circular section) parallel to the a-axis and the straight channel (0.53 × 0.56 nm, approximately elliptical cross section) parallel to the b-axis are connected [28], and a tortuous path exists along the c-axis direction (Fig. 1).
Ultra-selective high-flux membranes from directly …
Ultra-selective high-flux membranes from directly synthesized zeolite nanosheets. Nature 543, 690–694 ( 2017) Cite this article. A zeolite with structure type MFI 1, 2 is an aluminosilicate or ...
Preparation, mechanism and applications of oriented MFI zeolite …
Zeolite films can be suitable for catalytic membrane reactors. 40 The specific uses of zeolite film applications indicated in the literature 41 are plate reactors and that preparation of b ...
A review of zeolite materials used in membranes for water …
Zeolite membranes can be classified into three categories: (i) self-supported zeolite membranes, (ii) inorganic-supported zeolite membranes and (iii) zeolites mixed into a polymeric membrane matrix or top layer. The focus of this review is on nanosized zeolite particles incorporated into the polymeric structure of membranes, with specific ...
Room-Temperature Synthesis of Zeolite …
Room temperature (RT) synthesis of high-performance zeolite membranes, which is profound from techno-economic and eco-friendly perspectives, remains a grand challenge. In this work, we …
Control of zeolite framework flexibility for ultra-selective …
The CO 2 /CH 4 separation performance of DD3R zeolite membranes obtained in this work far surpassed the well-known "upper bound" defined by polymeric membranes 28 (e.g., polyimide 29, Matrimid ...
One-dimensional intergrowths in two-dimensional …
Zeolite MFI is a widely used catalyst and adsorbent that also holds promise as a thin-film membrane. The discovery of …
Ultrathin ZSM-5 zeolite nanosheet laminated …
The dip-coating and calcination processes were repeated once to ensure the elimination of pinholes or uncovered spots in the zeolite film. After firing at 500°C, the zeolite membrane layer was loaded with …
The development of oblique preferred orientations in zeolite films …
Zeolite films have important potential applications as membranes and sensors, because of their unique molecular sieving and adsorption properties. In the last decade many studies on various types of zeolite films and membranes have been published, and for a general background the reader is referred to several excellent …
Zeolite Membrane: From Microstructure to Separation Performance …
Special Issue Information. Dear Colleagues, Zeolite membrane has been widely investigated as an attractive tool in the development of separation processes of both liquid and gaseous components. The separation process targets dehydration, organic-organic separation, gas separation and so on. The microstructure of the membrane …
Zeolite Thin Films and Membranes: From …
The zeolite films and membranes can be classified into three types as shown in Fig. 13.1: zeolite-filled mixed matrix membranes (separated zeolite crystals in polymeric matrix), …
Microstructural engineering of zeolite membranes through …
The upper parts of the zeolite membrane shared comparable film characteristics independent of seed composition, according to FCOM images of the MFI membranes. On the other hand, the zeolite membrane prepared from a seed layer of 75 wt% zeolite and 25 wt% silica particles had the greatest N 2 /SF 6 gas selectivity of >175 …
Induction of zeolite membrane formation by implanting zeolite crystals
Zeolite membranes grown on different supports are attracting extensive research interest due to their wide applications as xylene isomer separation [[1], [2] ... Growth of uniformly oriented silica MFI and BEA zeolite films on substrates. Science, 334 (6062) (2011), pp. 1533-1538, 10.1126/science.1212472. Google Scholar [6]
Room-Temperature Synthesis of Zeolite Membranes toward …
Room temperature (RT) synthesis of high-performance zeolite membranes, which is profound from techno-economic and eco-friendly perspectives, remains a grand challenge. In this work, we pioneered the RT preparation of well-intergrown pure-silica MFI zeolite (Si-MFI) membranes, which was realized through adopting highly reactive NH 4 …
Impacts of zeolite nanoparticles on substrate properties of thin film
In this work, microporous substrates modified by zeolite nanoparticles were prepared and used for composite membrane making with the aim of reducing internal concentration polarization (ICP) effect of membranes during engineered osmosis applications. Nanocomposite substrates were fabricated via phase inversion technique …
Microstructural manipulation of MFI-type zeolite films/membranes
Some key topics are detailed and discussed, including (1) controllable synthesis of orientated zeolite film/membrane; (2) rational design and synthesis of zeolite film/membrane with ultrathin ...
Application of zeolite membranes, films and coatings
Preparation methods of zeolite molecular sieve membranes and films with and without support were reviewed. Unsupported films have been prepared by in situ synthesis, casting of zeolite nanoparticles and solid state transformation, and supported films have been obtained by in situ synthesis, vapor-phase synthesis, secondary growth, …
Influence of polymer support on gas transport in ultrathin zeolite
This is the case of thin film nanocomposite (TFN) membranes, which are designed to exploit what is known as the preferential flow path through an active nanophase [26, 27], as occurring also in mixed-matrix membranes (MMMs).This property arises from adding an inorganic nanophase dispersed in a polymer thin film, which improves …
Microstructural manipulation of MFI-type zeolite films/membranes
Since then, zeolite films/membranes have extensively been explored: fabricating continuous zeolite layers on dense substrates or porous supports to produce zeolite films or membranes with thicknesses ranging from tens of microns to a few micrometers for separation and catalysis. Koegler et al. prepared the oriented coatings of …
Separations | Free Full-Text | Small-Pore Zeolite Membranes…
The discussion in this review is limited to pure zeolite membranes, i.e., continuous zeolite films as the effective membrane materials. A thorough discussion of SAPO-34 zeolite membranes was recently conducted by Xu et al., and their article serves as a good reference for SAPO-34 zeolite membrane synthesis, which is not covered in …
Membranes | Free Full-Text | High-Performance FAU Zeolite Membranes
In this study, high-performance FAU (NaY type) zeolite membranes were successfully synthesized using small-sized seeds of 50 nm, and their gas separation performance was systematically evaluated. Employing nano-sized NaY seeds and an ultra-dilute reaction solution with a molar composition of 80 Na2O: 1Al2O3: 19 SiO2: …
Zeolite Membranes: Microstructure Characterization and …
Since their first synthesis in the 1940s, zeolites have found wide applications in catalysis, ion-exchange, and adsorption. Although the uniform, molecular-size pores of zeolites and their excellent thermal and chemical stability suggest that zeolites could be an ideal membrane material, continuous polycrystalline zeolite layers for separations were …
Zeolite films and membranes. Emerging applications
Instead it discusses recent developments in the field of zeolite films for three main areas of application: zeolite membranes for separations and delivery of molecules, zeolite coatings for catalytic microreactors and zeolite-based gas sensors. This work focuses on films consisting of zeolite only, and therefore the many examples of zeolite ...
Zeolite based films, membranes and membrane reactors: …
In zeolite-based membrane reactors the membrane normally consists of a thin film of a mesoporous or microporous zeolite on a macroporous support, typically α-Al 2 O 3, stainless steel or carbon. This thin film may simultaneously serve (i) as both a catalyst and a permselective membrane, (ii) as a permselective diffusion barrier or (iii) as an ...
Preparation of self-supporting NaA zeolite membranes
Because zeolite membranes are required to have sufficient mechanical strength without macroscopic defects to be used as a separation filter, two types of zeolite membranes can be considered: (1) thick zeolite polycrystalline films (self-supported) and (2) thin zeolite films supported by some porous materials (e.g., alumina, silica, and ...
A review of zeolite materials used in membranes for …
The focus of this review is on nanosized zeolite particles incorporated into the polymeric structure of membranes, with specific attention to a polyamide layer used in pressure …
