Green Preparation of Thin Films of Polybenzimidazole on Flat and Hollow Fiber Supports: Application to Hydrogen Separation

Weber²,

2022

J. Mater. Chem. A

Section: Gas Separation For H 2 /Co 2 Separation At Elevated Temperat...mentioning

confidence: 99%

Polybenzimidazoles (PBIs) and state-of-the-art PBI hollow fiber membranes for water, organic solvent and gas separations: a review

Weber²,

2022

J. Mater. Chem. A

“…Polybenzimidazoles (PBIs) type polymers are known for their high thermochemical stabilities and excellent mechanical properties. [1][2][3][4][5][6][7][8][9] They have been found useful in applications ranging from flame-resistant fabrics to aerospace materials and fuel cell membranes. [10][11][12][13][14][15][16] Fully aromatic poly[2,2-(m-phenylene)-5,5-bibenzimidazole] or meta-PBI (m-PBI) (Scheme 1) is the most common commercially available PBI polymer.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…High intrinsic H 2 selectivity over larger gas molecules, such as CO 2 , N 2 , and CH 4 , was demonstrated with PBI film membranes prepared using flat and hollow polyamide P84 fibers as a support material. [8] PBI has gained great interest also as a membrane material in vanadium redox flow batteries where ion-selectivity for vanadium was obtained with a thin layer of PBI polymer. [22] Polybenzimidazoles and their more complex derivatives are often classified as expensive specialty plastics due to their outstanding properties but also difficulties in manufacturing.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Molecular Layer Deposition of Thermally Stable Polybenzimidazole‐Like Thin Films and Nanostructures

Ghafourisaleh

Hatanpää

Vihervaara

et al. 2022

Adv Materials Inter

aliphatic or aromatic derivatives as monomers for optimizing application specific properties for bioactive materials and fuel cell membranes, for example. [17,18] In recent years, with the developments of using insulating polymer materials in electronic devices, needs for high-thermalresistance polymer dielectrics have been increasingly emphasized in order to ensure high reliability of devices operating at high temperatures. [19] While conventional polyethylene and polypropylene possess intrinsically excellent insulating properties, [20] they are facing great challenges in advanced electrical devices due to their limited service temperatures below 105 °C and increased leakage currents at elevated temperatures. [2,20,21] Another prevalent area for PBI lies in membrane applications such as H 2 separation membranes, fuel cells, and redox battery membranes. High intrinsic H 2 selectivity over larger gas molecules, such as CO 2 , N 2 , and CH 4 , was demonstrated with PBI film membranes prepared using flat and hollow polyamide P84 fibers as a support material. [8] PBI has gained great interest also as a membrane material in vanadium redox flow batteries where ion-selectivity for vanadium was obtained with a thin layer of PBI polymer. [22] Polybenzimidazoles and their more complex derivatives are often classified as expensive specialty plastics due to their outstanding properties but also difficulties in manufacturing. PBI plastics are known as the thermally most stable thermoplastics with a glass transition temperature (T g ) higher than 400 °C. [11] In a previous study by Iqbal et al. [19] PBI exhibited excellent thermal stability up to a temperature of 500 °C with a total weight loss of only 15%. The stability of PBI polymers drives from the high number of aromatic rings incorporated in the polymer chain. Aromatic rings are efficiently absorbing both thermal and radiation energy and aid in redistributing the excitation energy throughout the material. [18,19] Conventional PBI polymers are usually prepared via hightemperature polycondensation reactions in either solution or melt to achieve high degree of cyclization. [23][24][25] PBIs are typically synthesized from aromatic tetraamines (bis-o-diamines) and dicarboxylates (acids, esters, or amides) [26] (Scheme 2).PBI thin films are scarcely reported. Previous depositions were carried out either by a casting solution method from formic acid and dimethylsulfoxide (DMSO) solutions or dip-coating and blade-casting methods. [23] The deposition of polybenzimidazole (PBI)-like thin films by molecular layer deposition is reported here for the first time using isophthalic acid (IPA) and 3,3′-diaminobenzidine (DAB) as monomers and trimethylaluminum (TMA) as a linker precursor. Two precursor pulsing sequences are tested, the ABCB (TMA + IPA + DAB + IPA) and ABC (TMA + IPA + DAB) type MLD processes result in different types of PBI-like films. With the ABCB sequence thin film growth per cycle (GPC) of 6.0 Å is obtained at 225-280 °C, whereas GPC of 7.0 Å is obtained with the ABC s...

“…Polybenzimidazole (PBI) is a promising candidate for the separation of a pre-combustion gas mixture (H 2 /CO 2 ) due to its good chemical resistance, high thermal stability, high intrinsic H 2 /CO 2 selectivity as well as impressive compression strength [8][9][10]. Besides, recently, the green processability of PBI in ethanol has been demonstrated to produce highly selective coatings of this polymer both on flat and hollow fibre (HF) polymeric supports [11].…”

Section: Introductionmentioning

confidence: 99%

Pre-combustion gas separation by ZIF-8-polybenzimidazole mixed matrix membranes in the form of hollow fibres—long-term experimental study

et al. 2021

Self Cite

Polybenzimidazole (PBI) is a promising and suitable membrane polymer for the separation of the H 2 /CO 2 pre-combustion gas mixture due to its high performance in terms of chemical and thermal stability and intrinsic H 2 /CO 2 selectivity. However, there is a lack of long-term separation studies with this polymer, particularly when it is conformed as hollow fibre membrane. This work reports the continuous measurement of the H 2 /CO 2 separation properties of PBI hollow fibres, prepared as mixed matrix membranes with metal-organic framework (MOF) ZIF-8 as filler. To enhance the scope of the experimental approach, ZIF-8 was synthesized from the transformation of ZIF-L upon up-scaling the MOF synthesis into a 1 kg batch. The effects of membrane healing with poly(dimethylsiloxane), to avoid cracks and non-selective gaps, and operation conditions (use of sweep gas or not) were also examined at 200°C during approximately 51 days. In these conditions, for all the membrane samples studied, the H 2 permeance was in the 22–47 GPU range corresponding to 22–32 H 2 /CO 2 selectivity values. Finally, this work continues our previous report on this type of application (Etxeberria-Benavides et al . 2020 Sep. Purif. Technol. 237 , 116347 ( doi:10.1016/j.seppur.2019.116347 )) with important novelties dealing with the use of ZIF-8 for the mixed matrix membrane coming from a green methodology, the long-term gas separation testing for more than 50 days and the study on the membrane operation under more realistic conditions (e.g. without the use of sweep gas).