Friedel-Crafts Synthesis of New Porous Aromatic Frameworks for Stabilizing Gas Transport Properties of Highly Permeable Glassy Polymers

Effect of Support on Gas Transport Properties of PTMSP/UFFK and PTMSP/MFFK-1 Composite Membranes

“…Microfiltration industrial membranes MFFK-1 and UFFK manufactured by the Vladipor Scientific and Technical Center were taken as supports for the subsequent fabrication of composite membranes. In this work, we used poly(1-trimethylsilyl-1-propyne) (PTMSP) synthesized using the TaCl 5 /Al(i-C 4 H 9 ) 3 catalyst system in the Laboratory for the Synthesis of Selectively Permeable Polymers (at the Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences) as described in [9]. A thin layer of PTMSP was deposited on a porous support from a 0.5 wt % polymer solution in reagent-grade chloroform (Khimmed, Russia) by partial immersion of the support in a bath with the casting solution [10].…”

Aging of Thin-Film Composite Membranes Based on Crosslinked PTMSP/PEI Loaded with Highly Porous Carbon Nanoparticles of Infrared Pyrolyzed Polyacrylonitrile

“…However, glassy polymers possess an unrelaxed fractional free volume (FFV) due to their rigid structure and undergo physical aging because of macrochain rearrangements, resulting in the deterioration of membrane permeability with time (the so-called “aging effect”). Therefore, the effect of physical aging is significantly more pronounced for high-free-volume glassy polymers and is actively studied in the literature [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ].…”

“…Porous fillers of a hydrophobic nature with nanometer-scale pores and a uniform distribution in the polymeric matrix can lead to a certain restriction of the mobility of macrochains due to their interaction with polymer segments and, on the other hand, boost the FFV and gas permeance through the membrane, providing additional pathways for gas transport through such fillers. Porous aromatic frameworks (PAFs) with different structures and functional groups have gained a great deal of attention in recent years from this perspective [ 13 , 14 , 15 , 16 , 17 , 26 , 28 , 29 , 30 ]. The introduction of PAF particles with a size of up to a few hundred nanometers in high-free-volume glassy polymers increases gas transport and noticeably mitigates the physical aging of the membrane material because of the increase of the FFV and the partial intrusion of macrochain segments into the pores of the nanoparticles.…”

“…According to N 2 adsorption measurements, the apparent BET surface area and pore volume of PAF-11 are equal to 240 m 2 /g and 0.35 cm 3 /g, respectively [ 29 ]. At the same time, the apparent BET surface area and pore volume of IR-PAN-a are equal to 2450 m 2 /g and 1.06 cm 3 /g, respectively [ 35 ].…”

“…Furthermore, as mentioned by the authors of [ 22 ], PAF-like materials can be considered promising additives toward the reduction of physical aging in polymers of intrinsic microporosity, but the synthesis of such materials is quite complex and hinders commercial implementation. Therefore, investigations were conducted on the addition of hypercrosslinked polymers into PTMSP, i.e., poly(dichloroxylene) (p-DCX) [ 22 , 40 ] and hypercrosslinked polystyrene (HCL-PS) [ 41 ], which were first synthesized by Davankov et al [ 11 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 ]. From this perspective, a new type of IR-derived porous additive (IR-PAN) could be a promising alternative due to its energy- and time-efficient synthesis method.…”