Vacuum-Assisted Self-Healing Amphiphilic Copolymer Membranes for Gas Separation

Abstract

Membrane gas separation provides a multitude of benefits over alternative separation techniques, especially in terms of energy efficiency and environmental sustainability. While polymeric membranes have been extensively investigated for gas separations, their self-healing capabilities have often been neglected. In this work, we have developed innovative self-healing amphiphilic copolymers by strategically incorporating three functional segments: n-butyl acrylate (BA), N-(hydroxymethyl)acrylamide (NMA), and methacrylic acid (MAA). Utilizing these three functional components, we have synthesized two distinct amphiphilic copolymers, namely, AP NMA (PBA x -co-PNMA y ) and AP MAA (PBA x -co-PMAA y ). These copolymers have been meticulously designed for gas separation applications. During the creation of these amphiphilic copolymers, BA and NMA segments were selected due to their vital role in the ease of tuning mechanical and self-healing properties. The functional groups (−OH and −NH) present on the NMA segment interact with CO 2 through hydrogen bonding, thereby boosting CO 2 /N 2 separation and achieving superior selectivity. We assessed the self-healing potential of these amphiphilic copolymer membranes using two distinct strategies: conventional and vacuum-assisted self-healing. In the vacuum-assisted approach, a robust vacuum pump generates a suction force, leading to the formation of a cone-like shape in the membrane. This formation allows common fracture sites to adhere and trigger the self-healing process. As a result, AP NMA maintains its high gas permeability and CO 2 /N 2 selectivity even after the vacuum-assisted self-healing operation. The ideal CO 2 /N 2 selectivity of the AP NMA membrane aligns closely with the commercially available PEBAX-1657 membrane (17.54 vs 20.09). Notably, the gas selectivity of the AP NMA membrane can be readily restored after damage, in contrast to the PEBAX-1657 membrane, which loses its selectivity upon damage.

Elastic and Self-Healing Copolymer Coatings with Antimicrobial Function

“…Owing to the possibility of converting a wide variety of vinyl monomers (sometimes possessing functional groups) into high-molecular-weight polymers without rigorous purification of the monomers and solvents, FRP is considered to be one of the most feasible methods not only for the laboratory but also for industrial scale processes. In this work, polymerization was carried out for 24 h at 65 °C, resulting in a high yield of 90% with a number-average molecular weight Mn (GPC) of 60 000 g mol –1 and a PDI value of 1.19 . It should be noted that the choice of reaction time of 24 h was based on the certainty that the reaction would reach saturation conditions.…”

“…In this work, polymerization was carried out for 24 h at 65 °C, resulting in a high yield of 90% with a number-average molecular weight Mn (GPC) of 60 000 g mol –1 and a PDI value of 1.19. 39 It should be noted that the choice of reaction time of 24 h was based on the certainty that the reaction would reach saturation conditions. For effectiveness and cost savings in the production process, further investigation of kinetic polymerization is necessary.…”

“…The flexible and self-healing PBA x -co-PNMA y with a desired ratio between BA and NMA segments used of 0.8:0.2 and number-average molecular weight (M n ) of 60 000 g mol −1 was synthesized by the FRP method as described in a previous study. 39 Preparation of Modified Polymers (AP/b%CHG-graf ted-a% DTSACL) in the Bulk Form. 400 mg of AP and various mass percentages of DTSACL and CHG to the total polymer mass (Table 1) were blended with methanol as the solvent at room temperature for 15 min and stirred at 1000 rpm so that a homogeneous mixture could be obtained.…”

“…An earlier report by Chiu’s group proposed a poly­{( n -butyl acrylate) 0.8 - co -[ N -(hydroxymethyl)­acrylamide] 0.2 } copolymer (AP) with a number-average molecular weight of 60 000 g mol –1 , endowing high transparency as well as tunable mechanical, room-temperature self-healable, and humid-barrier properties, which was expected to be suitable as a host matrix for antimicrobial and antifouling coating applications. − To study the influences of antimicrobial agents, we exploited a series of various ratios of DTSACL and CHG covalently and noncovalently linked to the proposed AP via a thermal-triggered cross-linking reaction (Scheme ). The benefit of the synergistic effect based on grafting to and multiple cross-linking functions between AP segments and antimicrobial agents is to be noted.…”

Unveiling the Potential of Pt Nanoparticle-Decorated PEDOT:PSS Membranes for Efficient Gas Separation

“…Among various membrane materials, polymer provides the advantages of flexibility and cost-effectiveness . Until now, a variety of polymer materials have been employed to fabricate the membranes for gas separation, for example, polycarbonate, polysulfone, polyimides, etc., but the trade-off relationship associated with the membrane processes is still a matter of concern. , Alternatively, the addition of porous/nonporous, organic/inorganic filler material such as zeolites, graphene, and metal–organic frameworks possess the potential to enhance the separation characteristics either by providing suitable transportation channels or size-exclusive separation. − However, the agglomeration and phase segregation resulting from poor solubility and incompatibility of the materials degrade the mechanical stability of the membranes, causing difficulties in large-scale processing due to high levels of defects and brittleness in the membranes. To solve the paradox between membrane processability and separation performance, certain membrane materials, such as polymers of intrinsic microporosity, thermally rearranged polymers, and other microporous polymers, were employed, but the problems associated with them like inferior aging resistance, plasticization, etc., hinders their applicability across a wider spectrum of large-scale usage. , Further advanced polymer materials such as block copolymer were used to effectively sieve the gas molecules with good selectivity but the cost associated with them is a major concern .…”