Membranes with Intrinsic Micro-Porosity: Structure, Solubility, and Applications

Zhou, Haoli; Jin, Wanqin

doi:10.3390/membranes9010003

Cited by 27 publications

(19 citation statements)

References 109 publications

(206 reference statements)

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“…Many comprehensive reviews of various aspects of PIM research have been published and the current perspective does not aim to provide yet another. [3][4][5][6][7][8][9][10] Instead, it will reflect on the results of these studies to provide greater clarity on what makes PIMs distinct from other macromolecules by identifying their unique structural features and distinguishing properties.…”

Section: Introductionmentioning

confidence: 99%

Polymers of Intrinsic Microporosity (PIMs)

McKeown

2020

Polymer

121

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Based on cumulative research from the past two decades, this personal perspective defines the structurally unique features of Polymers of Intrinsic Microporosity (PIMs), which result in a distinct combination of properties, including solution-processability and microporosity, providing organic materials suitable for the fabrication of membranes that perform efficient molecular sieving. Highlights• Personal reflection on the development of Polymers of Intrinsic Microporosity (PIMs).• Explanation of why PIMs form a distinct class of polymer and microporous material.• Re-definition of PIMs based on their method of synthesis, structure and properties.• Rigidity and sub-nanometre pore size combine to make PIM membranes selective.• Free volume is largely interconnected but only for the transport of small gases.

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Section: Introductionmentioning

confidence: 99%

Polymers of Intrinsic Microporosity (PIMs)

McKeown

2020

Polymer

121

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“…Gas separation membranes are very important and have a promising future not only because of their scientific interest to chemists and scientists but also for their practical applications such as removal of contaminants and purification of resources important to chemical and materials engineers [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. Therefore, intensive and continuous studies on gas separation membranes have been carried out for many years that have resulted in some practical uses.…”

Section: Introductionmentioning

confidence: 99%

“…Because gas molecules are very small particles around 2.6–5.5 Å in kinetic diameter, membranes for gas separation should be dense (non-porous) or microporous and not have any defects whose sizes are more than several Å. Figure 1 summarizes three well-known permselective mechanisms useful for oxygen and nitrogen separation [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. The details of the three are described below.…”

Section: Introductionmentioning

confidence: 99%

Macromolecular Design for Oxygen/Nitrogen Permselective Membranes—Top-Performing Polymers in 2020—

et al. 2021

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Oxygen/nitrogen permselective membranes play particularly important roles in fundamental scientific studies and in a number of applications in industrial chemistry, but have not yet fulfilled their full potential. Organic polymers are the main materials used for such membranes because of the possibility of using sophisticated techniques of precise molecular design and their ready processability for making thin and large self-supporting membranes. However, since the difference in the properties of oxygen and nitrogen gas molecules is quite small, for example, their kinetic diameters are 3.46 Å and 3.64 Å, respectively, the architectures of the membrane macromolecules should be designed precisely. It has been reported often that oxygen permeability (PO2) and oxygen permselectivity (α = PO2/PN2) have trade-off relationships for symmetric membranes made from pure polymers. Some empirical upper bound lines have been reported in (ln α − ln PO2) plots since Robeson reported an upper bound line in 1991 for the first time. The main purpose of this review is to discuss suitable macromolecular structures that produce excellent oxygen/nitrogen permselective membranes. For this purpose, we first searched extensively and intensively for papers which had reported α and PO2 values through symmetric dense membranes from pure polymers. Then, we examined the chemical structures of the polymers showing the top performances in (ln α − ln PO2) plots, using their aged performances. Furthermore, we also explored progress in the molecular design in this field by comparing the best polymers reported by 2013 and those subsequently found up to now (2020) because of the rapid outstanding growth in this period. Finally, we discussed how to improve α and PO2 simultaneously on the basis of reported results using not only symmetric membranes of pure organic polymers but also composite asymmetric membranes containing various additives.

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“…were treated by the technique, and the most promising results were obtained for the polymers with higher gas permeability. Therefore, further development of materials with enhanced properties requires progress in novel methods for the fluorination of novel polymers with higher free volume, such as polymers of the PIM family [ 125 , 126 ], polynorbonenes and polytricyclononenes [ 127 ] as well as substituted polyacetylenes [ 128 ]. More detailed investigations of chemical structure and other characteristics of fluorinated layer should be performed on directly fluorinated conventional membrane polymers such as substituted celluloses, polystyrene, polyimides, polyethersulfones, etc.…”

Section: Discussionmentioning

confidence: 99%

Effect of Direct Fluorination on the Transport Properties and Swelling of Polymeric Materials: A Review

et al. 2021

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Fluorine-containing polymers occupy a peculiar niche among conventional polymers due to the unique combination of physicochemical properties. Direct surface fluorination of the polymeric materials is one of the approaches for the introduction of fluorine into the chemical structure that allows one to implement advantages of fluorinated polymers in a thin layer. Current review considers the influence of the surface interaction of the polymeric materials and membranes with elemental fluorine on gas, vapor and liquid transport as well as swelling and related phenomena. The increase in direct fluorination duration and concentration of fluorine in the fluorination mixture is shown to result mostly in a reduction of all penetrants permeability to a different extent, whereas selectivity of the selected gas pairs (He-H2, H2-CH4, He-CH4, CO2-CH4, O2-N2, etc.) increases. Separation parameters for the treated polymeric films approach Robeson’s upper bounds or overcome them. The most promising results were obtained for highly permeable polymer, polytrimethylsilylpropyne (PTMSP). The surface fluorination of rubbers in printing equipment leads to an improved chemical resistance of the materials towards organic solvents, moisturizing solutions and reduce diffusion of plasticizers, photosensitizers and other components of the polymeric blends. The direct fluorination technique can be also considered one of the approaches of fabrication of fuel cell membranes from non-fluorinated polymeric precursors that improves their methanol permeability, proton conductivity and oxidative stability.

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Membranes with Intrinsic Micro-Porosity: Structure, Solubility, and Applications

Cited by 27 publications

References 109 publications

Polymers of Intrinsic Microporosity (PIMs)

Polymers of Intrinsic Microporosity (PIMs)

Macromolecular Design for Oxygen/Nitrogen Permselective Membranes—Top-Performing Polymers in 2020—

Effect of Direct Fluorination on the Transport Properties and Swelling of Polymeric Materials: A Review

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