Intrinsic microporosity

The microstmcture and imperfection content of coatings produced by atomistic deposition processes can be varied over a very wide range to produce stmctures and properties similar to or totally different from bulk processed materials. In the latter case, the deposited materials may have high intrinsic stress, high point-defect concentration, extremely fine grain size, oriented microstmcture, metastable phases, incorporated impurities, and macro-and microporosity. AH of these may affect the physical, chemical, and mechanical properties of the coating. 

In addition, the polymers of intrinsic microporosity (PIMs), such as phthalocyanine networks and the Co phthalocyanine network-PIM (CoPc20), display high specific surface area, as confirmed by the N2 adsorption isotherm at 77 K, and by the adsorption of small organic probe molecules from aqueous solutions at 298 K [236], This material is basically microporous with an increased concentration of effective nanopores. 

The polymers of intrinsic microporosity (PIMs). These are rigid macromolecules composed of a fused-ring subunit which cannot pack space efficiently and hence form microporous materials (Figure 2.5) [68]. 

Figure 2.5 Molecular building units of polymers with intrinsic microporosity [69]. Reproduced with permission of the PCCP Owner Societies.

Polymers with intrinsic microporosity (PlMs) have recently been introduced... 

Tetraamino-9,9 -spirobifluorene was taken for the synthesis of polyamide (PA) and polyimide (PI) networks having an intrinsic microporosity, because the crosslike spatial orientation of spirobifluorene units provides loose packing of polymeric chains in final networks [263]. By reacting the tetraamine with terephthalic acid or pyromellitic acid dianhydride dissolved in A/-methylpyrrolidone or o-cresol, respectively, microporous materials were obtained as depicted in the following scheme ... 

The intensive search for other types of microporous materials that started less than a decade ago resulted in the development of polymers with intrinsic microporosity (PIMs see Chapter 9, Section 3.8) and... 

Polymers of intrinsic microporosity (PIMs Sect. 2.2) 500-1,064 a Both thermal and chemical stabUity high Linear PIMs are solution-processable [9, 46]... 

Budd PM, Ghanem BS, Makhseed S, McKeown NB, Msayib KJ, Tattershall CE. Polymers of intrinsic microporosity (PIMs) Robust, solution-processable, organic nanoporous... 

Emmler T, Heinrich K, Fritsch D, Budd PM, Chaukura N, Ehlers D, Raetzke K, Faupel F. Free volume investigation of polymers of intrinsic microporosity (PlMs) PIM-1 and PlMl copolymers incorporating ethanoanthracene units. Macromolecules 2010 43(14) 6075-6084. 

McKeown NB, Budd PM, Msayib KJ, GhanemBS, Kingston HI, TattershaU CE, Makhseed S, Reynolds KJ, Fritsch D. Polymers of intrinsic microporosity (PlMs) Bridging the void between microporous and polymeric materials. Chem Eur J 2005 11 2610-2620. 

Budd PM, McKeown NB, Ghanem BS, Msayib KJ, Fritsch D, Kingston HJ, Starannikova L, Belov N, Sanfirova O, Yampolskii Y, Shantarovich V. Gas permeation parameters and other physicochemical properties of a polymer of intrinsic microporosity Polybenzodioxane PIM-1. J Membr Sci 2008 325(2) 851-860. 

To surpass Robeson s upper bound, materials are emerging that rely on transport mechanisms other than solution-diffusion through glassy or rubbery polymeric materials. In particular, a number of materials have been developed that possess fixed microporosity (2 nm or less) in contrast to the activated, transient molecular gaps that give rise to diffusion in most polymers. These materials include amorphous and crystalline (zeolite) ceramics [68-69], molecular sieve carbons [70], polymers that possess intrinsic microporosity [71-72], and carbon nanotube membranes [73-76]. Transport in such materials is determined primarily by the average size and size distribution of the microporosity - the porosity can be tuned to allow discrimination between species that differ by less than one Angstrom in size. However, surface... 

N.B. McKeown and P.M. Budd, Polymers of intrinsic microporosity (PIMs) organic materials for membrane separations, heterogeneous catalysis and hydrogen storage, Chem. Soc. Rev., 35 (2006) 675-683. 

The inventors caU this polymer class polymers of intrinsic microporosity (PIMs) , because their porosity arises as a consequence of the molecular structure and is not generated solely through processing. The PIMs can exhibit analogous behavior to that of conventional materials, but, in addition, may be processed into convenient forms for use as membranes [291]. The gas-permeation properties of membranes formed from PIM-1 were investigated at the GKSS... 

C. E. Tattershall, Polymers of intrinsic microporosity (PIMs) robust, solu-tion-processable, organic nanoporous materials. Chemical Communications 2004, (2), 230 231. 

P.M. Budd, K.J. Msayib, C. E. Tatter-SHALL, B.S. Ghanem, K. J. Reynolds, N.B. McKeown, D. Fritsch, Gas separation membranes from polymers of intrinsic microporosity. Journal of Membrane Science 2005, 251, (1-2), 263-269. 

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