Ultramicroporous polymer

Spectral Ellipsometry Surface Plasmon Resonance Spectroscopy Ultramicroporous Polymer... 

Interaction Behaviour of the Ultramicroporous Polymer Makrolon by Optical Spectroscopic Methods... 

In this study, for an accurate understanding of the interaction behaviour of the ultramicroporous polymer Makrolon, as a receptor, under the influence of three alcohols is investigated by three transduction methods Spectral ellipsometry (SE), RIfS and SPR. 

Fig. 1 Pore-volume distribution of the ultramicroporous polymer and the accessible volume for analytes in dependence of the molecule volume (a). Scheme of interaction between pores and different sized molecules for smaller analytes more pores are accessible and the interaction between molecules and polymer backbone is weaker (b)...

The investigated polymer is a glassy, ultramicroporous polymer (Makrolon M2400, Bayer AG Leverkusen, Germany). All measurements were performed below the glass transition temperature (7g = 145 °C), so the glassy polymer chains are restricted in motion and cannot completely homogenize. 

The interaction behaviour of the homologous alcohols methanol, ethanol and 1-propanol and the ultramicroporous polymer Makrolon was investigated by three different optical methods spectral ellipsometry, surface plasmon resonance and reflectometric interference spectroscopy. 

In some cases, when the polymerization appears, the energy distribution of micropores is negligible in comparison with the energy of polymerization. That is possible when the temperature of the treatment of the primary material (if this one can be polymerized, e.g., silica, alumina) is low (less 300-350 °C). In such cases, traditional methods of nonequilibrium thermodynamics are not effective, and the micropore formation can be considered as the result of the polymerization process which is described by methods of polymer science. However, models of macromolecular systems do not always give enough information about micropores as the empty space between polymers. For such systems, the application of fractal methods can allow us to obtain additional information, while one has to take into account the fact that they cannot be applied to very narrow pores (ultramicropores which are found, for instance, in some silica gels). 

Porosity is divided by IUPAC (Rouquerol et al. 1994), based on pore size, into the following groups macropores (>50 nm), mesopores (2-50 nm), and micropores (<2 nm). Microporosity may then be subdivided into three subsequent categories supermicropores (1.4-2.0 nm), micropores (0.5-1.4 nm), and ultramicropores (<0.5 nm). Both mineral and organic soil components have pores with different diameter. The holes and channels in the polymer chain of humic substances as well as the interlayer space of the layered mineral have an important role in determining the specific surface area. The size of the interlayer space of layered minerals in a dry state is a few tenths of nanometers, so they are considered as micropores. 

As with reverse osmosis, ultrafiltration (UF) and microfiltration (MF) are pressure-driven membrane separation processes, with the membrane permselective for the solvent, usually water. MF and UF separate mainly by size exclusion of the solutes. MF retains particles of micrometer size UF retains particles of submicrometer size by ultramicroporous membranes. Typically, UF retains solutes in the 300 to 500,000 molecular weight range including biomolecules, polymers, sugars, and colloidal particles. 

The chapter is focused on the analysis of plysical properties of natural and synthetic zeolites having G1S-, PH1-, MER-, MON, MAZ-, EON-, PAU-, LTL-, MOZ, and LlT-framewoik topologies. These natural silicates are included in the Mineral Reference Manual [91N1] as group Vin F14. In addition to aluminosilicate systems, the review includes also the fiamewoik structures with other ions, such as Be, P, Ga, Ge as well as some metal phosphanates and ultramicroporous coordination polymers. Since of limited extent of the review, not all the zeolites mentioned in Tables 1 will be extensively analyzed, for some of them only references are given or a short description of their structures. 

Interestingly, even under the pressure lower than the saturated vapor pressure, the densities of the adsorbed phases of O2 were much greater than those of the corresponding bulk liquid phases. This indicates that the adsorbed molecules are significantly different from the bulk state and, therefore, are considered to be a new state characteristic of molecules confined in the ultramicropore of CPL-1. These phenomena have been observed in the linear chain of a coordination polymer O2 molecules are trapped and form the structure in the space between the ID coordination polymers [ 147,212,214]. 

McKeown NB, Gahnem B (2006) Towards polymer-based hydrogen storage materials engineering ultramicroporous cavities within polymers of intrinsic microporosity. Angew Chem Int EdEngl45(ll) 1804-1807... 

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