Molecular texturization properties, effects

J.L. Urraca, M.C. Carbajo, M.J. Torralvo, J. Gonzalez-Vazquez, G. Orellana and M.C. Moreno-Bondi, Effect of the template and functional monomer on the textural properties of molecularly imprinted polymers, Riosens. Bioelectron., 24 (1) 155-161,2008. 

Combining ZIF-8 437 silicalite-1 in poly-sulfone Udel P-3500 (ZIF-8/S1C-PSF MMM) did not improve the separation results compared to either SIC-PSF or ZIF-8-PSF alone in MMMs for CO2/CH4 and CO2/N2 gas mixtures. The relatively large silicalite-1 crystals probably could not be intercalated between small ZIF-8 particles. ZIF-8 alone produced the highest increase of CO2 permeability, which can be attributed to its textural properties and its small particle size, which however gave poorly dispersed aggregates. For O2/N2 and H2/CH4 gas separation, a ZIF-8-PSF MMM produced the best selectivity-permeability results compared to a Cu-BTC or SIC-PSF MMM. This may be due to an increase in free volume (as suggested for ZIF-8-polyimide MMMs) " together with an efficient molecular separation effect (based on diffusion differences) because of the small pore aperture window of ZIF-8 (3.4 A, 0.34 nm) compared to Cu-BTC (6 A, 0.6 nm) and SIC (5.5 A, 0.55 nm). ... 

Qi, P. X. and Onwulata, C. 1. (2011). Physical properties, molecular structures and protein quality of texturized whey protein isolate (WPl) Effect of extrusion moisture content. /. Dairy Sci. (Accepted for publication). doi 10.3168/jds.2010-3942. 

SPAN module. It was mentioned at the beginning that the special polyacrylonitrile fibers of SPAN have a wall thickness of 30 gm, which is considerably thicker than the 8 gm wall thickness of the SMC modules [19]. As a consequence, the presence of stronger capillary effects from the special porous fiber material of the SPAN module would be a reasonable conclusion. Furthermore, the texture of the special polyacrylonitrile fibers is expected to have better surface properties, supporting the permeation of molecules as compared with synthetically modified cellulose. In conclusion, both convection and diffusion effectively contribute to the filtration efficiency in a SPAN module, whereas for the SMC membrane, diffusion is the driving force for molecular exchange, the efficiency of which is also considerable and benefits from the large surface-to-volume ratio. 

Finally, the description of the solid s surface is important since it is in contact with the other compounds of the media. Therefore, the information about the surface must be combined with the description of the material at the molecular and textural levels in order to represent its catalytic activity, complexation properties, molecular sieving effect etc. 

The big difference between normal isotropic liquids and nematic liquids is the effect of anisotropy on the viscous and elastic properties of the material. Liquid crystals of low molecular weight can be Newtonian anisotropic fluids, whereas liquid crystalline polymers can be rate and strain dependent anisotropic non-Newtonian fluids. The anisotropy gives rise to 5 viscosities and 3 elastic constants. In addition, the effective flow properties are determined by the flow dependent and history dependent texture. This all makes the rheology of LCPs extremely complicated. 

From a food engineering point of view, food functionality is the specific response of foods to applied forces encountered during preparation, processing, storage, and consumption (Kokini et al., 1993). The understanding of food at the molecular level involves the application of both theoretical and experimental techniques of chemistry, physics, mathematics, fluid mechanics, biochemistry, and biophysics to understand how the molecular properties and interactions affect the final quality of the product. If the texture is to be controlled, then the effect of individual components of the formulation should be known. 

The above consideration lead essentially to a comparison with the model proposed for collagen fiber from rat-tail tendon. In effect, if it is possible to relate the hydration properties to structural or textural chemical differences in the samples, one can hope to explain the collagen-water interaction on a molecular basis. 

Chiu FC, Ung MH (2007) Thermal properties rmd phase morphology of melt-mixed poly (trimethylene terephthalate)/polycarbonate blends-mixing time effect. Polym Test 26 338-350 Chuah HH (2004) Effect of process variables on bulk development of air-textured poly (trimethylene terephthalate) bulk continuous filament. J Appl Polym Sci 92 1011-1017 Chuah HH, Lin VD, Soni U (2001) PTT molecular weight and Mark-Houwink equation. Polymer 42 7137-7139... 

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