Porous materials or a porous media can be encountered in our everyday life, both in industrial and household systems and in the nature. Generally speaking all solid and semisolid materials are porous to some degree e.g. different dense rock types, plastics etc. Porous materials are constantly finding more and more applications, both in industry and research. Many commercially important process in the industry utilize porous media e.g. flow of fluids through porous media for separation process and porous catalyst supports. This has strongly contributed to the development of porous media with controlled properties, which can be utilized for understanding the behavior of liquids confined in the material, and the morphology of these synthetic materials. This thesis work brings some insight and understanding of porous materials i.e. Controlled Pore Glass (CPG). Report also contains a brief explanation of Nuclear Magnetic Resonance (NMR) spectroscopy, diffusion NMR and other techniques such as Mercury porosimetry. The first part of the thesis is focused on determining the required amount of liquid i.e. octanol needed to achieve full pore saturation for different CPGs with varying pore sizes. This was achieved by taking into account that the transverse relaxation time T2 is sensitive in the ms-ns of motional correlation times, and that there are physical factors in porous material which affect the T2. Second part, diffusion NMR is used to study self-diffusion of octanol confined in CPG, thus bringing some insight on mass transfer limitations within porous systems. The report present results obtained from experiments with NMR and Diffusion NMR, discusses the issues that can arise when investigating porous materials and suggest solutions

The range of applications and versatility of NMR diffusion measurements [1,2] increase with the speed, accuracy, and the practical lower concentration limits that can be used. For example, faster measurements expand the horizons of diffusion measurements to study reaction kinetics [3,4], as well as simply increasing throughput. Our group has been investigating various approaches for improving the performance of NMR diffusion measurements. Here we present some of our recent advances.

It is well known that ions affect polymers in specific ways not solely based on electric charge, usually referred to as the Hoffmeister effect or ion specific effects. Poly(N-isopropylacrylamid) (PNIPAM) is a thermosensitive polymer with a LCST at 32℃. PNIPAM is a well studied polymer due to its similarities with denaturation of proteins in aqueous solutions. Utilizing diffusion NMR this report studied the effect different Hoffmeister anion concentrations have on the configuration of pre-transitional PNIPAM. A fractionation process was developed for PNIPAM, yielding a product of about 87 000 g/mol, used for diffusion measurements. Diffusion coefficients for PNIPAM in saline solutions ranging from 0 to 800 mM were measured for NaCl, NaClO4, NaSCN and NaI. Diffusion coefficients for PNIPAM were also measured at some concentrations of NaF, Na2SO4 and Na2CO3. Hydrodynamic radius was calculated from the diffusion coefficients. The report found a pre-transitional chain collapse of PNIPAM which increased with ionic concentrations of NaCl, NaClO4, NaSCN, NaF and Na2CO3, but not for NaI and Na2SO4. At 800 mM the hydrodynamic radius decreased with 9% for NaCl, 13% for NaClO4 and 5% for NaSCN. The hydrodynamic radius decreased with 19% at 300 mM Na2CO3 and with 10% at 400 mM NaF. There was a significant decrease in hydrodynamic radius for high concentrations of NaCl and NaClO4 but exact decrease needs to be replicated to validate the findings due to an unexpected large decrease in hydrodynamic radius already at 50 mM. Values for NaF and Na2CO3 should be replicated with internal standard to accomodate for possible precipitation of the longer polymer chains within the fraction.

NMR experiments performed under the effect of electric fields, either continuous or pulsed, can provide quantitative parameters related to ion association and ion transport in solution.  Electrophoretic NMR (eNMR) is based on a diffusion pulse-sequence with electric fields applied in the form of pulses. Magnetic field gradients enable the measurement of the electrophoretic mobility of charged species, a parameter that can be related to ionic association. The effective charge of the tetramethylammonium cation ion in water, dimethylsulphoxide (DMSO), acetonitrile, methanol and ethanol was estimated by eNMR and diffusion measurements and compared to the value predicted by the Debye-Hückel-Onsager limiting law. The difference between the predicted and measured effective charge was attributed to ion pairing which was found to be especially significant in ethanol. The association of a large set of cations to polyethylene oxide (PEO) in methanol, through the ion-dipole interaction, was quantified by eNMR. The trends found were in good agreement with the scarce data from other methods. Significant association was found for cations that have a surface charge density below a critical value. For short PEO chains, the charge per monomer was found to be significantly higher than for longer PEO chains when binding to the same cations. This was attributed to the high entropy cost required to rearrange a long chain in order to optimize the ion-dipole interactions with the cations. Moreover, it was suggested that short PEO chains may exhibit distinct binding modes in the presence of different cations, as supported by diffusion measurements, relaxation measurements and chemical shift data. The protonation state of a uranium (VI)-adenosine monophosphate (AMP) complex in aqueous solution was measured by eNMR in the alkaline pH range. The question whether or not specific oxygens in the ligand were protonated was resolved by considering the possible association of other species present in the solution to the complex. The methodology of eNMR was developed through the introduction of a new pulse-sequence which suppresses artifactual flow effects in highly conductive samples. In another experimental setup, using NMR imaging, a constant current was applied to a lithium ion (Li ion) battery model. Here, 7Li spin-echo imaging was used to probe the spin density in the electrolyte and thus visualize the development of Li+ concentration gradients. The Li+ transport number and salt diffusivity were obtained within an electrochemical transport model. The parameters obtained were in good agreement with data for similar electrolytes. The use of an alternative imaging method based on CTI (Constant Time Imaging) was explored and implemented. / <p>QC 20140825</p>