The objective of this research was to determine an appropriate adsorbent for the separation of CH₄ from CO₂, N₂, and O₂. To screen different adsorbents for this purpose, pure component adsorption isotherms and gas mixture isotherms were measured. Adsorption isotherms are critical data for modeling adsorption processes. Thus, determining an accurate and reliable method of measuring gas adsorption isotherms is crucial. Concentration pulse chromatography can be used to measure the slope of the isotherm. In the case of pure component adsorption, the slope at different partial pressures of adsorbate can be integrated to determine the adsorption isotherm. The accuracy of the concentration pulse chromatography method was compared to that of gravimetric analysis to find an appropriate technique to obtain pure component gas adsorption isotherms by measuring CH₄ isotherms on activated carbon at 25°C and up to 6.3 atm. Isotherm results from concentration pulse chromatography were identical to gravimetric results, but the use of a sufficiently long column for concentration pulse chromatography was crucial. Afterwards, gravimetric analysis was used to determine the performance of activated carbon (AC A-C) and carbon molecular sieve (CMS A-D) adsorbents for adsorbing CO₂ and N₂. Additionally, O₂ adsorption isotherms were measured for CMS's. At 25°C and above atmospheric pressure, AC-B showed the highest CO₂ capacity and CO₂/N₂ selectivity. The isosteric heat of adsorption values of CO₂, N₂, and O₂ for the CMS's were calculated; CMS-A and CMS-C had high isosteric heat of adsorption values for CO₂, above 40 kJ mol⁻¹. Finally, the performance of activated carbon in separating a binary mixture of CO₂ and N₂ was experimentally measured by obtaining binary gas mixture adsorption isotherms using concentration pulse chromatography technique between 30-70°C and 1-5 atm total pressure. The OLC activated carbon showed selectivity for CO₂ over N₂, with the experimental results showing a slight deviation from theoretical predictions of the binary adsorption isotherms. Compared to other adsorbents in the literature, OLC had similar CO₂ and N₂ adsorption capacities but higher CO₂/N₂ selectivity.

No description available.

The vast majority of commercial gas separation membrane systems are polymeric because of processing feasibility and cost. However, polymeric membranes designed for gas separations have been known to have a trade-off between permeability and selectivity as shown in Robeson's upper bound curves. The search for membrane materials that transcend Robeson's upper bound has been the critical issue in research focused on membranes for gas separation in the past decade. To that end, many researchers have explored the idea of mixed matrix membranes (MMMs). These membranes combine a polymer matrix with inorganic molecular sieves such as zeolites. The ideal filler material in MMMs should have excellent properties as a gas adsorbent or a molecular sieve, good dispersion properties in the polymer matrix of submicron thickness, and should form high quality interfaces with the polymer matrix. In order to increase gas permeance and selectivity of polymeric membranes by fabricating MMMs, we have fabricated mixed matrix membranes using carbon nanotubes (CNTs) and nano-sized mesoporous silica. Mixed matrix membranes containing randomly oriented CNTs showed that addition of nanotubes to a polymer matrix could improve its selectivity properties as well as permeability by increasing diffusivity. Overall increases in permeance and diffusivity for all tested gases suggested that carbon nanotubes can provide high diffusivity tunnels in the CNT within the polymer matrix. This result agreed well with molecular simulation estimations. In order to prepare ordered CNTs membranes, we have developed a simple, fast, commercially attractive, and scalable orientation method. The oriented CNT membrane sample showed higher permeability by one order of magnitude than the value predicted by a Knudsen model. This CNT membrane showed higher selectivities for CO₂ over other gas molecules because of preferential interaction of CO₂ with the amine functionalized nanotubes, demonstrating practical applications in gas separations. Recently, mesoporous molecular sieves have been used in MMMs to enhance permeability or selectivity. However, due to their micrometer scale in particle size, the composite membrane was extremely brittle and tended to crack at higher silica loading. In this study, we have developed fabrication techniques to prepare MMMs containing mesoporous MCM-41 nanoparticles on the order of ~50 nm in size. This smaller nanoparticle lead to higher polymer/particle interfacial area and provides opportunity to synthesize higher loading of molecular sieves in polymer matrix up to ~80 vol%. At 80 vol% of nano-sized MCM-41 silica loading, the permeability of the membrane increased dramatically by 300 %. Despite these increases in permeability, the separation factor of the MMMs changed only slightly. Therefore, these nanoscale molecular sieves are more suitable for commercialization of MMMs with very thin selective layers than are micro-sized zeolites or molecular sieves. / Ph. D.

Polymeric membranes for gas separation are limited in their performance by a trade-off between permeability and selectivity. New methods of design are necessary in making membranes, which can show both high permeability and selectivity. A mixed matrix membrane is one such particular design, which brings in the superior gas separation performance of inorganic membranes together with the easy processability and price of the polymers. In a mixed matrix membrane, the inorganic phase is dispersed in the polymeric continuous phase. Nanocomposite membranes have a more sophisticated design with a thin separation layer on top of a porous support. The objective of this research was to fabricate thin SWNT nanocomposite membranes for gas separation, which have both high permeability and selectivity. SWNT/polyacrylic nanocomposite membranes were fabricated by orienting the SWNTs by high vacuum filtration. The orientation of SWNTs on top of the porous support was sealed by UV polymerization. For making these membranes, the CNTs were purified and cut into small open tubes simultaneously functionalizing them with COOH groups. Gas sorption of CO2 in COOH functionalized SWNTs was lower than in purified SWNTs. Permeabilities in etched membrane were higher than Knudsen permeabilities by a factor of 8, and selectivities were similar to Knudsen selectivities. In order to increase the selectivities, SWNTs were functionalized with zwitterionic functional groups. Gas sorption in zwitterion functionalized SWNTs was very low compared to in COOH functionalized SWNTs. This result showed that the zwitterionic functional groups are kinetically blocking the gas molecules from entering the pore of the CNT. SWNT/polyamide nanocomposite membranes were fabricated using the zwitterion functionalized SWNTs by interfacial polymerization. The thickness of the separation layer was around 500nm. Gas permeabilities in the CNT membranes increased with increasing weight percentage of the SWNTs. Gas permeabilities were higher in COOH SWNT membrane than in zwitterion SWNT membrane. Gas selectivities were similar to the Knudsen selectivities, and also to the intrinsic selectivities in the pure polyamide membrane. The water flux in SWNT-polyamide membranes increased with increasing weight percentage of zwitterion functionalized SWNTs, along with a slight increase in the salt rejection. Membranes exhibited less than 1% variability in its performance over three days. / Ph. D.

Adsorption, separation and conversion of CO₂ from industrial processes are among the priorities of the scientific community aimed at mitigating the effects of greenhouse gases on the environment. One of the main focuses is the capture of CO₂ at stationary point sources from fossil fuel emissions using porous crystalline materials. Porous crystalline materials can reduce the energy costs associated with CO₂ capture by offering high adsorption rates, low material regeneration energy penalties and favorable kinetic pathways for CO₂ separation. MOFs consist of polymeric inorganic networks with adjustable chemical functionality and well-defined pores that make them ideal for these applications. The objective of this research was to test the potential for CO₂ capture on Zn-based MOFs by studying their sorption, transport and gas separation properties as adsorbents and continuous membranes. Three Zn-based MOFs with open Zn-metal sites were initially studied. Zn4(pdc)4(DMF)2•3DMF (1) exhibited the best properties for CO₂ capture and was investigated further under realistic CO₂ capture conditions. The MOF exhibited preferential CO₂ adsorption based on a high enthalpy of adsorption and selectivity of CO₂ over N₂ and CH₄. Sorption dynamics of CO₂ indicated fast adsorption and a low activation energy for sorption. Diffusion inside the pores is the rate-limiting step for diffusion, and changes in the process temperature can enhance CO₂ separation. Desorption kinetics indicated that CO₂ has longer residence times and lower activation energies for desorption than N₂ and CH₄. This suggests that the selective adsorption of CO₂ is favored. MOF/Polymer membranes were synthesized via a solvothermal method with structural defects sealed by a polymer coating. This method facilitates the permeation measurements of materials that cannot form uniform-defect-free layers. The membrane permeation of CO₂, CH₄, N₂ and H₂ exhibited a linear relation to the inverse square root of the molecular weight of the permanent gases, indicating that diffusion occurs in the Knudsen regime. Permselectivity was well-predicted by the Knudsen model with no temperature dependence, and transport occurs inside the pores of the membrane. MOF (1) exhibits ideal properties for future applications in CO₂ capture as an adsorbent. / Ph. D.

The demand for high performance electronic devices is ever increasing in today's world with advent of digital technology in every field. In order to support this fast paced growth and incursion of digital technology in society, smarter, smaller integrated circuits are required at a lower cost. This primary requirement drives semiconductor industries towards the integration of larger number of smaller transistors on a given circuit area. The past decades have seen a rapid evolution of material processing and fabrication techniques, as focus shifts from submicron to sub-nanometer length scales in device configuration. As the functional feature size of an integrated circuit decreases, the threshold of defect causing impurities rises drastically. Huge amount of resources are spent in downstream and upstream processing in order to restore system from contamination upsets and in the upkeep of Ultra-High-Purity (UHP) process streams to meet these stringent requirements. Contamination once introduced into the system also drastically reduces process yield and throughput resulting in huge losses in revenue. Regular UHP fluid distribution system maintenance as well as restorative operations involve a purging operation typically known as Steady State Purge (SSP). This purge operation involves large amount of expensive UHP gas and time. Depending on the scale of the system and type of process involved this results in significant tool, process downtimes and can have a wide range of environment, health and safety (ESH) ramifications. A novel purge process, referred to as Pressure Cyclic Purge (PCP) was studied for establishing gas phase contamination control in UHP applications. In understanding the basic mechanism of this technique and to analyze its extent of application in aiding purging operations, a coupled approach involving experimental investigation and computational process modelling was used. Representative and generic distribution sections such as main supply lines and sections with laterals were contaminated with a known amount of moisture as impurity. The dynamics of the impurity transport through the system from purging with SSP as well as PCP was captured by a highly sensitive analyzer. The surface interactions between the moisture and EPSS were characterized in terms of adsorption and desorption rate constants and surface site density. A computational process model trained using experimental data was then validated and used to study the steady and cyclic purge mechanisms and predict complex purge scenarios. Industrially relevant and applicable boundary conditions and system definitions were used to increases the utility of the computational tool. Although SSP compared closely with PCP on simple systems without laterals, a drastic difference in dry-down efficiency was noticed in systems with dead volumes in the form of capped laterals. Studies on system design parameters revealed that the disparity in performance was observed to increase with larger number and surface area of dead volumes, opening a path to critical understanding of the differences in process mechanisms. Beneficial transient pressure gradient induced convective flow in the dead volumes during cyclic purge was identified to be the main factor driving the enhanced dry down rate. Similar trends were observed on using surface concentration as the purge metric. Hybrid purge schemes involving a combination of SSP and PCP were found to yield higher benefit in terms of efficient use of purge gas. Removal of strongly interacting contaminant species showed a higher benefit from use of controlled PCP scheme. Although, parametric analysis carried out on the operating factors of cyclic purge suggested that the enhancement in dry down increased with higher pressure range, it was highly conditional towards configurational factors in design and operation such as system dimensions, holding time, cycling pattern, valve loss coefficients and the complex inter coupling between them. The robustness of the process simulator allows the development of optimal purge scenarios for a given set of system parameters in order to perform a controlled purge. The benefit of using a hybrid PCP scheme was evaluated in terms of UHP purge gas and process time as a function of purity baseline required. Apart from UHP gas distribution systems, process vessels, chambers and components along the process stream are also prone to molecular contamination and pose a threat to product integrity. The dead volumes acting as areas of contaminant accumulation represent cavities or dead spaces in flow control elements such as mass flow controllers (MFCs), gauges, valves or dead spaces in process chambers. Steady purge has very little effect in cleanup of such areas and more efficient methods are necessitated to raise purge efficiency. The analysis of application of PCP is extended to such components through the development of a robust and comprehensive process simulator. The computational model applies a three dimensional physical model to analyze purge scenarios with steady and cyclic purge. The results presented pertain to any generic gas phase contaminant and electronic grade steel surfaces. Close investigation of the purge process helped elaborate the cleaning mechanism. Critical steps driving the purge process were identified as - dilution of chamber by introduction of fresh gas during re-pressurization and chamber venting during depressurization. Surface and gas phase purging of chambers with dead spaces using steady and cyclic purge were studied and compared. Cyclic purge exhibited a higher rate of dry down. The effect of system, design and purge operating parameters on surface cleaning were studied. Although higher frequency cycles and larger operating pressure ranges optimized for a given geometry are found to deliver better pressure cyclic purge (PCP) performances, the benefit is found to be contingent to a strong interplay between system parameters. PCP is found to be advantageous than steady state purge (SSP) in terms of purge gas usage and operation time in reaching a certain purity baseline. Specialty process gases supplied to the fabrication facility are typically stored in the form of liquids in enormous tanks outside the fab. Ammonia is a widely used in UHP concentrations for a variety of process including epitaxial growth, MOCVD, etching and wet processes in the semiconductor industry. The recent development in LED research has risen the demand and supply for Ammonia based compounds. Stringent baselines are maintained for the impurities associated with the manufacturing of such gases (e.g. Moisture in Ammonia). Apart from the difference in the rates of evaporation of the individual species from the storage cylinder causing accumulation of slower evaporating species, external temperature fluctuations also generate unsteady flux of desired species. When concentrations rise above this threshold additional purification or in most cases discarding large volumes of unused gas is warranted, causing loss of resources and causing ESH issues. Bulk gases are usually delivered over long lengths of large diameter pipes which produce large density of adsorption sites for contaminants to accumulate and eventually release into the gas stream. In order to establish contamination control in the gas delivery system, the surface interactions of the multispecies system with the delivery line surface was characterized. Desired concentrations of moisture in ammonia and UHP nitrogen mixtures were produced in a gas mixing section capable of delivering controlled mass flow rates to an EPSS test bed. Transient moisture profiles during adsorption and desorption tests at various test bed temperatures, mass flow rates and moisture concentration were captured by a highly sensitive analyzer. A mathematical model for single and multi-species adsorption was used in conjunction with experimental data to determinate kinetics parameters for moisture, ammonia system in EPSS surface. The results indicate competitive site binding on EPSS between ammonia and water molecules. Also, the concentration distribution of each species between surface, gas phase is interdependent and in accordance to the kinetic parameters evaluated. Back diffusion of impurity is a major source of contaminant introduction into UHP streams. Back diffusion refers to the transport of contaminants against the flow of bulk process stream. Molecular species can back diffuse from dead volumes, during mixing operations etc., simply when there is a gradient of concentration. A steady state approach was used to analyze the mechanism and effects of various geometrical and operational parameters on back diffusion. High sensitivity moisture detectors were used to capture the dynamics of contamination in a section of a generic distribution system. Results showed that back diffusion can occur through VCR fittings, joints and valves under constant purge. General trends on the effect of design parameters on back diffusion were derived from studies on various orifice sizes, system dimensions, flow rates and test moisture concentrations. Coupled parametric studies helped identify critical variable groups to perform dimensionless analysis on back diffusion of moisture. Crucial points where back diffusion can be minimized or completely eliminated are identified to help set up guidelines for cyclic and steady purge parameters without excessive use of expensive UHP gas or installation of unnecessarily large factors of safety. Wet cleaning of micro/nano sized features is a highly frequent process step in the semiconductor industry. The operation is a huge consumer of ultra-pure water and one of the main areas where process time minimization is focused. Comprehensive process model is developed to simulate the mechanism and capture the dynamics of rinsing high aspect ratio Silicon features in the nanometer scale. Rinsing of model trench, post etch contaminated with ammonium residue is studied. Mass transport mechanisms such as convection, diffusion are coupled with surface processes like adsorption and desorption. The effect of charged species on the trench surface and in the bulk, the resultant induced electric field on the rinse dynamics and decay of surface species concentration is studied. General rinsing trends and critical points in change in mechanisms were identified with critical groups such as mass transfer coefficient and desorption coefficient. The model is useful in evaluating process efficiency in terms of rinse time and DI water consumption under varying process temperature, contaminant concentration, and rinse fluid flow rate. The generic build of the model allows extension of its functionality to other impurity-substrate material couples.

Master of Science / Department of Mechanical and Nuclear Engineering / Steven J. Eckels / NanoActiveTM metal oxide particles have the ability to destructively adsorb organophosphorus compounds and chlorocarbons. These nanomaterials with unique surface morphologies are subjected to separate, low concentrations of gaseous ammonia in air. NanoActiveTM materials based on magnesium oxide have large specific surface areas and defective sites that enhance surface reactivity and consequently improved adsorptivity. In gas contaminant removal by adsorption, presence of vast specific surface area is essential for effective gas-solid interaction to take place. This is also the case in many industrial and chemical applications such as purification of gases, separation and recovery of gases, catalysis etc,. Typically carbonaceous compounds are utilized and engineered in toxic gas control systems. The purpose of this study was to compare NanoActiveTM materials with carbon based compounds in the effectivity of toxic gas adsorption at low concentrations. A test facility was designed to investigate the adsorption properties of novel materials such as adorption capacity and adsorption rate. Adsorption capacity along with adsorption kinetics is a function of properties of the adsorbent and the adsorbate as well as experimental conditions. Nanomaterials were placed on a silica matrix and tested with increasing flow rates. Electrochemical sensing devices were placed at inlet and outlet of the facility to monitor real time continuous concentration profiles. Breakthrough curves were obtained from the packed bed column experiments and saturation limits of adsorbents were measured. Adsorption rates were obtained from the breakthrough curves using modified Wheeler-Jonas equation. The NanoActiveTM materials adsorbed ammonia though to a lesser extent than the Norit® compounds. This study also included measurement of pressure drop in packed beds. This information is useful in estimating energy losses in packed bed reactors. Brauner Emmet Teller tests were carried out for the calculation of surface area, pore volume and pore size of materials. These calculations suggest surface area alone had no notable influence on adsorption capacity and adsorption rates. This lead to the conclusion that adsorption was insignificant cause of absence of functional groups with affinity towards ammonia. In brief, adsorption of ammonia is possible on NanoActiveTM materials. However functional groups such as oxy-flouro compounds should be doped with novel materials to enhance the surface interactions.

The primary goal of this research concerns the synthesis and characterization of metal-organic frameworks (MOFs) grafted with pendant alkyl substituents to enhance stability and gas sorption properties for use in clean-energy related technologies. Initially, the focus of this work was on the synthesis and comparison of two isostructural MOFs built upon octahedral secondary building blocks; one with no alkyl substituents, and its dimethyl-substituted counterpart. The dimethyl-substituents are observed to enhance the stability of the framework, resulting in high Langmuir surface area (4859 m2 g-1) and hydrogen uptake capacity at 77 K and 1 bar (2.6 wt%). In the second section, the length of pendant alkoxy substituents in semi-flexible MOFs was evaluated through the synthesis and characterization of two isostructural MOFs, one with dimethoxy (PCN-38) and one with diethoxy pendant groups (PCN-39). While PCN-38 exhibited moderate surface area and hydrogen uptake capacities, PCN-39 underwent structural change upon activation leading to a redistribution of pore sizes and selective adsorption of hydrogen over larger gases. This structural transformation is believed to originate from optimal space filling of the pendant groups. In the third section, a series of NbO-type MOFs were synthesized with dimethoxy, diethoxy, dipropoxy, and dihexyloxy substituents and the relationship between chain length and framework stability identified. Increasing chain length was observed to increase moisture stability of the MOFs, resulting in a superhydrophobic material in the case of the dihexyloxy derivative. Thermal stability, however, decreased with increasing chain length, as evidenced from in situ synchrotron powder X-ray diffraction measurements (PXRD). This is in contrast to data obtained from thermogravimetric analysis and shows that the standard use of thermogravimetric analysis, which measures combustion temperatures, may not always provide an accurate description of the thermal stability of MOFs. The role of pendant groups in gas adsorption processes was evaluated through identification of side chains and guest species in the pores of MOFs through in situ synchrotron PXRD measurements. In summary, three separate isostructural series of MOFs with various pendant groups have been discussed in this dissertation, with the roles of those pendant groups toward crystal structure, stability, and gas sorption properties analyzed.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-05-04T18:30:45Z No. of bitstreams: 1 filipebarradealmeida.pdf: 7947999 bytes, checksum: dc362590639be1c4acb93cdcf62990c9 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-17T13:33:19Z (GMT) No. of bitstreams: 1 filipebarradealmeida.pdf: 7947999 bytes, checksum: dc362590639be1c4acb93cdcf62990c9 (MD5) / Made available in DSpace on 2017-05-17T13:33:19Z (GMT). No. of bitstreams: 1 filipebarradealmeida.pdf: 7947999 bytes, checksum: dc362590639be1c4acb93cdcf62990c9 (MD5) Previous issue date: 2016-07-28 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este trabalho apresenta a síntese e estudo de polímeros de coordenação para adsorção de gases. Especificamente, os compostos apresentados foram sintetizados pela combinação do ligante INH com um dos ligantes H2BDC, H3BTC e H4BTC coordenados aos íons Co2+, Zn2+ e Mn2+, sendo um total de sete compostos. Os compostos Zn-H2BDC e Mn-H2BDC formaram-se como complexos moleculares simples pelos ligantes INH e H2BDC coordenados aos íons Zn2+ e Mn2+, sendo caracterizados pelas técnicas de espectroscopia na região do infravermelho e espalhamento Raman, pela análise elementar (CHN), análise termogravimétrica (TGA e DrTGA) e por difração de raios X por monocristal. Os mesmos apresentaram várias interações intermoleculares diferenciadas e uma rica química supramolecular. Além desses compostos citados, todos os outros cinco compostos se formaram como polímeros de coordenação. Os compostos Co-H2BDC, Zn-H3BTC e Co-H3BTC apresentaram-se como polímeros de coordenação com possibilidade de serem usados em adsorção de gases. O composto Co-H2BDC foi formado pelos ligantes INH e H2BDC com o íon Co2+ e se formou como um polímero de coordenação 2D policatenado, já o composto Zn-H3BTC foi formado pelos ligantes INH e H3BTC e o íon Zn2+ e se formou como um polímero de coordenação 1D. Ambos os compostos foram caracterizados por técnicas usuais de espectroscopia tais como espectroscopia na região do infravermelho e espalhamento Raman, análise elementar (CHN), difração de raios X por monocristais e por policristais, este último com variação de temperatura; cálculos teórico-computacionais e testes de adsorção gasosa pela metodologia B. E. T.. O composto Co-H2BDC apresentou possíveis poros em relação ao eixo cristalográfico c, mas os mesmos não possuíram tamanho suficiente para estabilizar moléculas de gás N2 adsorvido. Além disso, os cálculos teórico-computacionais comprovaram a maior estabilização da estrutura dopada com Li+ e a magnetização da mesma. Para o composto Zn-H3BTC, foi verificado que a estrutura do mesmo não mantem sua cristalinidade com o aumento de temperatura, mas que o mesmo possivelmente não se decompõe na temperatura experimental do teste de adsorção gasosa, sendo que o mesmo apresentou capacidade de adsorção de gases caracteristicamente em multicamadas. O composto CoH3BTC foi formado pelos ligantes INH e H3BTC coordenados ao íon Co2+, formando um polímero de coordenação 2D que se empilham de forma invertida e em pares, formando uma estrutura lamelar com potenciais vazios nas lamelas. Este composto foi caracterizado por técnicas espectroscópicas, análise elementar (CHN), análise termogravimétrica (TGA e DrTGA) e difração de raios X por monocristais. Os compostos Co-H4BTC e Zn-H4BTC formaram-se como polímeros de coordenação 3D e 1D, composto pelos ligantes INH e H4BTC coordenados aos íons Co2+ e Zn2+, respectivamente. Ambos os composto foram caracterizados por técnicas usuais de espectroscopia como IV e espalhamento Raman, análise elementar (CHN) e difração de raios X por monocristais. / This work shows the synthesis and study of gas adsorption of coordination polymers. The compounds were synthetized by the combination of the ligand INH with one of the ligands H2BDC, H3BTC and H4BTC coordinated to Co2+, Zn2+ and Mn2+ ions, being seven compounds overall. The compounds Zn-H2BDC and Mn-H2BDC were formed as molecular complexes by the ligands INH and H2BDC coordinated to Zn2+ and Mn2+ ions, being characterized by spectroscopy techniques such as IR and Raman, elemental analysis (CHN), thermogravimetric analysis (TGA and DrTGA) and by single crystal X ray diffraction. The compounds showed several intermolecular interactions and a rich supramolecular chemistry. Besides the mentioned compounds, five other compounds were formed as coordination polymers. The compounds CoH2BDC, Zn-H3BTC and Co-H3BTC formed as coordination polymers with the possibility to be used in the gas adsorption. The compound Co-H2BDC was formed by the ligands INH and H2BDC with Co2+ ion forming a 2D polycatenated coordination polymer and the compound Zn-H3BTC was formed by the ligands INH and H3BTC with Zn2+ forming a 1D coordination polymer. Both compounds were characterized by spectroscopy techniques as IR and Raman, elemental analysis (CHN), by single crystal X ray diffraction and by polycrystals X ray diffraction, this last one applying temperature variation, by theoretical calculation using computational models and by B. E. T. gas adsorption methodology. It was verified that in the compound Co-H2BDC was formed pores in the axis c direction, but the pores does not have enough size to stabilize N2 gas molecule inside it. Additionally, in the theoretical calculations was confirmed the higher stability of Li-doped structure than the non Li-doped structure and further its magnetization. In the compound Zn-H3BTC was verified that its structure did not keep the crystallinity with increasing in temperature, but it did not decomposes in the experimental temperature to gas adsorption experiment. This compound showed gas adsorption properties in multilayers. The compound Co-H3BTC was formed by the ligands INH and H3BTC coordinated to the Co2+ forming a 2D coordination polymer that piles up in reverse way and in pairs. This configuration formed a lamellar structure and it was characterized by spectroscopy techniques as IR and Raman, elemental analysis (CHN), thermogravimetric analysis (TGA and DrTGA) and by X ray diffraction by single crystal. The compounds Co-H4BTC and Zn-H4BTC showed as 3D and 1D coordination polymers composed by INH and H4BTC ligands coordinated to the Co2+ and Zn2+ ions respectively. Both compounds were characterized by spectroscopy techniques such as IR and Raman, elemental analysis (CHN), by single crystal X ray diffraction.

Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-05-22T15:47:02Z No. of bitstreams: 1 felipemagestescaldini.pdf: 2661212 bytes, checksum: 68339e788685f873502440bba4b26794 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-22T17:40:25Z (GMT) No. of bitstreams: 1 felipemagestescaldini.pdf: 2661212 bytes, checksum: 68339e788685f873502440bba4b26794 (MD5) / Made available in DSpace on 2017-05-22T17:40:25Z (GMT). No. of bitstreams: 1 felipemagestescaldini.pdf: 2661212 bytes, checksum: 68339e788685f873502440bba4b26794 (MD5) Previous issue date: 2013-02-25 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este trabalho descreve a síntese e caracterização de oito compostos de coordenação, [Zn(PYA)2(H2O)2]n (1), [Mn(PYA)2(H2O)2]n (2), {[Co(2,5PDC)(H2O)2] .H2O}n (3), [Mn(2,5HPDC)2(H2O)2] (4), [Ni(2,3HPDC)2(H2O)2] (5), {[Cu(3,4HPDC)2(H2O)2] .DMSO}n (6), {[Co(3,4HPDC)2(H2O)2](H2O)(DMSO)}n (7) e {[Cu2(3,4HPDC)2(H2O)5]}n (8) contendo ligantes da família dos ácidos piridinodicarboxílicos, que são N-, O- doadores e podem proporcionar modos de coordenação interessantes frente aos íons metálicos da 1º série de transição selecionados para o trabalho (Mn2+, Co2+, Ni2+, Cu2+ e Zn2+). Os ligantes utilizados foram os ácidos 2,3 piridinodicarboxílico (2,3H2PDC), 2,5 piridinodicarboxílico (2,5H2PDC), 3,4 piridinodicarboxílico (3,4H2PDC), trans-3-(piridil)-acrílico (HPYA) e 3-(2-tienil)acrílico (HTA). Dos oito compostos descritos neste trabalho, apenas três são inéditos. Os compostos inéditos, (6), (7) e (8) foram caracterizados por análise elementar, análise térmica (TG e DTA), espectroscopia vibracional na região do infravermelho, e difração de raios X por monocristal. Nesses três compostos, em acordo com os dados espectroscópicos, a difração de raios X por monocristal mostrou que os ligantes se apresentam na forma parcialmente desprotonada e além disso, observou-se a formação de redes poliméricas. Em todos os casos, os arranjos supramoleculares são formados por ligações de hidrogênio. Todos os compostos apresentam o metal central em geometria octaédrica, com excessão do composto (8) que mostra dois centros de Cu(II), sendo um em geometria octaédrica e outro como pirâmide de base quadrada. Foi feita também a descrição topológica das redes poliméricas formadas, com auxilio do programa TOPOS. Dentre os compostos apresentados neste trabalho, apenas os compostos (4) e (5) não formam cadeias ou redes poliméricas. O teste de capacidade de adsorção de gás para o composto polimérico (6) foi feito através das isotermas de N2, utilizando o método BET. / This work describes the synthesis and characterization of eight coordination compounds, [Zn(PYA)2(H2O)2]n (1), [Mn(PYA)2(H2O)2]n (2), {[Co(2,5PDC)(H2O)2] .H2O}n (3), [Mn(2,5HPDC)2(H2O)2] (4), [Ni(2,3HPDC)2(H2O)2] (5), {[Cu(3,4HPDC)2(H2O)2] .DMSO}n (6), {[Co(3,4HPDC)2(H2O)2](H2O)(DMSO)}n (7) and {[Cu2(3,4HPDC)2(H2O)5]}n (8) containing N-,O-donor ligands from pyridinedicarboxylic acids family that can provide interesting coordination modes toward the first row transition metal ions (Mn2+, Co2+, Ni2+, Cu2+ e Zn2+). 2,3 pyridinedicarboxylic (2,3H2PDC), 2,5 pyridinedicarboxylic (2,5H2PDC), 3,4 pyridinedicarboxylic (3,4H2PDC), trans-3-(pyridyl)-acrylic (HPYA) and 3-(2-thienyl)acrylic acid (HTA) were used as ligands. Among the eight compounds described in this work, only three are unpublished. The novel compounds, (6), (7) and (8) were characterized by elemental analysis, thermal analysis (TG and DTA), infrared vibrational spectroscopy, and single crystal X-ray diffraction analysis. In these three compounds, in accordance with the spectroscopic data, single crystal X-ray diffraction analysis showed that the ligands are present in partially deprotonated form and furthermore, the formation of polymeric networks was observed. In all cases, supramolecular arrangements are formed by hydrogen bonds. All compounds show the metal center in octahedral geometry, except compound (8) that has two Cu (II) centers; one in octahedral geometry and other in a square pyramidal geometry. A topological description was also made for the polymeric networks formed, supported by the software TOPOS. Among all compounds presented in this work, only compounds (4) and (5) do not form polymeric chains or networks. The gas adsorption capacity test was realized for the polymeric compound (6), through N2 isothermal, using BET method.