Dissertationen: „Adsorption“

1

Bruce, L. J. „Hydrodynamics and adsorption within an expanded bed adsorption column“. Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.597027.

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In this thesis, relationships between the hydrodynamics and adsorption behaviour within EBA columns were examined and methods to improve EBA performance in terms of productivity, reproducibility and control were provided. The effect of column verticality was quantified and identified as a significant source of process variability. Column misalignment of only 0.15° off vertical resulted in a greater increase in liquid dispersion in 1 cm diameter columns compared to 5 cm diameter columns. Protein breakthrough curves for vertical and 0.15° off-vertical runs performed using a 5 cm diameter column were essentially indistinguishable, while applicability more protein could be applied to a vertical 1 cm diameter column compared to the same column misaligned by 0.15°. This degree of misalignment was not detectable by visual assessment of adsorbent particle movement within the column, therefore methods were developed to ensure column verticality for separations at the smaller scale. Equipment and methods for in-bed sampling of both liquid and solids were developed. A 5 cm diameter EBA column was modified to allow abstraction of samples from ports positioned along the columns wall. The modifications to the column did not significantly affect liquid dispersion or separation efficiency. It was demonstrated that on-line, in-bed sampling can provide higher control of a separation. The in-bed monitoring system was also used to study hydrodynamics within a vertical 5 cm diameter column with a perforated plate distributor, the same column aligned 0.15° off-vertical, and a 5 cm diameter column which employs a stirrer for flow distribution.

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2

Borthwick, D. S. „Adsorption kinetics and thermodynamics from single crystal adsorption calorimetry“. Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.596784.

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The interactions of CO, NO and O₂ with Pt{111}, pt{211}, and Pt{411} have been investigated with Single Crystal Adsorption Calorimetry (SCAC). Coverage-dependent heat of adsorption and sticking probability data for 300 K are presented, and are discussed with respect to the kinetics and thermodynamics of adsorption and desorption. CO adsorption proceeds molecularly on both Pt{111} and Pt{411}, with initial sticking probabilities of 0.78 and 0.80, and initial heats of adsorption of 176 kJ mol^-1 and 196 kJ mol^-1, respectively. Both adsorbate layers are found to be non-localised, having identical pre-exponential factors of 2x10¹⁵ s^-1. Discrepancies between isosteric and calorimetric heat of adsorption data at low coverage for CO/Pt{111} have been rationalised in terms of an entropy-driven localised/non-localised phase transition occurring above 300 K. Initial adsorption of NO occurs with a sticking probability of 0.84 on all three surfaces. The initial heat of adsorption for NO/Pt{411} indicates dissociative adsorption. The NO/Pt adsorbate layers are found to be highly localised, with pre-exponential factors in the range 10¹⁷ – 10²⁰ s^-1. This has been discussed in terms of desorption from highly compressed adsorbate layers in which co-operative effects are extant. O₂ adsorption proceeds dissociatively on all three surfaces, with the initial heats of adsorption all above 300 kJ mol^-1. Desorption occurs from localised adsorbate layers, with all systems having pre-exponential factors of 10¹⁸ s^-1. A kinetic compensation effect has been observed for the data of this thesis, as well as that of the SCAC literature, and is discussed within the context of the chemisorption entropy-enthalpy compensation.

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3

Mahle, John J. „Adsorption humidity effects, microparticle rate behavior, and thermal swing adsorption“. College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/3202.

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Thesis (Ph. D.) -- University of Maryland, College Park, 2005.
Thesis research directed by: Chemical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

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4

Enarsson, Lars-Erik. „Polyelectrolyte adsorption on oppositely charged surfaces - Conformation and adsorption kinetics“. Licentiate thesis, Stockholm : Royal Institute of Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4059.

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5

Edström, Emelie. „Solvent adsorption in SFC : Adsorption of methanol under supercritical conditions“. Thesis, Karlstads universitet, Institutionen för ingenjörs- och kemivetenskaper, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-35185.

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Chromatography is a widely used separation technique including many different modes, for example supercritical fluid chromatography (SFC) which uses a supercritical fluid as mobile phase. A supercritical fluid is achieved when a substance is subjected to a temperature and pressure above the critical point and the boundary between the liquid phase and gas phase is erased. The interest for SFC has increased in recent years, mainly for separation of chiral molecules in the pharmaceutical industry. What makes SFC interesting is that it is a quick, cost-efficient and green method. This is in part due to less organic solvent used in the mobile phase in SFC compared with liquid chromatography and that the carbon dioxide that represents the major part of the mobile phase is a by-product from other processes. In SFC modifiers, often small alcohols, are added to carbon dioxide based mobile phase in order to increase the solubility of polar compounds. In this study the adsorption of methanol to two different stationary phases; Kromasil-Diol and chiral Lux Cellulose-4 were studied. Adsorption is a phenomenon where surface interactions crate a higher density of molecules at the surface than in the bulk. The aim of this work has been to study the adsorption of modifier (methanol) to the stationary phase both to determine the extent of adsorption and the kinetics for system equilibration. These findings were then put into perspective of normal use of SFC for separation of molecules. There are a number of techniques for measuring adsorption; in this study the tracer pulse method is used. This is a pulse method where a concentration plateau is created and an isotope labelled molecule is injected. This was performed in the mobile phase composition from pure carbon dioxide to pure methanol. In addition to the tracer pulse experiments the isotope effect, the eluent flow, equilibration times for the column and retention times for a set of analytes were measured. For the Diol column no large isotope effect was observed, the method was also proved to be highly reproducible since several runs gave consistent results. Calculations based on the experimental data showed that a 6.3 Å thick layer was built up at a methanol fraction of 13% (v/v), corresponding to a monolayer. Changes of the methanol fraction below the saturation level has has greater effect on the retention factor for the analytes than at higher methanol fractions, when the monolayer was saturated. The conclusion of this is that SFC is more stable in the area where the layer has been built up. A preliminary study has been made for the chiral Lux Cellulose-4 column which was not as conclusive as for the Kromasil-Diol column. This type of column needs further studies to confirm the deviating observations and to investigate the cause for these.

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6

Lang, Matthew H. „Polyelectrolyte adsorption kinetics“. Diss., Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/5792.

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7

Kim, Hyunho Ph D. Massachusetts Institute of Technology. „Experimental characterization of adsorption and transport properties for advanced thermo-adsorptive batteries“. Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/93826.

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Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 77-79).
Thermal energy storage has received significant interest for delivering heating and cooling in both transportation and building sectors. It can minimize the use of on-board electric batteries for heating, ventilation and air-conditioning (HVAC) in electric vehicles (EVs) or reduce electricity consumption during peak demand in residential and commercial buildings. A compact and lightweight advanced thermo-adsorptive battery (ATB) is currently being developed to provide both heating and cooling. Additionally, if waste heat or solar energy were used to regenerate the ATB, the mechanical energy to run the cycle for vapor compression and transport, can be eliminated, thus, providing a significant benefit over conventional HVAC systems, especially when provision of electric energy is challenging. We present a detailed characterization of the thermophysical and transport properties of adsorptive materials for the development of the ATB. We discuss the feasibility of using contemporary adsorptive materials, such as zeolite 13X, by carrying out a detailed experimental and theoretical characterization. Enthalpy of desorption of zeolite 13X - water pair was characterized using the state of the art calorimetric technique. The experimental characterization and theoretical modeling of commercially available zeolite 13X (Sigma Aldrich, molecular sieves, 13X, powder, ~2 [mu]m average size) combined with carbon nano-materials, such as functionalized multi-walled carbon nanotube and graphene, are carried out to improve the effective thermal conductivity. Furthermore, we carried out performance characterization of a single-layer adsorption stack for the development of the ATB. Consequently, this thesis can serve as a framework for the development and characterization of adsorption-based thermal storage systems.
by Hyunho Kim.
S.M.

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8

Eve, Jemimah Kate. „Adsorption and co-adsorption on metal single crystals at cryogenic temperatures“. Thesis, University of York, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313949.

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9

Schurger, Uwe. „Investigation into solar powered adsorption cooling systems : adsorption technology and system analysis“. Thesis, De Montfort University, 2007. http://hdl.handle.net/2086/4122.

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Due to the fact that the worldwide energy consumption caused by cooling devices in buildings has been increasing steadily and also the fact that the pressure has been rising to provide this cooling energy with environmentally friendly technology, solar powe.re~ DEC-systems (Desiccative and Evaporative Cooling) have begun capturing increasing interest over the past few years. , However, up to now little experience has been gained in the operation of these systems and thus currently little information is available about the performance, the efficiency, the control strategy and the best component choice. This lack of knowledge has resulted in a low rate of acceptance of, this technology so far. The studies presented in this thesis serve as a contribution to the advancement of DEC technology by providing fundamental knowledge about the operation and attainable performance of these systems. A comprehensive study of desiccant wheels was undertaken which provides detailed information about the operation and the achievable dehumidification performance of this component. A detailed simulation model for desiccant wheels was developed and verified with measured data from a desiccant wheel test plant. Additionally, two commercially used DEC-systems (one in a public library in Spain and the other in a plastics processing factory building in Germany) were monitored for the purposes of evaluating the performance of these systems and resolving existing problems in their operation and control strategies. In spite of the generally positive validation of the planned and expected cooling performances in both cases, the monitoring also showed that there are considerable possibilitiesÃ‚Â· for improvement, especially with the regulation of the system.

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10

Carlisle, C. „Atomic-scale imaging of adsorption, oxidation and co-adsorption on Ag{111}“. Thesis, University of Cambridge, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.597289.

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The work presented in this thesis draws upon several uses of STM, from structural determination, when used in conjunction with theoretical simulations, to the observation of surface reactions and surface mediated interactions. Simulations have been used here for the first time to allow the complete structural determination of a complex reconstruction. The determination of the reconstruction's structure and composition has enabled further experiments involving the oxidation of the Ag{111} surface as well as adsorbate-oxygen interactions mediated by the surface. The source of inspiration for these studies has been the catalytic epoxidation of ethene on silver by atomic oxygen. Two 'surface' states of atomic oxygen have been observed. The first, denoted O_c, is considered to adsorb in interstitial sites within the top layer of AG{111}. Its adsorbate-adsorbate repulsive nature sees this species rapidly saturating at a coverage of just 0.05 ML, at which point the p(4x4)-O species becomes more stable and its growth is nucleated at step edges. On decomposition of the p(4x4)-O reconstruction, both Ag{111} triangular islands and fractures within the oxide appear across the terraces. Both features may play a significant role in the catalytic behaviour. Ethene adsorption on clean Ag{111} has provided information on the adsorption geometry, adsorption state and appearance in the STM image allowing confident interpretations of the coadsorbed ethene-oxygen system. Tip pulsing has been used to provide a controlled mechanism for the induced transition from the physisorbed intrinsic precursor state of ethene to that of the chemisorbed state. High-resolution images have enabled the direct observation of Friedel surface oscillations surrounding the chemisorbed state. To my knowledge, this is the first direct observation of such oscillations resulting from adsorbates.

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11

Haskaraman, Feyza. „Thermal and hydraulic analysis of the adsorption bed of the adsorptive thermal battery“. Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/105706.

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Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.
Cataloged from PDF version of thesis.
Includes bibliographical references (page 23).
Electric vehicles (EVs) have a drawback of relatively short drive range that affects their adoption rate. In order to increase the drive range of EVs, replacing heating, ventilation and air conditioning (HVAC) system with a novel absorbent system of materials and methods is widely investigated. This work focuses on the analysis of the design of such a system to suggest efficiency improvements. The thermal insulation and choice of pump required for the optimal function of the adsorptive bed that carries the novel material are analyzed respectively to understand system performance. A thermal resistance analysis was performed in order to understand the undesirable heat loss from the system that decreases the efficiency. Moreover, pressure loss in the piping system was determined theoretically to choose a compatible pump. This analysis also resulted in a modular code that can be used to test different design parameters for future work,
by Feyza Haskaraman.
S.B.

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12

Klingberg, Carlos Jiménez. „Selektive Adsorption von Immunglobulinen“. Köln Deutsche Zentralbibliothek für Medizin, 2010. http://d-nb.info/1000935701/34.

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13

Scheuch, Sven. „Die Adsorption argonhaltiger Gasgemische“. [S.l. : s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=966284232.

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14

Nassara, Ramiel. „Adsorption separation of ethyleneethane“. Thesis, University of Ottawa (Canada), 2008. http://hdl.handle.net/10393/27721.

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To offset rising energy costs, it is becoming a necessity to lower energy usage within industrial processes. Such can be said for the separation of olefin/paraffin mixtures. An example of such a mixture is ethylene/ethane. This highly energy intensive industrial separation employs cryogenic distillation to achieve a high purity product. Subsequently, the energy cost to run such a system is extremely high. Hybrid scenarios have been explored, with adsorption being a potential candidate. This work studied the potential of three adsorbents for the separation of ethylene/ethane: AgNO3/SiO2, CuCl/SiO 2, and CECA 13X. AgNO3/SiO2 and CuCl/SiO 2 were both prepared in the laboratory. Pure component constant volume experiments were conducted, along with binary mixture predictions for all three adsorbents at 3 different temperatures. The expected working capacities were also calculated for the three adsorbents. Finally, an economic analysis, without taking competitive adsorption in to factor, was conducted to give a rough idea of how much a potential PSA system would cost using the three adsorbents individually. CuCl/SiO2 yielded the most favorable results of the three adsorbents, but more studies were determined necessary on the optimization of the preparation of the adsorbent. AgNO3/SiO 2 was not completely ruled out, however. Both the adsorbents showed characteristics for a potential use within industry. CECA 13X was not considered a viable candidate for such a separation.

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15

Goren, Michal. „Nanoparticle adsorption onto surfaces“. Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=84250.

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The ability to produce materials in unique morphologies and structures is of great importance as a strategy in micro-and nanomaterial fabrication. Nanosized materials in particular are of great interest because of limited possibilities of producing them from their corresponding bulk materials ("top-down" approach). To a chemist, challenges lie in the synthesis of these nanostructures, as well as in producing them in a parallel fashion. One possible way of directly synthesizing a confined morphology is by templating, where the material to be synthesized is selectively grown on a surface feature of a unique pattern. As a result, the morphology of the synthesized material mirrors the surface pattern of the template.
This Thesis is concerned with the interface between surface chemistry and nano-chemistry through templating. Templated growth of polypyrrole (Ppy) on two different surfaces is described. Templating results in Ppy having unique nanomorphologies of wires and dots. A system where Ppy selectively grows on lipid bilayer edges (as per Qi, Proc.-Electrochem. Soc. 1997, 97-5, 173) is described. A general mechanism for Ppy deposition on surfaces is presented. A system where Ppy grows selectively on PS-PVP block copolymer surface micelles is also described. It is demonstrated that a template surface may be modified while templating occurs on it. Finally, the adsorption kinetics of nanoparticles onto self-assembled monolayers (SAMs) is studied in the context of differential surface energies being a driving force for the adsorption. The adsorption kinetics are studied using the Surface Plasmon Resonance (SPR) technique. This study reveals that there is a correlation between the driving force for adsorption and the adsorption kinetics.

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16

Battrum, M. J. „Gas separation by adsorption“. Thesis, University of Bath, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376289.

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17

Bird, Christopher E. „Single crystal adsorption microcalorimetry“. Thesis, University of Liverpool, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316775.

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18

Shukla, Lalita. „Polymer adsorption in pores“. Thesis, University of Bristol, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333958.

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19

Valiullin, Rustem, Jörg Kärger und Peter Monson. „Adsorption hysteresis in nanopores“. Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-196715.

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20

Navaei, Milad. „Quartz crystal microbalance adsorption apparatus for high pressure gas adsorption measurements in nanomaterials“. Thesis, Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/41057.

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The primary objective of this study was to develop a sensitive and cost-effective sorption system to analyze adsorption and diffusion of different gases on micro porous materials and nanotubes. A high pressure Quartz Crystal Microbalance (QCM) based adsorption apparatus for single-component gas was developed. A QCM is an acoustic-wave resonator in which the acoustic wave propagates through the crystal. Therefore, it is highly responsive to addition or removal of small amounts of mass adsorbed or deposited on the surface of the crystal. This mass sensitivity makes the QCM an ideal tool for the study of gas adsorption. The QCM-based adsorption apparatus is advantageous over the commercialized none-gravimetric and gravimetric equipment in a way that it is low-cost, highly sensitive and accurate for mass sorption applications, satisfactorily stable in a controlled environment, and can be used for thin films. The high pressure apparatus was calibrated using Matrimid 5218, whose thermodynamic properties and adsorption parameters are known. The Matrimid was spin-coated onto a 14 mm-diameter QCM, and sorption equilibrium data for were obtained for CO₂ gas at 25, 30, 48, and 52 ºC and partial pressure range between 0 to 4 bar. In order to compare the experimental data with available literature data, the experimental data was fitted into a dual-mode adsorption model. The model results from Henry's law and a Langmuir mechanism. Comparison of the experimental adsorption isotherm of Matrimide for CO₂ gas with literature data showed reasonable agreement between the experimental and literature data. In this study, the adsorption parameters of aluminosilicate nanotubes are observed. Aluminosilicate nanotubes are ideal materials for chemical sensing, molecule separation, and gas storage; hence, there is a need for adsorption and diffusion data on this material. The adsorption of CO₂, N₂, and CH₄ gases on aluminosilicate nanotubes samples has been studied in the temperature range of 20° to 120° Celsius and pressure range of 0 to 8 bar. The experimental results yield the CO₂ and N₂ heat of adsorptions of -32.9 and -28.1 kJ/mol respectively.

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21

Uner, Murat. „Adsorption Calorimetry In Supported Catalyst Characterization: Adsorption Structure Sensitivity On Pt/y-al2o3“. Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/2/12605511/index.pdf.

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In this study, the structure sensitivity of hydrogen, oxygen and carbon monoxide adsorption was investigated by changing the metal particle size of Pt/Al2O3 catalysts. 2 % Pt/Al2O3 catalysts were prepared by incipient wetness method
the particle size of the catalysts was manipulated by calcining at different temperatures. The dispersion values for the catalysts calcined in air at 683K, 773K and 823K were measured as 0.62, 0.20 and 0.03 respectively. The differential heats of adsorption of hydrogen, carbon monoxide and oxygen were measured using a SETARAM C80 Tian-Calvet calorimeter. No structure dependency was observed for hydrogen, carbon monoxide or oxygen initial heats of adsorption. The adsorbate:metal stoichiometries at saturation systematically decreased with increasing particle size. Hydrogen chemisorption sites with low and intermediate heats were lost when the particle size increased. On the other hand, oxygen and carbon monoxide initial heats and adsorption site energy distributions did not change appreciably with the metal particle size.

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22

Edström, Lena. „Adsorption Studies with Liquid Chromatography : Experimental Preparations for Thorough Determination of Adsorption Data“. Doctoral thesis, Uppsala universitet, Analytisk kemi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-216235.

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Analytical chemistry is a field with a vast variety of applications. A robust companion in the field is liquid chromatography, the method used in this thesis, which is an established workhorse and a versatile tool in many different disciplines. It can be used for identification and quantification of interesting compounds generally present in low concentrations, called analytical scale chromatography. It can also be used for isolation and purification of high value compounds, called preparative chromatography. The latter is usually conducted in large scale with high concentrations. With high concentrations it is also possible to determine something called adsorption isotherms. Determination of adsorption isotherms is a useful tool for quite a wide variety of reasons. It can be used for characterisation of chromatographic separation systems, and then gives information on the retention mechanism as well as provides the possibility to study column-column and batch-batch reproducibility. If a protein is immobilised on a solid support, adsorption isotherms can be used for pharmacological characterisation of drug-protein interactions. Moreover, they can be used for the study of unexpected chromatographic phenomena. If the adsorption isotherm is known it is also possible to simulate chromatograms, and subsequently optimise the separation process numerically. The gain of a numerically optimised separation process is higher purity or yield of valuable compounds such as pharmaceuticals or antioxidants, as well as reducing the solvent usage. Taken all together, it saves time, money and the environment. However, the process of the adsorption isotherm determination requires a number of careful experimental considerations and preparations, and these are the main focus of the thesis. Important steps along the way include the choice of separation system and of suitable analytes, preparation of mobile phases and sample solutions, calibration, determination of injection profiles and column void, and of course the adsorption isotherm determination method itself. It is also important to keep track of parameters such as temperature and pH. These issues are discussed in this thesis. At the end, a description of useful methods for processing of the raw adsorption isotherm data is presented, as well as a brief passage on methods for numerical optimisation.

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23

Christie, Emma Louise. „Deconstructing adsorption variability : investigating controls on pesticide adsorption in soil and modelling Koc“. Thesis, Durham University, 2013. http://etheses.dur.ac.uk/7347/.

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Due to potential environmental risks of pesticides, it is important that the fate of pesticides is known and that safer pesticides are developed in the future. This thesis focused on identifying controls on the Koc of pesticides in soil based on their structural parameters. This thesis also developed quantitative structure-activity relationship (QSAR) models to predict the environmental fate of new pesticides. To understand the controls on Koc, a range of multivariate statistical techniques were used including; principal component analysis, and analysis of variance. Predictive models were created using logistic regression, and multiple linear regression. The study found adsorption of pesticides in soil is controlled by a combination of size and solubility parameters. Logistic regression models were able to predict the adsorption potential of metabolites, relative to their parent based on metabolite structures. This study found that adsorption behaviour of pesticides was fairly specific to different chemical groups. A QSAR model for Koc was constructed for a group of early stage compounds and could predict Koc to just over an order of magnitude. The results of this study have implications for the pesticide development process. If developed further to include a wider range of chemical groups then the models have the potential to reduce the dependence on laboratory tests in the early stages of the development process. However, this study also questions the use of Koc as a predictive parameter and offers alternative solutions to predicting environmental fate of pesticides.

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24

Ibrahim, Jamal Mohamad Bin Mohamad. „Establishing scale inhibitor retention mechanisms in pure adsorption and coupled adsorption/precipitation treatments“. Thesis, Heriot-Watt University, 2012. http://hdl.handle.net/10399/2583.

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One of the most common and efficient ways for preventing formation of inorganic solids deposition such as carbonate and sulphate scales in reservoir and near wellbore formation is by applying scale inhibitor (SI) squeeze treatments. The two main mechanisms that govern the scale inhibitor retention and release process in the formation are by adsorption/desorption and precipitation/dissolution. They are described by different but related modelling approaches, and there is not complete agreement in the literature about when to use one mechanistic description or another. The equilibrium adsorption isotherm determines the general nature and extent of the scale inhibitor return process in the low concentration flow regime. However, the additional SI “loading” within the near wellbore formation may be greatly enhanced by precipitation. The dynamic effects of adsorption and precipitation, also have a strong bearing on a field squeeze treatment and may significantly affect the profile of the inhibitor return curve. Field observations are not accurate enough to distinguish between different mechanisms and a detailed analysis of a given retention mechanism (e.g. pure adsorption or coupled adsorption/ precipitation) requires carefully designed laboratory experiments at the appropriate “field relevant” conditions. In this study, we present novel experimental techniques systematically from static to dynamic tests, as follows; 1. Static Adsorption/Compatibility Experiments – these experiments were conducted on two phosphonate scale inhibitors; namely DETPMP (a penta-phosphonate) and OMTHP (an hexa-phosphonate) using sand, kaolinite and siderite as the mineral phase. Adsorption experiments were carried out at a range of adsorbent mass/ fluid volume ratios (m/V), since this indicates whether we are in the purely adsorbing or in the coupled adsorption/precipitation regime. 2. Dynamic Sand Pack Experiments – based on the static tests, OMTHP scale inhibitor and sand mineral were selected for dynamic tests as it has the most clearly interpretable results. The experiments were conducted using a sand pack flow apparatus at different flow rates using identical procedures, which demonstrates the non-equilibrium effects which occur in both adsorption and precipitation treatments. iii The experimental results from static tests show excellent agreement with the theory in different regions of pure adsorption and coupled adsorption/precipitation. Whereas for dynamic sand pack experiments, the effect on post flush effluent inhibitor concentration is in the same direction for each system under test, i.e. reduced flow rate leads to higher effluent concentrations and vice-versa. These results also show clearly how such laboratory measurements should be carried out to determine both the levels of SI retention and the precise retention mechanism. The generated data from this work will be used as a basis to further develop existing coupled adsorption-precipitation () models within the Flow Assurance Scale Team (FAST) in Institute of Petroleum Engineering, Heriot-Watt University to improve the future prediction of scale inhibitor squeeze treatments.

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25

Papakokkinos, Giorgos. „Computational modeling of adsorption packed bed reactors and solar-driven adsorption cooling systems“. Doctoral thesis, Universitat Politècnica de Catalunya, 2021. http://hdl.handle.net/10803/672099.

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Environmental concerns regarding climate change and ozone depletion urge for a paradigm shift in the cooling production. The cooling demand exhibits an alarmingly increasing trend, thus its satisfaction in a sustainable manner is imperative. Adsorption cooling systems (ACSs) are a potential candidate for a sustainable future of cooling production, since they can utilize solar energy or waste heat, as well as they can employ substances with zero ozone depletion and global warming potential. The objective of this thesis is to contribute to the investigation and improvement of ACSs, through the development of two computational models - which approach ACSs from different perspectives - and their respective utilization for the conduction of related numerical studies. The first research direction focuses on the design of the adsorption reactor, the most vital component of ACSs. Its geometrical configuration is determinant for the system performance. The reactor design is a crucial task since it creates a dichotomy between the two performance indicators - the Specific Cooling Power (SCP) and the Coefficient of Performance (COP). Individual optimizations based on the SCP and the COP would result in completely opposite geometrical configurations. A computational model for the simulation of adsorption packed bed reactors was developed, capable of simulating any potential reactor geometry. A multi-timestep approach is adopted, resulting in a drastic reduction of the computational cost of the simulations. Verification and validation assessments were performed in order to evaluate the reliability of the model. Two major studies were conducted within this research direction. The first aspires to provide a comparison between five reactor geometries, motivated by the lack of comparability across different studies in the literature. Thirteen cases of each geometry are simulated, by varying the fin thickness, fin length and solid volume fraction. The second study pertains to a thorough investigation of a geometry that remained underexplored hitherto - the hexagonal honeycomb adsorption reactor. A parametric study is conducted with respect to the three dimensions that define the geometry, as well as for various operating conditions. The second research direction is dedicated to the investigation of adsorption cooling systems, and in particular, to their integration within a wider thermal system, a solar-cooled building. Such integration is not straight-forward due to thermal inertia effects and the inherent cyclic operation of ACSs, as well as due to the dependence on an intermittent source and an auxiliary unit, with a clear objective to prioritize solar energy. A numerical model was developed using 1-d models for the adsorption reactors and 0-d models for the evaporator and condenser. The model is validated against experimental results found in the literature. The model is coupled to the generic optimization tool GenOpt, thus allowing the conduction of optimization studies. The ACS model is then coupled to solar collectors and thermal storage models, as well as to a building model. The latter was previously developed in the CTTC laboratory. This coupling results in a comprehensive simulation tool for adsorption-based solar-cooled buildings. A case study for a solar-cooled office is considered, with the objective to investigate the potential of satisfying its cooling demand using solar energy. A control strategy is proposed based on variable cycle duration, using optimized values for the instantaneous operating conditions. The variable cycle duration approach allows to satisfy the cooling demand using significantly less solar collectors or less auxiliary energy input. The potential carbon dioxide emissions avoidance is calculated between 28.1-90.7% with respect to four scenarios of electricity-driven systems of different performance and carbon emission intensity.
La preocupació mediambiental sobre el canvi climàtic i l'esgotament d'ozó exigeix un canvi de paradigma en la producció de fred. La demanda de refredament mostra una tendència alarmant creixent, així és imperatiu satisfer-la de forma sostenible. Els sistemes de refredament per adsorció (ACS) són un candidat per a un futur sostenible de la producció de fred, ja que poden utilitzar energia solar o calor residual, emprant substàncies amb zero potencial d'esgotament d'ozó i d'escalfament global. L'objectiu d'aquesta tesi és contribuir a la investigació i millora dels ACS, mitjançant el desenvolupament de dos models computacionals - que aborden els ACS des de diferents perspectives - i la seva utilització per a la realització d'estudis numèrics. La primera línia d'investigació se centra en el disseny del reactor d'adsorció, el component més important dels ACS. La seva configuració geomètrica és determinant pel rendiment de sistema. El seu disseny és una tasca crucial, ja que crea una dicotomia entre la potència específica de refrigeració (SCP) i el coeficient de rendiment (COP). Les optimitzacions individuals basades en el SCP i el COP resultarien a configuracions geomètriques completament oposades. S'ha desenvolupat un model computacional per a la simulació de reactors d'adsorció tipus "packed bed", capaç de simular reactors de qualsevol geometria. S'adopta una estratègia multi-timestep, que permet una dràstica reducció del cost computacional de les simulacions. La fiabilitat del model es va avaluar a través de processos de verificació i validació. Dins d'aquesta línia de recerca es van realitzar dos estudis principals. El primer aspira a proporcionar una comparació entre cinc geometries de reactors, motivat per la falta de comparabilitat entre diferents estudis en la literatura. Es simulen tretze casos de cada geometria, variant el gruix de les aletes, la seva longitud i la fracció de volum de sòlid. El segon estudi presenta la investigació d'una geometria sub-explorada previament, el reactor d'adsorció de honeycomb hexagonal. Es realitza un estudi paramètric pel que fa a les tres dimensions que defineixen la geometria, així com per a diverses condicions de funcionament. La segona línia de recerca es dedica a la investigació dels ACS. i en particular, a la seva integració dins d'un sistema tèrmic més ampli, un edifici refredat per energia solar. Aquesta integració no és senzilla a causa de la inèrcia tèrmica i a el funcionament cíclic inherent dels ACS, així com a la dependència d'una font intermitent i d'un sistema auxiliar, amb l'objectiu de prioritzar l'energia solar. S'ha desenvolupat un model numèric utilitzant models 1-d pels reactors i models 0-d per l'evaporador i el condensador. El model es va validar amb resultats experimentals trobats en la literatura. El model es va acoblar amb l'eina d'optimització genèrica GenOpt, permetent així estudis d'optimització. El model ACS es va acoblar amb models de col·lectors solars, emmagatzematge tèrmic i amb un model d'edifici. Aquest últim va ser desenvolupat prèviament al CTTC. Aquest acoblament resulta a una eina de simulació integral per a edificis refredats per energia solar utilitzant adsorció. Es considera un cas d'estudi per a una oficina refredada per energia solar, amb l'objectiu d'investigar el potencial de satisfer la seva demanda de fred utilitzant energia solar. Es proposa una estratègia de control basada en la duració variable del cicle, utilitzant valors optimitzats per a les condicions instantànies. La durada variable d'el cicle permet satisfer la demanda utilitzant una quantitat significativament menor de col·lectors solars o un menor aportació d'energia auxiliar. Les emissions de CO2 evitades es calculen entre 28.1-90.7% respecte a quatre escenaris de sistemes elèctrics de diferent rendiment i intensitat d'emissions de carboni.

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Diao, Rui. „Fundamental Study of Simple Gas Adsorption and Adsorption-Induced Deformation in Carbonaceous Materials“. Thesis, Curtin University, 2017. http://hdl.handle.net/20.500.11937/56504.

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This thesis has presented a fundamental study of simple gas adsorption and adsorption-induced deformation in carbonaceous materials including both graphite and porous carbon. Monte Carlo simulation was conducted to obtain the behaviours of adsorption and adsorption-induced solid deformation that are comparable to experimental studies including the adsorption isotherm, the strain isotherm and the isosteric heat, as well as the relevant microscopic properties that facilitate the understanding of underlying mechanisms.

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PIGNON, METIVIER HELENE. „Procedes de traitement d'eau par adsorption sur tissus de carbone active couplage ultrafiltration - adsorption“. Nantes, 2001. http://www.theses.fr/2001NANT2038.

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L'etude presentee porte sur les procedes d'adsorption en milieu aqueux mettant en uvre des materiaux recents : les tissus de carbone active. Le couplage de ces derniers avec l'ultrafiltration est envisage pour le traitement d'effluents complexes. Dans un premier temps, l'adsorption de pesticides et de colorants sur tissu de carbone active est etudiee en reacteur discontinu, par le biais de cinetiques et d'equilibres d'adsorption en systeme mono- et multicompose. Les vitesses et capacites d'adsorption des pesticides sont d'autant plus importantes que la solubilite du micropolluant est faible. En melange, la competition est surtout marquee dans le domaine des fortes concentrations. Enfin, la presence d'une matrice organique naturelle se revele etre sans influence sur l'adsorption de l'atrazine. Dans le cas des colorants, une approche par le biais de relations quantitatives structure - activite impliquant des indices topologiques montre que l'adsorption est d'autant plus rapide que le colorant est de petite taille et de geometrie plane. L'etude menee sur des melanges binaires met en evidence l'influence de l'affinite de l'adsorptif pour l'adsorbant et celle des vitesses d'adsorption des differents co-adsorptifs sur les phenomenes de competition. Dans un second temps, l'adsorption sur tissu de carbone active est couplee a l'ultrafiltration. Les performances de ce procede sont evaluees pour le traitement d'une eau de surface dopee en atrazine, puis pour des rejets colores, un effluent modele de type industrie textile et des encres pour cartouches de stylos. L'ultrafiltration pourvoit a l'elimination de la turbidite, ainsi qu'a celle des composes de forte masse molaire. L'adsorption sur tissu de carbone active vise quant a elle les composes de faible masse molaire. Quel que soit l'effluent etudie, le couplage ultrafiltration - adsorption sur tissu de carbone active se presente comme un procede performant pour le traitement de milieux aqueux complexes.

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Naden, Benjamin John. „Polymer adsorption to titania surfaces studied by adsorption isotherm, rheology and atomic force microscopy“. Thesis, Imperial College London, 2008. http://hdl.handle.net/10044/1/4257.

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This Ph.D. study investigates the adsorption of monomeric (isostearic acid, ISA) and oligomeric fatty acids (poly(hydroxystearic acid), PHS 1400 and PHS 3500) to nanoparticles of industrial interest in carriers with different solvent properties. It was found that it was necessary to apply a number of methods to study the adsorption and subsequent stabilisation of the particles by the dispersing molecules, namely adsorption isotherm methods, rheological techniques, atomic force microscopy and UV/vis spectroscopy. The particles (surface) studied consist of uncoated titania and a commercially available titania coated with a combination of alumina and silica. The use of gel permeation chromatography (GPC) to study the adsorption behaviour of polydisperse dispersants provided information not only about the amount of the dispersant adsorbed to the surface, but also the preferential adsorption of low molecular weight components. The displacement of large molecules by smaller ones could be monitored in order to gain insight into the types of adsorption mechanisms at work. It was found that small molecules were unable to fully displace their larger counterparts, suggesting that there was more than one adsorption mechanism in effect. This was supported by the adsorption study of one of the fatty acid dispersants which was esterified with methanol to remove the acid functionality. Adsorption at the particle surface still occurred, but at a much reduced rate. The preferential adsorption of the smaller molecules was also found to be largely eliminated. Adsorption isotherms showed Langmuir-like adsorption behaviour of the molecules to the surface, probably through a combination of acid-base interaction and other specific interactions between surfactant molecule and surface. Adsorption of the dispersant molecules at the particle surface was found to vary with solvent properties reflecting the equilibrium which is established between solubility of the dispersant in solution (χ) and that adsorbed on the surface (г) as a result of adsorption affinity (χs). Steric layer thickness δ could be varied by altering dispersion medium (and hence solvency of the stabilising chain) and by altering molecular weight of the surfactant. This had a significant effect upon the bulk properties of the suspended particles measured by rheological methods. For optimised dispersion performance with high solids load at low viscosity whilst maintaining descrete dispersed particles, as determined by assessing the optical properties of the suspension, the stabilising layer required is dependent upon the particle type and size: small particles require small steric layers. It was found that some degree of polydispersity was important for the oligomeric fatty acid dispersants. Although good adsorption characteristics were observed for the monodisperse monomeric dispersant, adsorption appeared to be optimum for the 1400 Mw oligomeric which had a high proportion of low molecular weight components as well as larger molecules present. Removal of the low molecular weight components from PHS 3500 resulted in interactions measured by AFM that appeared to indicate bridging behaviour due to reduced packing efficiency.

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Gil, Girol Stefanie. „Adsorption von Maleinsäureanhydrid auf Zinkoxid“. [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=971701741.

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Meier, Robert. „Adsorption von Sauerstoff auf Lanthanidmetallen“. [S.l. : s.n.], 1999. http://www.diss.fu-berlin.de/1999/39/index.html.

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Matsson, Maria. „Adsorption of polyhydroxyl based surfactants“. Doctoral thesis, KTH, Chemistry, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-421.

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Adsorption on solid surfaces from solution is a fundamental property of a surfactant. It might even be the most important aspect of surfactant behavior, since it influences many applications, such as cleaning, detergency, dispersion, separation, flotation, and lubrication. Consequently, fundamental investigations of surfactant adsorption are relevant to many areas.

The main aim of this thesis has been to elucidate the adsorption properties, primarily on the solid/water interface, of a particular class of polyhydroxyl based surfactants: the alkyl glucosides. By the use of ellipsometry, the equilibrium and kinetic aspects of adsorption on titanium dioxide with respect to structural effects has been studied. Furthermore, the effects of small amounts of cationic surfactant additives on the adsorption on silica have been investigated. The results have been compared with similar studies for other nonionic surfactants.

We have found that the surfactant structure has a strong effect on the adsorption properties. An increase in the surfactant chain length increases the cooperativity of the system. An increase in the head group polymerization decreases the cooperativity and the plateau adsorbed amount at equilibrium. The effect of surfactant structure on the adsorption kinetics depends on the concentration relative to the cmc, while the there is a decrease in the rate of desorption with increasing hydrophobic chain length independent of the concentration. The adsorption/desorption process is concluded to be diffusion driven, as suggested by the model used. When comparing these results with studies on ethylene oxide based surfactants, we conclude that the two types of surfactants exhibit similar trends on surfaces onto which they adsorb.

Adsorption from binary surfactant solutions is even more interesting than adsorption from single surfactant solutions, since it brings us one step closer to the systems used in applications. In addition, adsorption from a mixture can be very different from adsorption from any of the single surfactants in the mixture. Alkyl glucosides alone do not adsorb on silica, but addition of small amounts of a cationic surfactant to the alkyl glucoside solution allows for adsorption on silica. A comparison between the adsorption and bulk properties has shown that mixed micellization explains most, but not all, effects of the coadsorption properties. Changing the pH in the mixed systems reveals that a surfactant with a pH-dependent charge and the ability to adapt its charge to the environment, e.g. a surface, enhances the adsorbed amount over a wider range of pH values than a purely cationic surfactant.

It is well known that alkyl glucosides and ethylene oxides adsorb differently on different types of hydrophilic surfaces. As a consequence, replacing ethylene oxides with alkyl glucosides might not be all straight-forward; however, we have shown that the effect of the surface can be eliminated by the use of a cosurfactant.

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Lundstedt, Evert. „Adsorption av Sb på zeolit“. Thesis, Växjö University, School of Technology and Design, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:vxu:diva-1591.

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Detta examensarbete är en förundersökning till Glafos undersökning angående rening av glasbrukens processvatten från antimon med zeolit.

Förundersökningen gick ut på att via experiment ta reda på hur mycket antimon som adsorberas av behandlad (för optimering: dels med NaNO3 och dels med NaCl) och obehandlad zeolit (porstorlek 0.4 nm). pH mättes och ställdes eftersom det har betydelse för adsorptionen, åtminstone vid väldigt lågt pH. När lösningarna hade filtrerats mättes den kvarvarande antimonhalten med atomabsorptionsspektrofotometri. Mätningarna visade att i genomsnitt 53 % av Sb-halten i lösningarna hade adsorberats av zeoliten. Förundersökningen visade att det inte blir någon adsorption då pH är väldigt lågt (under 1). Den visade också att när pH är över 4 verkar det inte ha någon betydelse om zeoliten är behandlad eller inte.

Zeoliten bör behandlas med NaCl först i en tank med omrörning, sedan blandas i processvattnet (vars pH justerats till pH 4) i en tank eller bassäng och därefter filtreras.

Tidsfaktorn för hur lång tid det tar för zeoliten att nå jämvikt och temperaturens inverkan bör även undersökas.

The aim of this diploma work is to study the removal of antimony from glassworks process water using zeolites.

The experimental part of the studies were carried out to find the quantity of antimony adsorbed by the zeolite. The studies included treated (for optimization: partly with NaNO3 and partly with NaCl) and untreated zeolite. The pore size is 0.4 nm. pH was measured and adjusted because it is important for the antimony adsorption. When the solutions were filtrated the content of antimony left was measured with atomic absorption spectrophotometry. The measurements showed an average uptake of antimony by the zeolite of 53 %.The preinvestigation indicates that with a very low pH (below 1) there is no antimony adsorption. It also indicates that with pH above 4 it does not matter if the zeolite are treated or not.

In further investigations the zeolite should be treated with NaCl in a stirred tank, then be mixed in the process water (pH is set to 4) in a tank or basin and then be filtrated.

The time to reach equilibrium and the influence of temperature should also be investigated.

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Mathes, Johannes. „Protein Adsorption to Vial Surfaces“. Diss., lmu, 2010. http://nbn-resolving.de/urn:nbn:de:bvb:19-121255.

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Rasmussen, Inger-Anne. „Numerical study of hydrogen adsorption“. Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for energi- og prosessteknikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18589.

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The main objective of this thesis is to describe the transient thermodynamics during physisorption of hydrogen gas using a commercial numerical software.Simulations of thermal effects during adsorption are valuable tools for the efficient design of hydrogen adsorption storage systems. Transient mass and energy equations are used for describing the adsorption process. For this purpose, experimental adsorption data has to be presented analytically. Several models have been developed for this objective.The thesis consists of two parts. In the first, a literature study on adsorption theories and thermodynamic assumptions for development of transient mass and energy balances is conducted. The models are discussed, and from this, the Langmuir approach is selected to be used for numerical calculations. The model is implemented into a lumped-parameter analysis describing an infinitesimal element within an adsorbent bed, allowing for neglecting heat leaks into the system as well as the structural steel mass. The second part describes the simulations conducted in the study. The numerical software COMSOL Multiphysics 4.2.a is used for numerical calculations. Modules for implementation of the transient mass and energy balances are considered, before Heat Transfer in Porous Media and Brinkman Equations are applied, for heat transfer, pressure- and velocity calculations, respectively. The simulations are run for different initial and boundary conditions. The porous material is defined with Fe-btc properties. The simulation model is built step by step, and problems encountered are analyzed continuously in the process towards a complete model. After completion, the model geometry is adjusted and the porous material is changed to MOF-5 properties, to resemble a selected published paper. Numerical results are compared and discussed. Modeling restrictions for the present study is accounted for, and all choices made when considering the assigned task are justified. The report is completed by listing the conclusions drawn from the present study, and concrete suggestions for further work are given.Simulation results found in the present study differs slightly from the published research work. Instabilities in the solver results in a temperature dip in the simulated domain. This leads to an increased adsorption rate. Furthermore, it appears that mass is not conserved, which means that the inlet velocity of the feed gas does not change as expected when the adsorption is disabled from the model.

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Horstmann, Brenda Joan. „Affinity adsorption on agarose matrices“. Thesis, University of Cambridge, 1989. https://www.repository.cam.ac.uk/handle/1810/250951.

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Janzen, Johan. „Fibrinogen adsorption to human erythrocytes“. Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25820.

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Fibrinogen adsorption to human erythrocytes has been implicated as the mechanism responsible for the reversible aggregation of red cells. The object of this thesis was to measure the binding of fibrinogen to human erythrocytes and to compare the binding with aggregation behaviour. The binding of isolated ¹²⁵I-fibrinogen to red cells was estimated from the amount of radiolabel removed from solution upon addition of cells, from the amount of radiolabel retained in cell pellets produced by ultracentrifugation and corrected for intracellular radiolabel, and from radiolabel retained by cells after exhaustive washing in protein-free buffer. Binding of human albumin to red cells was determined by the same methods. The free energy of formation of red cell/red cell contacts due to isolated fibrinogen was determined by the method of Evans and Buxbaum (Biophys. J. 3̲4̲, 1-12, 1981). The solution depletion method required corrections for dilution effects and was not sensitive enough for detailed determination of binding of these proteins to red cells. Binding estimated from cell pellets and corrected for intracellular radiolabel increased linearily with protein concentration to 12 mg/mL for fibrinogen and 50 mg/mL for albumin. The binding at 1 mg/mL was between 50 and 250 molecules per cell for fibrinogen and between 1000 and 1400 molecules per cell for albumin. Binding determined from wash analyses was similar to pellet binding corrected for free radiolabel. The surface affinity of red cells for red cell beads was determined to be 1.8 ± 0.5 x 10⁻³ erg/cm² (mean ± SEM, n = 4) and 2.8 ± 0.8 x 10⁻³ erg/cm² (mean ± SEM, n = 28) at 4.4 and 8.8 mg/ml fibrinogen respectively. Adhesion between red cells and red cell beads occurred at 2.2 mg/mL fibrinogen, but was too weak to allow estimation of the surface affinity. The surface affinities and binding estimates allow calculation of the mean binding energy for fibrinogen to the red cell surface. The surface affinity per molecule, assuming 250 molecules per cell at 1 mg/mL, was 30 ± 10 and 24 ± 7 kilocalories/mole at 4.4 and 8.8 mg/mL respectively. The difference was not significant. This result poses a problem as binding energies of this order suggest that the adhesion would be irreversible. If fibrinogen binding were 1500 molecules per cell at 1 mg/mL a binding energy of 4 ± 1 kilocalories/mole would be implied. These results are interpreted as indicating that fibrinogen bound to red cells may be displaced during ultracentrifugation.
Medicine, Faculty of
Pathology and Laboratory Medicine, Department of
Graduate

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Vovk, Gregory. „Adsorption studies of tin chalcogenides“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq28761.pdf.

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Matsson, Maria K. „Adsorption of polyhydroxyl based surfactants /“. Stockholm : Chemical Science and Engineering, KTH, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-421.

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Alpay, Esat. „Rapid pressure swing adsorption processes“. Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333256.

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Manning-Benson, Samantha. „The dynamics of surfactant adsorption“. Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298708.

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Hart, J. „Separation of gases by adsorption“. Thesis, University of Bath, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234617.

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Hassaballah, A. A. „Drying of alcohol by adsorption“. Thesis, University of Nottingham, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376626.

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Newell, Helen E. „Alkane adsorption on metal surfaces“. Thesis, University of Nottingham, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243748.

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Steele, Carl James. „Gold adsorption on active carbon“. Thesis, University of Newcastle Upon Tyne, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321858.

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Lewis, D. „Enzyme adsorption to polystyrene latex“. Thesis, University of Strathclyde, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382347.

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Naumov, Sergej, Rustem Valiullin und Jörg Kärger. „Adsorption hysteresis phenomena in mesopores“. Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-194077.

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Walter, Andrew John. „Interfacial recognition and adsorption processes“. Thesis, University of Leicester, 2006. http://hdl.handle.net/2381/29975.

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The design and function of receptors for molecular recognition is of vital importance for the construction of novel sensors. Initially the project has investigated the relationship between the shape of the active site of the receptor and its sensitivity and selectivity for analytes in solution. The techniques of electrochemistry, NMR and molecular modelling have been used to study materials interactions. An optimum receptor design was established for a range of analytes so that the surface of an electrode could be modified to create an analytical sensor. The specific adsorption of both the receptor and the analyte on the electrode surface were probed to produce an amperometric sensor for mandelic and lactic acids.;Subsequently, the project has involved the investigation of small molecule adsorption, recognition and permeation at polymer plant wax constituent layers that model leaf cuticles. Correlations have been sought between the responses to these surfactants/adjuvants and the wax compositions. At low levels of interaction, the quartz crystal microbalance was used as a gravimetric sensor of these processes. At higher levels of interaction, when permeation of the film is sufficient to plasticise it, the rheological effects were used to explore solvent/small molecule permeation. In each case, qualitative data was used to diagnose film rigidity vs. viscoelasticity and quantitative data to determine film mass (thickness) or shear moduli, as appropriate. The experimental measurements have been supported by a computer model derived from the processes occurring at the interface and the resultant changes in film viscoelasatic properties are discussed.

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Murphy, Emma F. „Reduced protein adsorption on biomaterials“. Thesis, University of Surrey, 1999. http://epubs.surrey.ac.uk/844207/.

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The adsorption of lysozyme, bovine serum albumin (BSA) and fibrinogen onto the surfaces of a number of poly (methacrylate) based, phosphorylcholine (PC)-containing polymer films has been characterised by neutron reflection and spectroscopic ellipsometry. The work represents the first systematic study of these biocompatible materials, attempting to establish the relationship between the structure of the films and their effectiveness in reducing protein adsorption. The polymer surface was formed by dip-coating a thin film of polymer onto the polished silicon oxide. As the extent of reduction in protein adsorption may depend upon how the film is coated, initial work was to examine the effect of the coating conditions. We show that the improvement of the smoothness of the outer film surface can lead to the formation of a close-packed PC layer, resulting in the reduction of protein adsorption. The subsequent experiment was focused on the two model PC-polymers with (PC100B) and without (PC100A) 5% silyl cross-linking groups. It was found that although the structures of the films were drastically different, the residual amount of proteins adsorbed was comparable, indicating that the outer surfaces of the two films were similar in composition. The preliminary measurements using partially deuterated PC100B containing 5% silyl groups show that there is a preferential segregation of the hydrophobic and hydrophilic groups across the film, with the hydrophilic groups enriched at the outer surface. This work offers the first experimental evidence of the preferential expression of PC groups on the outer surface. In order to demonstrate the effectiveness of the PC-polymer surfaces in reducing protein adsorption, some parallel work has also been done on the model surfaces of bare SiO2, hydrophobed SiO2 and PMMA (polymethylmethacrylate). It was found that under similar solution conditions the PC-polymer surfaces can reduce protein adsorption by a factor of 3-5. It is particularly interesting that PC-polymer surfaces are most effective at deterring adsorption of large fibrous proteins, such as fibrinogen.

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Dalton, James Spencer. „The kinetics of surfactant adsorption“. Thesis, University of Bristol, 1999. http://hdl.handle.net/1983/d2ce527d-0373-4191-b2d9-8e9e7d81dd9f.

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Naumov, Sergej, Rustem Valiullin und Jörg Kärger. „Adsorption hysteresis phenomena in mesopores“. Diffusion fundamentals 6 (2007) 67, S. 1-2, 2007. https://ul.qucosa.de/id/qucosa%3A14247.

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