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You searched for subject:(Ultrathin Layer Chromatography). Showing records 1 – 2 of 2 total matches.

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University of Alberta

1. Jim, Steven R. Nanoengineered Glancing Angle Deposition Thin Films for Ultrathin-Layer Chromatography.

Degree: PhD, Department of Electrical and Computer Engineering, 2014, University of Alberta

Analytical separations are important methods of identifying and quantifying molecular compounds present in complex sample mixtures. These approaches are popular in biochemistry, medical diagnostics, quality control, and numerous other applications. In these techniques, constituent analytes are separated according to their characteristic physical and chemical properties. Planar chromatography analytical separations leverage the effects of these properties on competing interactions between the compounds, moving liquids, and stationary flat porous solids. Engineered solid-liquid interfaces can improve performance since these interactions occur at the nanoscale. Ultrathin-layer chromatography (UTLC) is a miniature form of planar chromatography in which sample analytes are carried by solvents that wick through < 10 um thick solids with extraordinarily fine pores. The technique achieves fast separations (minutes) over short distances (millimetres to centimetres) with high sensitivity. The strong dependence of UTLC performance on layer microstructure motivates pursuit of new chromatographic media. This dissertation studies UTLC layers produced using glancing angle deposition (GLAD). GLAD is an excellent platform for engineering nanostructured thin films of varied material, porosity, and architecture. It can achieve ~ 5 um thick columnar morphologies well-suited for UTLC that are unattainable or impractical using other techniques. Unique anisotropic media exhibited channel features that strongly influenced analyte migration direction and velocity. Further control of chromatographic behaviours was achieved using post-deposition enhancements. Fluorocarbon reactive ion etching (RIE) selectively modifies film microstructure, increases porosity, and decreases the surface area over which analytes may interact. Atomic layer deposition (ALD) applies extremely thin < 10 nm conformal coatings that produce alternative chromatographic surface chemistries over GLAD UTLC film scaffolds. These investigations required invention of new instrumentation and analysis techniques since conventional planar chromatography equipment is unoptimized for miniaturized GLAD UTLC plates. Approaches to fabricating, utilizing, characterizing, and enhancing nanoengineered GLAD UTLC media are considered in this thesis. The intriguing behaviours described within provide insight into the manner in which the microscopic features of GLAD films impact macroscopic development phenomena. These investigations simultaneously advanced both the capabilities of the UTLC planar chromatography technique and the understanding of GLAD nanostructured thin film materials.

Subjects/Keywords: ALD; concentration zone; chromatography; time-resolved ultrathin-layer chromatography; GLAD; atomic layer deposition; stationary phase; macroporous thin film; planar chromatography; densitogram; glancing angle deposition; nanocomposite; reactive ion etch; sorbent; thin-layer chromatography; ultrathin-layer chromatography; RIE; chromatogram; nanostructured thin film; columnar thin film; TR-UTLC; TLC; nanomaterial; UTLC

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Jim, S. R. (2014). Nanoengineered Glancing Angle Deposition Thin Films for Ultrathin-Layer Chromatography. (Doctoral Dissertation). University of Alberta. Retrieved from https://era.library.ualberta.ca/files/t148fj18d

Chicago Manual of Style (16th Edition):

Jim, Steven R. “Nanoengineered Glancing Angle Deposition Thin Films for Ultrathin-Layer Chromatography.” 2014. Doctoral Dissertation, University of Alberta. Accessed January 23, 2019. https://era.library.ualberta.ca/files/t148fj18d.

MLA Handbook (7th Edition):

Jim, Steven R. “Nanoengineered Glancing Angle Deposition Thin Films for Ultrathin-Layer Chromatography.” 2014. Web. 23 Jan 2019.

Vancouver:

Jim SR. Nanoengineered Glancing Angle Deposition Thin Films for Ultrathin-Layer Chromatography. [Internet] [Doctoral dissertation]. University of Alberta; 2014. [cited 2019 Jan 23]. Available from: https://era.library.ualberta.ca/files/t148fj18d.

Council of Science Editors:

Jim SR. Nanoengineered Glancing Angle Deposition Thin Films for Ultrathin-Layer Chromatography. [Doctoral Dissertation]. University of Alberta; 2014. Available from: https://era.library.ualberta.ca/files/t148fj18d

2. Kirchner, Teresa Byers. The fabrication of micro- and nano- scale deterministic and stochastic pillar arrays for planar separations.

Degree: 2015, University of Tennessee – Knoxville

Planar chromatography, unlike high performance liquid chromatography (HPLC), has not experienced a significant evolution in stationary phase media since the development of the technique. This has lead HPLC to become a much more popular and robust analytical method. Main factors that contribute to improved performance of chromatographic systems include a reduction in particle size, homogeneity of the stationary phase, and an increase in velocity of the mobile phase. In general, a reduction in particle size should lead to an improvement in the performance of all chromatography systems. However, the main obstacle of improving the performance of planar chromatography systems is that a reduction in particle size leads to a reduction in the capillary flow that governs solvent velocity. This decrease in solvent velocity leads to band broadening resulting in poor efficiency and resolution which are critical performance parameters for chromatographic systems. The research presented herein investigates the scaling down of dimensions to the micro- and nano-scale for pillar arrays in order to investigate the effect on plate height and chromatographic efficiency of these capillary action driven micro- and nano-fluidic systems. Sample application is a critical parameter that effects band broadening in UTLC systems. By taking advantage of the superhydrophobic nature of these arrays the development of a spotting method that demonstrates the ability to create reproducible sample spots that are less than 200 microns (micro- scale arrays) and 400nm (nano- scale arrays) within these arrays are highlighted in this dissertation. We have demonstrated the fabrication of deterministic micro-scale arrays that exhibit plate heights as low as 2┬Ám as well as deterministic and stochastic nanothin-layer chromatographic platforms. Most significantly these systems resulted in bands that were highly efficient, with plate heights in the nm range. This resulted in significant separations of analytical laser test dyes, environmentally significant NBD-derivatized amines, and, biologically relevant chemotherapy drugs (Adriamycin and Daunorubicin).

Subjects/Keywords: Chromatography; Lithography; Separations; Microfluidics; Ultrathin-Layer Chromatography; Pillar Arrays; Analytical Chemistry

Chromatography Mobile phase velocity Ultrathin-Layer Chromatography Ultraviolet Total Volume per Pillar… …Ultrathin-Layer chromatography (UTLC). Planar Chromatography requires minimal sample… …performance thin-layer chromatography and ultrathin-layer chromatography. 4 High-performance thin… …2 1.2 The development of traditional thin-layer chromatography… …3 1.3 Modern thin-layer chromatography… 

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Kirchner, T. B. (2015). The fabrication of micro- and nano- scale deterministic and stochastic pillar arrays for planar separations. (Doctoral Dissertation). University of Tennessee – Knoxville. Retrieved from https://trace.tennessee.edu/utk_graddiss/3344

Chicago Manual of Style (16th Edition):

Kirchner, Teresa Byers. “The fabrication of micro- and nano- scale deterministic and stochastic pillar arrays for planar separations.” 2015. Doctoral Dissertation, University of Tennessee – Knoxville. Accessed January 23, 2019. https://trace.tennessee.edu/utk_graddiss/3344.

MLA Handbook (7th Edition):

Kirchner, Teresa Byers. “The fabrication of micro- and nano- scale deterministic and stochastic pillar arrays for planar separations.” 2015. Web. 23 Jan 2019.

Vancouver:

Kirchner TB. The fabrication of micro- and nano- scale deterministic and stochastic pillar arrays for planar separations. [Internet] [Doctoral dissertation]. University of Tennessee – Knoxville; 2015. [cited 2019 Jan 23]. Available from: https://trace.tennessee.edu/utk_graddiss/3344.

Council of Science Editors:

Kirchner TB. The fabrication of micro- and nano- scale deterministic and stochastic pillar arrays for planar separations. [Doctoral Dissertation]. University of Tennessee – Knoxville; 2015. Available from: https://trace.tennessee.edu/utk_graddiss/3344

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