Gert Desmet

Bio: Gert Desmet is an academic researcher from Vrije Universiteit Brussel. The author has contributed to research in topics: Van Deemter equation & Dispersion (optics). The author has an hindex of 45, co-authored 396 publications receiving 7676 citations. Previous affiliations of Gert Desmet include University of Amsterdam & MESA+ Institute for Nanotechnology.

Geometry-independent plate height representation methods for the direct comparison of the kinetic performance of LC supports with a different size or morphology.

Abstract: The advantages of representing experimental plate height data as a plot of Kv/u02 or H2/Kv versus Kv/(Hu0) instead of as H versus u0 are discussed (Kv=column permeability). Multiplying the values on both axes by the ratio of a reference pressure drop and mobile-phase viscosity, the obtained plots directly yield the kinetic performance limits of the tested support structure, without any need for further numerical optimization. Directly showing the range of plate numbers or analysis times wherein the tested support geometry can yield faster separations or produce more plates than another support type, such kinetic plots are ideally suited to compare the performance of differently shaped or sized LC supports. The approach hence obviates the need for a common reference length, which is a clear problem if it is attempted to compare differently shaped supports on the basis of their flow resistance φ and reduced plate height h. It is also shown how an MS Excel template file, only requiring the user to paste the ...

Pressure-driven reverse-phase liquid chromatography separations in ordered nonporous pillar array columns.

Abstract: Building upon the micromachined column idea proposed by the group of Regnier in 1998, we report on the first high-resolution reversed-phase separations in micromachined pillar array columns under pressure-driven LC conditions. A three component mixture could be separated in 3 s using arrays of nonporous silicon pillars with a diameter of approximately 4.3 μm and an external porosity of 55%. Under slightly retained component conditions (retention factor k‘ = 0.65−1.2), plate heights of about H = 4 μm were obtained at a mobile phase velocity around u = 0.5 mm/s. In reduced terms, such plate heights are as low as hmin = 1. Also, since the flow resistance of the column is much smaller than in a packed column (mainly because of the higher external porosity of the pillar array), the separation impedance of the array was as small as E = 150, i.e., of the same order as the best currently existing monolithic columns. At pH = 3, yielding very low retention factors (k‘ = 0.13 and 0.23), plate heights as low as H = 2...

Silica–MOF Composites as a Stationary Phase in Liquid Chromatography

Abstract: Metal-organic framework materials (MOFs) are a class of microporous and crystalline materials with great potential for adsorption-based separations. Harnessing the separation ability of these materials in high-performance liquid chromatography (HPLC) requires the use of small and uniform particles in order to achieve good column packing. The well-known MOF material [Cu3(BTC)2] is, however, typically synthesized as a polydisperse mixture due to its nucleation and growth mechanism. It is demonstrated how a new synthesis method for [Cu3(BTC)2] enables the formation of the MOF inside the pores of silica beads often used in chromatography, leading to monodisperse silica–MOF composite spheres with a uniform particle size of 3 μm. When employed as an HPLC stationary phase, this material combines the good column packing properties of the silica and separation ability of the MOF material.

Micro Total Analysis Systems. 1. Introduction, Theory, and Technology

Abstract: Review

Metal–organic framework composites

Abstract: Metal–organic frameworks (MOFs), also known as porous coordination polymers (PCPs), synthesized by assembling metal ions with organic ligands have recently emerged as a new class of crystalline porous materials. The amenability to design as well as fine-tunable and uniform pore structures makes them promising materials for a variety of applications. Controllable integration of MOFs and functional materials is leading to the creation of new multifunctional composites/hybrids, which exhibit new properties that are superior to those of the individual components through the collective behavior of the functional units. This is a rapidly developing interdisciplinary research area. This review provides an overview of the significant advances in the development of diverse MOF composites reported till now with special emphases on the synergistic effects and applications of the composites. The most widely used and successful strategies for composite synthesis are also presented.