Assessing the Macroporous Structure of Monolithic Columns by Transmission Electron Microscopy

Courtois, Julien; Szumski, Michał; Georgsson, Fredrik; Irgum, Knut

doi:10.1021/ac0614902

Cited by 66 publications

(77 citation statements)

References 55 publications

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“…Sometimes a mixture of crosslinkers is used for preparation of the methacrylate monoliths. For example, Courtois et al reported preparation of poly-(GMA-co-TEGDMA-co-TRIM) monoliths [37,38]. The main advantage of DEGDMA and TEGDMA is the presence of dior triethylene glycol chains in their structures that grants a good flexibility to the crosslink.…”

Section: Crosslinkersmentioning

confidence: 99%

Preparation of methacrylate monoliths

Влах

Tennikova²

2007

J of Separation Science

147

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Rigid macroporous polymers developed in the early 1990s are widely used as efficient stationary phases for all types of chromatographic separations. The main advantages of so-called monolithic supports are their high hydraulic permeability and the dominance of the convection over the diffusion mechanism of mass-exchange under dynamic conditions that allow the separation to be carried out at extremely high flow rates and, consequently, during very short operation times. Among other types of macroporous polymers, the methacrylate-based monolithic materials represent the most popular and successfully explored class of sorbents. This review is an attempt to collect together the contributions of different groups working in the area of monolith preparation. Examples of different methcrylate monomers and crosslinkers, as well as porogenic solvents, including polymer ones, used in monolith preparation are discussed.

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Section: Crosslinkersmentioning

confidence: 99%

Preparation of methacrylate monoliths

Влах

Tennikova²

2007

J of Separation Science

147

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“…Performance and permeability can be controlled independently by controlling over macropore and mesopore size (Cabrera, 2004) Column performance Flow rate Lesser Higher (Cabrera, 2004) Back pressure Higher Lesser (Cabrera, 2004) Porosity Lesser Higher (Cabrera, 2004) Run time Higher Lesser (Cabrera, 2004) Efficiency (HETP, plate height) Lesser Higher (Cabrera, 2004) Precision and reproducibility (Liang, Dai, and Guiochon, 2003), Xray analysis, and transmission electron microscope (Courtois, Szumski, Georgsson, and Irgum, 2007).…”

Section: Column Permeabilitymentioning

confidence: 99%

Advances in monolithic silica columns for high-performance liquid chromatography

2017

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In a monolithic column stationary phase contains a continuous porous material, sealed against the wall of a tube, instead of beads. Due to the decrease in chemical usage, sample usage, improved sensitivity, reusable frit-less columns and less back pressure monolithic column are very popular in the field of capillary electrochromatography (CEC). This review attempts to give an overview of three different types of monolithic columns, i.e. silica-based, polymer-based, and hybrid monolithic column. Moreover, the review also focuses on its advantages and applications over last 5 years.

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“…A number of workers have used scanning electron microscopy (Liang et al, 2003, Motokawa et al, 2002, Dulay et al, 1998 and transmission electron microscopy (Courtois et al, 2006, Plummer et al, 1995. These techniques are, however, tedious to extend to quantitative characterization of the three-dimensional (3D) structure of µPBs.…”

Section: Introductionmentioning

confidence: 99%

A new method for reconstruction of the structure of micro-packed beds of spherical particles from desktop X-ray microtomography images. Part A. Initial structure generation and porosity determination

Kashani

Živković

Elekaei

et al. 2016

Chemical Engineering Science

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Citation: NAVVAB KASHANI, M. ...et al., 2016. A new method for reconstruction of the structure of micro-packed beds of spherical particles from desktop X-ray microtomography images. Part A. Initial structure generation and porosity determination. Chemical Engineering Science, 146, Additional Information:• This paper was accepted for publication in the journal Chemical En- AbstractMicro-packed beds (µPBs) are seeing increasing use in the process intensification context (e.g. micro-reactors), in separation and purification, particularly in the pharmaceutical and bio-products sectors, and in analytical chemistry. The structure of the stationary phase and of the void space it defines in such columns is of interest because it strongly influences performance. However, instrumental limitations -in particular the limited resolution of various imaging techniques relative to the particle and void space dimensions -have impeded experimental study of the structure of µPBs. We report here a new method that obviates this issue when the µPBs are composed of particles that may be approximated by monodisperse spheres. It achieves this by identifying in successive cross-sectional images of the bed the approximate centre and diameter of the particle cross-sections, replacing them with circles, and then assembling them to form the particles by identifying correlations between the successive images. Two important novel aspects of the method proposed here are it does not require specification of a threshold for binarizing the images, and it preserves the underlying spherical geometry of the packing. The new method is demonstrated through its application to a packing of a near-monodispersed 30.5 µm particles of high sphericity within a 200 µm square cross-section column imaged using a machine capable of 2.28 µm resolution. The porosity obtained was, within statistical uncertainty, the same as that determined via a direct method whilst use of a commonly used automatic thresholding technique yielded a result that was nearly 10% adrift, well beyond the experimental uncertainty. Extension of the method to packings of spherical particles that are less monodisperse or of different regular shapes (e.g. ellipsoids) is also discussed.

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Assessing the Macroporous Structure of Monolithic Columns by Transmission Electron Microscopy

Cited by 66 publications

References 55 publications

Preparation of methacrylate monoliths

Preparation of methacrylate monoliths

Advances in monolithic silica columns for high-performance liquid chromatography

A new method for reconstruction of the structure of micro-packed beds of spherical particles from desktop X-ray microtomography images. Part A. Initial structure generation and porosity determination

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