Characterization of asymmetry in microporous membranes by cross-sectional confocal laser scanning microscopy

Marroquin, Milagro; Bruce, Terri F.; Pellegrino, John; Wickramasinghe, S. Ranil; Husson, Scott M.

doi:10.1016/j.memsci.2011.06.024

Cited by 25 publications

(8 citation statements)

References 13 publications

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“…In this section we describe the use of the new probe for imaging using CLSM. Similar studies on membranes reported in the past use either fluorescently labeled protein [33,34] or a fluorescent dye adsorbed to the matrix [35][36][37] or both [38,39]. To our knowledge this is the first report of in situ analysis and imaging of ligand itself on a separation device.…”

Section: Quantitative Estimation Of Amidine Immobilized On Cellulose supporting

confidence: 56%

In situ analysis and imaging of aromatic amidine at varying ligand densities in solid phase

et al. 2019

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We report the development of a fast and accurate fluorescence-based assay for amidine linked to cellulose membranes and Sepharose gel. The assay is founded on the glyoxal reaction, which involves reaction of amidine group with glyoxal and an aromatic aldehyde, leading to the formation of a fluorophore that can be analyzed and quantified by fluorescence spectroscopy and imaging. While the assay has been reported previously for aromatic amidine estimation in solution phase, here we describe its adaptation and application to amidine linked to diverse forms of solid matrices, particularly benzamidine Sepharose and benzamidine-linked cellulose membranes. These functionalized porous matrices find important application in purification of serine proteases. The efficacy of a protein separation device is determined by, among other factors, the ligand (amidine) density. Hence, a sensitive and reproducible method for amidine quantitation in solid phase is needed. The glyoxal reaction was carried out on microbead-sized Sepharose gel and cellulose membranes. Calibration curves were developed for each phase, which established linearity in the range of 0-0.45 μmol per mL amidine for free amidine in solution, 0-0.45 μmol amidine per mL Sepharose gel, and 0-0.48 μmol per mL cellulose membrane. The assay showed high accuracy (~3.4 % error), precision (RSD <2%) and reproducibility. Finally, we show how this fluorescent labeling (glyoxal) method can provide a tool for imaging membranes and ligand distribution through confocal laser scanning microscopy.

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Section: Quantitative Estimation Of Amidine Immobilized On Cellulose supporting

confidence: 56%

In situ analysis and imaging of aromatic amidine at varying ligand densities in solid phase

et al. 2019

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“…However, one of the drawbacks of CLSM is the short penetration depth. Marroquin et al [43] developed a methodology to overcome this limitation by sectioning the membrane samples parallel to the z-axis, to give flat cross-section layers that could be analyzed with CLSM. This method has been used to obtain information on fouling caused by a protein (casein) and a polysaccharide (dextran) filtered with a MF polyethersulfone (PES) membrane [44].…”

Section: Confocal Laser Scanning Microscopymentioning

confidence: 99%

A review of in situ real-time monitoring techniques for membrane fouling in the biotechnology, biorefinery and food sectors

Rudolph

Virtanen

Ferrando

et al. 2019

Journal of Membrane Science

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Pressure-driven membrane processes are often used for the separation and purification of organic compounds originating from biomass. However, membrane fouling remains a challenge as these biobased streams have a very complex composition and comprise a high fouling tendency. Conventional, the fouling is monitored based on either a decrease in flux or an increase in pressure over time. Those conventional techniques provide no information on the location, composition or amount of fouling. As fouling is often cumulative, it will be detected as a loss of performance. Once fouling becomes irreversible, it is often not possible to clean the membrane without chemicals and the filtration/separation process has to be stopped eventually. In situ real-time monitoring of membrane fouling could provide dynamic information on the development of fouling, allowing optimization of the process. This paper reviews the state of the art in in situ monitoring techniques that could be applied to membrane processes in the biotechnology, biorefinery and food sectors and briefly reflects on the current awareness of in situ monitoring techniques among experienced industrial users of membrane processes. The physical principles as well as the strengths and weaknesses are addressed, and potentially, promising techniques are identified.

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“…A fundamental understanding of the influence of the dispersion process and the ability for characterization and comparison (e.g., by Figure 3. Coupling scheme of single particle/swarm mechanisms and particle sizes/shapes (according to [157]). mass or heat transfer coefficient, energy dissipation rate) needs to be combined with a quantification of the impact of physical property variation on the size distributions (e.g., due to impurities, changes in quality, progressing reaction).…”

Section: Particle Size Distributionsmentioning

confidence: 99%

Description of Disperse Multiphase Processes: Quo Vadis?

Hohl

Panckow

Schulz

et al. 2018

Chemie Ingenieur Technik

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The experimental accessibility of disperse systems often is a critical factor when it comes to the development of modeling approaches that intend to converge towards an exact solution. Often, integral or pseudo‐homogeneous values are used to reduce the complexity of the system, but a detailed single particle or interface analysis is crucial to understand relevant effects that also affect the swarm behavior. A high number of experimental techniques with respective limitations and advantages is available to quantify these effects. In this work, an overview on measurement techniques for momentum, heat and mass transfer in particle swarms as well as for the particle size distribution and interface characterization is provided. The industrial applicability is addressed by pointing out the vicinity to the process and the costs of different measurement techniques.

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Characterization of asymmetry in microporous membranes by cross-sectional confocal laser scanning microscopy

Cited by 25 publications

References 13 publications

In situ analysis and imaging of aromatic amidine at varying ligand densities in solid phase

In situ analysis and imaging of aromatic amidine at varying ligand densities in solid phase

A review of in situ real-time monitoring techniques for membrane fouling in the biotechnology, biorefinery and food sectors

Description of Disperse Multiphase Processes: Quo Vadis?

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