Sedimentation Techniques

Merkus, Henk G.

doi:10.1007/978-1-4020-9016-5_13

Cited by 6 publications

(6 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the analysis of particle size distribution in the lower micrometer range, methods such as laser diffraction, sedimentation methods as well as static or dynamic image analysis methods are suitable [ 19 ]. Particle shape in particular has a strong influence on the measured particle size, depending on the measurement method used.…”

Section: Particle Propertiesmentioning

confidence: 99%

Effects and interactions of metal oxides in microparticle‐enhanced cultivation of filamentous microorganisms

Laible

Dinius

Schrader

et al. 2021

Engineering in Life Sciences

View full text Add to dashboard Cite

Filamentous microorganisms are used as molecular factories in industrial biotechnology. In 2007, a new approach to improve productivity in submerged cultivation was introduced: microparticle-enhanced cultivation (MPEC). Since then, numerous studies have investigated the influence of microparticles on the cultivation. Most studies considered MPEC a morphology engineering approach, in which altered morphology results in increased productivity. But sometimes similar morphological changes lead to decreased productivity, suggesting that this hypothesis is not a sufficient explanation for the effects of microparticles. Effects of surface chemistry on particles were paid little attention, as particles were often considered chemically-inert and bioinert. However, metal oxide particles strongly interact with their environment. This review links morphological, physical, and chemical properties of microparticles with effects on culture broth, filamentous morphology, and molecular biology.More precisely, surface chemistry effects of metal oxide particles lead to ion leaching, adsorption of enzymes, and generation of reactive oxygen species.Therefore, microparticles interfere with gene regulation, metabolism, and activity of enzymes. To enhance the understanding of microparticle-based morphology engineering, further interactions between particles and cells are elaborated. The presented description of phenomena occurring in MPEC eases the targeted choice of microparticles, and thus, contributes to improving the productivity of microbial cultivation technology.

show abstract

Section: Particle Propertiesmentioning

confidence: 99%

Effects and interactions of metal oxides in microparticle‐enhanced cultivation of filamentous microorganisms

Laible

Dinius

Schrader

et al. 2021

Engineering in Life Sciences

View full text Add to dashboard Cite

show abstract

“…Considering the nanomaterial CuO we have focused on, the membrane UF separation protocol used here requires 30 min to achieve a diameter cut-off of <1.2 nm [with PES, molecular weight cut-off (MWCO) 3 kDa, see the Experimental Section]. Conventional separation by centrifugation with an Eppendorf 5430 R centrifuge with maximal settings (30,130 g ) resulted in a much larger cut-off diameter of ≈8 nm for CuONPs in water after 30 min of centrifugation . In order to achieve a UF comparable cut-off diameter of <1.2 nm with this centrifuge (Eppendorf 5430 R), a centrifugation duration of far more than 8 h would be required; even with an ultracentrifuge with 390,000 g , the duration would be approx.…”

Section: Introductionmentioning

confidence: 99%

“…Conventional separation by centrifugation with an Eppendorf 5430 R centrifuge with maximal settings (30,130 g ) resulted in a much larger cut-off diameter of ≈8 nm for CuONPs in water after 30 min of centrifugation. 23 In order to achieve a UF comparable cut-off diameter of <1.2 nm with this centrifuge (Eppendorf 5430 R), a centrifugation duration of far more than 8 h would be required; even with an ultracentrifuge with 390,000 g , the duration would be approx. 6 h. The correct assessment of faster dissolution kinetics of small nanoparticles would be very limited with such long separation times.…”

Section: Introductionmentioning

confidence: 99%

Improving Membrane Filtration for Copper Speciation: Optimal Salt Pretreatments of Polyethersulfone Membranes to Prevent Analyte Retention

et al. 2023

View full text Add to dashboard Cite

Membrane filtration has been increasingly used to separate dissolved metal ions from dispersed particles, commonly using ultrafiltration membranes, for example, polyethersulfone (PES) membranes with a molecular weight cut-off of 3 kDa. The disadvantage of this technique is an undesired retention of ions, resulting from Coulomb interactions with sulfonic acid groups of the membrane. Therefore, such a membrane acts similar to a cation exchanger column. We solved this drawback by a pretreatment of the PES membrane by other cations. Using CuSO 4 as a model compound, we compared the effectiveness of five cations using their salt solutions (Ca 2+ , Mg 2+ , Fe 2+ , Ag + , Ba 2+ ) as pretreatment agents and identified the most effective pretreatment component for a high recovery of copper ions. After membrane filtration without pretreatment, only 52 ± 10%, 64 ± 5%, 75 ± 8%, and 89 ± 7% of nominal Cu concentrations were obtained using initial concentrations of 0.2, 0.5, 1.0, and 4.0 mg L −1 , respectively. The efficiency of the investigated cations increased in the order Fe < Ag < Mg < Ca < Ba. Furthermore, we analyzed the most efficient concentration of the pretreatment agent. The best performance was achieved using 0.1 mol L −1 CaCl 2 which increased copper recovery to slightly below 100%, even at the lowest tested Cu concentration (recovery 93 ± 10% at 0.2 mg L −1 ). In the environmentally relevant Cu concentration range of 0.2 mg L -1 , 0.1 mol L −1 BaCl 2 was identified as the most efficient pretreatment (103 ± 11%).

show abstract

“…The knowledge of both the particle mass and the particle volume is required in the evaluation of the mean particle density

. Using the method of sedimentation analysis [5] for a single particle, it is possible to estimate the density difference

, where

is the density of fluid.…”

Section: Introductionmentioning

confidence: 99%

“…Usually, determination of the mean particle density

from gravimetric sedimentation is based on Stokes' law, which yields

where g is the gravitational acceleration,

is the fluid viscosity, and

is the steady-state (or terminal velocity) of the sedimenting particle, which is routinely assessed in experiment [5] .…”

Section: Introductionmentioning

confidence: 99%

Sedimentation of a starch microsphere: What is usually missed and why?

Argatov,

Krcic,

Kocherbitov

2023

Heliyon

View full text Add to dashboard Cite

Sedimentation Techniques

Cited by 6 publications

References 16 publications

Effects and interactions of metal oxides in microparticle‐enhanced cultivation of filamentous microorganisms

Effects and interactions of metal oxides in microparticle‐enhanced cultivation of filamentous microorganisms

Improving Membrane Filtration for Copper Speciation: Optimal Salt Pretreatments of Polyethersulfone Membranes to Prevent Analyte Retention

Sedimentation of a starch microsphere: What is usually missed and why?

Contact Info

Product

Resources

About