Prolonging density gradient stability

Langmuir : the ACS Journal of Surfaces and Colloids
Huda A JerriDarrell Velegol

Abstract

For bottom-up particle fabrication, separation of complex particle assemblies from their precursor colloidal building blocks is critical to producing useable quantities of materials. The separations are often done using a density gradient sedimentation due to its simplicity and scalability. When loading density gradients at volume fractions greater than 0.001, however, an inherent convective instability arises. By translating the Rayleigh-Benard instability from the heat-transfer literature into an analogous mass-transfer problem, the variables affecting the critical stability limit were effectively catalogued and examined. Experiments using submicrometer particles loaded onto sucrose and Ficoll density gradients matched theoretical trends and led to a series of useful heuristics for prolonging density gradient stability. Higher particle loading heights, lower volume fractions, and smaller gradient material diffusion coefficients were found to improve stability. Centrifugation was useful at short times, as particles were removed from top of the gradient where the stable density profile degrades to unstable, and the resulting density inversion arises as the sucrose diffuses upward.

References

Jan 7, 2003·Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics·T G Mason
Jul 26, 2003·Science·Alfons van Blaaderen
Jul 26, 2003·Science·Vinothan N ManoharanDavid J Pine
Nov 16, 2005·Langmuir : the ACS Journal of Surfaces and Colloids·Patrick M JohnsonAlfons van Blaaderen
Jul 15, 1957·Proceedings of the National Academy of Sciences of the United States of America·M MeselsonJ Vinograd
Oct 18, 2006·Langmuir : the ACS Journal of Surfaces and Colloids·Allison M YakeDarrell Velegol
Mar 14, 2008·Langmuir : the ACS Journal of Surfaces and Colloids·Joseph J McDermott, Darrell Velegol

❮ Previous
Next ❯

Citations

Jan 15, 2014·Langmuir : the ACS Journal of Surfaces and Colloids·Joseph B MillerErik K Hobbie
May 12, 2016·The Journal of Physical Chemistry. B·Miyu AraiHideki Nabika
Mar 7, 2017·Langmuir : the ACS Journal of Surfaces and Colloids·Yifan WangJohn C Crocker
Sep 18, 2014·Langmuir : the ACS Journal of Surfaces and Colloids·Tina LinDavid A Weitz

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.