Diffusion of low molecular weight compounds through algal gels

Presenter Information

Advisor(s)

Christopher Spiese

Confirmation

1

Document Type

Poster

Location

ONU McIntosh Center; Activities Room

Start Date

24-4-2026 12:00 PM

End Date

24-4-2026 12:50 PM

Abstract

Gels are heavily involved in marine ecosystems yet there is a lack of knowledge regarding how their formation inhibits diffusion of nutrients to cells. Alginate represents a marine gel that can be studied with low molecular weight inorganic compounds including nitrate, phosphate and ammonium, as well as organic polymers such as polyethylene glycol (PEG), polyvinyl pyrrolidine (PVP), and polyvinyl alcohol (PVA) in terms of diffusion rate. Diffusion-ordered NMR spectroscopy (DOSY) can be used for the direct measurement of diffusion constants in these gels by calculation through Bruker TopSpin version 3.2 software. Diffusion constants for the compounds of study in seawater and various w/v gels were compared. Ammonia diffusion was unable to be identified due to low peak strength. Nitrate and phosphate showed no statistically significant difference in diffusion up to 2% w/v alginate versus seawater. It has been previously reported there was a noticeable decrease in diffusion for alginate gels above 3% w/v (Garbayo et al., 2002). The organic polymers of high molecular weight exhibited a large decrease in diffusion through the gels. This study relates heavily to microbial ecology and understanding how gels to a certain extent do not restrict diffusion of molecules.

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Apr 24th, 12:00 PM Apr 24th, 12:50 PM

Diffusion of low molecular weight compounds through algal gels

ONU McIntosh Center; Activities Room

Gels are heavily involved in marine ecosystems yet there is a lack of knowledge regarding how their formation inhibits diffusion of nutrients to cells. Alginate represents a marine gel that can be studied with low molecular weight inorganic compounds including nitrate, phosphate and ammonium, as well as organic polymers such as polyethylene glycol (PEG), polyvinyl pyrrolidine (PVP), and polyvinyl alcohol (PVA) in terms of diffusion rate. Diffusion-ordered NMR spectroscopy (DOSY) can be used for the direct measurement of diffusion constants in these gels by calculation through Bruker TopSpin version 3.2 software. Diffusion constants for the compounds of study in seawater and various w/v gels were compared. Ammonia diffusion was unable to be identified due to low peak strength. Nitrate and phosphate showed no statistically significant difference in diffusion up to 2% w/v alginate versus seawater. It has been previously reported there was a noticeable decrease in diffusion for alginate gels above 3% w/v (Garbayo et al., 2002). The organic polymers of high molecular weight exhibited a large decrease in diffusion through the gels. This study relates heavily to microbial ecology and understanding how gels to a certain extent do not restrict diffusion of molecules.