The word of the day is electrostriction:
n. chiefly Physics change in the volume or shape of a substance, esp. a dielectric, resulting from the application of an electric field. (OED)
"With these approximations the following equation was derived... where Vi is the partial molal volume of the apolar part of the monomer, (Vs-vs) equals the electrostriction of the electrolyte in solution and beta0 is the compressibility of water at temperature T."
- Tausk et al., "Physical chemical studies of short-chain lecithin
homologues. I. Influence of the chain length of the fatty acid ester
and of electrolytes on the critical micelle concentration", Biophysical Chemistry 1:175 (1973)
Showing posts with label r.j.m. tausk. Show all posts
Showing posts with label r.j.m. tausk. Show all posts
Friday, August 03, 2012
Thursday, August 02, 2012
word of the day: coacervate
The word of the day is coecervate:
"At concentrations slightly above the critical micelle concentration a phase separation occurs by formation of a coacervate (in the erminology of Bungenberg de Jon: a unicomplexcoacervate)."
- Tausk et al., "Physical chemical studies of short-chain lecithin homologues. I. Influence of the chain length of the fatty acid ester and of electrolytes on the critical micelle concentration", Biophysical Chemistry 1:175 (1973)
Etymology:
Backformation < coacervation n.
Chem.
An aggregate forming viscous drops in a colloidal solution.
1929 De Jong & Kruyt in Proc. Konink. Akad. van Wetenschappen te Amsterdam XXXII. 853
The coacervate is a drop or a layer, in which the particles have flocked together as bees in a swarm. (OED)
"At concentrations slightly above the critical micelle concentration a phase separation occurs by formation of a coacervate (in the erminology of Bungenberg de Jon: a unicomplexcoacervate)."
- Tausk et al., "Physical chemical studies of short-chain lecithin homologues. I. Influence of the chain length of the fatty acid ester and of electrolytes on the critical micelle concentration", Biophysical Chemistry 1:175 (1973)
Tuesday, July 31, 2012
word of the day: smectic
The word of the day is smectic:
"From the recent work of de Haas and co-workers, it appeared that the mode of aggregation of lecithins plays an essential role in their interaction with porcine pancreatic lipase A. This enzyme catalyses the hydrolysis of the 2 fatty acid ester bonds. It was found to be very weakly active on dispersions of natural or synthetic lecithins, when aggregated in the form of smectic liquid crystals."
- Tausk et al., "Physical chemical studies of short-chain lecithin homologues. I. Influence of the chain length of the fatty acid ester and of electrolytes on the critical micelle concentration", Biophysical Chemistry 1:175 (1973)
Etymology:
< Latin smēcticus (Pliny), < Greek σμηκτικός , < σμήχειν to wipe, cleanse
1. Cleansing, abstersive, detergent. rare.
2. Physical Chem.
Applied to (the state of) a mesophase (a liquid crystal) in which the
molecules all have the same orientation and are arranged in well-defined
planes. (OED)
"From the recent work of de Haas and co-workers, it appeared that the mode of aggregation of lecithins plays an essential role in their interaction with porcine pancreatic lipase A. This enzyme catalyses the hydrolysis of the 2 fatty acid ester bonds. It was found to be very weakly active on dispersions of natural or synthetic lecithins, when aggregated in the form of smectic liquid crystals."
- Tausk et al., "Physical chemical studies of short-chain lecithin homologues. I. Influence of the chain length of the fatty acid ester and of electrolytes on the critical micelle concentration", Biophysical Chemistry 1:175 (1973)
Monday, July 30, 2012
word of the day: lecithin
The word of the day is lecithin:
i.e., phosphatidylcholine,
(PubChem)
phosphatidylethanolamine,
(PubChem)
etc.
"Physical chemical studies of short-chain lecithin homologues. I. Influence of the chain length of the fatty acid ester and of electrolytes on the critical micelle concentration", Tausk et al., Biophysical Chemistry 1:175 (1973)
I guess these days we'd just say "phospholipids"? Not quite sure what the significance of the choline part of the molecule is that it deserves its own term.
Etymology:
< French lécithine (N. T. Gobley 1850, in Jrnl. de Pharm. et de Chim. XVII. 411), < Greek λέκιθος yolk of egg
Chem.
a.
Any of a group of phospholipids found in plants and animals which are
esters of a phosphatidic acid with choline and on hydrolysis yield
choline, phosphoric acid, glycerol, and two fatty acids; also used as a
generic name for these compounds.
b.
A commercial mixture of lecithin with other phosphatides and often
other lipids obtained from natural products and used industrially, esp.
that from soya beans. (OED)
i.e., phosphatidylcholine,
phosphatidylethanolamine,
(PubChem)
etc.
"Physical chemical studies of short-chain lecithin homologues. I. Influence of the chain length of the fatty acid ester and of electrolytes on the critical micelle concentration", Tausk et al., Biophysical Chemistry 1:175 (1973)
I guess these days we'd just say "phospholipids"? Not quite sure what the significance of the choline part of the molecule is that it deserves its own term.
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