word of the day: coacervate

The word of the day is coecervate:

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)

word of the day: monotectic

The word of the day is monotectic:

The reversible transition, on cooling, of a liquid to a mixture of a second
liquid and a solid.  (IUPAC Compendium on Chemical Terminology)


"An equimolar mixture of dilauroyl phosphatidylcholine and distearoyl phosphatidylcholine, which shows a monotectic behaviour, is hydrolysed at all temperatures."

 - J.A.F. Op den Kamp et al., "Action of pancreatic phospholipase A2 on phosphatidylcholinebilayers in different physical states", Biochimica et Biophysica Acta 406:169 (1975).

Word of the day: eutectic

The word of the day is eutectic:

Etymology:  Greek εὔτηκτος easily melting (εὐ-eu- comb. form + τήκ-ειν to melt) + -ic suffix.

A. adj.

That is a eutectic; of or pertaining to a eutectic or its liquefaction or solidification; eutectic point, the melting-point of a eutectic, or the point representing it in a constitutional diagram. 

B. n.

A mixture which is distinguished from other mixtures of the same constituents in different proportions by having a single temperature at which it melts and freezes, this temperature being lower than the freezing-point of any of the constituents or of any other mixture of them. Also fig.  (OED)

"Two eutectic points are postulated to occur: one at a very low 1,2-DPG concentration and the other at a 1,2-DPG concentration slightly higher than 66 mol%."

 - López-García et al., "The phase behavior of mixed aqueous dispersions of dipalmitoyl derivatives of phosphatidylcholine and diacylglycerol", Biophysical Journal 66:1991 (June 1994)