单词 | micelle |
释义 | micellen. Chemistry and Biochemistry. 1. An individual particle of the dispersed phase of a colloidal system; spec. a spherical array formed by certain amphipathic molecules (e.g. soaps), esp. one formed in aqueous solution in which the hydrophobic region of the array is enclosed by a polar shell. Also: = micella n. 1a (historical). Cf. micella n. 2. ΘΚΠ the world > matter > chemistry > physical chemistry > colloid > [noun] > micelle micelle1901 micella1926 1901 Jrnl. Chem. Soc. 80 ii. 231 A ‘micelle’ is used to denote the smallest quantity of a colloid which possesses all the physical properties of the colloid and is formed by the association of molecules of large size. 1909 J. Alexander tr. R. Zsigmondy Colloids xxi. 221 It must not pass unnoticed that Nägeli had already advanced the idea that vegetable fibers are formed from micells, molecular complexes optically and structurally anisotropic. 1927 H. S. van Klooster tr. H. R. Kruyt Colloids vi. 102 The micell is the particle plus the entire double layer. 1936 Trans. Faraday Soc. 32 116 Oleic acid is bimolecular in apolar solvents, and forms polymolecular micelles in aqueous alkaline solution. 1948 S. Glasstone Textbk. Physical Chem. (ed. 2) xiv. 1267 At appreciable concentrations, however, the anions are believed to aggregate together to form ionic micelles. 1969 New Scientist 21 Aug. 379/1 The granules correspond to..casein micelles, being formed by the denaturation and aggregation of the milk proteins during the manufacture of cheese. 1971 Nature 9 July 118/1 The bulk of DDT carried in contaminated water is probably in an organic environment, dissolved in suspended liquid fats, in soap and in detergent micelles. 2000 Biochimica et Biophysica Acta 1486 243 A specific transporter that facilitates the movement of cholesterol from bile acid micelles into the brush border membranes of enterocytes. 2. A crystalline region in a cellulose microfibril or other polymer. Cf. crystallite n. 1d. Cf. micella n. 1b. Now rare (chiefly historical). ΚΠ 1934 Philos. Trans. (Royal Soc.) B. 224 139 It is..highly probable that the cellulose micelle is not a definitely discrete unit...The term is now used merely as an expression for vaguely defined regions wherein the cellulose is more perfectly crystalline than that outside them. 1934 C. C. Steele Introd. Plant Biochem. x. 96 In cellulose these units are linked together to give straight chains of different lengths, several of which are aligned parallel to each other,..forming a micellar bundle or micelle. 1946 Nature 10 Aug. 199/2 The main component of starch..is considered to be a network of primary valency chains, which are linked in crystalline micells in which water is bound in the lattice. 1968 Proc. Royal Soc. 1967–8 B. 169 142 The ‘fringed micelle’ structure widely accepted for cellulose before the advent of electron microscopy. 1992 M. Ingrouille Diversity & Evol. Land Plants 25 Larger fibrils..form chains or rods, with alternating dense crystalline areas, called micelles and linked by unordered fibrils. This entry has been updated (OED Third Edition, December 2001; most recently modified version published online March 2022). < |
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