ˈsmectic, a. (and n.)
[ad. L. smēcticus (Pliny), ad. Gr. σµηκτικός, f. σµήχειν to wipe, cleanse; cf. smegma.]
1. Cleansing, abstersive, detergent. rare.
| 1675 Evelyn Terra (1676) 40 Smooth to the touch, as the most Smectic Earths and Marles themselves. 1686 Plot Staffordsh. 124 The Smectic and Figuline Earths. 1858 Mayne Expos. Lex., Smecticus, cleaning;..smectic. |
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. Also as n., a smectic substance. Cf. nematic a. [ad. F. smectique (G. Friedel 1922, in Ann. de Physique XVIII. 276).]
| 1923 [see nematic a.]. 1936 Mineral. Abstr. VI. 237 In addition to the fuller's earths and smectic clays the series includes montmorillonite, confolensite, [etc.]. 1940 Glasstone Text-bk. Physical Chem. vii. 505 In the smectic state normal liquid flow does not occur: the movement is of a gliding nature, in one plane. 1971 New Scientist 14 Jan. 63/2 Once the smectic mesophase had formed, the continuous or ‘closed’ bimolecular sheets would isolate the aqueous compartments from their neighbours. 1974 Nature 25 Jan. 178/3 As yet uncategorised smectics probably exist, for example, the smectic phase of 4{p}-n-octyl-4-cyanobiphenyl described by Gray. |