Structural Modification Influences the Characteristics of Langmuir Monolayers from Aromatic Carboxylic Acids
✍ Scribed by P Dynarowicz-Ła̧tka; K Kita; P Milart; A Dhanabalan; A Cavalli; D.A da Silva Filho; O.N Oliveira Jr.
- Publisher
- Elsevier Science
- Year
- 2001
- Tongue
- English
- Weight
- 225 KB
- Volume
- 239
- Category
- Article
- ISSN
- 0021-9797
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✦ Synopsis
The molecular organization of purely aromatic, polyphenyl carboxylic acids, as Langmuir monolayers at the air/water interface, has been investigated by means of surface pressure and electric surface potential measurements upon film compression. The monolayer characteristics of the basic compound, a symmetrical triphenylbenzene (5 -phenyl-m-terphenyl) ring with a carboxylic group at the 4 position (namely 5 -phenyl-1,1 : 3 ,1 -terphenyl-4carboxylic acid), are compared with those of its derivatives containing hydrophilic (nitro) or hydrophobic (phenyl) substituents. The nature of the substituent as well as its position (2 or 4 ) has a profound influence on the monolayer properties. The results are discussed in view of molecular orientation deduced from values of effective dipole moments.