%0 Journal Article
%T Langmuir-Blodgett Films of Supported Polyester Dendrimers
%A Roc赤o Red車n
%A M. Pilar Carre車n-Castro
%A F. J. Mendoza-Mart赤nez
%J ISRN Organic Chemistry
%D 2012
%R 10.5402/2012/906839
%X Amphiphiles with a dendritic structure are attractive materials as they combine the features of dendrimers with the self-assembling properties and interfacial behavior of water-air affinities. We have synthesized three generations of polyester dendrimers and studied their interfacial properties on the Langmuir films. The behavior obtained was, as a rule, the lowest generation dendrimers behaving like traditional amphiphiles and the larger molecules presenting complicated isotherms. The Langmuir films of these compounds have been characterized by their surface pressure versus molecular area ( ) and Brewster angle microscopy (BAM) observations. 1. Introduction Various synthetic routes and structural modifications of dendrimers have been proposed, and several of their properties are now understood [1每4]. Therefore, potential applications of dendrimers at surfaces are clearly growing, for example, in surface-based catalysts [5, 6]; in the synthesis and stabilization of metal nanoparticles or as drug delivery supports [7]. Nevertheless, the general principles determining molecular conformation at the air-water interface are still under study [8每10], with unsolved questions such as the differences in the molecular shape near the interface and their relationship to the three-dimensional; the importance of the chemical functionalities of the different parts of the molecule; the shape of the formed monolayers, and so forth. So far, the knowledge of dendrimer structure in Langmuir films (at the air-water interface) comes largely from pressure-area ( - ) measurements, which are however open to multiple interpretations [11每16]. During the past few years there has been a considerable interest in the use of dendrimers as surface and interface active materials. The preparation of Langmuir films from amphiphilic dendrimers or monodendrons has been investigated by several research groups [17每21], since the Langmuir technique helps to access valuable information about the behavior of dendrimers at the air-water interface. Previous publications showed possible approaches to achieve surface activity for dendritic molecules, but few of them have described Langmuir films obtained from dendritic molecules [22每25] and their application. In this paper, we report the incorporation in Langmuir films of three generations of polyester dendrimers, in order to contribute to the understanding of the supported dendrimer properties and their behavior. 2. Experimental 3,5-Dihydroxybenzoic acid (DHBA) (97+%), 1,3,5-tris(2-hydroxyethyl) cyanuric acid (THECA) (97+%), and p-toluenesulfonic
%U http://www.hindawi.com/journals/isrn.organic.chemistry/2012/906839/