Direct observation by using Brewster angle microscopy of the diacetylene polimerization in mixed Langmuir film.
Mixed Langmuir monolayers of 10,12-Pentacosadiynoic acid (DA) and amphiphilic hemicyanine (HSP) have been fabricated at the air-water interface. The mixed monolayer has been proved to be completely homogeneous. The DA molecules are arranged in a single monolayer within the mixed Langmuir monolayer, as opposed to the typical trilayer architecture for the pure DA film. Brewster angle microscopy has been used to reveal the mesoscopic structure of the mixed Langmuir monolayer. Flower shape domains with internal anisotropy due the ordered alignment of hemicyanine groups have been observed. Given the absorption features of the hemicyanine groups at the wavelength used in the BAM experiments, the enhancement of reflection provoked by the absorption process leads to the observed anisotropy. The ordering of such groups is promoted by their strong self-aggregation tendency. Under UV irradiation at the air-water interface, polydiacetylene (PDA) has been fabricated. In spite a significant increase in the domains reflectivity has been observed owing to the modification in the mentioned enhanced reflection, the texture of the domains remains equal. The PDA polymer chain therefore grows in the same direction in which the HSP molecules are aligned. This study is expected to enrich the understanding and design of fabrication of PDA at interfaces.
Institute of Fine Chemistry and Nanochemistry, Department of Physical Chemistry and Applied Thermodynamics, University of Córdoba, Campus Universitario de Rabanales, Edificio Marie Curie, Córdoba E-14014, Spain.
Luisa
L
Ariza-Carmona
Institute of Fine Chemistry and Nanochemistry, Department of Physical Chemistry and Applied Thermodynamics, University of Córdoba, Campus Universitario de Rabanales, Edificio Marie Curie, Córdoba E-14014, Spain.
María T
MT
Martín-Romero
Institute of Fine Chemistry and Nanochemistry, Department of Physical Chemistry and Applied Thermodynamics, University of Córdoba, Campus Universitario de Rabanales, Edificio Marie Curie, Córdoba E-14014, Spain; Bionanoplasmonics Laboratory, CIC biomaGUNE, Paseo de Miramón 182, 20009 Donostia - San Sebastián, Spain. Electronic address: jjginer@uco.es.
Juan J
JJ
Giner-Casares
Institute of Fine Chemistry and Nanochemistry, Department of Physical Chemistry and Applied Thermodynamics, University of Córdoba, Campus Universitario de Rabanales, Edificio Marie Curie, Córdoba E-14014, Spain. Electronic address: lcamacho@uco.es.
Luis
L
Camacho
D002232:Carbocyanines / Q000737:chemistry*; D005231:Fatty Acids, Unsaturated / Q000737:chemistry*; D008567:Membranes, Artificial; D008853:Microscopy; D000078789:Polyacetylene Polymer; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry*; D053279:Polyynes / Q000138:chemical synthesis* / Q000737:chemistry*
C493048:10, 12-pentacosadiynoic acid; D002232:Carbocyanines; D005231:Fatty Acids, Unsaturated; D008567:Membranes, Artificial; D000078789:Polyacetylene Polymer; D011108:Polymers; C000601156:tetramethylene hemicyanine; D053279:Polyynes; C082361:polydiacetylene
Brewster angle microscopy; Domains; Langmuir monolayers; Polydiacetylene; UV–vis reflection spectroscopy