|
|
Article: Free-standing microcrystals of a fluorescent organic dye: preparation and spectroscopic study.
- Article from:
- International Journal of Photoenergy
- Article date:
- January 1, 2006
- Author:
CopyrightCOPYRIGHT 2006 Hindawi Publishing Corp. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
|
Suspensions of microcrystals were obtained from an organic fluorescent dye, 4-n-octylamino-7-nitrobenz-2-oxa-1, 3-diazole, by reprecipitation in water in the presence of various macromolecules: anionic or cationic PAMAM dendrimer, poly(acrylic acid, sodium salt), poly(acrylamide), and calf thymus DNA. The use of these additives allowed the size and shape of the microcrystals to be controlled. A study by UV/vis absorption and fluorescence spectroscopy revealed some common points, but also some interesting differences, in the optical behaviour of the five samples.
1. INTRODUCTION
Organic nano- and microcrystals are defined as very tiny particles, the size ...