Langmuir-Blodgett luminescent thin films of cellulose acetate containing Eu3+ and Tb3+ complexes

• Grant number: 20/03953-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): August 01, 2020
• Effective date (End): June 30, 2021
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Celso Molina
• Grantee: Mayara Macedo de Figueiredo
• Host Institution: Instituto de Ciências Ambientais, Químicas e Farmacêuticas (ICAQF). Universidade Federal de São Paulo (UNIFESP). Campus Diadema. Diadema , SP, Brazil
• Associated research grant: 14/50869-6 - INCT 2014: on Organic Electronics, AP.TEM

Abstract

Langmuir - Blodgett luminescent thin films have been using for several applications such as biosensors [1,2] , optoelectronics devices [3] and luminescent materials [4].Lanthanides ions such as Eu3+ e Tb3+ present special applications due to their thin lines emission bands interesting to be used in optical signals, thin layer in OLEDs showing orange-red and green emission, respectively. However, these ions present weak absorption in the UV region. Thus, B-diketone ligand shows high absorption in UV region and can transfer energy to lanthanides ions through antenna effect [5]. Moreover, Eu(tta)3(H2O)2 e Tb(acac)3(H2O)3 present intense emission in red and green color when energy transfer through ligand occur.Langmuir - Blodgett (LB) technique allows to obtain ultrathin films organized in mono and multilayers for applications in nanoscale in different areas such as optics, sensors, biomimetic membranes and so on [6].Considering biological applications where the biocompatible interfaces are desired for applications in biosensors or even in sustainable optical devices natural polymeric matrices are appropriated. Among several natural polymeric matrixes, cellulose derivative such as cellulose acetate (CA) is a good candidate. It presents high transparence in the visible range, good mechanical properties, biodegradable and biocompatible [7]. CA has been applied for biomolecules immobilization [8]. CA films obtained by LB has not been applied and opportunities in area is opened. Meirav and coauthors have prepared Ca films by LB aiming applications in support for biomolecules and metallic nanoparticles [9]. Lijun, have synthesized LB films using cellulose derivative containing aromatic chromophore groups [10].In the literature there is no works related to preparation of Langmuir e Langmuir Blodgett based on CA polymeric matrices containing rare earth complexes íons. In this sense, the motivation for this research project is focused on the understanding of preparing and characterizing of bioinspired luminescent films by Langmuir e Langmuir - Blodgett technique.Films will be characterized by tensiometer, Brewster Angle Microscopy (BAM), Infrared spectroscopy (PM-IRRAS), ultraviolet and Photoluminescence spectroscopies.This research project will be run in collaboration with Prof. Luciano Caseli, specialist in LB technique. The student has been following the MSc students in order to acquire experience in LB technique.