Banca de DEFESA: ANA CAROLINA FRADIQUE DE LYRA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : ANA CAROLINA FRADIQUE DE LYRA
DATE: 29/03/2022
TIME: 09:00
LOCAL: Google Meet
TITLE:

Synthesis, characterization and electrochemical polymerization of pyrrole-derived monomers for application in forensic chemistry for the development of latent fingerprints

KEY WORDS:

Pyrroles, Conjugated polymers, Fingerprints, Stainless steel

PAGES: 104
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Orgânica
SUMMARY:

The synthesis of four new pyrrole derivatives was performed through the reactions of Clauson-Kaas, esterification and bimolecular nucleophilic substitution (S_N2). The synthesized monomers were obtained with good yields and characterized by one-dimensional / two-dimensional Nuclear Magnetic Resonance (1D / 2D NMR) and Fourier Transform Infrared (FTIR). Polymeric films were acquired by electrochemical polymerization using the potentiostatic method (PST), by chronoamperometry, and using the galvanostatic method (GST), by chronopotentiometry. For both methods, was used an electrochemical cell containing the aqueous solution with 0.01 mol L^-1 of the monomer and 0.1 mol L^-1 of the electrolyte (LiClO₄), the reference electrode (Ag / AgCl), the auxiliary electrode (Platinum) and the working electrode (stainless steel plate). These methods were also used to obtain the copolymer film formed between PySSO₃Na and 3,4-ethylenedioxythiophene (EDOT) monomers. The characterization of the copolymer was made by comparing the absorption bands present in the FTIR spectra of the pure monomers and the copolymer. The electrodeposition was carried out on metallic substrates (stainless steel), containing latent fingerprints (IDLs) to be developed, applying a recent development method based in the deposition of the polymer on a conductive substrate. The polymer was deposited between the ridges of the fingerprint, without any interaction between the polymer (developer material) and the sebaceous residues (insulating material) of the fingerprint, resulting in the “negative” image of the IDL, consequently, revealing it. The quality evaluation of the revealed fingerprints was performed using the Griaule Forensic Fingerprint software, in which it was possible to identify the minutiae present in the fingerprints, and the Bandey Scale, obtaining a grade 4 for all post-treatment images with the software. In addition, Scanning Electron Microscopy (SEM) analysis was performed, and thus it was possible to identify minutiae of the fingerprint, as well as the polymer-sebaceous residues interface, showing that such materials are morphologically distinct.

BANKING MEMBERS:
Interna - 1543737 - ADRIANA SANTOS RIBEIRO
Externo à Instituição - ALEXANDRO MANGUEIRA LIMA DE ASSIS
Presidente - 2089941 - DIMAS JOSE DA PAZ LIMA
Interna - 1820117 - ISIS MARTINS FIGUEIREDO
Externo à Instituição - JOHNNATAN DUARTE DE FREITAS - IFAL