Banca de DEFESA: PRISCILA GONÇALVES DA COSTA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : PRISCILA GONÇALVES DA COSTA
DATA : 12/08/2021
HORA: 14:00
LOCAL: Defesa remota
TÍTULO:

Flexible paper-based devices nanofunctionalized with polydopamine for the transport of microfluids

 

PÁGINAS: 46
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Analítica
ESPECIALIDADE: Eletroanalítica
RESUMO:

In this work, in order to transport microfluids on flexible surfaces, it was proposed the construction of a paper-based device and functionalized with polydopamine. Because they are low cost and easy to handle, paper-based devices are competitive against traditional devices made on glass or metal substrate. Polydopamine, on the other hand, is promising for application in several sectors due to its biocompatibility and ease of adhesion on surfaces with different chemical and physical characteristics, which allows us to use it to form a thin layer of adhesion on the paper device. Thus, on a conventional paper substrate previously treated with wax and toner, hydrophobic materials, hydrophilic trails were constructed with thickness controlled by the time of self-polymerization of the dopa monomer, capable of accelerating the flow of aqueous microfluids deposited on the region. With a slight slope of the device and without the use of any external equipment, the microfluid in contact with the polymer is transported about 30 times faster than capillarity transport, the latter commonly used to transport microfluids on paper substrates. The high adhesion of polydopamine also allows the fixation of other materials on the surface, such as amorphous carbon used here as proof of concept. With the deposition of carbon black ink, it was possible to form trails with conductivity of up to 203,64 S/m with potential to be explored in the area of electrical and electrochemical devices. Polymerization time, contact angle and drop scroll angle tests were carried out to find the most efficient condition in the transport of microfluid, as well as tests of the ideal composition of the carbon black ink for low electrical resistance film formation. In addition to the tests mentioned, the entire device was characterized at each stage of construction using techniques such as Fourier transform infrared spectroscopy (FTIR), in which we have information from the functional groups predominant in the sample, confocal laser scanning microscopy, revealing the morphology of surfaces, scanning electron microscopy (SEM), with detailed images of amorphous carbon and its interface with substrate, Raman spectroscopy, whose spectrum reveals the D and G bands of the nanodomains conductors of the carbon black film, atomic force microscopy (AFM), where it is possible to observe the morphology of polydopamine nanofilm of only 5 nm thickness and infrared atomic force microscopy (AFM-IR) , where we obtain information on the chemical composition of the nanofilm.

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 050.966.059-22 - MURILO SANTHIAGO - CNPEM
Membro Titular - Examinador(a) Interno ao Programa - 1761120 - DANILO JUSTINO CARASTAN
Membro Titular - Examinador(a) Externo à Instituição - CECILIA DE CARVALHO CASTRO E SILVA - UPM
Membro Suplente - Examinador(a) Interno ao Programa - 1544341 - WENDEL ANDRADE ALVES
Membro Suplente - Examinador(a) Interno ao Programa - 007.041.553-62 - RENATO SOUSA LIMA - UNICAMP
Membro Suplente - Examinador(a) Externo à Instituição - WENDELL KARLOS TOMAZELLI COLTRO - UFG
Membro Suplente - Examinador(a) Externo à Instituição - LEANDRO WANG HANTAO - UNICAMP