Nanosensores opticos de polidiacetileno para el reconocimiento de moléculas de interes ambiental y alimentício

• Ano de defesa: 2013
• Autor(a) principal: Castellon Castrillon, Elkin Dario
• Orientador(a): Silva, Maria do Carmo Hespanhol da
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: spa
• Instituição de defesa: Universidade Federal de Viçosa
• Área do conhecimento CNPq: Química Analítica
• Link de acesso: http://www.locus.ufv.br/handle/123456789/9661

In this paper we propose the synthesis of an optical nanosensor for the detection of benzene, chlorinated solvents and melamine, novel nanostructures based on polydiacetylene (PDA) that are formed by monomers 10,12-pentacosadiinóico acid (PCDA) self-organized means amphiphilictriblock composed.The effect of the chemical structure and the balance of hydrophobic and hydrophilic triblock copolymers in colorimetric response (CR) of comparing with PCDA/L64 nanoblends PCDA vesicles in the presence of benzene. The UV-vis electronic spectrum shows that the largest intensity of the light absorbed nanoblend is due to a higher yield of the polymerization reaction of the diacetylene monomers nanoblenda that in the vesicle. Possibly due to the intermolecular interaction between benzene and propylene oxides alter the interaction between propylene oxide and PCDA reducing the rotational barrier of the carbon - carbon PCDA molecules allowing color change from blue to red.The effect of the chemical chlorinated structure of the transition colorimetric nanoblends of PCDA/L64. Showing PCDA/L64 nanosensor sensitivity has the same detection limit for chloroform and carbon tetrachloride, and this value close to 10 mM, therefore to dichloromethane is about 15 times greater than or equal to 150 mM. So this is verified nanosensor not specific for any of these chlorinated compounds may then distinguish a range of concentrations between dichloromethane and two chlorinated solvents.Determined the relative contribution of different intermolecular interactions to transition nanoblendas colorimetric PCDA / triblock caused by interaction with molecules of melamine. Showing that keeping the size of the hydrophobic region and the hydrophilic region growing by comparing nanoblends different copolymers, it is verified that the minimum concentration needed for melamine maximum occurs colorimetric transition remains the same, thus the colorimetric transition starts at concentrations melamine under nanostructures higher hydrophilic regions.This new nanosensor was efficient in detecting melamine which is known as a major adulterant of food and organic molecules of high environmental interest.