| Texto completo | |
| Autor(es): |
Loiola, Paula T. C.
;
Dias, Wanderleia D.
;
Souza, Monique S.
;
Ferbonink, Guilherme F.
;
Zaniolo, Matheus G.
;
Cerini, Maria F.
;
Atvars, Teresa D. Z.
;
Nome, Rene A.
Número total de Autores: 8
|
| Tipo de documento: | Artigo Científico |
| Fonte: | JOURNAL OF PHYSICAL ORGANIC CHEMISTRY; v. 27, n. 4, p. 6-pg., 2014-04-01. |
| Resumo | |
We report an experimental study of ethyl stearate/ethanol binary mixtures employing optical microscopy, rheology, dynamic light scattering, and femtosecond optical Kerr effect spectroscopy. Optical microscopy images show that at 25 degrees C this mixture is homogeneous up to 10wt% ethyl stearate mass fraction and it leads to crystallization of ethyl stearate from solution at higher mass fractions. Rheological measurements at 40 degrees C and 25 degrees C exhibited an increase in viscosity of the binary mixture with increasing ethyl stearate mass fraction, consistent with molar mass considerations. Moreover, closer inspection of the rheology data from 0 to 10wt% ethyl stearate mass fraction indicate a plateau in the viscosity near 10%, thus indicating how crystallization affects the rheological properties of the solution, even at 40 degrees C. Dynamic light scattering data are consistent with two major components at all mass fractions investigated: a small ethyl stearate aggregate consisting of approximately seven monomers and a micron-sized crystallite. Femtosecond time-resolved optical Kerr effect indicates slower nuclear relaxation with increasing ethyl stearate mass fraction, thus suggesting that low-frequency motions of the binary mixture are involved in the early events of crystal nucleation. Copyright (c) 2013 John Wiley & Sons, Ltd. (AU) | |
| Processo FAPESP: | 08/10593-0 - Medindo a dinâmica química de líquidos através de espectroscopia ultrarrápida |
| Beneficiário: | René Alfonso Nome Silva |
| Modalidade de apoio: | Auxílio à Pesquisa - Jovens Pesquisadores |
| Processo FAPESP: | 12/01425-2 - Como a estrutura vibrônica de moléculas orgânicas afeta a eficiência da transferência de energia eletrônica? |
| Beneficiário: | Guilherme Ferreira Ferbonink |
| Modalidade de apoio: | Bolsas no Brasil - Mestrado |
| Processo FAPESP: | 11/12502-5 - Medindo o coeficiente de difusão de componentes do biodiesel a partir de espectroscopia de femtossegundos e técnicas correlatas |
| Beneficiário: | Maria Fernanda Cerini |
| Modalidade de apoio: | Bolsas no Brasil - Iniciação Científica |
| Processo FAPESP: | 11/12531-5 - Desenvolvimento de interfaces hardware/software para experimentos de espectroscopia de femtossegundos |
| Beneficiário: | Matheus Garbe Zaniolo |
| Modalidade de apoio: | Bolsas no Brasil - Iniciação Científica |