TY - JOUR
T1 - Energy transfer and compatibility analysis of PVK/MEH-PPV blends processed via electrospraying and electrospinning
AU - Mondragón, Margarita
AU - Balderas, J. Uriel
AU - Jiménez, G. Lesly
AU - Sánchez-Espíndola, Ma Esther
AU - Falcony, Ciro
N1 - Publisher Copyright:
© 2014 Elsevier B.V. All rights reserved.
PY - 2014/11
Y1 - 2014/11
N2 - Solution polymer blends of a high molecular weight and a low molecular weight poly(9-vinyl carbazole) PVK with poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), at a fixed blend ratio of 95.5:0.5, were processed via electrospraying and electrospinning. SEM studies revealed that electrosprayed particles were produced when low molecular weight PVK was used, while electrospun fibers were successfully obtained from solutions containing high molecular weight PVK, over a concentration range of 4-10% (w/v). From the absorption spectra of the neat polymers it was determined that Urbach energy Euincrease and optical band gap Egdecreases due to the physical defects along the main chain introduced by these electrostatic processing methods. Photoluminescence spectroscopy revealed a particular applied voltage, which depends on concentration and molecular weight, where aggregation of PVK levels off. Luminescence quenching of MEH-PPV is also observed to increase with applied voltage consistent with possible energy transfer from shorter conjugation length segments to nearby longer conjugated segments. The ratio of the intensity of the excitation spectra of the PVK (donor, both PVKLor PVKH) and the MEH-PPV (acceptor), ID/IA, exhibited minima at this particular voltage and then levels off, indicating not only maximum interpenetration and thus compatibility of both polymers but also maximum energy transfer. Hence, we demonstrate that compatibility and energy transfer can be optimized varying concentration and applied voltage during both electrospraying and electrospinning processes.
AB - Solution polymer blends of a high molecular weight and a low molecular weight poly(9-vinyl carbazole) PVK with poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), at a fixed blend ratio of 95.5:0.5, were processed via electrospraying and electrospinning. SEM studies revealed that electrosprayed particles were produced when low molecular weight PVK was used, while electrospun fibers were successfully obtained from solutions containing high molecular weight PVK, over a concentration range of 4-10% (w/v). From the absorption spectra of the neat polymers it was determined that Urbach energy Euincrease and optical band gap Egdecreases due to the physical defects along the main chain introduced by these electrostatic processing methods. Photoluminescence spectroscopy revealed a particular applied voltage, which depends on concentration and molecular weight, where aggregation of PVK levels off. Luminescence quenching of MEH-PPV is also observed to increase with applied voltage consistent with possible energy transfer from shorter conjugation length segments to nearby longer conjugated segments. The ratio of the intensity of the excitation spectra of the PVK (donor, both PVKLor PVKH) and the MEH-PPV (acceptor), ID/IA, exhibited minima at this particular voltage and then levels off, indicating not only maximum interpenetration and thus compatibility of both polymers but also maximum energy transfer. Hence, we demonstrate that compatibility and energy transfer can be optimized varying concentration and applied voltage during both electrospraying and electrospinning processes.
KW - Blend
KW - Compatibility
KW - Electrospinning
KW - Electrospraying
KW - Förster energy transfer (FRET)
UR - http://www.scopus.com/inward/record.url?scp=84907225407&partnerID=8YFLogxK
U2 - 10.1016/j.orgel.2014.08.040
DO - 10.1016/j.orgel.2014.08.040
M3 - Artículo
SN - 1566-1199
VL - 15
SP - 2993
EP - 2999
JO - Organic Electronics
JF - Organic Electronics
IS - 11
ER -