Electrospun Nanofibers of Immiscible Blends Containing a Fluorescence Dye: Direct Investigation of Polymer Domains

Abstract

Poly(lactic acid) (PLA) and poly(ε-caprolactone) (PCL) are two immiscible polymers which are biodegradable and bioabsorbable, being therefore widely applied for medical materials. The formation of homogeneous fibers of PCL by electrospinning represents a difficult task due to the low viscosity of the solutions of this polymer in comparison to the PLA solutions. In addition, the development of simple techniques for the characterization of these systems represents a field of interest. In this paper, nanofibers of PLA/PCL (1:1 w/w) in a CHCl 3 :MeOH (3:1 w/w) solvent system with and without 4-[4-(dimethylamino)styryl]-1-methylpyridinium iodide (DSMI), a perichromic dye, were electrospun. The electrospun nanofibers obtained present a homogeneous diameter distribution, with average of 874 ± 205 nm in optimization condition for PLA/PCL and 627 ± 199 nm for PLA/PCL/DSMI. The analysis of the differences in the fluorescence emission of DSMI distributed in each polymer of the nanofibers allowed the direct investigation of the polymeric domains. It is proposed that these emission differences result from the preferential stabilization of resonant forms of the dye with each polymeric chain. For the PLA−DSMI system, green emission was observed, while for PCL−DSMI, red emission occurred. The fluorescence results corroborated thermal analyses, where the absence of solvents was possible to confirm. The nanofibers were compared with the dye anchored in an xerogel, which did not exhibit different emission regions due to its homogeneous distribution in the matrix.

Poly(amide11)-Incorporated Block Copolymers as Compatibilizers to Toughen a Poly(lactide)/Polyamide 11 Blend

“…17,18 On the other hand, the multiphase method utilizing block copolymers is challenging because it involves complex manufacturing processes. 19 As a result, many researchers have focused on blending PLA with other polymers, such as PLA/PBAT, 20−22 PLA/PCL, 23,24 PLA/PBS, 25 PLA/PEO, 26 PLA/PA, 27,28 PLA/PVDF, 29 PLA/ LDPE, 30 all of which have received significant attention in recent years because of their relatively easy accessibility and study. Among these, the bioderived polymer blend of PLA/PA11 has attracted increasing attention as a candidate to address the petroleum crisis and environmental issues.…”

“…The single-phase method has drawbacks such as the leaching of added substances, reduction in initial modulus, and yield stress. , On the other hand, the multiphase method utilizing block copolymers is challenging because it involves complex manufacturing processes . As a result, many researchers have focused on blending PLA with other polymers, such as PLA/PBAT, − PLA/PCL, , PLA/PBS, PLA/PEO, PLA/PA, , PLA/PVDF, PLA/LDPE, all of which have received significant attention in recent years because of their relatively easy accessibility and study.…”

Fabrication and Characterization of Nylon 66/PAN Nanofibrous Film Used as Separator of Lithium-Ion Battery

“…The above parameters directly affect the fiber morphology. Through the control of the parameters, the optimal state can be found and then a good fiber film can be produced [ 4 , 5 , 6 ]. In recent years, many studies have pointed out that the electrospun fiber membrane has high porosity and its unique pore structure can be used as a lithium battery separator [ 7 , 8 ].…”