Estimation of the poly (ε-caprolactone) [PCL] and α-cyclodextrin [α-CD] stoichiometric ratios in their inclusion complexes [ICs], and evaluation of porosity and fiber alignment in PCL nanofibers containing these ICs

Abstract

This paper describes the utilization of Proton-Nuclear Magnetic Resonance spectroscopy (1H NMR) to quantify the stoichiometric ratios between poly (ε-caprolactone) [PCL] and α-cyclodextrin (α-CD) present in their non-stoichiometric inclusion complexes [(n-s)-ICs]. This paper further describes the porosity and fiber alignment of PCL nanofibers nucleated by the [(n-s)-ICs] during electrospinning. 1H NMR indicated that the two non-stoichiometric inclusion complexes utilized in this study had differing stoichiometric ratios that were closely similar to those of the starting ratios used to make them. Studies on porosity and fiber alignments were conducted on the scanning electron microscope images using ImageJ. The data indicates that both fiber alignment as well as porosity values remain almost the same over all the samples. Thus we can conclude the improvement in mechanical properties was due only to the loading of the ICs, and their subsequent interaction with bulk unthreaded PCL.

Keywords

• 1H NMR
• Pseudorotaxane nanofibers
• Electrospinning
• Stoichiometric ratio
• Fiber alignment
• Porosity