Cyclodextrin functionalized nanofibers via electrospinning
Author
Çelebioğlu, Aslı
Advisor
Uyar, Tamer
Date
2014Publisher
Bilkent University
Language
English
Type
ThesisItem Usage Stats
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Abstract
Electrospinning is a commonly studied and widely applied technique for generating
nanofibers, with a diameter ranging from several tens of nanometers to a few
micrometers. The low-cost, simple set-up, relatively high production rate and
reproducibility increase the interests on this method in both academia and industry.
Electrospun nanofibers are produced from a broad range of materials with extremely
high surface area, very light-weight, nano-porous features and distinct
physical/mechanical properties. The general talk in this technique focuses on the
production of nanofibers from polymer base materials. However, very recent studies
demonstrated that, it is also possible to obtain nanofibers from non-polymeric
systems. For this novel development in electrospinning researches, we have achieved
to generate nanofibers from cyclodextrins (CD) without using a polymeric template.
CD are cyclic oligosaccharides consisting of α-(1,4)-linked glucopyranose units. The
truncated cone shape structure of CD provides a favorable place for various kinds of
organic molecules to form non-covalent host-guest inclusion complexes (IC). The
enhancements and progressing at the guest molecules property and situation, creating
with the inclusion complexation, make CD applicable in variety of areas including
filtration, pharmaceuticals, cosmetics, functional foods, textiles, analytic chemistry
etc.
In this thesis, we report on the electrospinning of CD nanofibers, represent their
functionalization and potential applications. Firstly, we produced CD nanofibers
from three different chemically modified CD types (hydroxypropyl-β-cyclodextrin
(HPβCD), hydroxypropyl-γ-cyclodextrin (HPγCD) and methyl-β-cyclodextrin
(MβCD)). Afterwards, the electrospinning of native CD (α-CD, β-CD and γ-CD)
nanofibers was achieved. The molecular entrapment capability of CD nanofibers was
shown by capturing toxic volatile organic compounds (VOCs) from the surrounding.
As the next step, the polymer-free nanofibers were obtained from the cyclodextrin
inclusion complexes (CD-IC) with antibacterial agent, vanillin and essential oils.
Here, we have also indicated applicability of CD-IC nanofibers as a result of
antibacterial test. The functionalization of the CD nanofibers was continued with the
green and one-step synthesis of metal nanoparticles (Ag-NP, Au-NP and Pd-NP)
incorporated nanofibers, in which CD were used as reducing, stabilizing agent and
fiber template. Even, the antibacterial, SERS and catalyst potential of these CD based
nanofibers were demonstrated for the related nanoparticles. Our research is expanded
to a new stage by the production of insoluble poly-CD nanofibers. We have worked
on different crosslinking agents to attain insoluble poly-CD nanofibers with uniform
morphology. After the optimization of poly-CD nanofibers, the most durable polyCD
nanowebs were selected for further analysis and evaluation of the filtration
performance in liquid environment. Within poly-CD nanofibers, we have eliminated
the solubility challenge of CD nanofibers that restrict their usage. So, we assume
that, poly-CD nanofibers will lead-up to generation of new advances for practices of
CD nanofibers. All studies showed that, the self-assembly and self-aggregation
property of CD are the prior requirements for the electrospinnability of these small
molecules. To conclude, very intriguing materials were obtained by integrating large
surface area of nanofibers with specific host-guest inclusion complexation capability
and non-toxic, biocompatible nature of the CD. Moreover, CD molecules, which are
generally used in the powder form, were rendered into more applicable nanofibers
form that will represent ease during their usage.
Keywords
Electrospinning, Cyclodextrin, Nanofibers, İnclusion Complex, Antibacterial Agent, Vanillin, Essential Oils, Nanoparticles, Silver, Gold, Palladium, Molecular Encapsulation, Antibacterial Activity, SERS, Catalyst, CrosslinkingElectrospinning
Cyclodextrin
Nanofibers
İnclusion Complex
Antibacterial Agent
Vanillin
Essential Oils
Nanoparticles
Silver
Gold
Palladium
Molecular Encapsulation
Antibacterial Activity
SERS
Catalyst
Crosslinking