Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Synthesis and self assembly of poly(2-isopropyl-2-oxazoline)-b-poly(2-phenyl-2-oxazoline)-b-poly(2-isopropyl-2-oxazoline)
Download
10513024.pdf
Date
2022-12-16
Author
Turan, Çağrı
Metadata
Show full item record
This work is licensed under a
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License
.
Item Usage Stats
353
views
132
downloads
Cite This
Polymersomes are polymeric vesicles formed through self-assembly of amphiphilic polymers. They can be used as nanoreactors for providing a stable compartment with a high concentration of the reactive enzymes or nanocarriers which may simultaneously release hydrophilic and hydrophobic drugs. Poly(2-alkyl-2-oxazolines) (PAOXs) are used in biomedical applications due to their important biological properties such as biocompatibility, antifouling, and stealth behavior. Besides, PAOXs with short alkane side chains exhibit temperature responsive behavior, making them promising materials for controlled release applications. Among PAOX family, poly(2-isopropyl-2-oxazoline) (PiPOX) has attracted attention due to its lower critical solution temperature behaviour at temperatures close to human body temperature. This thesis study reports on synthesis of a PAOX-based triblock copolymer, namely poly(2-isopropyl-2-oxazoline)-b-poly(2-phenyl-2-oxazoline)-b-poly(2-isopropyl-2-oxazoline) (PiPOX-b-PPhOX-b-PiPOX), by a three-step sequential monomer addition through cationic ring opening polymerization (CROP). PiPOX:PPhOX ratio was calculated as 1:1.7 through 1H Nuclear Magnetic Resonance (1H NMR) Spectroscopy. Molecular weight of PiPOX-b-PPhOX-b-PiPOX was determined through Gel Permeation Chromatograpy (GPC). The number average and weight average molecular molecular weights were found as ~8500 g/mol and ~9700 g/mol with a polydispersity index (PDI) of 1.14. The self-assembly of PiPOX-b-PPhOX-b-PiPOX was triggered in aqueous solution through solvent shifting or water-in-oil-in water double emulsion (W/O/W) methods. Hydrodynamic size of the aggregates was measured through dynamic light scattering (DLS) technique. Aggregates obtained through double emulsion method (~219 nm) were smaller in size than those prepared through solvent shifting method (~280 nm). Transition electron microscopy (TEM) and fluorescence microscopy (FM) imaging showed polymersome morphology for the aggregates for both methods. Water soluble PiPOX blocks are suggested to form the hydrophilic inner and outer region of polymersomes, whereas the hydrophobic PPhOX block is expected to form the polymersome membrane. The effect of temperature on aqueous solution behaviour of PiPOX-b-PPhOX-b-PiPOX polymersomes was examined by measuring the size of particles as a function of temperature using DLS technique. Above 40℃, polymersomes merged and formed polymersome clusters and this association among the polymersomes was found to be irreversible. Finally, encapsulation capability of PiPOX-b-PPhOX-b-PiPOX polymersomes was examined using glucose oxidase (GOx) as a model enzyme. TEM imaging indicated that GOx was encapsulated in the inner core region of polymersomes. In summary, this thesis study generated fundamental information about synthesis, self-assembly and temperature-responsive aqueous solution behavior of a PAOX-based triblock copolymer. Use of PiPOX-b-PPhOX-b-PiPOX polymersomes as temperature-responsive nanoreactors for enzymatic reactions will be further explored in future studies.
Subject Keywords
Polymersome
,
Poly(2-alkyl-2-oxazoline)
,
Solvent shifting
,
Double emulsion
,
Cationic ring opening polymerization
URI
https://hdl.handle.net/11511/101255
Collections
Graduate School of Natural and Applied Sciences, Thesis
Suggestions
OpenMETU
Core
Synthesis and electroactivity of pyrrole end-functionalized poly(2-methyl-2-oxazoline)
Çırpan, Ali; Toppare, Levent Kamil; YAGCI, Y (2001-11-01)
Poly (2-methyl-2-oxazoline) (PMeOZO) with pyrrole end groups was synthesized by cationic ring polymerization of 2-methyl-2-oxazoline initiated by benzyl bromide and subsequent modification of the halide end group. The structure and electroactivity of the macromonomer thus obtained were confirmed by spectral analysis and cyclic voltametry, respectively. The posssibility of chemical and electrochemical graft copolymerization of PMeOZO with pyrrole was also studied.
Synthesis and pyrolysis of ABC type miktoarm star copolymers with polystyrene, poly(lactic acid) and poly(ethylene glycol) arms
Ozlem, Suriye; Iskin, Birol; Yilmaz, Gorkem; Kukut, Manolya; Hacaloğlu, Jale; Yagci, Yusuf (2012-10-01)
An ABC type miktoarm star copolymer possessing polystyrene (PS), poly(lactic acid) (PLA) and poly(ethylene glycol) (PEG) arms was synthesized by combining Atom Transfer Radical Polymerization (ATRP) and Ring Opening Polymerization (ROP) with two click chemistries, namely thiol-ene and copper catalyzed azide-alkyne cycloaddition (CuAAC). For this purpose, a core 1-(allyloxy)-3-azidopropan-2-ol with allyl and azide functionalities was synthesized in two steps. Then, clickable polymers, polystyrene with thiol ...
Synthesis of zinc oxide nanoparticles elaborated by microemulsion method
Yildirim, Ozlem Altintas; Durucan, Caner (2010-09-17)
Zinc oxide (ZnO) nanoparticles were synthesized by a reverse microemulsion system formed from sodium bis(2-ethylhexyl)sulfosuccinate (Aerosol OT, or AOT):glycerol:n-heptane. The zinc precursor was zinc acetate dihydrate. The formation of ZnO nanoparticles was achieved by calcination of premature zinc glycerolate microemulsion product in air at 300, 400 and 500 degrees C. The crystal structure and the morphology of the ZnO nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron micr...
Synthesis and electropolymerization of a new ion sensitive ethylenedioxy-substituted terthiophene monomer bearing a quinoxaline moiety
Carbas, Buket Bezgin; Kivrak, Arif; Zora, Metin; Önal, Ahmet Muhtar (2012-07-15)
A new terthienyl based fluorescent polymer bearing pendant quinoxaline moieties directly attached to the 3-positions of the central thiophene ring was synthesized by electrochemical polymerization of 4-(2,5-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)thiophen-3-yl)Pyrrolo[1,2-a]quinoxaline (EE-Q). The corresponding polymer, poly(4-(2,5-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)thiophen-3-yl)pyrrolo[1,2-a]quinoxaline) P(EE-Q), was characterized by cyclic voltammetry, FT-IR and UV-vis spectroscopy. The po...
Synthesis and Spectroelectrochemistry of Dithieno(3,2-b:2 ',3 '-d)pyrrole Derivatives
Udum, Yasemin Arslan; Yildiz, Huseyin Bekir; Azak, Hacer; Sahin, Elif; Talaz, Oktay; Çırpan, Ali; Toppare, Levent Kamil (Wiley, 2014-09-05)
New pi-conjugated polymers containing dithieno(3,2-b: 2',3'-d) pyrrole (DTP) were successfully synthesized via electropolymerization. The effect of structural differences on the electrochemical and optoelectronic properties of the 4-[4H-dithieno(3,2-b: 2',3'-d) pyrrol-4-yl] aniline (DTP-aryl-NH2), 10-[4H-dithiyeno(3,2-b: 2',3'-d) pirol-4-il] dekan-1-amine (DTP-alkyl-NH2), and 1,10-bis[4H-dithieno(3,2-b:2',3'-d) pyrrol-4-yl] decane (DTP-alkyl-DTP) were investigated. The corresponding polymers were characteri...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
Ç. Turan, “Synthesis and self assembly of poly(2-isopropyl-2-oxazoline)-b-poly(2-phenyl-2-oxazoline)-b-poly(2-isopropyl-2-oxazoline),” M.S. - Master of Science, Middle East Technical University, 2022.