Browsing by Author "Pekcan, Önder"
Now showing items 1-20 of 31
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Cation Effect on Slow Release from Alginate Beads: A Fluorescence Study
Kaygusuz, Hakan; Erim, F. Bedia; Pekcan, Önder; Evingür, Gülşen Akın (Springer/Plenum Publishers, 2014)In this study, spherical alginate beads containing pyranine (P-y) as a fluorescence probe were prepared by ionotropic gelation of a sodium alginate solution. The steady state fluorescence technique was used to study pyranine ... -
Drying of polyacrylamide-multiwalled carbon nanotube (MWNT) composites with various MWNTs contents: a fluorescence study
Evingür, Gülşen Akın; Pekcan, Önder (Walter De Gruyter Gmbh, 2013)We studied the drying of polyacrylamide (PAAm)-multiwalled carbon nanotube (MWNT) composites, prepared by free radical crosslinking copolymerization in water, with a steady state fluorescence technique. Composite gels were ... -
Effect of Calcium Ion Concentration on Small Molecule Desorption from Alginate Beads
Evingür, Gülşen Akın; Kaygusuz, Hakan; Erim, F. Bedia; Pekcan, Önder (Taylor & Francis Inc, 2014)Spherical alginate beads were prepared by ionotropic gelation of sodium alginate through the use of calcium ions. Pyranine (Py) was added to the alginate solution as a small molecule probe for fluorescence studies. Desorption ... -
Effect of Content and Temperature On the Phase Transitions of Polymer Composites Doped By Kappa Carrageenan and Alginate
Evingür, Gülşen Akın; Pekcan, Önder (Elsevier Academic Press Inc, 2016)[No Abstract Available] -
Effect of multiwalled carbon nanotube (MWNT) on the behavior of swelling of polyacrylamide-MWNT composites
Evingür, Gülşen Akın; Pekcan, Önder (Sage Publications Ltd, 2014)The purpose of this paper is to discuss the role of multiwalled carbon nanotube in the swelling of polyacrylamide-multiwalled carbon nanotube composites. Swelling experiments were performed in water at various temperatures ... -
Effect of temperature and graphene oxide on the swelling of PAAm-GO composite gels
Osma, Büşra; Evingür, Gülşen Akın; Pekcan, Önder (Avestia Publishing, 2019)Graphene oxide (GO) is a two dimensional carbon material with similar one-atom thickness, and is a light material having extremely high strength and thermal stability [1]. Thus, GO is an efficient filler for the enhancement ... -
Elastic percolation of swollen polyacrylamide (PAAm)-multiwall carbon nanotubes composite
Evingür, Gülşen Akın; Pekcan, Önder (Taylor & Francis Ltd, 2012)Polyacrylamide (PAAm)-multiwalled carbon nanotube (MWNT) composites were prepared via free radical cross-linking copolymerization with different amounts of MWNTs varying in the range between 0.1 and 50 wt%. The mechanical ... -
Elastic Properties of a Swollen PAAm-NIPA Copolymer with Various NIPA Contents
Evingür, Gülşen Akın; Pekcan, Önder (Taylor & Francis Inc, 2014)Copolymer based on cross-linked polyacrylamide (PAAm) having N-isopropylacrylamide (NIPA) was prepared and their elastic properties were studied as a function of NIPA contents. NIPA content dependency of the shear modulus, ... -
Elastic properties of a swollen polyacrylamide (PAAm) gel doped with various multiwalled carbon nanotube (MWNT) contents
Evingür, Gülşen Akın; Pekcan, Önder (Carl Hanser Verlag, 2017)The toughness UT and shear modulus S of polyacrylamide (PAAm) multiwalled carbon nanotube (MWNTs) composites were studied with various MWNT contents. These composites were prepared via free radical crosslinking copolymerization ... -
Elasticity Study of PAAm-kappa C Composite Prepared in Various kappa C Content and Measured at Several Temperatures
Evingür, Gülşen Akın; Pekcan, Önder (Polish Acad Sciences Inst Physics, 2015)Polyacrylamide (PAAm)-kappa carrageenan (kappa C) composite gels were prepared via free radical crosslinking copolymerization with various (w/v) percentages of kappa C in the range between 0.5 and 3 (w/v)% of kappa C . ... -
Evaluation of the fractal dimension of polyacrylamide during gelation and swelling
Arda, Ertan; Kara, Selim; Pekcan, Önder; Evingür, Gülşen Akın (Elsevier, 2021)The photon scattering method was performed to monitor the free radical crosslinking copolymerization (FCC) of acrylamide (AAm) applied with N,N'-methylenebis (acrylamide) (Bis) in time. FCC experiments were conducted using ... -
Fluorescence study of effect of particle size in PS latex/Al2O3 nanocomposite films
Uğur, Şaziye; Sunay, M. Selin; Pekcan, Önder (Maney Publishing, 2015)Steady state fluorescence and BioUV-Visible techniques were used to study film formation of polystyrene (PS) latex and Al2O3 composites depending on PS particles size and Al2O3 content. Two film series (SmPS/Al2O3 and ... -
Fluorescence Study of Film Formation from PS Latex-TiO2 Composites: Effects of TiO2 Content, Film Thickness and Particle Size
Uğur, Şaziye; Sunay, M. Selin; Pekcan, Önder (Amer Scientific Publishers, 2015)Steady-state fluorescence (SSF) technique in conjunction with UV-visible (UVV) technique, atomic force microscope (AFM) and scanning electron microscope (SEM) is used for studying film formation from TiO2 covered polystyrene ... -
Fluorescence study of film formation from PS/Al2O3 nanocomposites
Pekcan, Önder; Ugur, Şaziye; Sunay, M. Selin (Elsevier Science Sa, 2014)Steady state fluorescence (SSF) and UV-vis (UVV) techniques were used to study the film formation behavior of pyrene (P) labeled polystyrene (PS) latex and Al2O3 (PS/Al2O3) composites depending on PS particles size and ... -
Fractal dimension and phase transition of graphene oxide (GO) doped polyacrylamide
Evingür, Gülşen Akın; Pekcan, Önder (Elsevier Sci Ltd, 2020)Graphene Oxide (GO)- Polyacrylamide composites prepared between 5 and 50 mu l GO were performed by Fluorescence Spectroscopy. The phase transition performed on the composites was measured by calculating the critical ... -
Gelation of PAAm-PVP composites: A fluorescence study
Evingür, Gülşen Akın; Kaygusuz, Hakan; Erim, F. Bedia; Pekcan, Önder (World Scientific Publ Co Pte Ltd, 2014)Hybrid hydrogels are a new class of composite materials. Polyacrylamide (PAAm) hydrogels are mainly produced by free radical crosslinking copolymerization (FCC) of AAm in the presence of N, N'-methylene bis (acrylamide) ... -
Investigation of Drying of Poly(N-isoproplacrylamide-co-acrylamide) by Fluorescence Technique
Evingür, Gülşen Akın; Pekcan, Önder (Wiley-Blackwell, 2013)The steady-state fluorescence technique was performed on drying of various molar percentages of poly(N-isopropylacrylamide-co- acrylamide) [poly(NIPA-co-AAc)] to elucidate the mechanism of temperature-induced phase separation ... -
Kinetic models for the dynamical behavior of polyacrylamide (PAAm)-kappa-carrageenan (kappa C) composite gels
Evingür, Gülşen Akın; Pekcan, Önder (Springer, 2015)A fluorescence method was employed for studying the drying and swelling of PAAm-kappa C composite gels, which were formed from acrylamide (AAm) and N, N'- methylenebisacrylamide (BIS) with various kappa-carrageenan (kappa ... -
Mechanical properties of graphene oxide-polyacrylamide composites before and after swelling in water
Evingür, Gülşen Akın; Pekcan, Önder (Springer, 2018)Polyacrylamide (PAAm) hydrogels have been proposed for use as promising biomaterials in biomedical and tissue engineering but their poor mechanical and water-retention properties have hindered their development. Graphene ... -
Monitoring of dynamical processes in PAAm-MWNTs composites by fluorescence method
Evingür, Gülşen Akın; Pekcan, Önder (Taylor & Francis Ltd, 2012)Polyacrylamide (PAAm)-multi walled carbon nanotube (MWNT) composites were prepared by free radical cross-linking copolymerization in water. Ammonium persulfate and N,N'-methylenebis (acrylamide) (BIS) were used as a free ...
