Investigation on emission features of TTBC aggregates in PVA fiber mats by electrospinning
tarafından
 
Özen, Bengisu.

Başlık
Investigation on emission features of TTBC aggregates in PVA fiber mats by electrospinning

Yazar
Özen, Bengisu.

Yazar Ek Girişi
Özen, Bengisu.

Yayın Bilgileri
[s.l.]: [s.n.], 2010.

Fiziksel Tanımlama
xii, 43 leaves.: ill. + 1 computer laser optical disc.

Özet
3 1,1.,3,3.-tetraethyl-5,5.,6,6.-tetrachlorobenzimidazolocarbocyanine (TTBC) is a frequently used cyanine dye that undergoes two different types of molecular aggregate (J and H-type). Dye molecules, in general, come into aggregation in ionic solutions and solid surfaces without control over the type and orientation of the resulting aggregate. In this research, we focused on electrospinning of aqueous poly(vinyl alcohol) (PVA)/TTBC solutions and investigated whether the aggregate formation could be controlled by solution and instrumental parameters of this process. Initially, TTBC was molecularly dispersed in aqueous PVA solution with a weight fraction of 0.001- 0.65 % and the precursor solution was subjected to electrospinning under electrical field ranging from 0.95-1.81 kV/cm. A stationary horizontal electrospinning set-up was used including two parallel-positioned metal strips as counter electrode. Both randomly-deposited and uniaxially aligned fibers were achieved. For the reason of comparison, reference films were prepared by spin-coating and film casting. Photoluminescence and polarized FTIR spectroscopy techniques were employed to examine spectral properties of the fibers. While H- and J-type aggregates coexist within spin-coated films and only J-aggregates exist within cast films, only H-type aggregates were observed within the fibers regardless of their alignment. A strong polarized emission was obtained from the unaxially aligned fibers due to the orientation of H-aggregates along the fibers. Consequently, electrospinning was found to be an alternative method to bring individually dispersed dye molecules into oriented H-type aggregates within submicron diameter fibers. Similar experimentation was also applied to TTBC/PS and Pyrene/Polystyrene(PS) systems to investigate aggregation behavior of dye molecules. TTBC exhibited similar behavior in PS/Dimethylformamide (DMF) system observed in PVA/H2O system. However, electrospinning has no remarkable influence on aggregation of pyrene in excimers. It slightly disassemble excimer structure.

Konu Başlığı
Dyes and dyeing -- Textile fibers,Synthetic.
 
Electrospinning.

Yazar Ek Girişi
Demir, M. Mustafa.

Tüzel Kişi Ek Girişi
İzmir Institute of Technology. Chemistry.

Tek Biçim Eser Adı
Thesis(Master)--İzmir Institute of Technology: Chemistry.
 
İzmir Institute of Technology: Chemistry--Thesis (Master).

Elektronik Erişim
Access to Electronic Version.


LibraryMateryal TürüDemirbaş NumarasıYer NumarasıDurumu/İade Tarihi
IYTE LibraryTezT000200TP904 .O99 2010Tez Koleksiyonu