Temperature dependence of tryptophan and tyrosine luminescence in poly(vinyl alcohol) films

1981 ◽  
Vol 34 (7) ◽  
pp. 1367 ◽  
Author(s):  
R Sakurovs ◽  
KP Ghiggino
Keyword(s):  
Triplet State ◽  
Temperature Dependence ◽  
Vinyl Alcohol ◽  
Kinetic Scheme ◽  
Activation Energies ◽  
Poly Vinyl Alcohol ◽  
Luminescent Probes ◽  
Single Temperature ◽  
Distinct Temperature

The temperature dependence of the fluorescence and phosphorescence from tyrosine and tryptophan in poly(vinyl alcohol) films has been studied over the temperature range 90-295 K. A kinetic scheme is proposed which allows the calculation of activation energies for excited singlet and triplet state deactivation processes. A single temperature-dependent radiationless process from the singlet state is observed for tyrosine and tryptophan, with activation energies of 5.2�0.4 and 7.1�0.6 kJ mol-1 respectively. However, two distinct temperature transitions have been detected for triplet-state relaxation at 180 and 255 K. The role of polymer phase transitions in determining excited state relaxation pathways of embedded luminescent probes is discussed.

Role of boric acid in the formation of poly(vinyl alcohol)–iodine complexes in undrawn films

Polymer ◽  
2010 ◽  
Vol 51 (3) ◽  
pp. 687-693 ◽  
Author(s):  
Kumiko Ohishi ◽  
Toshiaki Itadani ◽  
Tetsushi Hayashi ◽  
Toshio Nakai ◽  
Fumitaka Horii
Keyword(s):  
Boric Acid ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Iodine Complexes

The role of electrostatic repulsion in the gelation of poly(vinyl alcohol)/borax aqueous solutions

Soft Matter ◽  
2018 ◽  
Vol 14 (32) ◽  
pp. 6767-6773 ◽  
Author(s):  
Jingjing Li ◽  
Zhijie Zhang ◽  
Xiao Cao ◽  
Yonggang Liu ◽  
Quan Chen
Keyword(s):  
Aqueous Solutions ◽  
Vinyl Alcohol ◽  
Linear Viscoelasticity ◽  
Poly Vinyl Alcohol ◽  
Electrostatic Repulsion

This study examined linear viscoelasticity of semidilute non-entangled poly(vinyl alcohol) (PVA) and borax aqueous solutions: one borax molecule dissociates into two B(OH)3 molecules and two B(OH)4− ions, and the latter can crosslink the PVA chains.

Role of Poly(vinyl alcohol) in the Crystal Growth of Ammonium Perchlorate

2008 ◽  
Vol 8 (3) ◽  
pp. 1060-1066 ◽  
Author(s):  
Anuj A. Vargeese ◽  
Satyawati. S. Joshi ◽  
V. N. Krishnamurthy
Keyword(s):  
Crystal Growth ◽  
Ammonium Perchlorate ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol

Compatibilizing role of carbon nanotubes in poly(vinyl alcohol)/starch blend

2014 ◽  
Vol 67 (1-2) ◽  
pp. 147-153 ◽  
Author(s):  
Jobin Jose ◽  
S. K De ◽  
Mariam Al-Ali AlMa'adeed ◽  
Jolly Bhadra Dakua ◽  
P. A Sreekumar ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol

scholarly journals Pervaporative separation of water–ethanol mixtures using an Algerian Na+ montmorillonite nanoclay-incorporated poly(vinyl alcohol) nanocomposite membrane

RSC Advances ◽  
2020 ◽  
Vol 10 (65) ◽  
pp. 39531-39541
Author(s):  
Amina Allel ◽  
Mohamed Wahib Naceur ◽  
Hassiba Benguergoura ◽  
Alain Ledoux ◽  
Waseem Sharaf Saeed ◽  
...  
Keyword(s):  
Vinyl Alcohol ◽  
Separation Efficiency ◽  
Nanocomposite Membrane ◽  
Poly Vinyl Alcohol ◽  
Ethanol Mixture ◽  
Montmorillonite Nanoclay

This work aims to study the role of bentonite, Na+ montmorillonite (Na+MMT), as a filler to design a new poly(vinyl alcohol) (PVA)-based membrane for the pervaporation of an azeotropic water/ethanol mixture to enhance its separation efficiency.

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