Role of Polymer Chain Flexibility on the Viscoelasticity of Amorphous Polymers around the Glass Transition Zone

1996 ◽  
Vol 29 (5) ◽  
pp. 1595-1599 ◽  
Author(s):  
Tadashi Inoue ◽  
K. Osaki
Keyword(s):  
Glass Transition ◽  
Transition Zone ◽  
Polymer Chain ◽  
Amorphous Polymers ◽  
Chain Flexibility

scholarly journals Shear Birefringence Measurement on Amorphous Polymers around the Glass Transition Zone

1998 ◽  
Vol 26 (4) ◽  
pp. 237-241 ◽  
Author(s):  
Takayuki ONOGI ◽  
Tadashi INOUE ◽  
Kunihiro OSAKI
Keyword(s):  
Glass Transition ◽  
Transition Zone ◽  
Amorphous Polymers

scholarly journals The Role of the Disulfide Bridge in the Copper (II) Binding by the Cyclic His4-Peptide

2021 ◽  
Vol 22 (12) ◽  
pp. 6458
Author(s):  
Aleksandra Pieniężna ◽  
Weronika Witak ◽  
Aneta Szymańska ◽  
Justyna Brasuń
Keyword(s):  
Metal Ions ◽  
Coordination Mode ◽  
Transition Metal Ions ◽  
Disulfide Bridge ◽  
Chain Flexibility ◽  
Vis Spectroscopy ◽  
Ph Range ◽  
Cd Studies ◽  
Metal Ratios

In this paper, we present studies on the influence of the disulfide bridge on the copper (II) ions’ binding abilities by the cyclic His4-peptide. The studied ligand HKHPHRHC-S-S-C consists of nine amino acids. The cyclic structure was obtained through a disulfide bridge between two cysteinyl groups. Moreover, this peptide is characterized by the presence of four His residues in the sequence, which makes it an interesting ligand for transition metal ions. The potentiometric and spectroscopic (UV-Vis spectroscopy and circular dichroism spectroscopy (CD)) studies were carried out in various molar ligand to metal ratios: 2:1, 1:1, and 1:2, in the pH range of 2.5–11 at 25 °C. The results showed that the cyclic His4-peptide promotes dinuclear complexes in each of these systems and forms the final dinuclear species with the {NIm, 3N-amide}{NIm, 3N-amide} coordination mode. The obtained data shows that cyclization by the formation of the disulfide bond has an impact on the peptide chain flexibility and appearance of additional potential donors for metal ions and influences the copper (II) ions’ coordination.

Investigating the role of GeO2 in enhancing the thermal stability and proton mobility of proton-conducting phosphate glasses

2021 ◽  
Author(s):  
Takahisa Omata ◽  
Aman Sharma ◽  
Takuya Kinoshita ◽  
Issei Suzuki ◽  
Tomohiro Ishiyama ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Phosphate Glasses ◽  
Proton Mobility ◽  
Proton Conducting

In this study, the effect of GeO2 on the thermal stability and proton mobility (μH) of proton-conducting phosphate glasses was experimentally investigated using 22HO1/2−3NaO1/2−(12−x)LaO3/2−xGeO2−63PO5/2 glasses. Increasing glass transition temperature (Tg)...

scholarly journals Molecular insights on poly(N-isopropylacrylamide) coil-to-globule transition induced by pressure

2021 ◽  
Vol 23 (10) ◽  
pp. 5984-5991
Author(s):  
Letizia Tavagnacco ◽  
Ester Chiessi ◽  
Emanuela Zaccarelli
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Polymer Chain ◽  
Linear Polymer ◽  
Dynamics Simulations ◽  
Linear Polymer Chain

By using extensive all-atom molecular dynamics simulations of an atactic linear polymer chain, we unveil the role of pressure in the coil-to-globule transition of poly(N-isopropylacrylamide) (PNIPAM).

Sign in / Sign up

Export Citation Format

Share Document