Dilatational rheology studies on a semicrystalline ferroelectric copolymer at the air–water interface

RSC Advances ◽  
2016 ◽  
Vol 6 (20) ◽  
pp. 16673-16678
Author(s):  
Chandan Kumar ◽  
P. Viswanath

Dilatational rheology of Langmuir film of semicrystalline copolymer studied using oscillatory barrier technique show nonlinear behaviour. Evidence for low temperature phase transition, strain hardening and cross over behaviour with frequency is seen.

1998 ◽  
Vol 327-329 ◽  
pp. 391-394
Author(s):  
Keiichi Ikegami ◽  
Shin-ichi Kuroda ◽  
Tomoyuki Akutagawa ◽  
Taro Konuma ◽  
Takayoshi Nakamura ◽  
...  

1970 ◽  
Vol 41 (2) ◽  
pp. 836-838 ◽  
Author(s):  
Mitsuoki Nakahira ◽  
Shigeo Horiuchi ◽  
Hirotoshi Ooshima

Author(s):  
Khai-Nghi Truong ◽  
Carina Merkens ◽  
Martin Meven ◽  
Björn Faßbänder ◽  
Richard Dronskowski ◽  
...  

Single-crystal neutron diffraction experiments at 100 and 2.5 K have been performed to determine the structure of 3-(pyridin-4-yl)pentane-2,4-dione (HacacPy) with respect to its protonation pattern and to monitor a low-temperature phase transition. Solid HacacPy exists as the enol tautomer with a short intramolecular hydrogen bond. At 100 K, its donor···acceptor distance is 2.450 (8) Å and the compound adopts space group C2/c, with the N and para-C atoms of the pyridyl ring and the central C of the acetylacetone substituent on the twofold crystallographic axis. As a consequence of the axial symmetry, the bridging hydrogen is disordered over two symmetrically equivalent positions, and the carbon–oxygen bond distances adopt intermediate values between single and double bonds. Upon cooling, a structural phase transition to the t 2 subgroup P\bar 1 occurs; the resulting twins show an ordered acetylacetone moiety. The phase transition is fully reversible but associated with an appreciable hysteresis in the large single crystal under study: transition to the low-temperature phase requires several hours at 2.5 K and heating to 80 K is required to revert the transformation. No significant hysteresis is observed in a powder sample, in agreement with the second-order nature of the phase transition.


2011 ◽  
Vol 41 (2-4) ◽  
pp. 363-370
Author(s):  
Alisa Chernenkaya ◽  
Marina Kirman ◽  
Alexei Dmitriev ◽  
Roman Morgunov ◽  
Oksana Koplak ◽  
...  

1986 ◽  
Vol 57 (5) ◽  
pp. 339-341 ◽  
Author(s):  
T.J. Bastow ◽  
M.M. Elcombe ◽  
C.J. Howard

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