scholarly journals Phase Behavior of Amorphous/Semicrystalline Conjugated Polymer Blends

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1726
Author(s):  
Gada Muleta Fanta ◽  
Pawel Jarka ◽  
Urszula Szeluga ◽  
Tomasz Tański ◽  
Jung Yong Kim
Keyword(s):  
Polymer Blends ◽  
Phase Behavior ◽  
Conjugated Polymer ◽  
Structural Information ◽  
Polymer Solar Cells ◽  
Nonequilibrium Kinetics ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing ◽  
Xrd Patterns ◽  
Solid Liquid

We report the phase behavior of amorphous/semicrystalline conjugated polymer blends composed of low bandgap poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta [2,1-b;3,4-b′]dithiophene) -alt-4,7(2,1,3-benzothiadiazole)] (PCPDTBT) and poly{(N,N′-bis(2-octyldodecyl)naphthalene -1,4,5,8-bis(dicarboximide)-2,6-diyl)-alt-5,5′-(2,2′-bithiophene)} (P(NDI2OD-T2)). As usual in polymer blends, these two polymers are immiscible because ΔSm ≈ 0 and ΔHm > 0, leading to ΔGm > 0, in which ΔSm, ΔHm, and ΔGm are the entropy, enthalpy, and Gibbs free energy of mixing, respectively. Specifically, the Flory–Huggins interaction parameter (χ) for the PCPDTBT /P(NDI2OD-T2) blend was estimated to be 1.26 at 298.15 K, indicating that the blend was immiscible. When thermally analyzed, the melting and crystallization point depression was observed with increasing PCPDTBT amounts in the blends. In the same vein, the X-ray diffraction (XRD) patterns showed that the π-π interactions in P(NDI2OD-T2) lamellae were diminished if PCPDTBT was incorporated into the blends. Finally, the correlation of the solid-liquid phase transition and structural information for the blend system may provide insight for understanding other amorphous/semicrystalline conjugated polymers used as active layers in all-polymer solar cells, although the specific morphology of a film is largely affected by nonequilibrium kinetics.

Free Energy of Mixing of Cross-Linked Polymer Blends

Langmuir ◽  
2005 ◽  
Vol 21 (1) ◽  
pp. 240-250 ◽  
Author(s):  
Chowdhury K. Mamun
Keyword(s):  
Free Energy ◽  
Polymer Blends ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing

Neutron and Light Scattering Studies of Compatible Polymer Blends

1986 ◽  
Vol 79 ◽  
Author(s):  
E. W. Fischer
Keyword(s):  
Free Energy ◽  
Light Scattering ◽  
Polymer Blends ◽  
Gibbs Free Energy ◽  
Thermodynamic Description ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing

As it is well known the Flory-Huggins approach of the thermodynamic description of a mixture of two polymers A and B leads to an expression [1] for the Gibbs free energy of mixing ΔG

Prediction of the Phase Behaviour of Hydrogen-Bonded Polymer Blends

2006 ◽  
Vol 59 (8) ◽  
pp. 499 ◽  
Author(s):  
Michael M. Coleman ◽  
Paul C. Painter
Keyword(s):  
Polymer Blends ◽  
Functional Group ◽  
Equilibrium Constants ◽  
Phase Behaviour ◽  
Low Molecular Weight ◽  
Full Circle ◽  
Energy Of Mixing ◽  
The Subject ◽  
Free Energy Of Mixing ◽  
Hydrogen Bonded

In the early 1990s your authors believed that they had essentially solved the problem of predicting the phase behaviour of hydrogen-bonded polymer blends. A text devoted to this subject, Specific Interactions and the Miscibility of Polymer Blends, was published and we thought that it was now time to look around for something else to do. This was before a colleague, Boris Veytsman, pointed out that there was a flaw in our derivation of the free energy of mixing equation. It has taken us some 15 years to correct the theory and match the predictions of the phase behaviour of hydrogen-bonded blends that we presented in our 1991 book. So we have come full circle. The subject has become far more complicated, but at the same time far more interesting. Along the way we have discovered that the phase behaviour of hydrogen-bonded polymer blends can be successfully predicted using equilibrium constants determined from appropriate low molecular weight analogues, if chain connectivity effects such as intermolecular screening and functional group accessibility are included.

Phase Behavior of Polymer Blends

1990 ◽  
Vol 63 (1) ◽  
pp. 98-109 ◽  
Author(s):  
Charles C. Han
Keyword(s):  
Free Energy ◽  
Phase Behavior ◽  
Random Copolymer ◽  
Pair Interaction ◽  
Interaction Parameters ◽  
Binary Interaction ◽  
Energy Of Mixing ◽  
Binary Interaction Parameters ◽  
Free Energy Of Mixing ◽  
Microstructure Effect

Abstract We have demonstrated in two separate cases that SANS experiments can be used to obtain binary interaction parameters effectively and accurately. With measured χ as a function of composition and temperature, the free energy of mixing can be obtained at least numerically. The phase diagram including spinodal curves and cloud-point curves can be predicted. The second derivative of free energy of mixing w.r.t. composition, ∂2ƒ/∂ϕ2, can be used directly in the kinetics studies of spinodal decomposition. In the polybutadiene/polybutadiene case, individual pair interaction parameters can be separated out. Microstructure effect is the main contribution to the incompatibility of the blends. Nevertheless, with the use of the random copolymer theory, phase behavior can be predicted.

Interionic Pair Potential, hard sphere diameter and entropy of mixing of NaCd compound forming binary molten alloys under the framework of Pseudopotential theory

2014 ◽  
Vol 10 (6) ◽  
pp. 2843-2852
Author(s):  
Sujeet Kumar Chatterjee ◽  
Lokesh Chandra Prasad ◽  
Ajaya Bhattarai
Keyword(s):  
Nearest Neighbor ◽  
Effective Interaction ◽  
Pair Potential ◽  
Sphere Diameter ◽  
Compound Formation ◽  
Pseudopotential Theory ◽  
Energy Of Mixing ◽  
Asymmetric Behaviour ◽  
Statistical Mechanical ◽  
Free Energy Of Mixing

The observed asymmetric behaviour of mixing of  NaCd liquid alloys around equiatomic composition with smaller negative values for free energy of mixing at compound forming concentration, i.e. GMXS = -4.9KJ at Ccd =0.66 has  aroused our interest to undertake a theoretical investigation of this system.A simple statistical mechanical theory based on compound formation model has been used to investigate the energetics of formation of intermetallic compound Cd2Na in the melt through the study of entropy of mixing.Besides, the interionic interactions between component atoms Na and Cd of the alloys have been understood through the study of interionic pair potential фij(r), calculated from pseudopotential theory in the light of CF model.Our study of фij(r) suggest that the effective interaction between Na-Na atoms decreases on alloying with Cd atom, being minimum for compound forming alloy( Cd 0.66 Na 0.34 ).The nearest neighbor distance between Na-Na atoms does not alter on alloying. Like wise Na-Na,  effective interaction between  Cd-Cd atom decreases from pure state to NaCd alloys, being smaller at compound forming  concentration Cd 0.66 Na 0.34.The computed values of SM from pseudopotential theory are positive at all concentrations, but the agreement between theory and experimental is not satisfactory. This might be happening due to parameterisation of σ3 and Ψcompound.

Phase behavior of semicrystalline polymer blends

Polymer ◽  
2004 ◽  
Vol 45 (11) ◽  
pp. 3671-3679 ◽  
Author(s):  
Chieh-Tsung Lo ◽  
Soenke Seifert ◽  
Pappannan Thiyagarajan ◽  
Balaji Narasimhan
Keyword(s):  
Polymer Blends ◽  
Phase Behavior ◽  
Semicrystalline Polymer

Higher Order Conditional Probabilities and Thermodynamics of Binary Molten Alloys

1997 ◽  
Vol 11 (02n03) ◽  
pp. 93-106 ◽  
Author(s):  
O. Akinlade
Keyword(s):  
Free Energy ◽  
Experimental Evidence ◽  
Cluster Model ◽  
Excess Free Energy ◽  
Higher Order ◽  
Thermodynamic Quantities ◽  
Equiatomic Composition ◽  
Conditional Probabilities ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing

The recently introduced four atom cluster model is used to obtain higher order conditional probabilities that describe the atomic correlations in some molten binary alloys. Although the excess free energy of mixing for all the systems studied are almost symmetrical about the equiatomic composition, most other thermodynamic quantities are not and thus, the study enables us to explain the subtle differences in their physical characteristics required to describe the mechanism of the observed strong heterocoordination in Au–Zn or homocoordination in Cu–Ni within the same framework. More importantly, we obtain all calculated quantities for the whole concentration range thus complimenting experimental evidence.

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